Merge pull request #213 from BaaRai/feat/secrets-at-rest

Encrypt stored secrets at rest in PostgreSQL

.env.example

@@ -6,6 +6,10 @@ ARTEX_BIND_ADDR=127.0.0.1
 # Reverse proxies (comma-separated CIDRs) whose X-Forwarded-For the login rate
 # limit trusts. Empty: the header is ignored. See "Reverse proxy deployment" in README.md.
 ARTEX_TRUSTED_PROXIES=
+# Optional key for the secrets encrypted in the database (32 bytes, base64 or hex,
+# e.g. `openssl rand -base64 32`). Empty: keys/secret.key, generated at first start.
+# Set it when ./keys is not persistent. Losing the key loses the stored secrets.
+# ARTEX_SECRET_KEY=
 POSTGRES_USER=artex
 POSTGRES_PASSWORD=change-me-please
 POSTGRES_DB=artex

.gitignore

@@ -47,6 +47,7 @@ Thumbs.db
 
 # JWT signing key (generated at runtime, stored in the project root, never committed)
 /jwt.key
+/secret.key
 /keys/
 
 # local environment generated by Docker deployment (contains passwords/keys, not committed)

README.md

@@ -181,6 +181,14 @@ gunzip -c backups/artex-db-<timestamp>.sql.gz | docker compose exec -T postgres
   psql -U "$POSTGRES_USER" -d "$POSTGRES_DB"
 ```
 
+Stored secrets (LLM API keys, MCP env, task credentials, notification channel
+config) are encrypted in the database with the key in `keys/secret.key`
+(generated at first start, mode 0600, next to `jwt.key`). **A database backup
+without that key can no longer restore those secrets**: back up `keys/` with the
+dump, separately. Deployments without a persistent disk set `ARTEX_SECRET_KEY`
+(32 bytes, base64 or hex, e.g. `openssl rand -base64 32`) instead. ARTEX refuses
+to start when the database holds encrypted secrets and no key is available.
+
 Daily cron example (03:20, operator crontab):
 
 ```

cmd/artex/main.go

@@ -13,7 +13,6 @@ import (
 	"os/signal"
 	"path/filepath"
 	"runtime"
-	"strings"
 	"syscall"
 	"time"
 
@@ -98,15 +97,8 @@ func run() int {
 		skillDir = abs
 	}
 	log.Printf("[config] skill directory: %s", skillDir)
-	// JWT signing key directory: ARTEX_JWT_KEY_DIR (the Docker image points it at
-	// the /app/keys volume) or the base dir. Never the browsable data dir.
-	keyDir := strings.TrimSpace(os.Getenv("ARTEX_JWT_KEY_DIR"))
-	if keyDir == "" {
-		keyDir = config.BaseDir()
-	}
-	if abs, err := filepath.Abs(keyDir); err == nil {
-		keyDir = abs
-	}
+	// JWT signing key directory (also holds secret.key, see server.NewManager).
+	keyDir := config.KeyDir()
 	log.Printf("[config] JWT key directory: %s", keyDir)
 	// Proxies whose X-Forwarded-For the login rate limit reads; empty trusts none.
 	trusted, err := server.ParseTrustedProxies(os.Getenv("ARTEX_TRUSTED_PROXIES"))

config/config.go

@@ -54,6 +54,19 @@ func BaseDir() string {
 	return dir
 }
 
+// KeyDir holds jwt.key and secret.key: ARTEX_JWT_KEY_DIR (the Docker image points
+// it at the /app/keys volume) or the base dir. Never the browsable data dir.
+func KeyDir() string {
+	dir := strings.TrimSpace(os.Getenv("ARTEX_JWT_KEY_DIR"))
+	if dir == "" {
+		dir = BaseDir()
+	}
+	if abs, err := filepath.Abs(dir); err == nil {
+		dir = abs
+	}
+	return dir
+}
+
 // isGoRunDir reports whether dir is where `go run` parked its executable: under
 // the system temp dir (cache miss), or anywhere inside a Go build cache
 // (…/go-build/…, the cache-hit case — NOT under os.TempDir(), which is why the

db/config.go

@@ -99,7 +99,7 @@ const profileColsKey = `id,name,format,COALESCE(base_url,''),COALESCE(proxy,''),
 // scanProfile reads one row in the profileCols / profileColsKey column order. The
 // 7th column lands in APIKeyHint or APIKey depending on which list the caller used.
 func scanProfile(sc interface{ Scan(...any) error }, into *string, p *LLMProfile) error {
-	return sc.Scan(&p.ID, &p.Name, &p.Format, &p.BaseURL, &p.Proxy, &p.Model, into,
+	err := sc.Scan(&p.ID, &p.Name, &p.Format, &p.BaseURL, &p.Proxy, &p.Model, into,
 		&p.RatePerSecond, &p.RatePerMinute, &p.ContextWindowK, &p.ReasoningEffort, &p.IsDefault, &p.Priority, &p.PoolExclude, &p.ThinkingType, &p.Streaming,
 		&p.MaxTokens, &p.MaxTokensField, &p.SessionHeaderKey,
 		&p.Retry.Connect.Attempts, &p.Retry.Connect.IntervalMS,
@@ -107,6 +107,11 @@ func scanProfile(sc interface{ Scan(...any) error }, into *string, p *LLMProfile
 		&p.Retry.Stream.Attempts, &p.Retry.Stream.IntervalMS,
 		&p.PriceInputPerM, &p.PriceOutputPerM, &p.PriceCacheReadPerM, &p.PriceCacheWritePerM,
 		&p.UserAgent)
+	if err != nil || into != &p.APIKey {
+		return err
+	}
+	p.APIKey, err = openSecret(colLLMKey, p.APIKey)
+	return err
 }
 
