fix: Fixed endpoint

agent/internal/grpc/client.go

@@ -11,6 +11,7 @@ import (
 	"google.golang.org/grpc/credentials"
 	"google.golang.org/grpc/credentials/insecure"
 	"google.golang.org/grpc/encoding"
+	"google.golang.org/grpc/keepalive"
 )
 
 func init() {
@@ -26,7 +27,15 @@ func New(serverURL string, useTLS bool) (*Client, error) {
 	serverURL = strings.TrimPrefix(serverURL, "https://")
 	serverURL = strings.TrimPrefix(serverURL, "http://")
 
-	var dialOpts []grpc.DialOption
+	// Send a ping every 30s so proxies with a 60s idle timeout don't kill the
+	// long-lived CommandStream when no commands are flowing.
+	dialOpts := []grpc.DialOption{
+		grpc.WithKeepaliveParams(keepalive.ClientParameters{
+			Time:                30 * time.Second,
+			Timeout:             10 * time.Second,
+			PermitWithoutStream: false,
+		}),
+	}
 
 	if useTLS {
 		tlsCfg := &tls.Config{

custom-secrets-vault-gin-guide.md

@@ -0,0 +1,707 @@
+# Custom Secrets Vault + ESO Webhook Integration
+
+Self-hosted secrets API at `https://keymanager.hostxtra.co.uk/secrets`
+backed by MongoDB with Gin, exposed to K3s via ESO's Webhook provider.
+
+---
+
+## Architecture
+
+```
+MongoDB (encrypted at rest)
+  └── secrets collection: { group, key, encryptedValue, updatedAt }
+        ↑ CRUD via Go API (Gin)
+Go API (keymanager secrets service)
+  └── GET    /secrets/:group        ← ESO webhook calls this
+  └── PUT    /secrets/:group        ← admin writes secrets to a group
+  └── DELETE /secrets/:group        ← admin deletes entire group
+  └── DELETE /secrets/:group/:key   ← admin deletes one key from a group
+        ↓ bearer token auth (read token for ESO, admin token for writes)
+ESO Webhook ClusterSecretStore
+  └── ExternalSecret (per namespace)
+        └── K8s Secret
+              └── Deployment env vars
+```
+
+**Data model:** A "group" is a logical namespace for a set of related secrets —
+e.g. `myapp-prod`, `postgres`, `infra`. Each group contains one or more
+key/value pairs stored individually as encrypted documents in MongoDB.
+
+**Encryption:** AES-256-GCM per value, random nonce per write, master key
+loaded from the `MASTER_KEY` environment variable (32-byte hex string).
+
+---
+
+## Part 1 — The Go API
+
+### 1.1 — Project structure
+
+```
+keymanager/
+├── cmd/
+│   └── server/
+│       └── main.go
+├── internal/
+│   ├── crypto/
+│   │   └── crypto.go
+│   ├── store/
+│   │   └── store.go
+│   └── api/
+│       └── api.go
+├── go.mod
+└── Dockerfile
+```
+
+### 1.2 — `go.mod`
+
+```
+module github.com/yourusername/keymanager
+
+go 1.23
+
+require (
+    go.mongodb.org/mongo-driver v1.17.0
+    github.com/gin-gonic/gin v1.10.0
+)
+```
+
+### 1.3 — `internal/crypto/crypto.go`
+
+AES-256-GCM encryption. Each value gets a unique random nonce so identical
+plaintext values produce different ciphertext on every write.
+
+```go
+package crypto
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"encoding/base64"
+	"errors"
+	"io"
+)
+
+// Encrypt encrypts plaintext using AES-256-GCM.
+// Returns base64(nonce + ciphertext).
+func Encrypt(key []byte, plaintext string) (string, error) {
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return "", err
+	}
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return "", err
+	}
+	nonce := make([]byte, gcm.NonceSize())
+	if _, err := io.ReadFull(rand.Reader, nonce); err != nil {
+		return "", err
+	}
+	ciphertext := gcm.Seal(nonce, nonce, []byte(plaintext), nil)
+	return base64.StdEncoding.EncodeToString(ciphertext), nil
+}
+
+// Decrypt decrypts a base64(nonce + ciphertext) produced by Encrypt.
+func Decrypt(key []byte, encoded string) (string, error) {
+	data, err := base64.StdEncoding.DecodeString(encoded)
+	if err != nil {
+		return "", err
+	}
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return "", err
+	}
+	gcm, err := cipher.NewGCM(block)
+	if err != nil {
+		return "", err
+	}
+	if len(data) < gcm.NonceSize() {
+		return "", errors.New("ciphertext too short")
+	}
+	nonce, ciphertext := data[:gcm.NonceSize()], data[gcm.NonceSize():]
+	plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)
+	if err != nil {
+		return "", err
+	}
+	return string(plaintext), nil
+}
+```
+
+### 1.4 — `internal/store/store.go`
+
+MongoDB storage. Each document represents one key within a group.
+
+```go
+package store
+
+import (
+	"context"
+	"time"
+
+	"go.mongodb.org/mongo-driver/bson"
+	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
+)
+
+type SecretDoc struct {
+	Group          string    `bson:"group"`
+	Key            string    `bson:"key"`
+	EncryptedValue string    `bson:"encryptedValue"`
+	UpdatedAt      time.Time `bson:"updatedAt"`
+}
+
+type Store struct {
+	col *mongo.Collection
+}
+
+func New(client *mongo.Client, dbName string) (*Store, error) {
+	col := client.Database(dbName).Collection("secrets")
+
+	// Unique compound index on (group, key)
+	_, err := col.Indexes().CreateOne(context.Background(), mongo.IndexModel{
+		Keys:    bson.D{{Key: "group", Value: 1}, {Key: "key", Value: 1}},
+		Options: options.Index().SetUnique(true),
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return &Store{col: col}, nil
+}
+
+// GetGroup returns all SecretDocs belonging to the given group.
+func (s *Store) GetGroup(ctx context.Context, group string) ([]SecretDoc, error) {
+	cursor, err := s.col.Find(ctx, bson.M{"group": group})
+	if err != nil {
+		return nil, err
+	}
+	var docs []SecretDoc
+	if err := cursor.All(ctx, &docs); err != nil {
+		return nil, err
+	}
+	return docs, nil
+}
+
+// Upsert writes or updates a single key within a group.
+func (s *Store) Upsert(ctx context.Context, group, key, encryptedValue string) error {
+	filter := bson.M{"group": group, "key": key}
+	update := bson.M{"$set": bson.M{
+		"encryptedValue": encryptedValue,
+		"updatedAt":      time.Now(),
+	}}
+	_, err := s.col.UpdateOne(ctx, filter, update, options.Update().SetUpsert(true))
+	return err
+}
+
+// DeleteGroup removes all keys belonging to a group.
+func (s *Store) DeleteGroup(ctx context.Context, group string) error {
+	_, err := s.col.DeleteMany(ctx, bson.M{"group": group})
+	return err
+}
+
+// DeleteKey removes a single key from a group.
+func (s *Store) DeleteKey(ctx context.Context, group, key string) error {
+	_, err := s.col.DeleteOne(ctx, bson.M{"group": group, "key": key})
+	return err
+}
+```
+
+### 1.5 — `internal/api/api.go`
+
+Gin handlers. Two token tiers: ESO gets a read-only token, admins get a write token.
+
+```go
+package api
+
+import (
+	"encoding/hex"
+	"net/http"
+	"os"
+
+	"github.com/gin-gonic/gin"
+	"github.com/yourusername/keymanager/internal/crypto"
+	"github.com/yourusername/keymanager/internal/store"
+)
+
+type API struct {
+	store      *store.Store
+	masterKey  []byte
+	esoToken   string
+	adminToken string
+}
+
+func New(s *store.Store) *API {
+	keyHex := os.Getenv("MASTER_KEY")
+	key, err := hex.DecodeString(keyHex)
+	if err != nil || len(key) != 32 {
+		panic("MASTER_KEY must be a 64-character hex string (32 bytes)")
+	}
+	return &API{
+		store:      s,
+		masterKey:  key,
+		esoToken:   os.Getenv("ESO_TOKEN"),
+		adminToken: os.Getenv("ADMIN_TOKEN"),
+	}
+}
+
+func (a *API) RegisterRoutes(r *gin.Engine) {
+	secrets := r.Group("/secrets")
+
+	// Read routes — ESO token
+	secrets.GET("/:group", a.bearerAuth(a.esoToken), a.getGroup)
+
+	// Write routes — admin token
+	secrets.PUT("/:group", a.bearerAuth(a.adminToken), a.putGroup)
+	secrets.DELETE("/:group", a.bearerAuth(a.adminToken), a.deleteGroup)
+	secrets.DELETE("/:group/:key", a.bearerAuth(a.adminToken), a.deleteKey)
+}
+
+// bearerAuth returns a Gin middleware that validates a Bearer token.
+func (a *API) bearerAuth(expected string) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		auth := c.GetHeader("Authorization")
+		const prefix = "Bearer "
+		if len(auth) <= len(prefix) || auth[:len(prefix)] != prefix {
+			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "missing bearer token"})
+			return
+		}
+		token := auth[len(prefix):]
+		if token != expected {
+			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid token"})
+			return
+		}
+		c.Next()
+	}
+}
+
+// getGroup handles GET /secrets/:group
+// Returns a flat JSON object { "KEY": "value", ... } for ESO to consume.
+// Returns 404 if the group has no secrets — ESO treats 404 as "deleted".
+func (a *API) getGroup(c *gin.Context) {
+	group := c.Param("group")
+
+	docs, err := a.store.GetGroup(c.Request.Context(), group)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "store error"})
+		return
+	}
+	if len(docs) == 0 {
+		c.JSON(http.StatusNotFound, gin.H{"error": "group not found"})
+		return
+	}
+
+	result := make(map[string]string, len(docs))
+	for _, doc := range docs {
+		val, err := crypto.Decrypt(a.masterKey, doc.EncryptedValue)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "decrypt error"})
+			return
+		}
+		result[doc.Key] = val
+	}
+
+	c.JSON(http.StatusOK, result)
+}
+
+// putGroup handles PUT /secrets/:group
+// Body: { "KEY": "value", ... } — upserts each key in the group.
+func (a *API) putGroup(c *gin.Context) {
+	group := c.Param("group")
+
+	var payload map[string]string
+	if err := c.ShouldBindJSON(&payload); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid JSON body"})
+		return
+	}
+	if len(payload) == 0 {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "body must contain at least one key"})
+		return
+	}
+
+	for key, val := range payload {
+		encrypted, err := crypto.Encrypt(a.masterKey, val)
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "encrypt error"})
+			return
+		}
+		if err := a.store.Upsert(c.Request.Context(), group, key, encrypted); err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": "store error"})
+			return
+		}
+	}
+
+	c.Status(http.StatusNoContent)
+}
+
+// deleteGroup handles DELETE /secrets/:group
+// Removes the entire group and all its keys.
+func (a *API) deleteGroup(c *gin.Context) {
+	group := c.Param("group")
+
+	if err := a.store.DeleteGroup(c.Request.Context(), group); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "store error"})
+		return
+	}
+	c.Status(http.StatusNoContent)
+}
+
+// deleteKey handles DELETE /secrets/:group/:key
+// Removes a single key from a group.
+func (a *API) deleteKey(c *gin.Context) {
+	group := c.Param("group")
+	key := c.Param("key")
+
+	if err := a.store.DeleteKey(c.Request.Context(), group, key); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "store error"})
+		return
+	}
+	c.Status(http.StatusNoContent)
+}
+```
+
+### 1.6 — `cmd/server/main.go`
+
+```go
+package main
+
+import (
+	"context"
+	"log"
+	"os"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"go.mongodb.org/mongo-driver/mongo"
+	"go.mongodb.org/mongo-driver/mongo/options"
+
+	"github.com/yourusername/keymanager/internal/api"
+	"github.com/yourusername/keymanager/internal/store"
+)
+
+func main() {
+	mongoURI := os.Getenv("MONGODB_URI")
+	if mongoURI == "" {
+		mongoURI = "mongodb://localhost:27017"
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	client, err := mongo.Connect(ctx, options.Client().ApplyURI(mongoURI))
+	if err != nil {
+		log.Fatalf("MongoDB connect: %v", err)
+	}
+	if err := client.Ping(ctx, nil); err != nil {
+		log.Fatalf("MongoDB ping: %v", err)
+	}
+	log.Println("Connected to MongoDB")
+
+	s, err := store.New(client, "keymanager")
+	if err != nil {
+		log.Fatalf("Store init: %v", err)
+	}
+
+	gin.SetMode(gin.ReleaseMode)
+	r := gin.New()
+	r.Use(gin.Logger(), gin.Recovery())
+
+	a := api.New(s)
+	a.RegisterRoutes(r)
+
+	log.Println("Secrets API listening on :8080")
+	if err := r.Run(":8080"); err != nil {
+		log.Fatalf("Server error: %v", err)
+	}
+}
+```
+
+### 1.7 — `Dockerfile`
+
+```dockerfile
+FROM golang:1.23-alpine AS builder
+WORKDIR /app
+COPY go.mod go.sum ./
+RUN go mod download
+COPY . .
+RUN go build -o secrets-api ./cmd/server
+
+FROM alpine:3.20
+RUN apk add --no-cache ca-certificates
+WORKDIR /app
+COPY --from=builder /app/secrets-api .
+EXPOSE 8080
+CMD ["./secrets-api"]
+```
+
+---
+
+## Part 2 — Deploying the API
+
+### 2.1 — Generate your secrets
+
+```bash
+# 32-byte master key — back this up in your password manager
+openssl rand -hex 32
+
+# ESO read token
+openssl rand -hex 32
+
+# Admin token
+openssl rand -hex 32
+```
+
+### 2.2 — Docker Compose
+
+```yaml
+services:
+  secrets-api:
+    image: ghcr.io/yourusername/keymanager-secrets:latest
+    restart: unless-stopped
+    environment:
+      MONGODB_URI: mongodb://mongo:27017
+      MASTER_KEY: "<your-32-byte-hex-key>"
+      ESO_TOKEN: "<your-eso-token>"
+      ADMIN_TOKEN: "<your-admin-token>"
+    ports:
+      - "127.0.0.1:8082:8080"
+```
+
+### 2.3 — Caddyfile
+
+```caddyfile
+keymanager.hostxtra.co.uk {
+    # ... existing KeyManager routes ...
+
+    handle /secrets* {
+        reverse_proxy localhost:8082
+    }
+}
+```
+
+```bash
+caddy reload --config /etc/caddy/Caddyfile
+```
+
+### 2.4 — Smoke test
+
+```bash
+export ADMIN="<your-admin-token>"
+export ESO="<your-eso-token>"
+export BASE="https://keymanager.hostxtra.co.uk/secrets"
+
+# Write a group
+curl -s -X PUT $BASE/myapp-prod \
+  -H "Authorization: Bearer $ADMIN" \
+  -H "Content-Type: application/json" \
+  -d '{"DB_PASSWORD": "supersecret123", "API_KEY": "myapikey456"}'
+# → 204 No Content
+
+# Read back (as ESO would)
+curl -s $BASE/myapp-prod \
+  -H "Authorization: Bearer $ESO"
+# → {"API_KEY":"myapikey456","DB_PASSWORD":"supersecret123"}
+
+# Delete a single key
+curl -s -X DELETE $BASE/myapp-prod/API_KEY \
+  -H "Authorization: Bearer $ADMIN"
+# → 204 No Content
+
+# Confirm it's gone
+curl -s $BASE/myapp-prod \
+  -H "Authorization: Bearer $ESO"
+# → {"DB_PASSWORD":"supersecret123"}
+
+# Delete the whole group
+curl -s -X DELETE $BASE/myapp-prod \
+  -H "Authorization: Bearer $ADMIN"
+# → 204 No Content
+
+# Confirm 404
+curl -s -o /dev/null -w "%{http_code}" $BASE/myapp-prod \
+  -H "Authorization: Bearer $ESO"
+# → 404
+```
+
+---
+
+## Part 3 — ESO Webhook Integration
+
+### 3.1 — Install ESO
+
+```bash
+helm repo add external-secrets https://charts.external-secrets.io
+helm repo update
+helm upgrade --install external-secrets external-secrets/external-secrets \
+  --namespace external-secrets \
+  --create-namespace \
+  --set installCRDs=true \
+  --wait
+```
+
+### 3.2 — Store ESO token as a K8s Secret
+
+The `external-secrets.io/type=webhook` label is required — without it the
+webhook provider is not permitted to read the secret.
+
+```bash
+kubectl create secret generic keymanager-eso-token \
+  --namespace external-secrets \
+  --from-literal=token="<your-eso-token>"
+
+kubectl label secret keymanager-eso-token \
+  --namespace external-secrets \
+  external-secrets.io/type=webhook
+```
+
+### 3.3 — ClusterSecretStore
+
+```yaml
+# cluster-secret-store.yaml
+apiVersion: external-secrets.io/v1
+kind: ClusterSecretStore
+metadata:
+  name: keymanager-store
+spec:
+  provider:
+    webhook:
+      url: "https://keymanager.hostxtra.co.uk/secrets/{{ .remoteRef.key }}"
+      method: GET
+      result:
+        jsonPath: "$"
+      headers:
+        Content-Type: "application/json"
+        Authorization: "Bearer {{ .auth.token }}"
+      secrets:
+        - name: auth
+          secretRef:
+            name: keymanager-eso-token
+            namespace: external-secrets
+```
+
+```bash
+kubectl apply -f cluster-secret-store.yaml
+kubectl get clustersecretstore keymanager-store
+```
+
+### 3.4 — ExternalSecret
+
+The `remoteRef.key` value is the group name — ESO substitutes it into the
+URL template, calling `GET /secrets/myapp-prod`.
+
+```yaml
+# external-secret.yaml
+apiVersion: v1
+kind: Namespace
+metadata:
+  name: myapp
+---
+apiVersion: external-secrets.io/v1
+kind: ExternalSecret
+metadata:
+  name: myapp-secrets
+  namespace: myapp
+spec:
+  refreshInterval: 15m
+  secretStoreRef:
+    name: keymanager-store
+    kind: ClusterSecretStore
+  target:
+    name: myapp-secrets
+    creationPolicy: Owner
+  dataFrom:
+    - extract:
+        key: myapp-prod        # group name → GET /secrets/myapp-prod
+```
+
+Or to pull specific keys from a group:
+
+```yaml
+  data:
+    - secretKey: DB_PASSWORD
+      remoteRef:
+        key: myapp-prod        # group name
+        property: DB_PASSWORD  # key within the group's JSON response
+```
+
+```bash
+kubectl apply -f external-secret.yaml
+
+kubectl get externalsecret myapp-secrets -n myapp
+# STATUS: SecretSynced
+
+# Decode and verify values
+kubectl get secret myapp-secrets -n myapp -o json | \
+  jq '.data | map_values(@base64d)'
+```
+
+### 3.5 — Deployment
+
+```yaml
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: myapp
+  namespace: myapp
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: myapp
+  template:
+    metadata:
+      labels:
+        app: myapp
+      annotations:
+        reloader.stakater.com/auto: "true"   # optional: auto-restart on secret change
+    spec:
+      containers:
+        - name: myapp
+          image: your-image:latest
+          envFrom:
+            - secretRef:
+                name: myapp-secrets
+```
+
+---
+
+## Part 4 — Day-to-Day Secret Management
+
+```bash
+export ADMIN="<your-admin-token>"
+export BASE="https://keymanager.hostxtra.co.uk/secrets"
+
+# Create or update a group (upserts — safe to re-run)
+curl -s -X PUT $BASE/postgres \
+  -H "Authorization: Bearer $ADMIN" \
+  -H "Content-Type: application/json" \
+  -d '{"POSTGRES_PASSWORD": "dbpass", "POSTGRES_USER": "app"}'
+
+# Add a new key to an existing group (existing keys are untouched)
+curl -s -X PUT $BASE/postgres \
+  -H "Authorization: Bearer $ADMIN" \
+  -H "Content-Type: application/json" \
+  -d '{"POSTGRES_DB": "mydb"}'
+
+# Remove a single key from a group
+curl -s -X DELETE $BASE/postgres/POSTGRES_USER \
+  -H "Authorization: Bearer $ADMIN"
+
+# Remove an entire group
+curl -s -X DELETE $BASE/postgres \
+  -H "Authorization: Bearer $ADMIN"
+
+# Force ESO to re-sync immediately after a rotation
+kubectl annotate externalsecret myapp-secrets -n myapp \
+  force-sync=$(date +%s) --overwrite
+```
+
+---
+
+## Quick Reference
+
+| Endpoint | Token | Description |
+|---|---|---|
+| `GET /secrets/:group` | ESO token | Returns all keys in group as JSON |
+| `PUT /secrets/:group` | Admin token | Upserts keys into group |
+| `DELETE /secrets/:group` | Admin token | Deletes entire group |
+| `DELETE /secrets/:group/:key` | Admin token | Deletes one key from group |

