Add policy-based authz and token delegation

- Replace requireAdmin (role-based) guards on all REST endpoints
  with RequirePolicy middleware backed by the existing policy engine;
  built-in admin wildcard rule (-1) preserves existing admin behaviour
  while operator rules can now grant targeted access to non-admin
  accounts (e.g. a system account allowed to list accounts)
- Wire policy engine into Server: loaded from DB at startup,
  reloaded after every policy-rule create/update/delete so changes
  take effect immediately without a server restart
- Add service_account_delegates table (migration 000008) so a human
  account can be delegated permission to issue tokens for a specific
  system account without holding the admin role
- Add token-download nonce mechanism: a short-lived (5 min),
  single-use random nonce is stored server-side after token issuance;
  the browser downloads the token as a file via
  GET /token/download/{nonce} (Content-Disposition: attachment)
  instead of copying from a flash message
- Add /service-accounts UI page for non-admin delegates
- Add TestPolicyEnforcement and TestPolicyDenyRule integration tests

Security:
- Policy engine uses deny-wins, default-deny semantics; admin wildcard
  is a compiled-in built-in and cannot be deleted via the API
- Token download nonces are 128-bit crypto/rand values, single-use,
  and expire after 5 minutes; a background goroutine evicts stale entries
- alg header validation and Ed25519 signing unchanged

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

PROGRESS.md

@@ -2,7 +2,42 @@
 
 Source of truth for current development state.
 ---
-All phases complete. **v1.0.0 tagged.** All packages pass `go test ./...`; `golangci-lint run ./...` clean.
+All phases complete. **v1.0.0 tagged.** All packages pass `go test ./...`; `golangci-lint run ./...` clean (pre-existing warnings only).
+
+### 2026-03-15 — Service account token delegation and download
+
+**Problem:** Only admins could issue tokens for service accounts, and the only way to retrieve the token was a flash message (copy-paste). There was no delegation mechanism for non-admin users.
+
+**Solution:** Added token-issue delegation and a one-time secure file download flow.
+
+**DB (`internal/db/`):**
+- Migration `000008`: new `service_account_delegates` table — tracks which human accounts may issue tokens for a given system account
+- `GrantTokenIssueAccess`, `RevokeTokenIssueAccess`, `ListTokenIssueDelegates`, `HasTokenIssueAccess`, `ListDelegatedServiceAccounts` functions
+
+**Model (`internal/model/`):**
+- New `ServiceAccountDelegate` type
+- New audit event constants: `EventTokenDelegateGranted`, `EventTokenDelegateRevoked`
+
+**UI (`internal/ui/`):**
+- `handleIssueSystemToken`: now allows admins and delegates (not just admins); after issuance stores token in a short-lived (5 min) single-use download nonce; returns download link in the HTMX fragment
+- `handleDownloadToken`: serves the token as `Content-Disposition: attachment` via the one-time nonce; nonce deleted on first use to prevent replay
+- `handleGrantTokenDelegate` / `handleRevokeTokenDelegate`: admin-only endpoints to manage delegate access for a system account
+- `handleServiceAccountsPage`: new `/service-accounts` page for non-admin delegates to see their assigned service accounts and issue tokens
+- New `tokenDownloads sync.Map` in `UIServer` with background cleanup goroutine
+
+**Routes:**
+- `POST /accounts/{id}/token` — changed from admin-only to authed+CSRF, authorization checked in handler
+- `GET /token/download/{nonce}` — new, authed
+- `POST /accounts/{id}/token/delegates` — new, admin-only
+- `DELETE /accounts/{id}/token/delegates/{grantee}` — new, admin-only
+- `GET /service-accounts` — new, authed (delegates' token management page)
+
+**Templates:**
+- `token_list.html`: shows download link after issuance
+- `token_delegates.html`: new fragment for admin delegate management
+- `account_detail.html`: added "Token Issue Access" section for system accounts
+- `service_accounts.html`: new page listing delegated service accounts with issue button
+- `base.html`: non-admin nav now shows "Service Accounts" link
 