 func (d *DB) ListProfiles() ([]*LLMProfile, error) {
@@ -182,12 +187,16 @@ func (d *DB) SaveProfile(p *LLMProfile) (int64, error) {
 	if len(p.APIKey) >= 4 {
 		hint = "…" + p.APIKey[len(p.APIKey)-4:]
 	}
+	key, err := sealSecret(colLLMKey, p.APIKey)
+	if err != nil {
+		return 0, err
+	}
 	r := p.Retry.Clamped()
 	if p.ID == 0 {
 		var id int64
 		err := d.QueryRow(`INSERT INTO llm_profiles(name,format,base_url,proxy,model,api_key,api_key_hint,rate_per_second,rate_per_minute,context_window_k,reasoning_effort,priority,pool_exclude,thinking_type,streaming,max_tokens,max_tokens_field,session_header_key,retry_connect_attempts,retry_connect_interval_ms,retry_empty_attempts,retry_empty_interval_ms,retry_stream_attempts,retry_stream_interval_ms,user_agent)
 VALUES ($1,$2,NULLIF($3,''),NULLIF($4,''),$5,NULLIF($6,''),NULLIF($7,''),$8,$9,$10,$11,$12,$13,$14,$15,$16,$17,$18,$19,$20,$21,$22,$23,$24,$25) RETURNING id`,
-			p.Name, p.Format, p.BaseURL, p.Proxy, p.Model, p.APIKey, hint, p.RatePerSecond, p.RatePerMinute, p.ContextWindowK, p.ReasoningEffort, p.Priority, p.PoolExclude, p.ThinkingType, p.Streaming, p.MaxTokens, p.MaxTokensField, p.SessionHeaderKey,
+			p.Name, p.Format, p.BaseURL, p.Proxy, p.Model, key, hint, p.RatePerSecond, p.RatePerMinute, p.ContextWindowK, p.ReasoningEffort, p.Priority, p.PoolExclude, p.ThinkingType, p.Streaming, p.MaxTokens, p.MaxTokensField, p.SessionHeaderKey,
 			r.Connect.Attempts, r.Connect.IntervalMS, r.Empty.Attempts, r.Empty.IntervalMS, r.Stream.Attempts, r.Stream.IntervalMS, p.UserAgent).Scan(&id)
 		if err == nil {
 			_, err = d.saveProfilePrices(id, p)
@@ -203,8 +212,8 @@ VALUES ($1,$2,NULLIF($3,''),NULLIF($4,''),$5,NULLIF($6,''),NULLIF($7,''),$8,$9,$
 		}
 		return p.ID, err
 	}
-	_, err := d.Exec(`UPDATE llm_profiles SET name=$1,format=$2,base_url=NULLIF($3,''),proxy=NULLIF($4,''),model=$5,api_key=$6,api_key_hint=$7,rate_per_second=$8,rate_per_minute=$9,context_window_k=$10,reasoning_effort=$11,priority=$12,pool_exclude=$13,thinking_type=$14,streaming=$15,max_tokens=$16,max_tokens_field=$17,session_header_key=$18,retry_connect_attempts=$19,retry_connect_interval_ms=$20,retry_empty_attempts=$21,retry_empty_interval_ms=$22,retry_stream_attempts=$23,retry_stream_interval_ms=$24,user_agent=$25 WHERE id=$26`,
-		p.Name, p.Format, p.BaseURL, p.Proxy, p.Model, p.APIKey, hint, p.RatePerSecond, p.RatePerMinute, p.ContextWindowK, p.ReasoningEffort, p.Priority, p.PoolExclude, p.ThinkingType, p.Streaming, p.MaxTokens, p.MaxTokensField, p.SessionHeaderKey,
+	_, err = d.Exec(`UPDATE llm_profiles SET name=$1,format=$2,base_url=NULLIF($3,''),proxy=NULLIF($4,''),model=$5,api_key=$6,api_key_hint=$7,rate_per_second=$8,rate_per_minute=$9,context_window_k=$10,reasoning_effort=$11,priority=$12,pool_exclude=$13,thinking_type=$14,streaming=$15,max_tokens=$16,max_tokens_field=$17,session_header_key=$18,retry_connect_attempts=$19,retry_connect_interval_ms=$20,retry_empty_attempts=$21,retry_empty_interval_ms=$22,retry_stream_attempts=$23,retry_stream_interval_ms=$24,user_agent=$25 WHERE id=$26`,
+		p.Name, p.Format, p.BaseURL, p.Proxy, p.Model, key, hint, p.RatePerSecond, p.RatePerMinute, p.ContextWindowK, p.ReasoningEffort, p.Priority, p.PoolExclude, p.ThinkingType, p.Streaming, p.MaxTokens, p.MaxTokensField, p.SessionHeaderKey,
 		r.Connect.Attempts, r.Connect.IntervalMS, r.Empty.Attempts, r.Empty.IntervalMS, r.Stream.Attempts, r.Stream.IntervalMS, p.UserAgent, p.ID)
 	if err == nil {
 		_, err = d.saveProfilePrices(p.ID, p)
@@ -875,7 +884,12 @@ func (d *DB) ListMCP() ([]*MCPServer, error) {
 			rows.Close()
 			return nil, err
 		}
-		m.Args, m.Env = json.RawMessage(args), json.RawMessage(env)
+		plainEnv, err := openSecret(colMCPEnv, string(env))
+		if err != nil {
+			rows.Close()
+			return nil, err
+		}
+		m.Args, m.Env = json.RawMessage(args), json.RawMessage(plainEnv)
 		out = append(out, &m)
 	}
 	if err := rows.Err(); err != nil {
@@ -970,6 +984,10 @@ func (d *DB) SaveMCP(m *MCPServer) (int64, error) {
 	if env == "" {
 		env = "{}"
 	}
+	env, err := sealSecret(colMCPEnv, env)
+	if err != nil {
+		return 0, err
+	}
 	timeout := m.TimeoutSeconds
 	if timeout <= 0 {
 		timeout = 120
@@ -980,7 +998,7 @@ func (d *DB) SaveMCP(m *MCPServer) (int64, error) {
 			m.Name, m.Transport, m.Command, args, env, m.URL, m.Enabled, m.Insecure, timeout).Scan(&id)
 		return id, err
 	}
-	_, err := d.Exec(`UPDATE mcp_servers SET name=$1,transport=$2,command=NULLIF($3,''),args=$4,env=$5,url=NULLIF($6,''),enabled=$7,insecure=$8,timeout_seconds=$9 WHERE id=$10`,
+	_, err = d.Exec(`UPDATE mcp_servers SET name=$1,transport=$2,command=NULLIF($3,''),args=$4,env=$5,url=NULLIF($6,''),enabled=$7,insecure=$8,timeout_seconds=$9 WHERE id=$10`,
 		m.Name, m.Transport, m.Command, args, env, m.URL, m.Enabled, m.Insecure, timeout, m.ID)
 	return m.ID, err
 }

db/notification.go

@@ -88,6 +88,11 @@ func scanNotificationChannel(sc interface{ Scan(...any) error }) (*NotificationC
 	if err := sc.Scan(&c.ID, &c.Name, &c.Kind, &enabled, &c.Config, &c.Mode, &c.Filter, &c.RatePerMin, &c.CreatedAt, &c.UpdatedAt); err != nil {
 		return nil, err
 	}
+	cfg, err := openSecret(colNotifConfig, string(c.Config))
+	if err != nil {
+		return nil, err
+	}
+	c.Config = json.RawMessage(cfg)
 	c.Enabled = &enabled
 	return &c, nil
 }
@@ -152,19 +157,23 @@ func (d *DB) SaveNotificationChannel(ctx context.Context, c *NotificationChannel
 	if c.Filter == nil {
 		c.Filter = json.RawMessage(`{}`)
 	}
+	cfg, err := sealSecret(colNotifConfig, string(c.Config))
+	if err != nil {
+		return 0, err
+	}
 	enabled := c.IsEnabled()
 
 	if c.ID == 0 {
 		var id int64
 		err := d.QueryRowContext(ctx, `INSERT INTO notification_channels(name,kind,enabled,config,mode,filter,rate_per_min)
 VALUES($1,$2,$3,$4,$5,$6,$7) RETURNING id`,
-			c.Name, c.Kind, enabled, string(c.Config), c.Mode, string(c.Filter), c.RatePerMin).Scan(&id)
+			c.Name, c.Kind, enabled, string(cfg), c.Mode, string(c.Filter), c.RatePerMin).Scan(&id)
 		return id, err
 	}
 	res, err := d.ExecContext(ctx, `UPDATE notification_channels
 SET name=$2, kind=$3, enabled=$4, config=$5, mode=$6, filter=$7, rate_per_min=$8
 WHERE id=$1`,
-		c.ID, c.Name, c.Kind, enabled, string(c.Config), c.Mode, string(c.Filter), c.RatePerMin)
+		c.ID, c.Name, c.Kind, enabled, string(cfg), c.Mode, string(c.Filter), c.RatePerMin)
 	if err != nil {
 		return 0, err
 	}
@@ -393,6 +402,11 @@ FROM notification_channels WHERE enabled ORDER BY id`)
 		if err := rows.Scan(&c.ID, &c.Name, &c.Kind, &c.Config, &c.Mode, &c.Filter, &c.RatePerMin); err != nil {
 			return nil, err
 		}
+		cfg, err := openSecret(colNotifConfig, string(c.Config))
+		if err != nil {
+			return nil, err
+		}
+		c.Config = json.RawMessage(cfg)
 		out = append(out, &c)
 	}
 	return out, rows.Err()