server/cmd/main.go

@@ -23,6 +23,10 @@ func main() {
 	}
 	log.Println("connected to MongoDB")
 
+	if err := services.EnsureSecretIndexes(); err != nil {
+		log.Printf("warning: failed to ensure secret indexes: %v", err)
+	}
+
 	redisAddr := getEnv("REDIS_ADDR", "localhost:6379")
 	if err := auth.InitRedis(redisAddr); err != nil {
 		log.Fatalf("failed to connect to Redis: %v", err)
@@ -38,7 +42,7 @@ func main() {
 		ticker := time.NewTicker(2 * time.Minute)
 		defer ticker.Stop()
 		for range ticker.C {
-			if err := services.MarkOfflineServers(5 * time.Minute); err != nil {
+			if err := services.MarkOfflineServers(); err != nil {
 				log.Printf("mark offline error: %v", err)
 			}
 		}

server/internal/api/handlers.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"net/http"
 	"os"
+	"strconv"
 
 	"github.com/gin-gonic/gin"
 	"github.com/mrhid6/vantage/server/internal/auth"
@@ -11,10 +12,24 @@ import (
 	"github.com/mrhid6/vantage/server/internal/services"
 )
 
+func actorFromCtx(c *gin.Context) string {
+	if sess := auth.GetSessionFromContext(c); sess != nil && sess.Email != "" {
+		return sess.Email
+	}
+	return "admin"
+}
+
 func RegisterRoutes(r *gin.Engine) {
 	r.GET("/install", handleInstallScript)
 	r.GET("/update", handleUpdateScript)
 
+	// ESO read endpoint — bearer-token auth, not session auth, so Kubernetes
+	// External Secrets Operator can call it. Lives under /api (so the reverse
+	// proxy routes it to the backend) but on a distinct subpath to avoid
+	// colliding with the session-authed GET /api/secrets/:group. Returns a
+	// group as flat JSON.
+	r.GET("/api/secrets/:group/values", secretsReadAuth(), esoGetGroup)
+
 	// Auth endpoints (no session required)
 	r.GET("/auth/login", auth.HandleLogin)
 	r.GET("/auth/callback", auth.HandleCallback)
@@ -37,6 +52,20 @@ func RegisterRoutes(r *gin.Engine) {
 
 		apiGroup.GET("/agent/latest-version", getLatestAgentVersion)
 
+		apiGroup.GET("/audit", listAuditEvents)
+
+		apiGroup.GET("/settings", getSettings)
+		apiGroup.PUT("/settings", saveSettings)
+		apiGroup.POST("/settings/secrets-token", rotateSecretsToken)
+
+		apiGroup.GET("/secrets", listSecretGroups)
+		apiGroup.POST("/secrets", createSecretGroup)
+		apiGroup.GET("/secrets/:group", getSecretGroup)
+		apiGroup.PUT("/secrets/:group", putSecretGroup)
+		apiGroup.POST("/secrets/:group/reveal", revealSecret)
+		apiGroup.DELETE("/secrets/:group", deleteSecretGroup)
+		apiGroup.DELETE("/secrets/:group/:key", deleteSecretKey)
+
 		apiGroup.GET("/keys", listKeys)
 		apiGroup.POST("/keys", createKey)
 		apiGroup.GET("/keys/:id", getKey)
@@ -75,6 +104,7 @@ func newServer(c *gin.Context) {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 		return
 	}
+	services.LogEvent("server.created", actorFromCtx(c), s.ServerID, "", "pre-registration token issued")
 
 	giteaHost := os.Getenv("GITEA_HOST")
 	if giteaHost == "" {
@@ -120,10 +150,16 @@ func getServer(c *gin.Context) {
 
 func deleteServer(c *gin.Context) {
 	id := c.Param("id")
+	s, _ := services.GetServer(id)
 	if err := services.DeleteServer(id); err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 		return
 	}
+	hostname := id
+	if s != nil {
+		hostname = s.Hostname
+	}
+	services.LogEvent("server.deleted", actorFromCtx(c), id, "", fmt.Sprintf("server %s deleted", hostname))
 	c.JSON(http.StatusOK, gin.H{"deleted": true})
 }
 
@@ -160,6 +196,7 @@ func generateKey(c *gin.Context) {
 		return
 	}
 
+	services.LogEvent("key.generation_dispatched", actorFromCtx(c), s.ServerID, "", fmt.Sprintf("key generation dispatched (label=%s type=%s)", body.Label, body.KeyType))
 	c.JSON(http.StatusAccepted, gin.H{
 		"message":    "key generation command sent to agent",
 		"command_id": cmdID,
@@ -192,6 +229,7 @@ func createKey(c *gin.Context) {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 		return
 	}
+	services.LogEvent("key.uploaded", actorFromCtx(c), "", key.KeyID, fmt.Sprintf("key '%s' uploaded", key.Label))
 	c.JSON(http.StatusCreated, key)
 }
 
@@ -227,10 +265,16 @@ func getKey(c *gin.Context) {
 
 func deleteKey(c *gin.Context) {
 	id := c.Param("id")
+	k, _ := services.GetKey(id)
 	if err := services.DeleteKey(id); err != nil {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 		return
 	}
+	label := id
+	if k != nil {
+		label = k.Label
+	}
+	services.LogEvent("key.deleted", actorFromCtx(c), "", id, fmt.Sprintf("key '%s' deleted", label))
 	c.JSON(http.StatusOK, gin.H{"deleted": true})
 }
 