 ### 2026-03-14 — Vault seal/unseal lifecycle
 

internal/db/accounts.go

@@ -1397,3 +1397,116 @@ func (db *DB) Rekey(newSalt, newSigningKeyEnc, newSigningKeyNonce []byte, totpRo
 	}
 	return nil
 }
+
+// GrantTokenIssueAccess records that granteeID may issue tokens for the system
+// account identified by accountID.  Idempotent: a second call for the same
+// (account, grantee) pair is silently ignored via INSERT OR IGNORE.
+func (db *DB) GrantTokenIssueAccess(accountID, granteeID int64, grantedBy *int64) error {
+	_, err := db.sql.Exec(`
+		INSERT OR IGNORE INTO service_account_delegates
+		    (account_id, grantee_id, granted_by, granted_at)
+		VALUES (?, ?, ?, ?)
+	`, accountID, granteeID, grantedBy, now())
+	if err != nil {
+		return fmt.Errorf("db: grant token issue access: %w", err)
+	}
+	return nil
+}
+
+// RevokeTokenIssueAccess removes the delegate grant for granteeID on accountID.
+// Returns ErrNotFound if no such grant exists.
+func (db *DB) RevokeTokenIssueAccess(accountID, granteeID int64) error {
+	result, err := db.sql.Exec(`
+		DELETE FROM service_account_delegates
+		WHERE account_id = ? AND grantee_id = ?
+	`, accountID, granteeID)
+	if err != nil {
+		return fmt.Errorf("db: revoke token issue access: %w", err)
+	}
+	n, err := result.RowsAffected()
+	if err != nil {
+		return fmt.Errorf("db: revoke token issue access rows: %w", err)
+	}
+	if n == 0 {
+		return ErrNotFound
+	}
+	return nil
+}
+
+// ListTokenIssueDelegates returns all delegate grants for the given system account.
+func (db *DB) ListTokenIssueDelegates(accountID int64) ([]*model.ServiceAccountDelegate, error) {
+	rows, err := db.sql.Query(`
+		SELECT d.id, d.account_id, d.grantee_id, d.granted_by, d.granted_at,
+		       a.uuid, a.username
+		FROM service_account_delegates d
+		JOIN accounts a ON a.id = d.grantee_id
+		WHERE d.account_id = ?
+		ORDER BY d.granted_at ASC
+	`, accountID)
+	if err != nil {
+		return nil, fmt.Errorf("db: list token issue delegates: %w", err)
+	}
+	defer func() { _ = rows.Close() }()
+
+	var out []*model.ServiceAccountDelegate
+	for rows.Next() {
+		var d model.ServiceAccountDelegate
+		var grantedAt string
+		if err := rows.Scan(
+			&d.ID, &d.AccountID, &d.GranteeID, &d.GrantedBy, &grantedAt,
+			&d.GranteeUUID, &d.GranteeName,
+		); err != nil {
+			return nil, fmt.Errorf("db: scan token issue delegate: %w", err)
+		}
+		t, err := parseTime(grantedAt)
+		if err != nil {
+			return nil, err
+		}
+		d.GrantedAt = t
+		out = append(out, &d)
+	}
+	return out, rows.Err()
+}
+
+// HasTokenIssueAccess reports whether actorID has been granted permission to
+// issue tokens for the system account identified by accountID.
+func (db *DB) HasTokenIssueAccess(accountID, actorID int64) (bool, error) {
+	var count int
+	err := db.sql.QueryRow(`
+		SELECT COUNT(1) FROM service_account_delegates
+		WHERE account_id = ? AND grantee_id = ?
+	`, accountID, actorID).Scan(&count)
+	if err != nil {
+		return false, fmt.Errorf("db: has token issue access: %w", err)
+	}
+	return count > 0, nil
+}
+
+// ListDelegatedServiceAccounts returns system accounts for which actorID has
+// been granted token-issue access.
+func (db *DB) ListDelegatedServiceAccounts(actorID int64) ([]*model.Account, error) {
+	rows, err := db.sql.Query(`
+		SELECT a.id, a.uuid, a.username, a.account_type, COALESCE(a.password_hash,''),
+		       a.status, a.totp_required,
+		       a.totp_secret_enc, a.totp_secret_nonce,
+		       a.created_at, a.updated_at, a.deleted_at
+		FROM service_account_delegates d
+		JOIN accounts a ON a.id = d.account_id
+		WHERE d.grantee_id = ? AND a.status != 'deleted'
+		ORDER BY a.username ASC
+	`, actorID)
+	if err != nil {
+		return nil, fmt.Errorf("db: list delegated service accounts: %w", err)
+	}
+	defer func() { _ = rows.Close() }()
+
+	var out []*model.Account
+	for rows.Next() {
+		a, err := db.scanAccountRow(rows)
+		if err != nil {
+			return nil, err
+		}
+		out = append(out, a)
+	}
+	return out, rows.Err()
+}