db/notification_delivery.go

@@ -95,6 +95,11 @@ func scanNotificationDelivery(sc interface{ Scan(...any) error }) (*Notification
 		&channel.ID, &channel.Name, &channel.Kind, &chEnabled, &channel.Config, &channel.Mode, &channel.Filter, &channel.RatePerMin); err != nil {
 		return nil, err
 	}
+	cfg, err := openSecret(colNotifConfig, string(channel.Config))
+	if err != nil {
+		return nil, err
+	}
+	channel.Config = json.RawMessage(cfg)
 	dl.LastError = lastErr.String
 	if batchID.Valid {
 		dl.BatchID = &batchID.Int64

db/schema.sql

@@ -1439,7 +1439,7 @@ CREATE TABLE IF NOT EXISTS notification_channels (
     -- dingtalk DingTalk / feishu Feishu (Lark) / wecom WeCom (WeChat Work) / webhook generic / telegram / email
     kind         TEXT NOT NULL,
     enabled      BOOLEAN NOT NULL DEFAULT true,
-    -- Credentials (stored in plaintext, masked when echoed to the UI; see maskChannelSecrets on the server side).
+    -- Credentials (encrypted at rest by db/secrets.go, masked when echoed to the UI; see notify.MaskConfig).
     -- The six channel kinds differ wildly in fields, so one JSONB column + strict per-kind validation on the Go
     -- side avoids a pile of NULL columns per channel:
     --   dingtalk {webhook,secret}

db/secrets.go

@@ -0,0 +1,328 @@
+package db
+
+import (
+	"bytes"
+	"context"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"database/sql"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync/atomic"
+)
+
+// Secrets at rest: AES-256-GCM, a random nonce per value, AAD "<table>.<column>".
+// TEXT stores "enc:v1:<base64(nonce||ciphertext)>"; JSONB stores
+// {"__artex_enc":"enc:v1:..."} over the canonical JSON. Empty values stay empty.
+// A value that fails to decrypt is an error, never returned as-is.
+
+const (
+	secretPrefix  = "enc:v1:"
+	sealedJSONKey = "__artex_enc"
+	secretKeyEnv  = "ARTEX_SECRET_KEY"
+	secretKeyFile = "secret.key"
+)
+
+type secretColumn struct {
+	table, col string
+	json       bool
+}
+
+func (c secretColumn) aad() string { return c.table + "." + c.col }
+
+// valueExpr is the SQL text that holds the ciphertext, if any.
+func (c secretColumn) valueExpr() string {
+	if c.json {
+		return c.col + "->>'" + sealedJSONKey + "'"
+	}
+	return c.col
+}
+
+var (
+	colLLMKey      = secretColumn{"llm_profiles", "api_key", false}
+	colMCPEnv      = secretColumn{"mcp_servers", "env", true}
+	colCredPass    = secretColumn{"task_credentials", "password", false}
+	colNotifConfig = secretColumn{"notification_channels", "config", true}
+	secretColumns  = []secretColumn{colLLMKey, colMCPEnv, colCredPass, colNotifConfig}
+)
+
+type secretBox struct{ aead cipher.AEAD }
+
+var activeSecretBox atomic.Pointer[secretBox]
+
+func newSecretBox(key []byte) (*secretBox, error) { // key: 32 bytes, see parseSecretKey
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+	aead, err := cipher.NewGCM(block)
+	return &secretBox{aead}, err
+}
+
+func isEncrypted(v string) bool { return strings.HasPrefix(v, secretPrefix) }
+
+func (b *secretBox) encrypt(aad, plain string) (string, error) {
+	if plain == "" {
+		return "", nil
+	}
+	nonce := make([]byte, b.aead.NonceSize())
+	if _, err := rand.Read(nonce); err != nil {
+		return "", err
+	}
+	return secretPrefix + base64.StdEncoding.EncodeToString(b.aead.Seal(nonce, nonce, []byte(plain), []byte(aad))), nil
+}
+
+func (b *secretBox) decrypt(aad, v string) (string, error) {
+	raw, err := base64.StdEncoding.DecodeString(strings.TrimPrefix(v, secretPrefix))
+	n := b.aead.NonceSize()
+	if err != nil || len(raw) < n {
+		return "", fmt.Errorf("decrypt %s: malformed ciphertext", aad)
+	}
+	plain, err := b.aead.Open(nil, raw[:n], raw[n:], []byte(aad))
+	if err != nil {
+		return "", fmt.Errorf("decrypt %s: authentication failed (wrong key or altered value)", aad)
+	}
+	return string(plain), nil
+}
+
+// sealedJSON returns the ciphertext of a {"__artex_enc":"enc:v1:..."} envelope.
+func sealedJSON(raw string) (string, bool) {
+	if !strings.Contains(raw, `"`+sealedJSONKey+`"`) {
+		return "", false
+	}
+	var m map[string]json.RawMessage
+	var s string
+	if json.Unmarshal([]byte(raw), &m) != nil || len(m) != 1 || json.Unmarshal(m[sealedJSONKey], &s) != nil || !isEncrypted(s) {
+		return "", false
+	}
+	return s, true
+}
+
+func isSealed(c secretColumn, v string) bool {
+	if c.json {
+		_, ok := sealedJSON(v)
+		return ok
+	}
+	return isEncrypted(v)
+}
+
+// seal encrypts one column value. JSON is canonicalized first; an empty object
+// or null stays as is, and a top-level key named like the envelope is refused.
+func (b *secretBox) seal(c secretColumn, v string) (string, error) {
+	if !c.json {
+		return b.encrypt(c.aad(), v)
+	}
+	dec := json.NewDecoder(bytes.NewReader([]byte(v)))
+	dec.UseNumber()
+	var parsed any
+	if err := dec.Decode(&parsed); err != nil {
+		return "", fmt.Errorf("%s: invalid JSON", c.aad())
+	}
+	m, isObject := parsed.(map[string]any)
+	if _, reserved := m[sealedJSONKey]; reserved {
+		return "", fmt.Errorf("%s: key %q is reserved", c.aad(), sealedJSONKey)
+	}
+	if parsed == nil || (isObject && len(m) == 0) {
+		return v, nil // {} or null: nothing to hide
+	}
+	canon, err := json.Marshal(parsed)
+	if err != nil {
+		return "", err
+	}
+	enc, err := b.encrypt(c.aad(), string(canon))
+	if err != nil {
+		return "", err
+	}
+	out, err := json.Marshal(map[string]string{sealedJSONKey: enc})
+	return string(out), err
+}
+
+func (b *secretBox) open(c secretColumn, v string) (string, error) {
+	if c.json {
+		v, _ = sealedJSON(v)
+	}
+	return b.decrypt(c.aad(), v)
+}
+
+var errNoSecretKey = errors.New("secrets at rest: key not initialized")