@@ -249,6 +293,7 @@ func assignKey(c *gin.Context) {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 		return
 	}
+	services.LogEvent("key.assigned", actorFromCtx(c), body.ServerID, keyID, fmt.Sprintf("key %s assigned to server %s", keyID, body.ServerID))
 	c.JSON(http.StatusCreated, a)
 }
 
@@ -260,6 +305,7 @@ func revokeAssignment(c *gin.Context) {
 		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
 		return
 	}
+	services.LogEvent("key.revoked", actorFromCtx(c), serverID, keyID, fmt.Sprintf("key %s revoked from server %s", keyID, serverID))
 	c.JSON(http.StatusOK, gin.H{"revoked": true})
 }
 
@@ -285,6 +331,7 @@ func updateAgent(c *gin.Context) {
 		c.JSON(http.StatusServiceUnavailable, gin.H{"error": err.Error()})
 		return
 	}
+	services.LogEvent("agent.update_dispatched", actorFromCtx(c), s.ServerID, "", fmt.Sprintf("agent update dispatched to %s (version %s)", s.Hostname, version))
 	c.JSON(http.StatusAccepted, gin.H{
 		"message": "update command sent to agent",
 		"version": version,
@@ -303,6 +350,7 @@ func applyUpdates(c *gin.Context) {
 		c.JSON(http.StatusServiceUnavailable, gin.H{"error": err.Error()})
 		return
 	}
+	services.LogEvent("updates.applied", actorFromCtx(c), s.ServerID, "", fmt.Sprintf("package update command dispatched to %s", s.Hostname))
 	c.JSON(http.StatusAccepted, gin.H{"message": "apply updates command sent to agent"})
 }
 
@@ -362,6 +410,47 @@ echo "vantage-agent updated to ${VERSION} and restarted."
 	c.String(http.StatusOK, script)
 }
 
+func listAuditEvents(c *gin.Context) {
+	limit := int64(100)
+	if l := c.Query("limit"); l != "" {
+		if n, err := strconv.ParseInt(l, 10, 64); err == nil && n > 0 {
+			limit = n
+		}
+	}
+	events, err := services.ListAuditEvents(limit)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, events)
+}
+
+func getSettings(c *gin.Context) {
+	s, err := services.GetSettings()
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, s)
+}
+
+func saveSettings(c *gin.Context) {
+	var body struct {
+		Alerts models.AlertSettings `json:"alerts"`
+		Email  models.EmailSettings `json:"email"`
+	}
+	if err := c.ShouldBindJSON(&body); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	if err := services.SaveSettings(body.Alerts, body.Email); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	services.LogEvent("settings.updated", actorFromCtx(c), "", "", "alert settings updated")
+	c.JSON(http.StatusOK, gin.H{"saved": true})
+}
+
 func handleInstallScript(c *gin.Context) {
 	serverID := c.Query("server_id")
 	token := c.Query("token")

server/internal/api/secrets.go

@@ -0,0 +1,188 @@
+package api
+
+import (
+	"fmt"
+	"net/http"
+	"regexp"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"github.com/mrhid6/vantage/server/internal/services"
+)
+
+// groupNamePattern restricts group and key names to characters that are safe
+// in URLs and Kubernetes/env contexts.
+var groupNamePattern = regexp.MustCompile(`^[A-Za-z0-9._-]+$`)
+
+func validName(s string) bool {
+	return s != "" && len(s) <= 128 && groupNamePattern.MatchString(s)
+}
+
+// secretsReadAuth validates the ESO bearer token on the public read endpoint.
+func secretsReadAuth() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		const prefix = "Bearer "
+		auth := c.GetHeader("Authorization")
+		if len(auth) <= len(prefix) || !strings.EqualFold(auth[:len(prefix)], prefix) {
+			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "missing bearer token"})
+			return
+		}
+		if !services.VerifySecretsReadToken(auth[len(prefix):]) {
+			c.AbortWithStatusJSON(http.StatusUnauthorized, gin.H{"error": "invalid token"})
+			return
+		}
+		c.Next()
+	}
+}
+
+// esoGetGroup handles GET /secrets/:group for the External Secrets Operator.
+// Returns a flat JSON object { "KEY": "value", ... }; 404 if the group is empty
+// (ESO treats 404 as "deleted").
+func esoGetGroup(c *gin.Context) {
+	group := c.Param("group")
+	values, err := services.GetSecretGroupDecrypted(group)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "store error"})
+		return
+	}
+	if len(values) == 0 {
+		c.JSON(http.StatusNotFound, gin.H{"error": "group not found"})
+		return
+	}
+	c.JSON(http.StatusOK, values)
+}
+
+func listSecretGroups(c *gin.Context) {
+	groups, err := services.ListSecretGroups()
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, groups)
+}
+
+// createSecretGroup handles POST /api/secrets. A group is implicit, so it must
+// be created with at least one key/value pair.
+func createSecretGroup(c *gin.Context) {
+	var body struct {
+		Group  string            `json:"group" binding:"required"`
+		Values map[string]string `json:"values"`
+	}
+	if err := c.ShouldBindJSON(&body); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	if !validName(body.Group) {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid group name"})
+		return
+	}
+	if len(body.Values) == 0 {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "a group must be created with at least one key"})
+		return
+	}
+	for k := range body.Values {
+		if !validName(k) {
+			c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("invalid key name: %s", k)})
+			return
+		}
+	}
+	if err := services.UpsertSecrets(body.Group, body.Values); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	services.LogEvent("secret.updated", actorFromCtx(c), "", "", fmt.Sprintf("group '%s' created with keys: %s", body.Group, strings.Join(services.SortedKeys(body.Values), ", ")))
+	c.JSON(http.StatusCreated, gin.H{"group": body.Group})
+}
+
+func getSecretGroup(c *gin.Context) {
+	group := c.Param("group")
+	secrets, err := services.GetSecretGroup(group)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	if len(secrets) == 0 {
+		c.JSON(http.StatusNotFound, gin.H{"error": "group not found"})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"group": group, "secrets": secrets})
+}
+
+// putSecretGroup upserts one or more keys into an existing (or new) group.
+func putSecretGroup(c *gin.Context) {
+	group := c.Param("group")
+	if !validName(group) {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid group name"})
+		return
+	}
+	var values map[string]string
+	if err := c.ShouldBindJSON(&values); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid JSON body"})
+		return
+	}
+	if len(values) == 0 {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "body must contain at least one key"})
+		return
+	}
+	for k := range values {
+		if !validName(k) {
+			c.JSON(http.StatusBadRequest, gin.H{"error": fmt.Sprintf("invalid key name: %s", k)})
+			return
+		}
+	}
+	if err := services.UpsertSecrets(group, values); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	services.LogEvent("secret.updated", actorFromCtx(c), "", "", fmt.Sprintf("group '%s' keys updated: %s", group, strings.Join(services.SortedKeys(values), ", ")))
+	c.JSON(http.StatusOK, gin.H{"saved": true})
+}
+
+func revealSecret(c *gin.Context) {
+	group := c.Param("group")
+	var body struct {
+		Key string `json:"key" binding:"required"`
+	}
+	if err := c.ShouldBindJSON(&body); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+	value, err := services.RevealSecret(group, body.Key)
+	if err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": err.Error()})
+		return
+	}
+	services.LogEvent("secret.revealed", actorFromCtx(c), "", "", fmt.Sprintf("value of '%s/%s' revealed", group, body.Key))
+	c.JSON(http.StatusOK, gin.H{"value": value})
+}
+
+func deleteSecretKey(c *gin.Context) {
+	group := c.Param("group")
+	key := c.Param("key")
+	if err := services.DeleteSecret(group, key); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	services.LogEvent("secret.deleted", actorFromCtx(c), "", "", fmt.Sprintf("key '%s' deleted from group '%s'", key, group))
+	c.JSON(http.StatusOK, gin.H{"deleted": true})
+}
+
+func deleteSecretGroup(c *gin.Context) {
+	group := c.Param("group")
+	if err := services.DeleteSecretGroup(group); err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	services.LogEvent("secretgroup.deleted", actorFromCtx(c), "", "", fmt.Sprintf("group '%s' deleted", group))
+	c.JSON(http.StatusOK, gin.H{"deleted": true})
+}
+
+func rotateSecretsToken(c *gin.Context) {
+	token, err := services.RotateSecretsReadToken()
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	services.LogEvent("secrets.token_rotated", actorFromCtx(c), "", "", "ESO read token rotated")
+	c.JSON(http.StatusOK, gin.H{"token": token})
+}

server/internal/grpc/server.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"net"
+	"time"
 
 	"github.com/mrhid6/vantage/server/internal/grpc/pb"
 	"github.com/mrhid6/vantage/server/internal/models"
@@ -12,6 +13,7 @@ import (
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/encoding"
+	"google.golang.org/grpc/keepalive"
 	"google.golang.org/grpc/status"
 )
 
@@ -147,7 +149,20 @@ func StartGRPC(port int) error {
 		return fmt.Errorf("failed to listen: %w", err)
 	}
 
-	s := grpc.NewServer()
+	s := grpc.NewServer(
+		// Accept client keepalive pings as fast as every 20s so the 30s agent
+		// ping interval is always within the allowed window.
+		grpc.KeepaliveEnforcementPolicy(keepalive.EnforcementPolicy{
+			MinTime:             20 * time.Second,
+			PermitWithoutStream: false,
+		}),
+		grpc.KeepaliveParams(keepalive.ServerParameters{
+			// Server also pings the client after 45s of inactivity so both
+			// sides can detect a dead connection without waiting for a timeout.
+			Time:    45 * time.Second,
+			Timeout: 10 * time.Second,
+		}),
+	)
 	pb.RegisterVantageServer(s, &vantageServer{})
 
 	log.Printf("gRPC server listening on :%d", port)

server/internal/models/audit.go

@@ -0,0 +1,17 @@
+package models
+
+import (
+	"time"
+
+	"go.mongodb.org/mongo-driver/v2/bson"
+)
+
+type AuditEvent struct {
+	ID        bson.ObjectID `bson:"_id,omitempty" json:"id"`
+	EventType string        `bson:"event_type" json:"event_type"`
+	Actor     string        `bson:"actor" json:"actor"`
+	ServerID  string        `bson:"server_id,omitempty" json:"server_id,omitempty"`
+	KeyID     string        `bson:"key_id,omitempty" json:"key_id,omitempty"`
+	Details   string        `bson:"details" json:"details"`
+	CreatedAt time.Time     `bson:"created_at" json:"created_at"`
+}

server/internal/models/secret.go

@@ -0,0 +1,24 @@
+package models
+
+import (
+	"time"
+
+	"go.mongodb.org/mongo-driver/v2/bson"
+)
+
+// Secret is a single key/value pair within a group. The value is stored
+// encrypted (AES-256-GCM) and is never serialized to JSON.
+type Secret struct {
+	ID             bson.ObjectID `bson:"_id,omitempty" json:"-"`
+	Group          string        `bson:"group" json:"group"`
+	Key            string        `bson:"key" json:"key"`
+	EncryptedValue string        `bson:"encrypted_value" json:"-"`
+	UpdatedAt      time.Time     `bson:"updated_at" json:"updated_at"`
+}
+
+// GroupSummary describes a group in the list view.
+type GroupSummary struct {
+	Group     string    `json:"group"`
+	KeyCount  int       `json:"key_count"`
+	UpdatedAt time.Time `json:"updated_at"`
+}

server/internal/models/settings.go

@@ -0,0 +1,39 @@
+package models
+
+import (
+	"time"
+
+	"go.mongodb.org/mongo-driver/v2/bson"
+)
+
+type AlertSettings struct {
+	Enabled                 bool   `bson:"enabled" json:"enabled"`
+	WebhookURL              string `bson:"webhook_url" json:"webhook_url"`
+	OfflineThresholdMinutes int    `bson:"offline_threshold_minutes" json:"offline_threshold_minutes"`
+}
+
+type EmailSettings struct {
+	Enabled  bool     `bson:"enabled" json:"enabled"`
+	SMTPHost string   `bson:"smtp_host" json:"smtp_host"`
+	SMTPPort int      `bson:"smtp_port" json:"smtp_port"`
+	Username string   `bson:"username" json:"username"`
+	Password string   `bson:"password" json:"password"`
+	FromAddr string   `bson:"from_addr" json:"from_addr"`
+	ToAddrs  []string `bson:"to_addrs" json:"to_addrs"`
+	UseTLS   bool     `bson:"use_tls" json:"use_tls"`
+}
+
+// SecretsSettings holds configuration for the secrets vault / ESO integration.
+// The read token is stored as a SHA-256 hash and never returned to clients.
+type SecretsSettings struct {
+	ReadTokenHash string    `bson:"read_token_hash,omitempty" json:"-"`
+	ReadTokenSet  bool      `bson:"-" json:"read_token_set"`
+	RotatedAt     time.Time `bson:"rotated_at,omitempty" json:"rotated_at,omitempty"`
+}
+
+type Settings struct {
+	ID      bson.ObjectID   `bson:"_id,omitempty" json:"-"`
+	Alerts  AlertSettings   `bson:"alerts" json:"alerts"`
+	Email   EmailSettings   `bson:"email" json:"email"`
+	Secrets SecretsSettings `bson:"secrets" json:"secrets"`
+}