internal/db/migrations/000008_service_account_delegates.up.sql

@@ -0,0 +1,15 @@
+-- service_account_delegates tracks which human accounts are permitted to issue
+-- tokens for a given system account without holding the global admin role.
+-- Admins manage delegates; delegates can issue/rotate tokens for the specific
+-- system account only and cannot modify any other account settings.
+CREATE TABLE IF NOT EXISTS service_account_delegates (
+    id          INTEGER PRIMARY KEY,
+    account_id  INTEGER NOT NULL REFERENCES accounts(id) ON DELETE CASCADE,
+    grantee_id  INTEGER NOT NULL REFERENCES accounts(id) ON DELETE CASCADE,
+    granted_by  INTEGER REFERENCES accounts(id),
+    granted_at  TEXT    NOT NULL DEFAULT (strftime('%Y-%m-%dT%H:%M:%SZ','now')),
+    UNIQUE (account_id, grantee_id)
+);
+
+CREATE INDEX IF NOT EXISTS idx_sa_delegates_account ON service_account_delegates (account_id);
+CREATE INDEX IF NOT EXISTS idx_sa_delegates_grantee ON service_account_delegates (grantee_id);

internal/model/model.go

@@ -210,8 +210,25 @@ const (
 	EventPGCredAccessRevoked = "pgcred_access_revoked" //nolint:gosec // G101: audit event type, not a credential
 
 	EventPasswordChanged = "password_changed"
+
+	EventTokenDelegateGranted = "token_delegate_granted"
+	EventTokenDelegateRevoked = "token_delegate_revoked"
 )
 
+// ServiceAccountDelegate records that a specific account has been granted
+// permission to issue tokens for a given system account.  Only admins can
+// add or remove delegates; delegates can issue/rotate tokens for that specific
+// system account and nothing else.
+type ServiceAccountDelegate struct {
+	GrantedAt   time.Time `json:"granted_at"`
+	GrantedBy   *int64    `json:"-"`
+	GranteeUUID string    `json:"grantee_id"`
+	GranteeName string    `json:"grantee_username"`
+	ID          int64     `json:"-"`
+	AccountID   int64     `json:"-"`
+	GranteeID   int64     `json:"-"`
+}
+
 // PolicyRuleRecord is the database representation of a policy rule.
 // RuleJSON holds a JSON-encoded policy.RuleBody (all match and effect fields).
 // The ID, Priority, and Description are stored as dedicated columns.

internal/server/handlers_policy.go

@@ -217,6 +217,9 @@ func (s *Server) handleCreatePolicyRule(w http.ResponseWriter, r *http.Request)
 	s.writeAudit(r, model.EventPolicyRuleCreated, createdBy, nil,
 		fmt.Sprintf(`{"rule_id":%d,"description":%q}`, rec.ID, rec.Description))
 
+	// Reload the in-memory engine so the new rule takes effect immediately.
+	s.reloadPolicyEngine()
+
 	rv, err := policyRuleToResponse(rec)
 	if err != nil {
 		middleware.WriteError(w, http.StatusInternalServerError, "internal error", "internal_error")
@@ -325,6 +328,9 @@ func (s *Server) handleUpdatePolicyRule(w http.ResponseWriter, r *http.Request)
 	s.writeAudit(r, model.EventPolicyRuleUpdated, actorID, nil,
 		fmt.Sprintf(`{"rule_id":%d}`, rec.ID))
 