+
+// sealSecret encrypts a value before it is written to column c.
+func sealSecret(c secretColumn, v string) (string, error) {
+	if b := activeSecretBox.Load(); b != nil {
+		return b.seal(c, v)
+	}
+	return "", errNoSecretKey
+}
+
+// openSecret decrypts a value read from column c. A value that is not sealed is
+// a legacy plaintext row (the startup backfill encrypts those) and passes through.
+func openSecret(c secretColumn, v string) (string, error) {
+	if !isSealed(c, v) {
+		return v, nil
+	}
+	if b := activeSecretBox.Load(); b != nil {
+		return b.open(c, v)
+	}
+	return "", errNoSecretKey
+}
+
+// parseSecretKey accepts 32 bytes encoded as base64 or hex.
+func parseSecretKey(s string) ([]byte, error) {
+	s = strings.TrimSpace(s)
+	if k, err := base64.StdEncoding.DecodeString(s); err == nil && len(k) == 32 {
+		return k, nil
+	}
+	if k, err := hex.DecodeString(s); err == nil && len(k) == 32 {
+		return k, nil
+	}
+	return nil, errors.New("must be 32 bytes, base64 or hex encoded")
+}
+
+// InitSecrets loads the key (ARTEX_SECRET_KEY, else keyDir/secret.key, else a new
+// one, refused when encrypted data exists) and encrypts legacy plaintext, under
+// the schema advisory lock so concurrent instances backfill once.
+func (d *DB) InitSecrets(keyDir string) error {
+	ctx := context.Background()
+	return withSchemaMigrationLock(ctx, d.DB, func(conn *sql.Conn) error {
+		key, err := loadSecretKey(ctx, conn, keyDir)
+		if err != nil {
+			return err
+		}
+		box, err := newSecretBox(key)
+		if err != nil {
+			return err
+		}
+		// A key other than the one that sealed the data fails here, at startup.
+		for _, c := range secretColumns {
+			var v string
+			err := conn.QueryRowContext(ctx, `SELECT `+c.valueExpr()+` FROM `+c.table+` WHERE `+c.valueExpr()+` LIKE 'enc:v1:%' LIMIT 1`).Scan(&v)
+			if err == nil {
+				_, err = box.decrypt(c.aad(), v)
+			}
+			if err != nil && err != sql.ErrNoRows {
+				return fmt.Errorf("secret key check: %w", err)
+			}
+		}
+		n, err := backfillSecrets(ctx, conn, box)
+		if err != nil {
+			return err
+		}
+		log.Printf("[secrets] at-rest encryption ready; backfill encrypted %d plaintext value(s)", n)
+		activeSecretBox.Store(box)
+		return nil
+	})
+}
+
+func loadSecretKey(ctx context.Context, conn *sql.Conn, keyDir string) ([]byte, error) {
+	if v := strings.TrimSpace(os.Getenv(secretKeyEnv)); v != "" {
+		k, err := parseSecretKey(v)
+		if err != nil {
+			return nil, fmt.Errorf("%s %w", secretKeyEnv, err)
+		}
+		return k, nil
+	}
+	path := filepath.Join(keyDir, secretKeyFile)
+	if data, err := os.ReadFile(path); err == nil {
+		k, err := parseSecretKey(string(data))
+		if err != nil {
+			return nil, fmt.Errorf("secret key %s %w", path, err)
+		}
+		return k, nil
+	} else if !os.IsNotExist(err) {
+		return nil, fmt.Errorf("read secret key: %w", err)
+	}
+	var parts []string
+	for _, c := range secretColumns {
+		parts = append(parts, `(SELECT count(*) FROM `+c.table+` WHERE `+c.valueExpr()+` LIKE 'enc:v1:%')`)
+	}
+	var n int64
+	if err := conn.QueryRowContext(ctx, `SELECT `+strings.Join(parts, "+")).Scan(&n); err != nil {
+		return nil, err
+	}
+	if n > 0 {
+		return nil, fmt.Errorf("the database holds %d encrypted secret(s) but no key is available: set %s or restore %s (refusing to generate a new key over encrypted data)", n, secretKeyEnv, path)
+	}
+	key := make([]byte, 32)
+	if _, err := rand.Read(key); err != nil {
+		return nil, err
+	}
+	if err := os.MkdirAll(keyDir, 0o700); err != nil {
+		return nil, fmt.Errorf("create secret key dir: %w", err)
+	}
+	f, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_EXCL, 0o600) // never overwrite a key
+	if err != nil {
+		return nil, fmt.Errorf("write secret key: %w", err)
+	}
+	if _, err = f.WriteString(base64.StdEncoding.EncodeToString(key) + "\n"); err == nil {
+		err = f.Close()
+	}
+	if err != nil {
+		f.Close()
+		_ = os.Remove(path)
+		return nil, fmt.Errorf("write secret key: %w", err)
+	}
+	log.Printf("[secrets] new secret key written to %s", path)
+	return key, nil
+}
+
+// backfillSecrets encrypts every plaintext value once; sealed values are
+// skipped, so it is idempotent. Each UPDATE matches the value it read, so a
+// concurrent write is never overwritten.
+func backfillSecrets(ctx context.Context, conn *sql.Conn, box *secretBox) (int, error) {
+	total := 0
+	for _, c := range secretColumns {
+		var ids []int64
+		var olds, news []string
+		rows, err := conn.QueryContext(ctx, `SELECT id, `+c.col+`::text FROM `+c.table+` WHERE `+c.col+` IS NOT NULL`)
+		if err != nil {
+			return total, err
+		}
+		for rows.Next() {
+			var id int64
+			var old string
+			if err = rows.Scan(&id, &old); err != nil {
+				break
+			}
+			if isSealed(c, old) {
+				continue
+			}
+			nv, serr := box.seal(c, old)
+			if serr != nil {
+				err = fmt.Errorf("backfill %s id=%d: %w", c.aad(), id, serr)
+				break
+			}
+			if isSealed(c, nv) { // empty values stay as they are
+				ids, olds, news = append(ids, id), append(olds, old), append(news, nv)
+			}
+		}
+		rows.Close()
+		if err == nil {
+			err = rows.Err()
+		}
+		if err != nil {
+			return total, err
+		}
+		cast := ""
+		if c.json {
+			cast = "::jsonb"
+		}
+		for i, id := range ids {
+			res, err := conn.ExecContext(ctx, `UPDATE `+c.table+` SET `+c.col+`=$1`+cast+` WHERE id=$2 AND `+c.col+`::text=$3`, news[i], id, olds[i])
+			if err != nil {
+				return total, fmt.Errorf("backfill %s id=%d: %w", c.aad(), id, err)
+			}
+			if n, _ := res.RowsAffected(); n > 0 {
+				total++
+			}
+		}
+	}
+	return total, nil
+}