server/internal/services/audit.go

@@ -0,0 +1,50 @@
+package services
+
+import (
+	"context"
+	"log"
+	"time"
+
+	"github.com/mrhid6/vantage/server/internal/db"
+	"github.com/mrhid6/vantage/server/internal/models"
+	"go.mongodb.org/mongo-driver/v2/bson"
+	"go.mongodb.org/mongo-driver/v2/mongo/options"
+)
+
+func LogEvent(eventType, actor, serverID, keyID, details string) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	event := models.AuditEvent{
+		EventType: eventType,
+		Actor:     actor,
+		ServerID:  serverID,
+		KeyID:     keyID,
+		Details:   details,
+		CreatedAt: time.Now(),
+	}
+	if _, err := db.Col("audit_logs").InsertOne(ctx, event); err != nil {
+		log.Printf("audit log error: %v", err)
+	}
+}
+
+func ListAuditEvents(limit int64) ([]models.AuditEvent, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	opts := options.Find().
+		SetSort(bson.D{{Key: "created_at", Value: -1}}).
+		SetLimit(limit)
+
+	cursor, err := db.Col("audit_logs").Find(ctx, bson.M{}, opts)
+	if err != nil {
+		return nil, err
+	}
+	defer cursor.Close(ctx)
+
+	var events []models.AuditEvent
+	if err := cursor.All(ctx, &events); err != nil {
+		return nil, err
+	}
+	return events, nil
+}

server/internal/services/crypto.go

@@ -22,7 +22,9 @@ func encryptionKey() ([]byte, error) {
 	return key, nil
 }
 
-func encryptPrivateKey(plaintext string) (string, error) {
+// encryptString encrypts a plaintext value with AES-256-GCM using the
+// shared KEY_ENCRYPTION_KEY, returning hex(nonce + ciphertext).
+func encryptString(plaintext string) (string, error) {
 	key, err := encryptionKey()
 	if err != nil {
 		return "", err
@@ -43,7 +45,8 @@ func encryptPrivateKey(plaintext string) (string, error) {
 	return hex.EncodeToString(sealed), nil
 }
 
-func decryptPrivateKey(ciphertextHex string) (string, error) {
+// decryptString reverses encryptString.
+func decryptString(ciphertextHex string) (string, error) {
 	key, err := encryptionKey()
 	if err != nil {
 		return "", err
@@ -70,3 +73,7 @@ func decryptPrivateKey(ciphertextHex string) (string, error) {
 	}
 	return string(plaintext), nil
 }
+
+func encryptPrivateKey(plaintext string) (string, error) { return encryptString(plaintext) }
+
+func decryptPrivateKey(ciphertextHex string) (string, error) { return decryptString(ciphertextHex) }

server/internal/services/secrets.go

@@ -0,0 +1,174 @@
+package services
+
+import (
+	"context"
+	"fmt"
+	"sort"
+	"time"
+
+	"github.com/mrhid6/vantage/server/internal/db"
+	"github.com/mrhid6/vantage/server/internal/models"
+	"go.mongodb.org/mongo-driver/v2/bson"
+	"go.mongodb.org/mongo-driver/v2/mongo"
+	"go.mongodb.org/mongo-driver/v2/mongo/options"
+)
+
+// EnsureSecretIndexes creates the unique compound index on (group, key).
+func EnsureSecretIndexes() error {
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	_, err := db.Col("secrets").Indexes().CreateOne(ctx, mongo.IndexModel{
+		Keys:    bson.D{{Key: "group", Value: 1}, {Key: "key", Value: 1}},
+		Options: options.Index().SetUnique(true),
+	})
+	return err
+}
+
+// ListSecretGroups returns a summary of every group with its key count and
+// most recent update time.
+func ListSecretGroups() ([]models.GroupSummary, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	pipeline := mongo.Pipeline{
+		{{Key: "$group", Value: bson.D{
+			{Key: "_id", Value: "$group"},
+			{Key: "key_count", Value: bson.D{{Key: "$sum", Value: 1}}},
+			{Key: "updated_at", Value: bson.D{{Key: "$max", Value: "$updated_at"}}},
+		}}},
+		{{Key: "$sort", Value: bson.D{{Key: "_id", Value: 1}}}},
+	}
+
+	cursor, err := db.Col("secrets").Aggregate(ctx, pipeline)
+	if err != nil {
+		return nil, err
+	}
+	defer cursor.Close(ctx)
+
+	var rows []struct {
+		Group     string    `bson:"_id"`
+		KeyCount  int       `bson:"key_count"`
+		UpdatedAt time.Time `bson:"updated_at"`
+	}
+	if err := cursor.All(ctx, &rows); err != nil {
+		return nil, err
+	}
+
+	groups := make([]models.GroupSummary, 0, len(rows))
+	for _, r := range rows {
+		groups = append(groups, models.GroupSummary{
+			Group:     r.Group,
+			KeyCount:  r.KeyCount,
+			UpdatedAt: r.UpdatedAt,
+		})
+	}
+	return groups, nil
+}
+
+// GetSecretGroup returns the keys within a group, sorted by key name, without
+// decrypted values.
+func GetSecretGroup(group string) ([]models.Secret, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	cursor, err := db.Col("secrets").Find(ctx, bson.M{"group": group},
+		options.Find().SetSort(bson.D{{Key: "key", Value: 1}}))
+	if err != nil {
+		return nil, err
+	}
+	defer cursor.Close(ctx)
+
+	var docs []models.Secret
+	if err := cursor.All(ctx, &docs); err != nil {
+		return nil, err
+	}
+	return docs, nil
+}
+
+// GetSecretGroupDecrypted returns a flat map of key → plaintext value for a
+// group. Used by the ESO read endpoint.
+func GetSecretGroupDecrypted(group string) (map[string]string, error) {
+	docs, err := GetSecretGroup(group)
+	if err != nil {
+		return nil, err
+	}
+	result := make(map[string]string, len(docs))
+	for _, doc := range docs {
+		val, err := decryptString(doc.EncryptedValue)
+		if err != nil {
+			return nil, fmt.Errorf("decrypt %s/%s: %w", group, doc.Key, err)
+		}
+		result[doc.Key] = val
+	}
+	return result, nil
+}
+
+// RevealSecret returns the decrypted value of a single key.
+func RevealSecret(group, key string) (string, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	var doc models.Secret
+	err := db.Col("secrets").FindOne(ctx, bson.M{"group": group, "key": key}).Decode(&doc)
+	if err == mongo.ErrNoDocuments {
+		return "", fmt.Errorf("secret not found")
+	}
+	if err != nil {
+		return "", err
+	}
+	return decryptString(doc.EncryptedValue)
+}
+
+// UpsertSecrets encrypts and writes each key/value pair into the group.
+func UpsertSecrets(group string, values map[string]string) error {
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+
+	for key, val := range values {
+		encrypted, err := encryptString(val)
+		if err != nil {
+			return fmt.Errorf("encrypt %s: %w", key, err)
+		}
+		_, err = db.Col("secrets").UpdateOne(ctx,
+			bson.M{"group": group, "key": key},
+			bson.M{"$set": bson.M{
+				"encrypted_value": encrypted,
+				"updated_at":      time.Now(),
+			}},
+			options.UpdateOne().SetUpsert(true),
+		)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// SortedKeys returns the map keys sorted — handy for stable audit messages.
+func SortedKeys(m map[string]string) []string {
+	keys := make([]string, 0, len(m))
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	return keys
+}
+
+// DeleteSecret removes a single key from a group.
+func DeleteSecret(group, key string) error {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	_, err := db.Col("secrets").DeleteOne(ctx, bson.M{"group": group, "key": key})
+	return err
+}
+
+// DeleteSecretGroup removes an entire group and all its keys.
+func DeleteSecretGroup(group string) error {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	_, err := db.Col("secrets").DeleteMany(ctx, bson.M{"group": group})
+	return err
+}

server/internal/services/servers.go

@@ -197,12 +197,49 @@ func StoreAvailableUpdates(serverID string, pkgs []models.PackageUpdate) error {
 	return err
 }
 
-func MarkOfflineServers(threshold time.Duration) error {
-	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+func MarkOfflineServers() error {
+	settings, _ := GetSettings()
+	thresholdMinutes := 5
+	if settings != nil && settings.Alerts.OfflineThresholdMinutes > 0 {
+		thresholdMinutes = settings.Alerts.OfflineThresholdMinutes
+	}
+	threshold := time.Duration(thresholdMinutes) * time.Minute
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()
 
 	cutoff := time.Now().Add(-threshold)
-	_, err := db.Col("servers").UpdateMany(ctx,
+
+	// Find servers about to transition to offline so we can alert on them.
+	cursor, err := db.Col("servers").Find(ctx, bson.M{
+		"status":    "active",
+		"last_seen": bson.M{"$lt": cutoff},
+	})
+	if err != nil {
+		return err
+	}
+	defer cursor.Close(ctx)
+
+	var goingOffline []models.Server
+	if err := cursor.All(ctx, &goingOffline); err != nil {
+		return err
+	}
+
+	if len(goingOffline) == 0 {
+		return nil
+	}
+
+	for _, s := range goingOffline {
+		LogEvent("server.offline", "system", s.ServerID, "", fmt.Sprintf("%s (%s) went offline", s.Hostname, s.IPAddress))
+		if settings != nil && settings.Alerts.Enabled && settings.Alerts.WebhookURL != "" {
+			go SendOfflineWebhook(settings.Alerts.WebhookURL, s.Hostname, s.ServerID, s.IPAddress)
+		}
+		if settings != nil && settings.Email.Enabled {
+			go SendOfflineEmail(settings.Email, s.Hostname, s.ServerID, s.IPAddress)
+		}
+	}
+
+	_, err = db.Col("servers").UpdateMany(ctx,
 		bson.M{
 			"status":    "active",
 			"last_seen": bson.M{"$lt": cutoff},