+	// Reload the in-memory engine so rule changes take effect immediately.
+	s.reloadPolicyEngine()
+
 	updated, err := s.db.GetPolicyRule(rec.ID)
 	if err != nil {
 		middleware.WriteError(w, http.StatusInternalServerError, "internal error", "internal_error")
@@ -358,6 +364,9 @@ func (s *Server) handleDeletePolicyRule(w http.ResponseWriter, r *http.Request)
 	s.writeAudit(r, model.EventPolicyRuleDeleted, actorID, nil,
 		fmt.Sprintf(`{"rule_id":%d,"description":%q}`, rec.ID, rec.Description))
 
+	// Reload the in-memory engine so the deleted rule is removed immediately.
+	s.reloadPolicyEngine()
+
 	w.WriteHeader(http.StatusNoContent)
 }
 

internal/server/server.go

@@ -13,6 +13,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"io/fs"
 	"log/slog"
 	"net"
@@ -27,6 +28,7 @@ import (
 	"git.wntrmute.dev/kyle/mcias/internal/db"
 	"git.wntrmute.dev/kyle/mcias/internal/middleware"
 	"git.wntrmute.dev/kyle/mcias/internal/model"
+	"git.wntrmute.dev/kyle/mcias/internal/policy"
 	"git.wntrmute.dev/kyle/mcias/internal/token"
 	"git.wntrmute.dev/kyle/mcias/internal/ui"
 	"git.wntrmute.dev/kyle/mcias/internal/validate"
@@ -40,15 +42,154 @@ type Server struct {
 	cfg    *config.Config
 	logger *slog.Logger
 	vault  *vault.Vault
+	polEng *policy.Engine
 }
 