db/secrets_test.go

@@ -0,0 +1,197 @@
+package db
+
+import (
+	"context"
+	"encoding/base64"
+	"encoding/hex"
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+var testSecretKey = []byte("0123456789abcdef0123456789abcdef")
+
+func TestSecretBoxCrypto(t *testing.T) {
+	b, _ := newSecretBox(testSecretKey)
+	c1, err := b.encrypt("t.c", "hunter2")
+	if err != nil {
+		t.Fatal(err)
+	}
+	c2, _ := b.encrypt("t.c", "hunter2")
+	if !isEncrypted(c1) || isEncrypted("hunter2") || c1 == c2 || strings.Contains(c1, "hunter2") {
+		t.Fatalf("want distinct enc:v1: ciphertexts, got %q %q", c1, c2)
+	}
+	if p, err := b.decrypt("t.c", c1); err != nil || p != "hunter2" {
+		t.Fatalf("round trip: %q %v", p, err)
+	}
+	if _, err := b.decrypt("t.other", c1); err == nil {
+		t.Fatal("wrong AAD must fail")
+	}
+	raw, _ := base64.StdEncoding.DecodeString(strings.TrimPrefix(c1, secretPrefix))
+	raw[len(raw)-1] ^= 1
+	if _, err := b.decrypt("t.c", secretPrefix+base64.StdEncoding.EncodeToString(raw)); err == nil {
+		t.Fatal("tampered ciphertext must fail")
+	}
+	if v, _ := b.encrypt("t.c", ""); v != "" {
+		t.Fatal("empty must stay empty")
+	}
+	sealed, err := b.seal(colMCPEnv, `{"b":1, "a":"tok"}`)
+	if err != nil || !isSealed(colMCPEnv, sealed) || strings.Contains(sealed, "tok") {
+		t.Fatalf("not sealed: %s %v", sealed, err)
+	}
+	if p, err := b.open(colMCPEnv, sealed); err != nil || p != `{"a":"tok","b":1}` {
+		t.Fatalf("canonical JSON round trip: %q %v", p, err)
+	}
+	if _, err := b.seal(colMCPEnv, `{"__artex_enc":"x"}`); err == nil {
+		t.Fatal("reserved key must be refused")
+	}
+	if out, _ := b.seal(colMCPEnv, `{}`); out != `{}` {
+		t.Fatalf("empty object must stay empty, got %s", out)
+	}
+}
+
+type secretRows struct{ llm, mcp, cred, ch, task int64 }
+
+var plainSecrets = []string{"sk-plain-llm", "mcp-plain-tok", "plain-pass", "hook-plain-secret"}
+
+// secretFixture writes one secret to each location, through the db API or, for
+// a legacy database, as raw plaintext SQL.
+func secretFixture(t *testing.T, d *DB, legacy bool) (r secretRows) {
+	t.Helper()
+	task, err := d.CreateTask("secrets at rest", "goal", nil, 0, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	r.task = task.ID
+	t.Cleanup(func() {
+		_ = d.DeleteTask(r.task)
+		d.Exec(`DELETE FROM llm_profiles WHERE id=$1`, r.llm)
+		d.Exec(`DELETE FROM mcp_servers WHERE id=$1`, r.mcp)
+		d.Exec(`DELETE FROM notification_channels WHERE id=$1`, r.ch)
+	})
+	env, cfg := `{"Authorization":"mcp-plain-tok"}`, `{"url":"https://h.example","headers":{"X":"hook-plain-secret"}}`
+	if legacy {
+		ins := func(id *int64, q string, args ...any) {
+			if err := d.QueryRow(q, args...).Scan(id); err != nil {
+				t.Fatal(err)
+			}
+		}
+		ins(&r.llm, `INSERT INTO llm_profiles(name,format,model,api_key) VALUES ('t-sec','openai','m','sk-plain-llm') RETURNING id`)
+		ins(&r.mcp, `INSERT INTO mcp_servers(name,transport,env) VALUES ('t-sec','http',$1) RETURNING id`, env)
+		ins(&r.cred, `INSERT INTO task_credentials(task_id,domain,username,password) VALUES ($1,'x.example','u','plain-pass') RETURNING id`, r.task)
+		ins(&r.ch, `INSERT INTO notification_channels(name,kind,config) VALUES ('t-sec','webhook',$1) RETURNING id`, cfg)
+		return r
+	}
+	r.llm, err = d.SaveProfile(&LLMProfile{Name: "t-sec", Format: "openai", Model: "m", APIKey: "sk-plain-llm"})
+	if err == nil {
+		r.mcp, err = d.SaveMCP(&MCPServer{Name: "t-sec", Transport: "http", Env: json.RawMessage(env)})
+	}
+	if err == nil {
+		var c TaskCredential
+		c, err = d.UpsertTaskCredential(r.task, TaskCredentialInput{Domain: "x.example", Username: "u", Password: "plain-pass"})
+		r.cred = c.ID
+	}
+	if err == nil {
+		r.ch, err = d.SaveNotificationChannel(context.Background(), &NotificationChannel{Name: "t-sec", Kind: "webhook", Config: json.RawMessage(cfg)})
+	}
+	if err != nil {
+		t.Fatal(err)
+	}
+	return r
+}
+
+// rawSecrets reads the four columns as stored in PostgreSQL.
+func rawSecrets(t *testing.T, d *DB, r secretRows) string {
+	t.Helper()
+	var a, b, c, e string
+	if err := d.QueryRow(`SELECT (SELECT api_key FROM llm_profiles WHERE id=$1), (SELECT env::text FROM mcp_servers WHERE id=$2),
+(SELECT password FROM task_credentials WHERE id=$3), (SELECT config::text FROM notification_channels WHERE id=$4)`,
+		r.llm, r.mcp, r.cred, r.ch).Scan(&a, &b, &c, &e); err != nil {
+		t.Fatal(err)
+	}
+	if !isEncrypted(a) || !isSealed(colMCPEnv, b) || !isEncrypted(c) || !isSealed(colNotifConfig, e) {
+		t.Fatal("a stored secret is not encrypted")
+	}
+	all := strings.Join([]string{a, b, c, e}, "|")
+	for _, p := range plainSecrets {
+		if strings.Contains(all, p) {
+			t.Fatalf("plaintext %q found at rest", p)
+		}
+	}
+	return all
+}
+
+// assertPlainReads checks that every db read path returns the decrypted secret.
+func assertPlainReads(t *testing.T, d *DB, r secretRows) {
+	t.Helper()
+	got := ""
+	if p, err := d.ProfileByID(r.llm); err == nil && p != nil {
+		got += p.APIKey
+	}
+	ms, _ := d.ListMCP()
+	for _, m := range ms {
+		if m.ID == r.mcp {
+			got += string(m.Env)
+		}
+	}
+	if creds, err := d.TaskCredentials(r.task); err == nil && len(creds) == 1 {
+		got += creds[0].Password
+	}
+	if ch, err := d.NotificationChannelByID(context.Background(), r.ch); err == nil {
+		got += string(ch.Config)
+	}
+	for _, p := range plainSecrets {
+		if !strings.Contains(got, p) {
+			t.Fatalf("%q not read back in clear", p)
+		}
+	}
+}
+
+func TestSecretsAtRestWriteRead(t *testing.T) {
+	d, err := Open(testDSN(t))
+	if err != nil {
+		t.Skipf("postgres unavailable (%v) — skipping", err)
+	}
+	t.Cleanup(func() { d.Close() }) // after the fixture cleanup
+	r := secretFixture(t, d, false)
+	rawSecrets(t, d, r)
+	assertPlainReads(t, d, r)
+	if _, err := d.SaveMCP(&MCPServer{Name: "t-sec-reserved", Transport: "http", Env: json.RawMessage(`{"__artex_enc":"x"}`)}); err == nil {
+		t.Fatal("reserved key must be refused on write")
+	}
+}
+
+func TestSecretsBackfillLegacyAndKeyChecks(t *testing.T) {
+	d, err := Open(testDSN(t))
+	if err != nil {
+		t.Skipf("postgres unavailable (%v) — skipping", err)
+	}
+	t.Cleanup(func() { d.Close() }) // after the fixture cleanup
+	r := secretFixture(t, d, true)
+	t.Setenv(secretKeyEnv, base64.StdEncoding.EncodeToString(testSecretKey))
+	if err := d.InitSecrets(t.TempDir()); err != nil {
+		t.Fatal(err)
+	}
+	first := rawSecrets(t, d, r)
+	assertPlainReads(t, d, r)
+	if err := d.InitSecrets(t.TempDir()); err != nil || rawSecrets(t, d, r) != first {
+		t.Fatalf("second backfill must leave ciphertexts untouched (%v)", err)
+	}
+
+	// Encrypted data, no env key, no key file: refuse, and write no new key.
+	t.Setenv(secretKeyEnv, "")
+	dir := t.TempDir()
+	if err := d.InitSecrets(dir); err == nil || !strings.Contains(err.Error(), "no key is available") {
+		t.Fatalf("want refusal without a key, got %v", err)
+	}
+	if _, err := os.Stat(filepath.Join(dir, secretKeyFile)); !os.IsNotExist(err) {
+		t.Fatal("a new key was generated over encrypted data")
+	}
+	t.Setenv(secretKeyEnv, hex.EncodeToString([]byte("ffffffffffffffffffffffffffffffff")))
+	if err := d.InitSecrets(dir); err == nil || !strings.Contains(err.Error(), "secret key check") {
+		t.Fatalf("want wrong-key refusal, got %v", err)
+	}
+	assertPlainReads(t, d, r) // the active key is unchanged
+}