server/internal/services/settings.go

@@ -0,0 +1,220 @@
+package services
+
+import (
+	"bytes"
+	"context"
+	"crypto/rand"
+	"crypto/sha256"
+	"crypto/subtle"
+	"crypto/tls"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"net/smtp"
+	"strings"
+	"time"
+
+	"github.com/mrhid6/vantage/server/internal/db"
+	"github.com/mrhid6/vantage/server/internal/models"
+	"go.mongodb.org/mongo-driver/v2/bson"
+	"go.mongodb.org/mongo-driver/v2/mongo"
+	"go.mongodb.org/mongo-driver/v2/mongo/options"
+)
+
+var defaultSettings = models.Settings{
+	Alerts: models.AlertSettings{
+		Enabled:                 false,
+		WebhookURL:              "",
+		OfflineThresholdMinutes: 5,
+	},
+	Email: models.EmailSettings{
+		SMTPPort: 587,
+	},
+}
+
+func GetSettings() (*models.Settings, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	var s models.Settings
+	err := db.Col("settings").FindOne(ctx, bson.M{}).Decode(&s)
+	if err == mongo.ErrNoDocuments {
+		cp := defaultSettings
+		return &cp, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	s.Secrets.ReadTokenSet = s.Secrets.ReadTokenHash != ""
+	return &s, nil
+}
+
+func hashToken(token string) string {
+	sum := sha256.Sum256([]byte(token))
+	return hex.EncodeToString(sum[:])
+}
+
+// RotateSecretsReadToken generates a new ESO read token, stores its SHA-256
+// hash, and returns the plaintext token exactly once.
+func RotateSecretsReadToken() (string, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	raw := make([]byte, 32)
+	if _, err := rand.Read(raw); err != nil {
+		return "", err
+	}
+	token := hex.EncodeToString(raw)
+
+	_, err := db.Col("settings").UpdateOne(ctx,
+		bson.M{},
+		bson.M{"$set": bson.M{
+			"secrets.read_token_hash": hashToken(token),
+			"secrets.rotated_at":      time.Now(),
+		}},
+		options.UpdateOne().SetUpsert(true),
+	)
+	if err != nil {
+		return "", err
+	}
+	return token, nil
+}
+
+// VerifySecretsReadToken reports whether the supplied token matches the stored
+// hash, using a constant-time comparison.
+func VerifySecretsReadToken(token string) bool {
+	if token == "" {
+		return false
+	}
+	s, err := GetSettings()
+	if err != nil || s.Secrets.ReadTokenHash == "" {
+		return false
+	}
+	expected, err := hex.DecodeString(s.Secrets.ReadTokenHash)
+	if err != nil {
+		return false
+	}
+	got := sha256.Sum256([]byte(token))
+	return subtle.ConstantTimeCompare(expected, got[:]) == 1
+}
+
+func SaveSettings(alerts models.AlertSettings, email models.EmailSettings) error {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	if alerts.OfflineThresholdMinutes <= 0 {
+		alerts.OfflineThresholdMinutes = 5
+	}
+	if email.SMTPPort <= 0 {
+		email.SMTPPort = 587
+	}
+
+	_, err := db.Col("settings").UpdateOne(ctx,
+		bson.M{},
+		bson.M{"$set": bson.M{"alerts": alerts, "email": email}},
+		options.UpdateOne().SetUpsert(true),
+	)
+	return err
+}
+
+func SendOfflineWebhook(webhookURL, hostname, serverID, ipAddress string) {
+	payload := map[string]any{
+		"event":      "server.offline",
+		"hostname":   hostname,
+		"server_id":  serverID,
+		"ip_address": ipAddress,
+		"timestamp":  time.Now().UTC().Format(time.RFC3339),
+		"message":    fmt.Sprintf("Server %s (%s) has gone offline", hostname, ipAddress),
+	}
+	body, err := json.Marshal(payload)
+	if err != nil {
+		log.Printf("webhook marshal error: %v", err)
+		return
+	}
+	resp, err := http.Post(webhookURL, "application/json", bytes.NewReader(body))
+	if err != nil {
+		log.Printf("webhook delivery error for %s: %v", hostname, err)
+		return
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode >= 400 {
+		log.Printf("webhook returned %d for %s", resp.StatusCode, hostname)
+	}
+}
+
+func SendOfflineEmail(cfg models.EmailSettings, hostname, serverID, ipAddress string) {
+	if !cfg.Enabled || cfg.SMTPHost == "" || len(cfg.ToAddrs) == 0 {
+		return
+	}
+
+	subject := fmt.Sprintf("Vantage Alert: %s is offline", hostname)
+	bodyText := fmt.Sprintf(
+		"Server %s (%s) has gone offline.\r\n\r\nServer ID: %s\r\nTimestamp: %s\r\n",
+		hostname, ipAddress, serverID, time.Now().UTC().Format(time.RFC3339),
+	)
+
+	msg := []byte(fmt.Sprintf(
+		"From: %s\r\nTo: %s\r\nSubject: %s\r\nContent-Type: text/plain; charset=UTF-8\r\n\r\n%s",
+		cfg.FromAddr,
+		strings.Join(cfg.ToAddrs, ", "),
+		subject,
+		bodyText,
+	))
+
+	addr := fmt.Sprintf("%s:%d", cfg.SMTPHost, cfg.SMTPPort)
+	var auth smtp.Auth
+	if cfg.Username != "" {
+		auth = smtp.PlainAuth("", cfg.Username, cfg.Password, cfg.SMTPHost)
+	}
+
+	var sendErr error
+	if cfg.UseTLS {
+		sendErr = sendMailTLS(addr, cfg.SMTPHost, auth, cfg.FromAddr, cfg.ToAddrs, msg)
+	} else {
+		sendErr = smtp.SendMail(addr, auth, cfg.FromAddr, cfg.ToAddrs, msg)
+	}
+	if sendErr != nil {
+		log.Printf("email alert error for %s: %v", hostname, sendErr)
+	}
+}
+
+// sendMailTLS dials with implicit TLS (port 465) instead of STARTTLS.
+func sendMailTLS(addr, host string, auth smtp.Auth, from string, to []string, msg []byte) error {
+	conn, err := tls.Dial("tcp", addr, &tls.Config{ServerName: host})
+	if err != nil {
+		return fmt.Errorf("tls dial: %w", err)
+	}
+	c, err := smtp.NewClient(conn, host)
+	if err != nil {
+		return fmt.Errorf("smtp client: %w", err)
+	}
+	defer c.Close()
+
+	if auth != nil {
+		if err := c.Auth(auth); err != nil {
+			return fmt.Errorf("smtp auth: %w", err)
+		}
+	}
+	if err := c.Mail(from); err != nil {
+		return err
+	}
+	for _, rcpt := range to {
+		if err := c.Rcpt(strings.TrimSpace(rcpt)); err != nil {
+			return err
+		}
+	}
+	w, err := c.Data()
+	if err != nil {
+		return err
+	}
+	if _, err := w.Write(msg); err != nil {
+		return err
+	}
+	if err := w.Close(); err != nil {
+		return err
+	}
+	return c.Quit()
+}
+

web/app/audit/page.tsx

@@ -0,0 +1,106 @@
+"use client";
+
+import { useQuery } from "@tanstack/react-query";
+import { api, AuditEvent } from "@/lib/api";
+import { Card } from "@/components/ui";
+import { Table, Thead, Tbody, Tr, Th, Td } from "@/components/ui";
+
+const EVENT_LABELS: Record<string, string> = {
+  "server.created":             "Server Created",
+  "server.deleted":             "Server Deleted",
+  "server.offline":             "Server Offline",
+  "key.uploaded":               "Key Uploaded",
+  "key.deleted":                "Key Deleted",
+  "key.assigned":               "Key Assigned",
+  "key.revoked":                "Key Revoked",
+  "key.generation_dispatched":  "Key Generation",
+  "agent.update_dispatched":    "Agent Updated",
+  "updates.applied":            "Updates Applied",
+  "settings.updated":           "Settings Updated",
+};
+
+const EVENT_COLOURS: Record<string, string> = {
+  "server.offline":  "text-danger",
+  "server.deleted":  "text-danger",
+  "key.deleted":     "text-danger",
+  "key.revoked":     "text-warning",
+  "server.created":  "text-success",
+  "key.uploaded":    "text-success",
+  "key.assigned":    "text-success",
+};
+
+function formatDate(dateStr: string) {
+  return new Date(dateStr).toLocaleString();
+}
+
+function EventTypeBadge({ type }: { type: string }) {
+  const label = EVENT_LABELS[type] ?? type;
+  const colour = EVENT_COLOURS[type] ?? "text-text-secondary";
+  return (
+    <span className={`font-mono text-xs font-medium ${colour}`}>{label}</span>
+  );
+}
+
+export default function AuditPage() {
+  const { data: events, isLoading, error } = useQuery({
+    queryKey: ["audit"],
+    queryFn: () => api.listAuditEvents(200),
+    refetchInterval: 30_000,
+  });
+
+  return (
+    <div className="p-8">
+      <div className="mb-6">
+        <h1 className="text-2xl font-bold text-text-primary">Audit Log</h1>
+        <p className="mt-1 text-sm text-text-secondary">
+          All administrative actions and server status changes
+        </p>
+      </div>
+
+      <Card padding={false}>
+        {isLoading ? (
+          <div className="flex items-center justify-center py-20">
+            <div className="h-8 w-8 animate-spin rounded-full border-2 border-border border-t-accent" />
+          </div>
+        ) : error ? (
+          <div className="py-20 text-center text-danger">Failed to load audit log.</div>
+        ) : events && events.length > 0 ? (
+          <Table>
+            <Thead>
+              <Tr>
+                <Th>Time</Th>
+                <Th>Event</Th>
+                <Th>Actor</Th>
+                <Th>Details</Th>
+              </Tr>
+            </Thead>
+            <Tbody>
+              {events.map((e: AuditEvent) => (
+                <Tr key={e.id}>
+                  <Td>
+                    <span className="whitespace-nowrap font-mono text-xs text-text-secondary">
+                      {formatDate(e.created_at)}
+                    </span>
+                  </Td>
+                  <Td>
+                    <EventTypeBadge type={e.event_type} />
+                  </Td>
+                  <Td>
+                    <span className="text-sm text-text-primary">{e.actor}</span>
+                  </Td>
+                  <Td>
+                    <span className="text-sm text-text-secondary">{e.details}</span>
+                  </Td>
+                </Tr>
+              ))}
+            </Tbody>
+          </Table>
+        ) : (
+          <div className="py-20 text-center">
+            <p className="text-text-secondary text-sm">No audit events recorded yet.</p>
+          </div>
+        )}
+      </Card>
+    </div>
+  );
+}