 // New creates a Server with the given dependencies.
+// The policy engine is initialised and loaded from the database on construction.
 func New(database *db.DB, cfg *config.Config, v *vault.Vault, logger *slog.Logger) *Server {
+	eng := policy.NewEngine()
+	if err := loadEngineRules(eng, database); err != nil {
+		logger.Warn("policy engine initial load failed; built-in defaults will apply", "error", err)
+	}
 	return &Server{
 		db:     database,
 		cfg:    cfg,
 		vault:  v,
 		logger: logger,
+		polEng: eng,
+	}
+}
+
+// loadEngineRules reads all policy rules from the database and loads them into eng.
+// Enabled/disabled and validity-window filtering is handled by the engine itself.
+func loadEngineRules(eng *policy.Engine, database *db.DB) error {
+	records, err := database.ListPolicyRules(false)
+	if err != nil {
+		return fmt.Errorf("list policy rules: %w", err)
+	}
+	prs := make([]policy.PolicyRecord, len(records))
+	for i, r := range records {
+		prs[i] = policy.PolicyRecord{
+			ID:          r.ID,
+			Priority:    r.Priority,
+			Description: r.Description,
+			RuleJSON:    r.RuleJSON,
+			Enabled:     r.Enabled,
+			NotBefore:   r.NotBefore,
+			ExpiresAt:   r.ExpiresAt,
+		}
+	}
+	return eng.SetRules(prs)
+}
+
+// reloadPolicyEngine reloads operator rules from the database into the engine.
+// Called after any create, update, or delete of a policy rule so that the
+// in-memory cache stays consistent with the database.
+func (s *Server) reloadPolicyEngine() {
+	if err := loadEngineRules(s.polEng, s.db); err != nil {
+		s.logger.Error("reload policy engine", "error", err)
+	}
+}
+
+// accountTypeLookup returns an AccountTypeLookup closure that resolves the
+// account type ("human" or "system") for the given subject UUID.  Used by the
+// RequirePolicy middleware to populate PolicyInput.AccountType.
+func (s *Server) accountTypeLookup() middleware.AccountTypeLookup {
+	return func(subjectUUID string) string {
+		acct, err := s.db.GetAccountByUUID(subjectUUID)
+		if err != nil {
+			return ""
+		}
+		return string(acct.AccountType)
+	}
+}
+
+// policyDenyLogger returns a PolicyDenyLogger that records policy denials in
+// the audit log as EventPolicyDeny events.
+func (s *Server) policyDenyLogger() middleware.PolicyDenyLogger {
+	return func(r *http.Request, claims *token.Claims, action policy.Action, res policy.Resource, matchedRuleID int64) {
+		s.writeAudit(r, model.EventPolicyDeny, nil, nil,
+			fmt.Sprintf(`{"subject":%q,"action":%q,"resource_type":%q,"rule_id":%d}`,
+				claims.Subject, action, res.Type, matchedRuleID))
+	}
+}
+
+// buildAccountResource assembles the policy.Resource for endpoints that
+// target a specific account ({id} path parameter).  Looks up the account's
+// UUID, username (for ServiceName), and tags from the database.
+// Returns an empty Resource on lookup failure; deny-by-default in the engine
+// means this safely falls through to a denial for owner-scoped rules.
+func (s *Server) buildAccountResource(r *http.Request, _ *token.Claims) policy.Resource {
+	id := r.PathValue("id")
+	if id == "" {
+		return policy.Resource{}
+	}
+	acct, err := s.db.GetAccountByUUID(id)
+	if err != nil {
+		return policy.Resource{}
+	}
+	tags, _ := s.db.GetAccountTags(acct.ID)
+	return policy.Resource{
+		OwnerUUID:   acct.UUID,
+		ServiceName: acct.Username,
+		Tags:        tags,
+	}
+}
+
+// buildTokenResource assembles the policy.Resource for token-issue requests.
+// The request body contains account_id (UUID); the resource owner is that account.
+// Because this builder reads the body it must be called before the body is
+// consumed by the handler — the middleware calls it before invoking next.
+func (s *Server) buildTokenResource(r *http.Request, _ *token.Claims) policy.Resource {
+	// Peek at the account_id without consuming the body.
+	// We read the body into a small wrapper struct to get the target UUID.
+	// The actual handler re-reads the body via decodeJSON, so this is safe
+	// because http.MaxBytesReader is applied by the handler, not here.
+	var peek struct {
+		AccountID string `json:"account_id"`
+	}
+	body, err := io.ReadAll(io.LimitReader(r.Body, maxJSONBytes))
+	if err != nil {
+		return policy.Resource{}
+	}
+	// Restore the body for the downstream handler.
+	r.Body = io.NopCloser(strings.NewReader(string(body)))
+	if err := json.Unmarshal(body, &peek); err != nil || peek.AccountID == "" {
+		return policy.Resource{}
+	}
+	acct, err := s.db.GetAccountByUUID(peek.AccountID)
+	if err != nil {
+		return policy.Resource{}
+	}
+	tags, _ := s.db.GetAccountTags(acct.ID)
+	return policy.Resource{
+		OwnerUUID:   acct.UUID,
+		ServiceName: acct.Username,
+		Tags:        tags,
+	}
+}
+
+// buildJTIResource assembles the policy.Resource for token-revoke requests.
+// Looks up the token record by {jti} to identify the owning account.
+func (s *Server) buildJTIResource(r *http.Request, _ *token.Claims) policy.Resource {
+	jti := r.PathValue("jti")
+	if jti == "" {
+		return policy.Resource{}
+	}
+	rec, err := s.db.GetTokenRecord(jti)
+	if err != nil {
+		return policy.Resource{}
+	}
+	acct, err := s.db.GetAccountByID(rec.AccountID)
+	if err != nil {
+		return policy.Resource{}
+	}
+	tags, _ := s.db.GetAccountTags(acct.ID)
+	return policy.Resource{
+		OwnerUUID:   acct.UUID,
+		ServiceName: acct.Username,
+		Tags:        tags,
 	}
 }
 