db/task_credentials.go

@@ -10,9 +10,8 @@ import (
 // task creation (source=user, e.g. a program-provided alias account) or registered
 // by the agent itself and recorded so it is not forgotten (source=agent).
 //
-// Passwords are stored in the local Postgres, plaintext — the same trust domain as
-// captured traffic evidence, which already contains credentials by nature. The UI
-// masks them by default; anything injected into agent context transits to the LLM
+// Passwords are encrypted at rest (secrets.go) and masked by the HTTP API; the
+// agent tools read them decrypted. Anything injected into agent context transits to the LLM
 // provider, so only dedicated test accounts belong here.
 type TaskCredential struct {
 	ID        int64     `json:"id"`
@@ -64,6 +63,10 @@ func (d *DB) UpsertTaskCredential(taskID int64, in TaskCredentialInput) (TaskCre
 	if err != nil {
 		return TaskCredential{}, err
 	}
+	pass, err := sealSecret(colCredPass, in.Password)
+	if err != nil {
+		return TaskCredential{}, err
+	}
 	var c TaskCredential
 	err = d.QueryRow(`
 		INSERT INTO task_credentials (task_id, domain, username, password, source, note)
@@ -74,8 +77,9 @@ func (d *DB) UpsertTaskCredential(taskID int64, in TaskCredentialInput) (TaskCre
 		    note     = CASE WHEN EXCLUDED.note = '' THEN task_credentials.note ELSE EXCLUDED.note END,
 		    updated_at = now()
 		RETURNING id, task_id, domain, username, password, source, note, created_at, updated_at`,
-		taskID, in.Domain, in.Username, in.Password, in.Source, in.Note).
+		taskID, in.Domain, in.Username, pass, in.Source, in.Note).
 		Scan(&c.ID, &c.TaskID, &c.Domain, &c.Username, &c.Password, &c.Source, &c.Note, &c.CreatedAt, &c.UpdatedAt)
+	c.Password = in.Password
 	return c, err
 }
 
@@ -95,6 +99,9 @@ func (d *DB) TaskCredentials(taskID int64) ([]TaskCredential, error) {
 		if err := rows.Scan(&c.ID, &c.TaskID, &c.Domain, &c.Username, &c.Password, &c.Source, &c.Note, &c.CreatedAt, &c.UpdatedAt); err != nil {
 			return nil, err
 		}
+		if c.Password, err = openSecret(colCredPass, c.Password); err != nil {
+			return nil, err
+		}
 		out = append(out, c)
 	}
 	return out, rows.Err()

db/testmain_test.go

@@ -18,6 +18,8 @@ func TestMain(m *testing.M) {
 	// contending on shared tables and the advisory lock below stops
 	// serializing go test ./... across packages.
 	SuffixTestDatabase("db")
+	box, _ := newSecretBox(testSecretKey)
+	activeSecretBox.Store(box)
 	dsn, _, err := DSN()
 	if err != nil {
 		// No DB configured — tests that need PG will skip themselves.

docker-compose.yml

@@ -35,6 +35,8 @@ services:
       ARTEX_LLM_BASE_URL: ${ARTEX_LLM_BASE_URL:-}
       ARTEX_LLM_PROXY: ${ARTEX_LLM_PROXY:-}
       ARTEX_JWT_KEY_DIR: /app/keys
+      # Optional: key for secrets at rest; empty = keys/secret.key (generated at first start).
+      ARTEX_SECRET_KEY: ${ARTEX_SECRET_KEY:-}
       ARTEX_TRUSTED_PROXIES: ${ARTEX_TRUSTED_PROXIES:-}
       # Untrusted-output boundary: on by default (empty = on); ARTEX_UNTRUSTED_BOUNDARY=0 in .env
       # disables it. Cost: about 154 bytes per tool result plus one system note.

server/env_scrub.go

@@ -3,8 +3,8 @@ package server
 import "os"
 
 // secretEnv lists the credentials read from the environment only at startup:
-// ARTEX_PG_DSN by NewManager, the API keys by agent.FromEnv inside New.
-var secretEnv = []string{"ARTEX_PG_DSN", "ANTHROPIC_API_KEY", "OPENAI_API_KEY"}
+// ARTEX_PG_DSN and ARTEX_SECRET_KEY by NewManager, the API keys by agent.FromEnv inside New.
+var secretEnv = []string{"ARTEX_PG_DSN", "ARTEX_SECRET_KEY", "ANTHROPIC_API_KEY", "OPENAI_API_KEY"}
 
 // ScrubSecretEnv removes secretEnv from the process environment once startup has
 // read it. Child processes (agent shells, custom tools, MCP stdio servers) copy

server/env_scrub_test.go

@@ -46,6 +46,7 @@ func TestNewAppliesSecretScrubOption(t *testing.T) {
 	if dsn := os.Getenv("ARTEX_PG_DSN"); dsn != "" {
 		t.Setenv("ARTEX_PG_DSN", dsn)
 	}
+	t.Setenv("ARTEX_SECRET_KEY", os.Getenv("ARTEX_SECRET_KEY"))
 	t.Setenv("ANTHROPIC_API_KEY", "scrub-probe")
 	t.Setenv("OPENAI_API_KEY", "scrub-probe")
 

server/manager.go

@@ -17,6 +17,7 @@ import (
 	"time"
 
 	"github.com/Autumn-27/artex/agent"
+	"github.com/Autumn-27/artex/config"
 	pgdb "github.com/Autumn-27/artex/db"
 	"github.com/Autumn-27/artex/enrich"
 	"github.com/Autumn-27/artex/guard"
@@ -391,6 +392,11 @@ func NewManager(dir, proxyAddr string) (*Manager, error) {
 	if err != nil {
 		return nil, err
 	}
+	// Before anything reads a stored secret: load the key, encrypt legacy plaintext.
+	if err := pg.InitSecrets(config.KeyDir()); err != nil {
+		pg.Close()
+		return nil, fmt.Errorf("secrets at rest: %w", err)
+	}
 	if err := pg.RecoverFindingRetests(); err != nil {
 		pg.Close()
 		return nil, fmt.Errorf("recover finding retests: %w", err)