web/app/secrets/[group]/page.tsx

@@ -0,0 +1,311 @@
+"use client";
+
+import { useState } from "react";
+import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
+import { useParams, useRouter } from "next/navigation";
+import Link from "next/link";
+import { api, Secret } from "@/lib/api";
+import { Button, Card, CardHeader, CardTitle } from "@/components/ui";
+import { Table, Thead, Tbody, Tr, Th, Td } from "@/components/ui";
+
+const inputClass =
+    "w-full rounded-lg border border-border bg-surface-2 px-3 py-2 text-sm text-text-primary placeholder-text-secondary/50 focus:border-accent focus:outline-none focus:ring-1 focus:ring-accent";
+
+// Name of the ClusterSecretStore the generated manifests reference.
+const STORE_NAME = "vantage-store";
+
+function CopyBlock({ label, yaml }: { label: string; yaml: string }) {
+    const [copied, setCopied] = useState(false);
+
+    async function copy() {
+        await navigator.clipboard.writeText(yaml);
+        setCopied(true);
+        setTimeout(() => setCopied(false), 2000);
+    }
+
+    return (
+        <div>
+            <div className="mb-1.5 flex items-center justify-between">
+                <span className="text-sm font-medium text-text-secondary">{label}</span>
+                <Button type="button" variant="ghost" size="sm" onClick={copy}>
+                    {copied ? "Copied!" : "Copy"}
+                </Button>
+            </div>
+            <pre className="overflow-x-auto rounded-lg border border-border bg-surface-2 p-3 font-mono text-xs leading-relaxed text-text-primary">{yaml}</pre>
+        </div>
+    );
+}
+
+function YamlModal({ group, onClose }: { group: string; onClose: () => void }) {
+    const [namespace, setNamespace] = useState(group);
+    const readUrl = typeof window !== "undefined" ? window.location.origin : "https://vantage.example.com";
+    const ns = namespace.trim() || group;
+
+    const externalSecret = `apiVersion: external-secrets.io/v1
+kind: ExternalSecret
+metadata:
+  name: ${group}
+  namespace: ${ns}
+spec:
+  refreshInterval: 15m
+  secretStoreRef:
+    name: ${STORE_NAME}
+    kind: ClusterSecretStore
+  target:
+    name: ${group}
+    creationPolicy: Owner
+  dataFrom:
+    - extract:
+        key: ${group}`;
+
+    const clusterStore = `apiVersion: external-secrets.io/v1
+kind: ClusterSecretStore
+metadata:
+  name: ${STORE_NAME}
+spec:
+  provider:
+    webhook:
+      url: "${readUrl}/api/secrets/{{ .remoteRef.key }}/values"
+      method: GET
+      result:
+        jsonPath: "$"
+      headers:
+        Content-Type: "application/json"
+        Authorization: "Bearer {{ .auth.token }}"
+      secrets:
+        - name: auth
+          secretRef:
+            name: vantage-eso-token
+            namespace: external-secrets`;
+
+    return (
+        <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 p-4 backdrop-blur-sm">
+            <div className="max-h-[90vh] w-full max-w-2xl overflow-y-auto rounded-xl border border-border bg-surface p-6">
+                <h2 className="mb-1 text-lg font-semibold text-text-primary">
+                    Kubernetes manifests for <span className="font-mono">{group}</span>
+                </h2>
+                <p className="mb-5 text-sm text-text-secondary">Apply the ExternalSecret in your app&apos;s namespace to sync this group into a Kubernetes Secret via ESO.</p>
+
+                <div className="mb-5">
+                    <label className="mb-1.5 block text-sm font-medium text-text-secondary">Namespace</label>
+                    <input type="text" value={namespace} onChange={(e) => setNamespace(e.target.value)} placeholder={group} className={`${inputClass} font-mono`} />
+                </div>
+
+                <div className="space-y-5">
+                    <CopyBlock label="ExternalSecret (apply per namespace)" yaml={externalSecret} />
+
+                    <details className="group">
+                        <summary className="cursor-pointer text-sm font-medium text-text-secondary hover:text-text-primary">One-time cluster setup: ClusterSecretStore</summary>
+                        <p className="mb-3 mt-2 text-xs text-text-tertiary">
+                            Apply this once per cluster. It requires a Secret named <span className="font-mono">vantage-eso-token</span> in the <span className="font-mono">external-secrets</span>{" "}
+                            namespace holding the read token from Settings, labelled <span className="font-mono">external-secrets.io/type=webhook</span>.
+                        </p>
+                        <CopyBlock label="ClusterSecretStore" yaml={clusterStore} />
+                    </details>
+                </div>
+
+                <div className="mt-6 flex justify-end">
+                    <Button variant="ghost" onClick={onClose}>
+                        Close
+                    </Button>
+                </div>
+            </div>
+        </div>
+    );
+}
+
+function SecretRow({ group, secret }: { group: string; secret: Secret }) {
+    const queryClient = useQueryClient();
+    const [revealed, setRevealed] = useState<string | null>(null);
+    const [copied, setCopied] = useState(false);
+
+    const { mutate: reveal, isPending: revealing } = useMutation({
+        mutationFn: () => api.revealSecret(group, secret.key),
+        onSuccess: (res) => setRevealed(res.value),
+    });
+
+    const { mutate: remove, isPending: removing } = useMutation({
+        mutationFn: () => api.deleteSecret(group, secret.key),
+        onSuccess: () => queryClient.invalidateQueries({ queryKey: ["secret-group", group] }),
+    });
+
+    async function copy() {
+        if (revealed == null) return;
+        await navigator.clipboard.writeText(revealed);
+        setCopied(true);
+        setTimeout(() => setCopied(false), 2000);
+    }
+
+    return (
+        <Tr>
+            <Td>
+                <span className="font-mono font-medium text-text-primary">{secret.key}</span>
+            </Td>
+            <Td>{revealed == null ? <span className="font-mono text-text-tertiary">••••••••••••</span> : <span className="font-mono text-xs break-all text-text-primary">{revealed}</span>}</Td>
+            <Td>
+                <span className="text-text-secondary text-xs">{new Date(secret.updated_at).toLocaleString()}</span>
+            </Td>
+            <Td>
+                <div className="flex justify-end gap-2">
+                    {revealed == null ? (
+                        <Button variant="ghost" size="sm" loading={revealing} onClick={() => reveal()}>
+                            Reveal
+                        </Button>
+                    ) : (
+                        <>
+                            <Button variant="ghost" size="sm" onClick={copy}>
+                                {copied ? "Copied!" : "Copy"}
+                            </Button>
+                            <Button variant="ghost" size="sm" onClick={() => setRevealed(null)}>
+                                Hide
+                            </Button>
+                        </>
+                    )}
+                    <Button
+                        variant="ghost"
+                        size="sm"
+                        loading={removing}
+                        className="text-danger hover:text-danger"
+                        onClick={() => {
+                            if (confirm(`Delete key "${secret.key}"?`)) remove();
+                        }}
+                    >
+                        Delete
+                    </Button>
+                </div>
+            </Td>
+        </Tr>
+    );
+}
+
+function AddKeyCard({ group }: { group: string }) {
+    const queryClient = useQueryClient();
+    const [key, setKey] = useState("");
+    const [value, setValue] = useState("");
+
+    const {
+        mutate: add,
+        isPending,
+        error,
+    } = useMutation({
+        mutationFn: () => api.putSecrets(group, { [key.trim()]: value }),
+        onSuccess: () => {
+            queryClient.invalidateQueries({ queryKey: ["secret-group", group] });
+            setKey("");
+            setValue("");
+        },
+    });
+
+    return (
+        <Card>
+            <CardHeader>
+                <CardTitle>Add / Update Key</CardTitle>
+            </CardHeader>
+            <p className="mb-4 text-sm text-text-secondary">Adding a key that already exists overwrites its value. Others are left untouched.</p>
+            {error && <div className="mb-4 rounded-lg border border-danger/30 bg-danger/10 px-3 py-2 text-sm text-danger">{(error as Error).message}</div>}
+            <div className="flex items-end gap-3">
+                <div className="flex-1">
+                    <label className="mb-1.5 block text-sm font-medium text-text-secondary">Key</label>
+                    <input type="text" value={key} onChange={(e) => setKey(e.target.value)} placeholder="API_KEY" className={`${inputClass} font-mono`} />
+                </div>
+                <div className="flex-1">
+                    <label className="mb-1.5 block text-sm font-medium text-text-secondary">Value</label>
+                    <input type="text" value={value} onChange={(e) => setValue(e.target.value)} placeholder="myapikey456" className={`${inputClass} font-mono`} />
+                </div>
+                <Button variant="primary" loading={isPending} disabled={!key.trim() || !value} onClick={() => add()}>
+                    Save
+                </Button>
+            </div>
+        </Card>
+    );
+}
+
+export default function SecretGroupPage() {
+    const params = useParams();
+    const router = useRouter();
+    const queryClient = useQueryClient();
+    const group = decodeURIComponent(String(params.group));
+    const [showYaml, setShowYaml] = useState(false);
+
+    const { data, isLoading, error } = useQuery({
+        queryKey: ["secret-group", group],
+        queryFn: () => api.getSecretGroup(group),
+    });
+
+    const { mutate: deleteGroup, isPending: deleting } = useMutation({
+        mutationFn: () => api.deleteSecretGroup(group),
+        onSuccess: () => {
+            queryClient.invalidateQueries({ queryKey: ["secret-groups"] });
+            router.push("/secrets");
+        },
+    });
+
+    return (
+        <div className="p-8">
+            {showYaml && <YamlModal group={group} onClose={() => setShowYaml(false)} />}
+
+            <Link href="/secrets" className="mb-4 inline-flex items-center gap-1 text-sm text-text-secondary hover:text-text-primary">
+                ← Back to secrets
+            </Link>
+
+            <div className="mb-6 flex items-center justify-between">
+                <div>
+                    <h1 className="font-mono text-2xl font-bold text-text-primary">{group}</h1>
+                    <p className="mt-1 text-sm text-text-secondary">
+                        ESO reads this group at <span className="font-mono">GET /api/secrets/{group}/values</span>
+                    </p>
+                </div>
+                <div className="flex items-center gap-3">
+                    <Button variant="ghost" onClick={() => setShowYaml(true)}>
+                        <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
+                            <path strokeLinecap="round" strokeLinejoin="round" d="M17.25 6.75L22.5 12l-5.25 5.25m-10.5 0L1.5 12l5.25-5.25m7.5-3l-4.5 16.5" />
+                        </svg>
+                        ExternalSecret YAML
+                    </Button>
+                    <Button
+                        variant="ghost"
+                        className="text-danger hover:text-danger"
+                        loading={deleting}
+                        onClick={() => {
+                            if (confirm(`Delete the entire "${group}" group and all its keys?`)) deleteGroup();
+                        }}
+                    >
+                        Delete Group
+                    </Button>
+                </div>
+            </div>
+
+            <div className="space-y-6">
+                <AddKeyCard group={group} />
+
+                <Card padding={false}>
+                    {isLoading ? (
+                        <div className="flex items-center justify-center py-20">
+                            <div className="h-8 w-8 animate-spin rounded-full border-2 border-border border-t-accent" />
+                        </div>
+                    ) : error ? (
+                        <div className="py-20 text-center text-danger">Failed to load group. It may have been deleted.</div>
+                    ) : data && data.secrets.length > 0 ? (
+                        <Table>
+                            <Thead>
+                                <Tr>
+                                    <Th>Key</Th>
+                                    <Th>Value</Th>
+                                    <Th>Updated</Th>
+                                    <Th />
+                                </Tr>
+                            </Thead>
+                            <Tbody>
+                                {data.secrets.map((s: Secret) => (
+                                    <SecretRow key={s.key} group={group} secret={s} />
+                                ))}
+                            </Tbody>
+                        </Table>
+                    ) : (
+                        <div className="py-16 text-center text-text-secondary">This group has no keys. Add one above.</div>
+                    )}
+                </Card>
+            </div>
+        </div>
+    );
+}

web/app/secrets/page.tsx

@@ -0,0 +1,180 @@
+"use client";
+
+import { useState } from "react";
+import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
+import Link from "next/link";
+import { api, SecretGroupSummary } from "@/lib/api";
+import { Button, Card } from "@/components/ui";
+import { Table, Thead, Tbody, Tr, Th, Td } from "@/components/ui";
+
+const inputClass =
+  "w-full rounded-lg border border-border bg-surface-2 px-3 py-2 text-sm text-text-primary placeholder-text-secondary/50 focus:border-accent focus:outline-none focus:ring-1 focus:ring-accent";
+
+function NewGroupModal({ onClose }: { onClose: () => void }) {
+  const queryClient = useQueryClient();
+  const [group, setGroup] = useState("");
+  const [key, setKey] = useState("");
+  const [value, setValue] = useState("");
+
+  const { mutate: create, isPending, error } = useMutation({
+    mutationFn: () =>
+      api.createSecretGroup(group.trim(), { [key.trim()]: value }),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["secret-groups"] });
+      onClose();
+    },
+  });
+
+  return (
+    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 p-4 backdrop-blur-sm">
+      <div className="w-full max-w-lg rounded-xl border border-border bg-surface p-6">
+        <h2 className="mb-1 text-lg font-semibold text-text-primary">New Secret Group</h2>
+        <p className="mb-4 text-sm text-text-secondary">
+          A group must be created with at least one key. You can add more keys afterwards.
+        </p>
+
+        {error && (
+          <div className="mb-4 rounded-lg border border-danger/30 bg-danger/10 px-3 py-2 text-sm text-danger">
+            {(error as Error).message}
+          </div>
+        )}
+
+        <div className="space-y-4">
+          <div>
+            <label className="mb-1.5 block text-sm font-medium text-text-secondary">Group name</label>
+            <input
+              type="text"
+              value={group}
+              onChange={(e) => setGroup(e.target.value)}
+              placeholder="e.g. myapp-prod"
+              className={`${inputClass} font-mono`}
+            />
+          </div>
+          <div className="grid grid-cols-2 gap-3">
+            <div>
+              <label className="mb-1.5 block text-sm font-medium text-text-secondary">First key</label>
+              <input
+                type="text"
+                value={key}
+                onChange={(e) => setKey(e.target.value)}
+                placeholder="DB_PASSWORD"
+                className={`${inputClass} font-mono`}
+              />
+            </div>
+            <div>
+              <label className="mb-1.5 block text-sm font-medium text-text-secondary">Value</label>
+              <input
+                type="text"
+                value={value}
+                onChange={(e) => setValue(e.target.value)}
+                placeholder="supersecret123"
+                className={`${inputClass} font-mono`}
+              />
+            </div>
+          </div>
+        </div>
+
+        <div className="mt-6 flex justify-end gap-3">
+          <Button variant="ghost" onClick={onClose}>Cancel</Button>
+          <Button
+            variant="primary"
+            loading={isPending}
+            disabled={!group.trim() || !key.trim() || !value}
+            onClick={() => create()}
+          >
+            Create Group
+          </Button>
+        </div>
+      </div>
+    </div>
+  );
+}
+
+export default function SecretsPage() {
+  const [showNew, setShowNew] = useState(false);
+
+  const { data: groups, isLoading, error } = useQuery({
+    queryKey: ["secret-groups"],
+    queryFn: api.listSecretGroups,
+  });
+
+  return (
+    <div className="p-8">
+      {showNew && <NewGroupModal onClose={() => setShowNew(false)} />}
+
+      <div className="mb-6 flex items-center justify-between">
+        <div>
+          <h1 className="text-2xl font-bold text-text-primary">Secrets</h1>
+          <p className="mt-1 text-sm text-text-secondary">
+            {groups?.length ?? 0} group{groups?.length !== 1 ? "s" : ""} · encrypted at rest, exposed to Kubernetes via ESO
+          </p>
+        </div>
+        <Button variant="primary" onClick={() => setShowNew(true)}>
+          <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
+            <path strokeLinecap="round" strokeLinejoin="round" d="M12 4.5v15m7.5-7.5h-15" />
+          </svg>
+          New Group
+        </Button>
+      </div>
+
+      <Card padding={false}>
+        {isLoading ? (
+          <div className="flex items-center justify-center py-20">
+            <div className="h-8 w-8 animate-spin rounded-full border-2 border-border border-t-accent" />
+          </div>
+        ) : error ? (
+          <div className="py-20 text-center text-danger">
+            Failed to load secrets. Is the backend running?
+          </div>
+        ) : groups && groups.length > 0 ? (
+          <Table>
+            <Thead>
+              <Tr>
+                <Th>Group</Th>
+                <Th>Keys</Th>
+                <Th>Last Updated</Th>
+                <Th />
+              </Tr>
+            </Thead>
+            <Tbody>
+              {groups.map((g: SecretGroupSummary) => (
+                <Tr key={g.group}>
+                  <Td>
+                    <span className="font-mono font-medium text-text-primary">{g.group}</span>
+                  </Td>
+                  <Td>
+                    <span className="text-text-secondary">
+                      {g.key_count} key{g.key_count !== 1 ? "s" : ""}
+                    </span>
+                  </Td>
+                  <Td>
+                    <span className="text-text-secondary text-xs">
+                      {new Date(g.updated_at).toLocaleString()}
+                    </span>
+                  </Td>
+                  <Td>
+                    <Link href={`/secrets/${encodeURIComponent(g.group)}`}>
+                      <Button variant="ghost" size="sm">View →</Button>
+                    </Link>
+                  </Td>
+                </Tr>
+              ))}
+            </Tbody>
+          </Table>
+        ) : (
+          <div className="py-20 text-center">
+            <div className="mx-auto mb-4 flex h-12 w-12 items-center justify-center rounded-full bg-surface-2">
+              <svg className="h-6 w-6 text-text-secondary" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
+                <path strokeLinecap="round" strokeLinejoin="round" d="M16.5 10.5V6.75a4.5 4.5 0 10-9 0v3.75m-.75 11.25h10.5a2.25 2.25 0 002.25-2.25v-6.75a2.25 2.25 0 00-2.25-2.25H6.75a2.25 2.25 0 00-2.25 2.25v6.75a2.25 2.25 0 002.25 2.25z" />
+              </svg>
+            </div>
+            <p className="text-text-secondary">No secret groups yet.</p>
+            <Button variant="primary" size="sm" className="mt-4" onClick={() => setShowNew(true)}>
+              Create your first group
+            </Button>
+          </div>
+        )}
+      </Card>
+    </div>
+  );
+}

web/app/servers/[id]/page.tsx

@@ -1,4 +1,4 @@
-"use client";
+"use client";
 
 import { useState } from "react";
 import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
@@ -314,6 +314,15 @@ export default function ServerDetailPage() {
     return (
         <div className="p-8">
             {showGenerateModal && <GenerateKeyModal onClose={() => setShowGenerateModal(false)} onSubmit={(opts) => generateKey(opts)} isPending={isGenerating} />}
+            {showUpdatesModal && server.available_updates && (
+                <UpdatesModal
+                    updates={server.available_updates}
+                    onClose={() => setShowUpdatesModal(false)}
+                    onApply={() => applyUpdates()}
+                    isApplying={isApplying}
+                    applySuccess={applySuccess}
+                />
+            )}
 