@@ -114,44 +255,92 @@ func (s *Server) Handler() http.Handler {
 
 	// Authenticated endpoints.
 	requireAuth := middleware.RequireAuth(s.vault, s.db, s.cfg.Tokens.Issuer)
-	requireAdmin := func(h http.Handler) http.Handler {
-		return requireAuth(middleware.RequireRole("admin")(h))
+
+	// Policy middleware factory: chains requireAuth → RequirePolicy → next.
+	// All protected endpoints use this instead of the old requireAdmin wrapper
+	// so that operator-defined policy rules (not just the admin role) control
+	// access.  The built-in admin wildcard rule (ID -1) preserves existing
+	// admin behaviour; additional operator rules can grant non-admin accounts
+	// access to specific actions.
+	//
+	// Security: deny-wins + default-deny in the engine mean that any
+	// misconfiguration results in 403, never silent permit.
+	acctTypeLookup := s.accountTypeLookup()
+	denyLogger := s.policyDenyLogger()
+	requirePolicy := func(
+		action policy.Action,
+		resType policy.ResourceType,
+		builder middleware.ResourceBuilder,
+	) func(http.Handler) http.Handler {
+		pol := middleware.RequirePolicy(s.polEng, action, resType, builder, acctTypeLookup, denyLogger)
+		return func(next http.Handler) http.Handler {
+			return requireAuth(pol(next))
+		}
 	}
 
-	// Auth endpoints (require valid token).
+	// Resource builders for endpoints that target a specific account or token.
+	buildAcct := middleware.ResourceBuilder(s.buildAccountResource)
+	buildToken := middleware.ResourceBuilder(s.buildTokenResource)
+	buildJTI := middleware.ResourceBuilder(s.buildJTIResource)
+
+	// Auth endpoints (require valid token; self-service rules in built-in defaults
+	// allow any authenticated principal to perform these operations).
 	mux.Handle("POST /v1/auth/logout", requireAuth(http.HandlerFunc(s.handleLogout)))
 	mux.Handle("POST /v1/auth/renew", requireAuth(http.HandlerFunc(s.handleRenew)))
 	mux.Handle("POST /v1/auth/totp/enroll", requireAuth(http.HandlerFunc(s.handleTOTPEnroll)))
 	mux.Handle("POST /v1/auth/totp/confirm", requireAuth(http.HandlerFunc(s.handleTOTPConfirm)))
 