server/secrets_api_test.go

@@ -0,0 +1,146 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"strconv"
+	"strings"
+	"testing"
+
+	"github.com/Autumn-27/artex/db"
+)
+
+// No read endpoint returns a stored secret in clear, and a masked placeholder
+// sent back on write never replaces the stored secret.
+func TestSecretsNeverReturnedInClear(t *testing.T) {
+	s, _, request := trafficEvidenceServer(t)
+	pg := s.m.PG()
+	secrets := []string{"sk-llm-plain-0001", "mcp-env-plain-0002", "cred-plain-0003", "SECding-plain-0004", "tok-plain-0005"}
+	task, err := s.m.CreateTask("secrets api", "goal", nil, 0, 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	taskID, _ := strconv.ParseInt(task.ID, 10, 64)
+	llmID, err := pg.SaveProfile(&db.LLMProfile{Name: "t-secapi", Format: "openai", Model: "m", APIKey: secrets[0]})
+	mcpID, err2 := pg.SaveMCP(&db.MCPServer{Name: "t-secapi", Transport: "http", Env: json.RawMessage(`{"X-API-Key":"` + secrets[1] + `","EMPTY":""}`)})
+	_, err3 := pg.UpsertTaskCredential(taskID, db.TaskCredentialInput{Domain: "x.example", Username: "u", Password: secrets[2]})
+	chID, err4 := pg.SaveNotificationChannel(context.Background(), &db.NotificationChannel{Name: "t-secapi", Kind: "dingtalk",
+		Config: json.RawMessage(`{"webhook":"https://oapi.example/send?access_token=` + secrets[4] + `","secret":"` + secrets[3] + `"}`)})
+	t.Cleanup(func() {
+		pg.Exec(`DELETE FROM llm_profiles WHERE id=$1`, llmID)
+		pg.Exec(`DELETE FROM mcp_servers WHERE id=$1`, mcpID)
+		pg.Exec(`DELETE FROM notification_channels WHERE id=$1`, chID)
+		pg.DeleteTask(taskID)
+	})
+	for _, e := range []error{err, err2, err3, err4} {
+		if e != nil {
+			t.Fatal(e)
+		}
+	}
+
+	for _, path := range []string{"/api/llm/profiles", "/api/llm", "/api/mcp", "/api/notify/channels", "/api/tasks/" + task.ID + "/credentials"} {
+		resp := request("GET", path, "")
+		for _, sec := range secrets {
+			if resp.Code != 200 || strings.Contains(resp.Body.String(), sec) {
+				t.Fatalf("GET %s: HTTP %d or a secret returned in clear", path, resp.Code)
+			}
+		}
+	}
+
+	// MCP: echo the masked list entry back with a name change; the key survives.
+	var list struct{ Servers []db.MCPServer }
+	_ = json.Unmarshal(request("GET", "/api/mcp", "").Body.Bytes(), &list)
+	for _, m := range list.Servers {
+		if m.ID != mcpID {
+			continue
+		}
+		if string(m.Env) != `{"EMPTY":"","X-API-Key":"__masked__"}` {
+			t.Fatalf("mcp env not masked as expected: %s", m.Env)
+		}
+		m.Name = "t-secapi-renamed"
+		body, _ := json.Marshal(m)
+		if resp := request("POST", "/api/mcp", string(body)); resp.Code != 200 {
+			t.Fatalf("mcp save: HTTP %d %s", resp.Code, resp.Body.String())
+		}
+	}
+	all, _ := pg.ListMCP()
+	for _, m := range all {
+		if m.ID == mcpID && !strings.Contains(string(m.Env), secrets[1]) {
+			t.Fatal("masked placeholder replaced the stored MCP secret")
+		}
+	}
+	if resp := request("POST", "/api/mcp", `{"name":"t-secapi-new","transport":"http","env":{"K":"__masked__"}}`); resp.Code != 400 {
+		t.Fatalf("a placeholder with nothing stored must be refused, got HTTP %d", resp.Code)
+	}
+
+	// Task credential: a masked password on write is refused, the stored one kept.
+	if resp := request("POST", "/api/tasks/"+task.ID+"/credentials", `{"domain":"x.example","username":"u","password":"__masked__"}`); resp.Code != 400 {
+		t.Fatalf("masked credential write must be refused, got HTTP %d", resp.Code)
+	}
+	if creds, _ := pg.TaskCredentials(taskID); len(creds) != 1 || creds[0].Password != secrets[2] {
+		t.Fatal("stored credential changed")
+	}
+}
+
+// A masked MCP env value is only kept while the destination (transport,
+// command, args, url) is unchanged; otherwise the secrets must be re-entered.
+func TestMCPMaskedEnvDestinationGuard(t *testing.T) {
+	s, _, request := trafficEvidenceServer(t)
+	pg := s.m.PG()
+	const secret = "mcp-guard-secret-0006"
+	httpID, err := pg.SaveMCP(&db.MCPServer{Name: "t-guard-http", Transport: "http", URL: "http://127.0.0.1:9/a",
+		Env: json.RawMessage(`{"K":"` + secret + `"}`)})
+	if err != nil {
+		t.Fatal(err)
+	}
+	stdioID, err := pg.SaveMCP(&db.MCPServer{Name: "t-guard-stdio", Transport: "stdio", Command: "npx",
+		Args: json.RawMessage(`["pkg"]`), Env: json.RawMessage(`{"K":"` + secret + `"}`)})
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { pg.DeleteMCP(httpID); pg.DeleteMCP(stdioID) })
+	stored := func(id int64) db.MCPServer {
+		all, _ := pg.ListMCP()
+		for _, m := range all {
+			if m.ID == id {
+				return *m
+			}
+		}
+		t.Fatalf("mcp %d missing", id)
+		return db.MCPServer{}
+	}
+	save := func(id int64, edit func(*db.MCPServer), want int) {
+		t.Helper()
+		m := stored(id)
+		m.Env = maskMCPEnv(m.Env)
+		edit(&m)
+		body, _ := json.Marshal(m)
+		if resp := request("POST", "/api/mcp", string(body)); resp.Code != want {
+			t.Fatalf("want HTTP %d, got %d %s", want, resp.Code, resp.Body.String())
+		}
+	}
+	keeps := func(id int64, url string) {
+		t.Helper()
+		if m := stored(id); !strings.Contains(string(m.Env), secret) || m.URL != url {
+			t.Fatalf("stored row changed: url=%q", m.URL)
+		}
+	}
+
+	save(httpID, func(m *db.MCPServer) { m.Name = "t-guard-http2" }, 200)
+	keeps(httpID, "http://127.0.0.1:9/a")
+	save(httpID, func(m *db.MCPServer) { m.URL = "http://127.0.0.1:9/evil" }, 400)
+	keeps(httpID, "http://127.0.0.1:9/a")
+	save(httpID, func(m *db.MCPServer) { m.Transport = "sse" }, 400)
+	keeps(httpID, "http://127.0.0.1:9/a")
+	save(stdioID, func(m *db.MCPServer) { m.Command = "sh" }, 400)
+	save(stdioID, func(m *db.MCPServer) { m.Args = json.RawMessage(`["other"]`) }, 400)
+	keeps(stdioID, "")
+	save(stdioID, func(m *db.MCPServer) { m.Args = json.RawMessage(`[ "pkg" ]`) }, 200) // same args, other spacing
+	keeps(stdioID, "")
+	save(httpID, func(m *db.MCPServer) {
+		m.URL, m.Env = "http://127.0.0.1:9/b", json.RawMessage(`{"K":"new-explicit-value"}`)
+	}, 200)
+	if m := stored(httpID); m.URL != "http://127.0.0.1:9/b" || !strings.Contains(string(m.Env), "new-explicit-value") {
+		t.Fatal("explicit env with a new url was not saved")
+	}
+}

server/server_mgmt.go

@@ -25,6 +25,7 @@ import (
 
 	"github.com/Autumn-27/artex/agent"
 	"github.com/Autumn-27/artex/db"
+	"github.com/Autumn-27/artex/notify"
 	"github.com/Autumn-27/norma/llm"
 	"github.com/Autumn-27/norma/skill"
 )
@@ -857,9 +858,80 @@ func (s *Server) pgListMCP(w http.ResponseWriter, r *http.Request) {
 	if ms == nil {
 		ms = []*db.MCPServer{}
 	}
+	for _, m := range ms {
+		m.Env = maskMCPEnv(m.Env)
+	}
 	writeJSON(w, 200, map[string]any{"servers": ms})
 }
 