             <div className="mb-6 flex items-start justify-between">
                 <div>
@@ -329,6 +338,18 @@ export default function ServerDetailPage() {
                     <p className="mt-1 font-mono text-sm text-text-secondary">{server.ip_address}</p>
                 </div>
                 <div className="flex gap-2">
+                    {server.available_updates && server.available_updates.length > 0 && (
+                        <Button
+                            variant="secondary"
+                            onClick={() => setShowUpdatesModal(true)}
+                            className="border-warning/50 text-warning hover:border-warning hover:bg-warning/10"
+                        >
+                            <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
+                                <path strokeLinecap="round" strokeLinejoin="round" d="M12 9v3.75m-9.303 3.376c-.866 1.5.217 3.374 1.948 3.374h14.71c1.73 0 2.813-1.874 1.948-3.374L13.949 3.378c-.866-1.5-3.032-1.5-3.898 0L2.697 16.126zM12 15.75h.007v.008H12v-.008z" />
+                            </svg>
+                            {server.available_updates.length} OS Update{server.available_updates.length !== 1 ? "s" : ""}
+                        </Button>
+                    )}
                     <Button variant="secondary" onClick={() => setShowGenerateModal(true)}>
                         <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
                             <path

web/app/servers/page.tsx

@@ -2,19 +2,40 @@
 
 import { useQuery } from "@tanstack/react-query";
 import Link from "next/link";
-import { api, Server, ServerStatus } from "@/lib/api";
-import { Badge, Button, Card } from "@/components/ui";
+import { api, Server } from "@/lib/api";
+import { Button, Card } from "@/components/ui";
 import { Table, Thead, Tbody, Tr, Th, Td } from "@/components/ui";
 
-function statusVariant(status: ServerStatus) {
-  switch (status) {
-    case "active":
-      return "success";
-    case "pending":
-      return "warning";
-    case "offline":
-      return "danger";
-  }
+
+type DotStatus = "offline" | "needs-update" | "has-package-updates" | "ok";
+
+function resolveStatus(server: Server, latestVersion: string | undefined): DotStatus {
+  if (server.status === "offline" || server.status === "pending") return "offline";
+  if (latestVersion && server.agent_version && server.agent_version !== latestVersion) return "needs-update";
+  if (server.available_updates && server.available_updates.length > 0) return "has-package-updates";
+  return "ok";
+}
+
+const DOT_CLASSES: Record<DotStatus, string> = {
+  offline:             "bg-danger",
+  "needs-update":      "bg-orange-500",
+  "has-package-updates": "bg-yellow-400",
+  ok:                  "bg-success",
+};
+
+const DOT_LABELS: Record<DotStatus, string> = {
+  offline:             "Offline",
+  "needs-update":      "Agent needs updating",
+  "has-package-updates": "Package updates available",
+  ok:                  "OK",
+};
+
+function StatusDot({ status }: { status: DotStatus }) {
+  return (
+    <span title={DOT_LABELS[status]} className="flex items-center">
+      <span className={`inline-block h-2.5 w-2.5 rounded-full ${DOT_CLASSES[status]}`} />
+    </span>
+  );
 }
 
 function formatLastSeen(dateStr: string): string {
@@ -39,6 +60,13 @@ export default function ServersPage() {
     refetchInterval: 30_000,
   });
 
+  const { data: latestVersionData } = useQuery({
+    queryKey: ["agent-latest-version"],
+    queryFn: api.getLatestAgentVersion,
+    staleTime: 5 * 60_000,
+  });
+  const latestVersion = latestVersionData?.version;
+
   return (
     <div className="p-8">
       <div className="mb-6 flex items-center justify-between">
@@ -96,9 +124,7 @@ export default function ServersPage() {
                     <span className="text-text-secondary">{server.os_info}</span>
                   </Td>
                   <Td>
-                    <Badge variant={statusVariant(server.status)}>
-                      {server.status}
-                    </Badge>
+                    <StatusDot status={resolveStatus(server, latestVersion)} />
                   </Td>
                   <Td>
                     <span className="text-text-secondary">

web/app/settings/page.tsx

@@ -0,0 +1,393 @@
+"use client";
+
+import { useEffect, useState } from "react";
+import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
+import { api, AlertSettings, EmailSettings } from "@/lib/api";
+import { Button, Card, CardHeader, CardTitle } from "@/components/ui";
+
+function Toggle({ enabled, onChange }: { enabled: boolean; onChange: (v: boolean) => void }) {
+  return (
+    <button
+      type="button"
+      onClick={() => onChange(!enabled)}
+      className={`relative inline-flex h-6 w-11 flex-shrink-0 items-center rounded-full transition-colors focus:outline-none ${
+        enabled ? "bg-accent" : "bg-surface-2 border border-border"
+      }`}
+    >
+      <span
+        className={`inline-block h-4 w-4 transform rounded-full bg-white shadow transition-transform ${
+          enabled ? "translate-x-6" : "translate-x-1"
+        }`}
+      />
+    </button>
+  );
+}
+
+function ToggleRow({
+  label,
+  description,
+  enabled,
+  onChange,
+}: {
+  label: string;
+  description: string;
+  enabled: boolean;
+  onChange: (v: boolean) => void;
+}) {
+  return (
+    <div className="flex items-center justify-between rounded-lg border border-border bg-surface-2 px-4 py-3">
+      <div>
+        <p className="text-sm font-medium text-text-primary">{label}</p>
+        <p className="text-xs text-text-secondary">{description}</p>
+      </div>
+      <Toggle enabled={enabled} onChange={onChange} />
+    </div>
+  );
+}
+
+function Field({
+  label,
+  hint,
+  children,
+}: {
+  label: string;
+  hint?: string;
+  children: React.ReactNode;
+}) {
+  return (
+    <div>
+      <label className="mb-1.5 block text-sm font-medium text-text-secondary">{label}</label>
+      {children}
+      {hint && <p className="mt-1 text-xs text-text-tertiary">{hint}</p>}
+    </div>
+  );
+}
+
+const inputClass =
+  "w-full rounded-lg border border-border bg-surface-2 px-3 py-2 text-sm text-text-primary placeholder:text-text-tertiary focus:border-accent/50 focus:outline-none focus:ring-1 focus:ring-accent/30";
+
+function SecretsTokenCard({
+  tokenSet,
+  rotatedAt,
+}: {
+  tokenSet: boolean;
+  rotatedAt?: string;
+}) {
+  const queryClient = useQueryClient();
+  const [token, setToken] = useState<string | null>(null);
+  const [copied, setCopied] = useState(false);
+  const readUrl =
+    typeof window !== "undefined"
+      ? `${window.location.origin}/api/secrets/<group>/values`
+      : "/api/secrets/<group>/values";
+
+  const { mutate: rotate, isPending } = useMutation({
+    mutationFn: api.rotateSecretsToken,
+    onSuccess: (res) => {
+      setToken(res.token);
+      queryClient.invalidateQueries({ queryKey: ["settings"] });
+    },
+  });
+
+  async function copy() {
+    if (!token) return;
+    await navigator.clipboard.writeText(token);
+    setCopied(true);
+    setTimeout(() => setCopied(false), 2000);
+  }
+
+  return (
+    <Card>
+      <CardHeader>
+        <CardTitle>Secrets Read Token (ESO)</CardTitle>
+      </CardHeader>
+      <p className="mb-5 text-sm text-text-secondary">
+        Kubernetes External Secrets Operator authenticates to the read endpoint with this bearer
+        token. Point your <span className="font-mono">ClusterSecretStore</span> at{" "}
+        <span className="font-mono text-text-primary">{readUrl}</span>.
+      </p>
+
+      <div className="mb-4 flex items-center gap-2 text-sm">
+        <span
+          className={`inline-block h-2 w-2 rounded-full ${tokenSet ? "bg-success" : "bg-text-tertiary"}`}
+        />
+        <span className="text-text-secondary">
+          {tokenSet ? "A read token is configured" : "No read token configured yet"}
+          {tokenSet && rotatedAt && ` · rotated ${new Date(rotatedAt).toLocaleString()}`}
+        </span>
+      </div>
+
+      {token && (
+        <div className="mb-4 rounded-lg border border-warning/30 bg-warning/10 p-3">
+          <p className="mb-2 text-xs font-medium text-warning">
+            Copy this token now — it will not be shown again.
+          </p>
+          <div className="flex items-center gap-2">
+            <code className="flex-1 overflow-x-auto rounded bg-surface-2 px-2 py-1.5 font-mono text-xs text-text-primary">
+              {token}
+            </code>
+            <Button type="button" variant="ghost" size="sm" onClick={copy}>
+              {copied ? "Copied!" : "Copy"}
+            </Button>
+          </div>
+        </div>
+      )}
+
+      <Button type="button" variant="primary" loading={isPending} onClick={() => rotate()}>
+        {tokenSet ? "Rotate Token" : "Generate Token"}
+      </Button>
+      {tokenSet && (
+        <p className="mt-2 text-xs text-text-tertiary">
+          Rotating invalidates the previous token. Update the Kubernetes secret afterwards.
+        </p>
+      )}
+    </Card>
+  );
+}
+
+export default function SettingsPage() {
+  const queryClient = useQueryClient();
+
+  const { data: settings, isLoading } = useQuery({
+    queryKey: ["settings"],
+    queryFn: api.getSettings,
+  });
+
+  // Webhook / offline alerting state
+  const [alertsEnabled, setAlertsEnabled] = useState(false);
+  const [webhookURL, setWebhookURL] = useState("");
+  const [thresholdMinutes, setThresholdMinutes] = useState(5);
+
+  // Email state
+  const [emailEnabled, setEmailEnabled] = useState(false);
+  const [smtpHost, setSmtpHost] = useState("");
+  const [smtpPort, setSmtpPort] = useState(587);
+  const [smtpUser, setSmtpUser] = useState("");
+  const [smtpPass, setSmtpPass] = useState("");
+  const [fromAddr, setFromAddr] = useState("");
+  const [toAddrs, setToAddrs] = useState(""); // comma-separated in UI
+  const [useTLS, setUseTLS] = useState(false);
+
+  const [saved, setSaved] = useState(false);
+
+  useEffect(() => {
+    if (!settings) return;
+    setAlertsEnabled(settings.alerts.enabled);
+    setWebhookURL(settings.alerts.webhook_url ?? "");
+    setThresholdMinutes(settings.alerts.offline_threshold_minutes || 5);
+    setEmailEnabled(settings.email?.enabled ?? false);
+    setSmtpHost(settings.email?.smtp_host ?? "");
+    setSmtpPort(settings.email?.smtp_port || 587);
+    setSmtpUser(settings.email?.username ?? "");
+    setSmtpPass(settings.email?.password ?? "");
+    setFromAddr(settings.email?.from_addr ?? "");
+    setToAddrs((settings.email?.to_addrs ?? []).join(", "));
+    setUseTLS(settings.email?.use_tls ?? false);
+  }, [settings]);
+
+  const { mutate: save, isPending } = useMutation({
+    mutationFn: (payload: { alerts: AlertSettings; email: EmailSettings }) =>
+      api.saveSettings(payload),
+    onSuccess: () => {
+      queryClient.invalidateQueries({ queryKey: ["settings"] });
+      setSaved(true);
+      setTimeout(() => setSaved(false), 3000);
+    },
+  });
+
+  function handleSubmit(e: React.FormEvent) {
+    e.preventDefault();
+    const toList = toAddrs
+      .split(",")
+      .map((s) => s.trim())
+      .filter(Boolean);
+
+    save({
+      alerts: {
+        enabled: alertsEnabled,
+        webhook_url: webhookURL,
+        offline_threshold_minutes: thresholdMinutes,
+      },
+      email: {
+        enabled: emailEnabled,
+        smtp_host: smtpHost,
+        smtp_port: smtpPort,
+        username: smtpUser,
+        password: smtpPass,
+        from_addr: fromAddr,
+        to_addrs: toList,
+        use_tls: useTLS,
+      },
+    });
+  }
+
+  if (isLoading) {
+    return (
+      <div className="flex h-full items-center justify-center">
+        <div className="h-8 w-8 animate-spin rounded-full border-2 border-border border-t-accent" />
+      </div>
+    );
+  }
+
+  return (
+    <div className="p-8">
+      <div className="mb-6">
+        <h1 className="text-2xl font-bold text-text-primary">Settings</h1>
+        <p className="mt-1 text-sm text-text-secondary">Configure alerting and monitoring behaviour</p>
+      </div>
+
+      <form onSubmit={handleSubmit} className="max-w-xl space-y-6">
+        {/* Webhook alerting */}
+        <Card>
+          <CardHeader>
+            <CardTitle>Webhook Alerting</CardTitle>
+          </CardHeader>
+          <p className="mb-5 text-sm text-text-secondary">
+            POST a JSON payload to a URL when a server goes offline. Compatible with Slack,
+            Discord, n8n, and any service that accepts JSON.
+          </p>
+          <div className="space-y-4">
+            <ToggleRow
+              label="Enable webhook alerts"
+              description="Webhook fires only when this is on"
+              enabled={alertsEnabled}
+              onChange={setAlertsEnabled}
+            />
+            <Field
+              label="Webhook URL"
+              hint={`POST body: { event, hostname, server_id, ip_address, timestamp, message }`}
+            >
+              <input
+                type="url"
+                value={webhookURL}
+                onChange={(e) => setWebhookURL(e.target.value)}
+                placeholder="https://hooks.slack.com/... or https://discord.com/api/webhooks/..."
+                className={inputClass}
+              />
+            </Field>
+            <Field
+              label="Offline threshold (minutes)"
+              hint="How long a server must be silent before being marked offline. Agents poll every 30s, so 5 minutes is a safe minimum."
+            >
+              <input
+                type="number"
+                min={1}
+                max={60}
+                value={thresholdMinutes}
+                onChange={(e) => setThresholdMinutes(Number(e.target.value))}
+                className="w-32 rounded-lg border border-border bg-surface-2 px-3 py-2 text-sm text-text-primary focus:border-accent/50 focus:outline-none focus:ring-1 focus:ring-accent/30"
+              />
+            </Field>
+          </div>
+        </Card>
+
+        {/* Email alerting */}
+        <Card>
+          <CardHeader>
+            <CardTitle>Email Notifications</CardTitle>
+          </CardHeader>
+          <p className="mb-5 text-sm text-text-secondary">
+            Send an email when a server goes offline. Uses the same offline threshold as the
+            webhook setting above.
+          </p>
+          <div className="space-y-4">
+            <ToggleRow
+              label="Enable email alerts"
+              description="Emails are only sent when this is on"
+              enabled={emailEnabled}
+              onChange={setEmailEnabled}
+            />
+            <div className="grid grid-cols-3 gap-3">
+              <Field label="SMTP Host" hint="">
+                <input
+                  type="text"
+                  value={smtpHost}
+                  onChange={(e) => setSmtpHost(e.target.value)}
+                  placeholder="smtp.gmail.com"
+                  className={inputClass}
+                />
+              </Field>
+              <Field label="Port" hint="">
+                <input
+                  type="number"
+                  value={smtpPort}
+                  onChange={(e) => setSmtpPort(Number(e.target.value))}
+                  placeholder="587"
+                  className={inputClass}
+                />
+              </Field>
+              <div className="flex flex-col justify-center pt-5">
+                <ToggleRow
+                  label="TLS (port 465)"
+                  description="Use implicit TLS instead of STARTTLS"
+                  enabled={useTLS}
+                  onChange={(v) => {
+                    setUseTLS(v);
+                    setSmtpPort(v ? 465 : 587);
+                  }}
+                />
+              </div>
+            </div>
+            <div className="grid grid-cols-2 gap-3">
+              <Field label="Username">
+                <input
+                  type="text"
+                  value={smtpUser}
+                  onChange={(e) => setSmtpUser(e.target.value)}
+                  placeholder="user@example.com"
+                  className={inputClass}
+                  autoComplete="username"
+                />
+              </Field>
+              <Field label="Password">
+                <input
+                  type="password"
+                  value={smtpPass}
+                  onChange={(e) => setSmtpPass(e.target.value)}
+                  placeholder="App password or SMTP password"
+                  className={inputClass}
+                  autoComplete="new-password"
+                />
+              </Field>
+            </div>
+            <Field label="From address">
+              <input
+                type="email"
+                value={fromAddr}
+                onChange={(e) => setFromAddr(e.target.value)}
+                placeholder="vantage@example.com"
+                className={inputClass}
+              />
+            </Field>
+            <Field
+              label="To addresses"
+              hint="Separate multiple addresses with commas"
+            >
+              <input
+                type="text"
+                value={toAddrs}
+                onChange={(e) => setToAddrs(e.target.value)}
+                placeholder="admin@example.com, ops@example.com"
+                className={inputClass}
+              />
+            </Field>
+          </div>
+        </Card>
+
+        <div className="flex items-center gap-3">
+          <Button type="submit" variant="primary" loading={isPending}>
+            {saved ? "Saved!" : "Save Settings"}
+          </Button>
+          {saved && <span className="text-sm text-success">Settings saved successfully.</span>}
+        </div>
+      </form>
+
+      <div className="mt-6 max-w-xl">
+        <SecretsTokenCard
+          tokenSet={settings?.secrets?.read_token_set ?? false}
+          rotatedAt={settings?.secrets?.rotated_at}
+        />
+      </div>
+    </div>
+  );
+}