-	// Admin-only endpoints.
-	mux.Handle("DELETE /v1/auth/totp", requireAdmin(http.HandlerFunc(s.handleTOTPRemove)))
-	mux.Handle("POST /v1/token/issue", requireAdmin(http.HandlerFunc(s.handleTokenIssue)))
-	mux.Handle("DELETE /v1/token/{jti}", requireAdmin(http.HandlerFunc(s.handleTokenRevoke)))
-	mux.Handle("GET /v1/accounts", requireAdmin(http.HandlerFunc(s.handleListAccounts)))
-	mux.Handle("POST /v1/accounts", requireAdmin(http.HandlerFunc(s.handleCreateAccount)))
-	mux.Handle("GET /v1/accounts/{id}", requireAdmin(http.HandlerFunc(s.handleGetAccount)))
-	mux.Handle("PATCH /v1/accounts/{id}", requireAdmin(http.HandlerFunc(s.handleUpdateAccount)))
-	mux.Handle("DELETE /v1/accounts/{id}", requireAdmin(http.HandlerFunc(s.handleDeleteAccount)))
-	mux.Handle("GET /v1/accounts/{id}/roles", requireAdmin(http.HandlerFunc(s.handleGetRoles)))
-	mux.Handle("PUT /v1/accounts/{id}/roles", requireAdmin(http.HandlerFunc(s.handleSetRoles)))
-	mux.Handle("POST /v1/accounts/{id}/roles", requireAdmin(http.HandlerFunc(s.handleGrantRole)))
-	mux.Handle("DELETE /v1/accounts/{id}/roles/{role}", requireAdmin(http.HandlerFunc(s.handleRevokeRole)))
+	// Policy-gated endpoints (formerly admin-only; now controlled by the engine).
+	mux.Handle("DELETE /v1/auth/totp",
+		requirePolicy(policy.ActionRemoveTOTP, policy.ResourceTOTP, buildAcct)(http.HandlerFunc(s.handleTOTPRemove)))
+	mux.Handle("POST /v1/token/issue",
+		requirePolicy(policy.ActionIssueToken, policy.ResourceToken, buildToken)(http.HandlerFunc(s.handleTokenIssue)))
+	mux.Handle("DELETE /v1/token/{jti}",
+		requirePolicy(policy.ActionRevokeToken, policy.ResourceToken, buildJTI)(http.HandlerFunc(s.handleTokenRevoke)))
+	mux.Handle("GET /v1/accounts",
+		requirePolicy(policy.ActionListAccounts, policy.ResourceAccount, nil)(http.HandlerFunc(s.handleListAccounts)))
+	mux.Handle("POST /v1/accounts",
+		requirePolicy(policy.ActionCreateAccount, policy.ResourceAccount, nil)(http.HandlerFunc(s.handleCreateAccount)))
+	mux.Handle("GET /v1/accounts/{id}",
+		requirePolicy(policy.ActionReadAccount, policy.ResourceAccount, buildAcct)(http.HandlerFunc(s.handleGetAccount)))
+	mux.Handle("PATCH /v1/accounts/{id}",
+		requirePolicy(policy.ActionUpdateAccount, policy.ResourceAccount, buildAcct)(http.HandlerFunc(s.handleUpdateAccount)))
+	mux.Handle("DELETE /v1/accounts/{id}",
+		requirePolicy(policy.ActionDeleteAccount, policy.ResourceAccount, buildAcct)(http.HandlerFunc(s.handleDeleteAccount)))
+	mux.Handle("GET /v1/accounts/{id}/roles",
+		requirePolicy(policy.ActionReadRoles, policy.ResourceAccount, buildAcct)(http.HandlerFunc(s.handleGetRoles)))
+	mux.Handle("PUT /v1/accounts/{id}/roles",
+		requirePolicy(policy.ActionWriteRoles, policy.ResourceAccount, buildAcct)(http.HandlerFunc(s.handleSetRoles)))
+	mux.Handle("POST /v1/accounts/{id}/roles",
+		requirePolicy(policy.ActionWriteRoles, policy.ResourceAccount, buildAcct)(http.HandlerFunc(s.handleGrantRole)))
+	mux.Handle("DELETE /v1/accounts/{id}/roles/{role}",
+		requirePolicy(policy.ActionWriteRoles, policy.ResourceAccount, buildAcct)(http.HandlerFunc(s.handleRevokeRole)))
 	mux.Handle("GET /v1/pgcreds", requireAuth(http.HandlerFunc(s.handleListAccessiblePGCreds)))
-	mux.Handle("GET /v1/accounts/{id}/pgcreds", requireAdmin(http.HandlerFunc(s.handleGetPGCreds)))
-	mux.Handle("PUT /v1/accounts/{id}/pgcreds", requireAdmin(http.HandlerFunc(s.handleSetPGCreds)))
-	mux.Handle("GET /v1/audit", requireAdmin(http.HandlerFunc(s.handleListAudit)))
-	mux.Handle("GET /v1/accounts/{id}/tags", requireAdmin(http.HandlerFunc(s.handleGetTags)))
-	mux.Handle("PUT /v1/accounts/{id}/tags", requireAdmin(http.HandlerFunc(s.handleSetTags)))
-	mux.Handle("PUT /v1/accounts/{id}/password", requireAdmin(http.HandlerFunc(s.handleAdminSetPassword)))
+	mux.Handle("GET /v1/accounts/{id}/pgcreds",
+		requirePolicy(policy.ActionReadPGCreds, policy.ResourcePGCreds, buildAcct)(http.HandlerFunc(s.handleGetPGCreds)))
+	mux.Handle("PUT /v1/accounts/{id}/pgcreds",
+		requirePolicy(policy.ActionWritePGCreds, policy.ResourcePGCreds, buildAcct)(http.HandlerFunc(s.handleSetPGCreds)))
+	mux.Handle("GET /v1/audit",
+		requirePolicy(policy.ActionReadAudit, policy.ResourceAuditLog, nil)(http.HandlerFunc(s.handleListAudit)))
+	mux.Handle("GET /v1/accounts/{id}/tags",
+		requirePolicy(policy.ActionReadTags, policy.ResourceAccount, buildAcct)(http.HandlerFunc(s.handleGetTags)))
+	mux.Handle("PUT /v1/accounts/{id}/tags",
+		requirePolicy(policy.ActionWriteTags, policy.ResourceAccount, buildAcct)(http.HandlerFunc(s.handleSetTags)))
+	mux.Handle("PUT /v1/accounts/{id}/password",
+		requirePolicy(policy.ActionUpdateAccount, policy.ResourceAccount, buildAcct)(http.HandlerFunc(s.handleAdminSetPassword)))
 