+// maskMCPEnv replaces every non-empty env value (API keys, auth headers) with
+// notify.MaskedPrefix so the API never returns it in clear.
+func maskMCPEnv(raw json.RawMessage) json.RawMessage {
+	var env map[string]any
+	if json.Unmarshal(raw, &env) != nil || env == nil {
+		return json.RawMessage(`{}`)
+	}
+	for k, v := range env {
+		if v != "" {
+			env[k] = notify.MaskedPrefix
+		}
+	}
+	out, _ := json.Marshal(env)
+	return out
+}
+
+// unmaskMCPEnv puts the stored value back for every env key sent as the mask,
+// so a client echoing the list response never overwrites the stored secret.
+// As in notify.PrepareConfigUpdate, a stored secret is only kept for the
+// destination it was configured for: when transport, command, args or url
+// change, every env value must be re-entered (or cleared) explicitly.
+func unmaskMCPEnv(pg *db.DB, m *db.MCPServer) error {
+	var env, storedEnv map[string]any
+	if json.Unmarshal(m.Env, &env) != nil {
+		return nil // not an object: SaveMCP stores or rejects it as before
+	}
+	all, err := pg.ListMCP()
+	if err != nil {
+		return err
+	}
+	var stored *db.MCPServer
+	for _, cur := range all {
+		if m.ID != 0 && cur.ID == m.ID {
+			stored = cur
+			_ = json.Unmarshal(cur.Env, &storedEnv)
+		}
+	}
+	moved := stored != nil && (stored.Transport != m.Transport || stored.Command != m.Command ||
+		stored.URL != m.URL || canonicalMCPArgs(stored.Args) != canonicalMCPArgs(m.Args))
+	for k, v := range env {
+		if s, ok := v.(string); ok && notify.IsMasked(s) {
+			old, ok := storedEnv[k]
+			if !ok {
+				return fmt.Errorf("env %q: masked value but nothing stored to keep", k)
+			}
+			if moved {
+				return fmt.Errorf("the MCP destination (transport, command, args or url) changed: re-enter the env values (%q is masked) or clear them; stored secrets are not sent to a new destination", k)
+			}
+			env[k] = old
+		}
+	}
+	m.Env, err = json.Marshal(env)
+	return err
+}
+
+// canonicalMCPArgs normalizes args JSON for comparison; empty means [] as in SaveMCP.
+func canonicalMCPArgs(raw json.RawMessage) string {
+	var v any
+	if len(raw) == 0 || string(raw) == "null" {
+		return "[]"
+	}
+	if json.Unmarshal(raw, &v) != nil {
+		return string(raw)
+	}
+	out, _ := json.Marshal(v)
+	return string(out)
+}
+
 func (s *Server) pgSaveMCP(w http.ResponseWriter, r *http.Request) {
 	pg := s.pg(w)
 	if pg == nil {
@@ -871,6 +943,10 @@ func (s *Server) pgSaveMCP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	isNew := m.ID == 0
+	if err := unmaskMCPEnv(pg, &m); err != nil {
+		writeErr(w, 400, err.Error())
+		return
+	}
 	id, err := pg.SaveMCP(&m)
 	if err != nil {
 		writeErr(w, 500, err.Error())

server/task_credentials.go

@@ -6,18 +6,23 @@ import (
 	"strconv"
 
 	"github.com/Autumn-27/artex/db"
+	"github.com/Autumn-27/artex/notify"
 )
 
 // Task credential HTTP handlers (#3). The agent-side write path is the
 // save_task_credential tool; these routes serve the UI (task detail tab) and the
 // creation dialog.
 
-// taskCredentialDTO masks nothing — the admin is the credential owner — but the
-// frontend renders passwords masked with an explicit reveal.
+// taskCredentialDTO masks the password server-side; an empty password stays
+// empty (the "agent generates" mode). Agent tools read the stored value directly.
 func taskCredentialDTO(c db.TaskCredential) map[string]any {
+	pass := c.Password
+	if pass != "" {
+		pass = notify.MaskedPrefix
+	}
 	return map[string]any{
 		"id": c.ID, "task_id": c.TaskID, "domain": c.Domain, "username": c.Username,
-		"password": c.Password, "source": c.Source, "note": c.Note,
+		"password": pass, "source": c.Source, "note": c.Note,
 		"created_at": c.CreatedAt, "updated_at": c.UpdatedAt,
 	}
 }
@@ -63,6 +68,10 @@ func (s *Server) addTaskCredential(w http.ResponseWriter, r *http.Request) {
 		writeErr(w, 400, "bad json: "+err.Error())
 		return
 	}
+	if notify.IsMasked(req.Password) {
+		writeErr(w, 400, "password is a masked placeholder; enter the real password")
+		return
+	}
 	// source=user: manual adds from the UI (e.g. relaying an OTP-verified account).
 	// An empty password stays allowed here — the "agent generates" mode.
 	c, err := s.m.PG().UpsertTaskCredential(id, db.TaskCredentialInput{

server/task_credentials_test.go

@@ -63,7 +63,7 @@ func TestTaskCredentialsFlow(t *testing.T) {
 	if len(list) != 2 {
 		t.Fatalf("want 2 credentials, got %d: %s", len(list), resp.Body.String())
 	}
-	if list[0].Domain != "target.example.com" || list[0].Username != "alias@test" || list[0].Password != "s3cret!" || list[0].Note != "program alias account" {
+	if list[0].Domain != "target.example.com" || list[0].Username != "alias@test" || list[0].Password != "__masked__" || list[0].Note != "program alias account" {
 		t.Fatalf("declared credential mismatch: %+v", list[0])
 	}
 	if list[1].Password != "" {

server/testmain_test.go

@@ -17,6 +17,8 @@ func TestMain(m *testing.M) {
 	// contending on shared tables and the advisory lock below stops
 	// serializing go test ./... across packages.
 	db.SuffixTestDatabase("server")
+	// Fixed test key via env: NewManager's InitSecrets then writes no key file.
+	os.Setenv("ARTEX_SECRET_KEY", "MDEyMzQ1Njc4OWFiY2RlZjAxMjM0NTY3ODlhYmNkZWY=")
 	dsn, _, err := db.DSN()
 	if err != nil {
 		os.Exit(m.Run())

web/src/app/(main)/function/tasks/detail/_tabs/credentials-tab.tsx

@@ -2,7 +2,7 @@
 
 import * as React from "react";
 
-import { CopyIcon, EyeIcon, EyeOffIcon, PlusIcon, TrashIcon } from "lucide-react";
+import { PlusIcon, TrashIcon } from "lucide-react";
 
 import { Badge } from "@/components/ui/badge";
 import { Button } from "@/components/ui/button";
@@ -15,11 +15,10 @@ import type { TaskCredential } from "@/lib/types";
 
 // Credentials tab (#3): the task's test accounts — user-declared (program alias
 // accounts) and agent-recorded (accounts the workers registered themselves).
-// Passwords render masked; reveal and copy are explicit.
+// Passwords are masked server-side and never sent to the browser.
 export function CredentialsTab({ taskId }: { taskId: string }) {
   const [items, setItems] = React.useState<TaskCredential[] | null>(null);
   const [error, setError] = React.useState("");
-  const [revealed, setRevealed] = React.useState<Set<number>>(new Set());
   const [domain, setDomain] = React.useState("");
   const [username, setUsername] = React.useState("");
   const [password, setPassword] = React.useState("");
@@ -74,15 +73,6 @@ export function CredentialsTab({ taskId }: { taskId: string }) {
     }
   }
 
-  function toggle(id: number) {
-    setRevealed((prev) => {
-      const next = new Set(prev);
-      if (next.has(id)) next.delete(id);
-      else next.add(id);
-      return next;
-    });
-  }
-
   return (
     <Card>
       <CardHeader>
@@ -115,24 +105,8 @@ export function CredentialsTab({ taskId }: { taskId: string }) {
                 </Badge>
                 <div className="ml-auto flex items-center gap-1">
                   <code className="max-w-40 truncate rounded bg-muted px-2 py-0.5 text-sm">
-                    {c.password === "" ? "— agent generates —" : revealed.has(c.id) ? c.password : "•".repeat(Math.min(c.password.length, 12))}
+                    {c.password === "" ? "— agent generates —" : "stored, hidden"}
                   </code>
-                  {c.password !== "" ? (
-                    <>
-                      <Button size="icon" variant="ghost" className="size-7" aria-label={revealed.has(c.id) ? "Hide password" : "Reveal password"} onClick={() => toggle(c.id)}>
-                        {revealed.has(c.id) ? <EyeOffIcon /> : <EyeIcon />}
-                      </Button>
-                      <Button
-                        size="icon"
-                        variant="ghost"
-                        className="size-7"
-                        aria-label="Copy password"
-                        onClick={() => navigator.clipboard?.writeText(c.password).catch(() => {})}
-                      >
-                        <CopyIcon />
-                      </Button>
-                    </>
-                  ) : null}
                   <Button size="icon" variant="ghost" className="size-7" aria-label="Delete credential" onClick={() => remove(c.id)}>
                     <TrashIcon />
                   </Button>