web/components/Sidebar.tsx

@@ -27,9 +27,37 @@ function KeyIcon() {
   );
 }
 
+function SecretIcon() {
+  return (
+    <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
+      <path strokeLinecap="round" strokeLinejoin="round" d="M16.5 10.5V6.75a4.5 4.5 0 10-9 0v3.75m-.75 11.25h10.5a2.25 2.25 0 002.25-2.25v-6.75a2.25 2.25 0 00-2.25-2.25H6.75a2.25 2.25 0 00-2.25 2.25v6.75a2.25 2.25 0 002.25 2.25z" />
+    </svg>
+  );
+}
+
+function AuditIcon() {
+  return (
+    <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
+      <path strokeLinecap="round" strokeLinejoin="round" d="M9 12h3.75M9 15h3.75M9 18h3.75m3 .75H18a2.25 2.25 0 002.25-2.25V6.108c0-1.135-.845-2.098-1.976-2.192a48.424 48.424 0 00-1.123-.08m-5.801 0c-.065.21-.1.433-.1.664 0 .414.336.75.75.75h4.5a.75.75 0 00.75-.75 2.25 2.25 0 00-.1-.664m-5.8 0A2.251 2.251 0 0113.5 2.25H15c1.012 0 1.867.668 2.15 1.586m-5.8 0c-.376.023-.75.05-1.124.08C9.095 4.01 8.25 4.973 8.25 6.108V8.25m0 0H4.875c-.621 0-1.125.504-1.125 1.125v11.25c0 .621.504 1.125 1.125 1.125h9.75c.621 0 1.125-.504 1.125-1.125V9.375c0-.621-.504-1.125-1.125-1.125H8.25zM6.75 12h.008v.008H6.75V12zm0 3h.008v.008H6.75V15zm0 3h.008v.008H6.75V18z" />
+    </svg>
+  );
+}
+
+function SettingsIcon() {
+  return (
+    <svg className="h-5 w-5" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={1.5}>
+      <path strokeLinecap="round" strokeLinejoin="round" d="M9.594 3.94c.09-.542.56-.94 1.11-.94h2.593c.55 0 1.02.398 1.11.94l.213 1.281c.063.374.313.686.645.87.074.04.147.083.22.127.324.196.72.257 1.075.124l1.217-.456a1.125 1.125 0 011.37.49l1.296 2.247a1.125 1.125 0 01-.26 1.431l-1.003.827c-.293.24-.438.613-.431.992a6.759 6.759 0 010 .255c-.007.378.138.75.43.99l1.005.828c.424.35.534.954.26 1.43l-1.298 2.247a1.125 1.125 0 01-1.369.491l-1.217-.456c-.355-.133-.75-.072-1.076.124a6.57 6.57 0 01-.22.128c-.331.183-.581.495-.644.869l-.213 1.28c-.09.543-.56.941-1.11.941h-2.594c-.55 0-1.02-.398-1.11-.94l-.213-1.281c-.062-.374-.312-.686-.644-.87a6.52 6.52 0 01-.22-.127c-.325-.196-.72-.257-1.076-.124l-1.217.456a1.125 1.125 0 01-1.369-.49l-1.297-2.247a1.125 1.125 0 01.26-1.431l1.004-.827c.292-.24.437-.613.43-.992a6.932 6.932 0 010-.255c.007-.378-.138-.75-.43-.99l-1.004-.828a1.125 1.125 0 01-.26-1.43l1.297-2.247a1.125 1.125 0 011.37-.491l1.216.456c.356.133.751.072 1.076-.124.072-.044.146-.087.22-.128.332-.183.582-.495.644-.869l.214-1.281z" />
+      <path strokeLinecap="round" strokeLinejoin="round" d="M15 12a3 3 0 11-6 0 3 3 0 016 0z" />
+    </svg>
+  );
+}
+
 const navItems: NavItem[] = [
   { href: "/servers", label: "Servers", icon: <ServerIcon /> },
   { href: "/keys", label: "SSH Keys", icon: <KeyIcon /> },
+  { href: "/secrets", label: "Secrets", icon: <SecretIcon /> },
+  { href: "/audit", label: "Audit Log", icon: <AuditIcon /> },
+  { href: "/settings", label: "Settings", icon: <SettingsIcon /> },
 ];
 
 export function Sidebar() {

web/lib/api.ts

@@ -42,6 +42,56 @@ export interface Assignment {
   revoked_at: string | null;
 }
 
+export interface AuditEvent {
+  id: string;
+  event_type: string;
+  actor: string;
+  server_id?: string;
+  key_id?: string;
+  details: string;
+  created_at: string;
+}
+
+export interface AlertSettings {
+  enabled: boolean;
+  webhook_url: string;
+  offline_threshold_minutes: number;
+}
+
+export interface EmailSettings {
+  enabled: boolean;
+  smtp_host: string;
+  smtp_port: number;
+  username: string;
+  password: string;
+  from_addr: string;
+  to_addrs: string[];
+  use_tls: boolean;
+}
+
+export interface SecretsSettings {
+  read_token_set: boolean;
+  rotated_at?: string;
+}
+
+export interface Settings {
+  alerts: AlertSettings;
+  email: EmailSettings;
+  secrets: SecretsSettings;
+}
+
+export interface SecretGroupSummary {
+  group: string;
+  key_count: number;
+  updated_at: string;
+}
+
+export interface Secret {
+  group: string;
+  key: string;
+  updated_at: string;
+}
+
 export interface NewServerResponse {
   server_id: string;
   pre_reg_token: string;
@@ -141,6 +191,68 @@ export const api = {
     });
   },
 
+  // Audit
+  listAuditEvents(limit?: number): Promise<AuditEvent[]> {
+    const qs = limit ? `?limit=${limit}` : "";
+    return request<AuditEvent[]>(`/audit${qs}`);
+  },
+
+  // Settings
+  getSettings(): Promise<Settings> {
+    return request<Settings>("/settings");
+  },
+
+  saveSettings(settings: { alerts: AlertSettings; email: EmailSettings }): Promise<{ saved: boolean }> {
+    return request<{ saved: boolean }>("/settings", {
+      method: "PUT",
+      body: JSON.stringify(settings),
+    });
+  },
+
+  rotateSecretsToken(): Promise<{ token: string }> {
+    return request<{ token: string }>("/settings/secrets-token", { method: "POST" });
+  },
+
+  // Secrets
+  listSecretGroups(): Promise<SecretGroupSummary[]> {
+    return request<SecretGroupSummary[]>("/secrets");
+  },
+
+  createSecretGroup(group: string, values: Record<string, string>): Promise<{ group: string }> {
+    return request<{ group: string }>("/secrets", {
+      method: "POST",
+      body: JSON.stringify({ group, values }),
+    });
+  },
+
+  getSecretGroup(group: string): Promise<{ group: string; secrets: Secret[] }> {
+    return request<{ group: string; secrets: Secret[] }>(`/secrets/${encodeURIComponent(group)}`);
+  },
+
+  putSecrets(group: string, values: Record<string, string>): Promise<{ saved: boolean }> {
+    return request<{ saved: boolean }>(`/secrets/${encodeURIComponent(group)}`, {
+      method: "PUT",
+      body: JSON.stringify(values),
+    });
+  },
+
+  revealSecret(group: string, key: string): Promise<{ value: string }> {
+    return request<{ value: string }>(`/secrets/${encodeURIComponent(group)}/reveal`, {
+      method: "POST",
+      body: JSON.stringify({ key }),
+    });
+  },
+
+  deleteSecret(group: string, key: string): Promise<void> {
+    return request<void>(`/secrets/${encodeURIComponent(group)}/${encodeURIComponent(key)}`, {
+      method: "DELETE",
+    });
+  },
+
+  deleteSecretGroup(group: string): Promise<void> {
+    return request<void>(`/secrets/${encodeURIComponent(group)}`, { method: "DELETE" });
+  },
+
   // Keys
   listKeys(): Promise<Key[]> {
     return request<Key[]>("/keys");