 	// Self-service password change (requires valid token; actor must match target account).
 	mux.Handle("PUT /v1/auth/password", requireAuth(http.HandlerFunc(s.handleChangePassword)))
-	mux.Handle("GET /v1/policy/rules", requireAdmin(http.HandlerFunc(s.handleListPolicyRules)))
-	mux.Handle("POST /v1/policy/rules", requireAdmin(http.HandlerFunc(s.handleCreatePolicyRule)))
-	mux.Handle("GET /v1/policy/rules/{id}", requireAdmin(http.HandlerFunc(s.handleGetPolicyRule)))
-	mux.Handle("PATCH /v1/policy/rules/{id}", requireAdmin(http.HandlerFunc(s.handleUpdatePolicyRule)))
-	mux.Handle("DELETE /v1/policy/rules/{id}", requireAdmin(http.HandlerFunc(s.handleDeletePolicyRule)))
+	mux.Handle("GET /v1/policy/rules",
+		requirePolicy(policy.ActionListRules, policy.ResourcePolicy, nil)(http.HandlerFunc(s.handleListPolicyRules)))
+	mux.Handle("POST /v1/policy/rules",
+		requirePolicy(policy.ActionManageRules, policy.ResourcePolicy, nil)(http.HandlerFunc(s.handleCreatePolicyRule)))
+	mux.Handle("GET /v1/policy/rules/{id}",
+		requirePolicy(policy.ActionListRules, policy.ResourcePolicy, nil)(http.HandlerFunc(s.handleGetPolicyRule)))
+	mux.Handle("PATCH /v1/policy/rules/{id}",
+		requirePolicy(policy.ActionManageRules, policy.ResourcePolicy, nil)(http.HandlerFunc(s.handleUpdatePolicyRule)))
+	mux.Handle("DELETE /v1/policy/rules/{id}",
+		requirePolicy(policy.ActionManageRules, policy.ResourcePolicy, nil)(http.HandlerFunc(s.handleDeletePolicyRule)))
 
 	// UI routes (HTMX-based management frontend).
 	uiSrv, err := ui.New(s.db, s.cfg, s.vault, s.logger)
@@ -1320,13 +1509,13 @@ func (s *Server) handleListAccessiblePGCreds(w http.ResponseWriter, r *http.Requ
 	type pgCredResponse struct {
 		CreatedAt          time.Time `json:"created_at"`
 		UpdatedAt          time.Time `json:"updated_at"`
-		ID                 int64     `json:"id"`
-		Port               int       `json:"port"`
 		Host               string    `json:"host"`
 		Database           string    `json:"database"`
 		Username           string    `json:"username"`
 		ServiceAccountID   string    `json:"service_account_id"`
 		ServiceAccountName string    `json:"service_account_name,omitempty"`
+		ID                 int64     `json:"id"`
+		Port               int       `json:"port"`
 	}
 
 	response := make([]pgCredResponse, len(creds))

internal/server/server_test.go

@@ -2,10 +2,10 @@ package server
 
 import (
 	"bytes"
-	"crypto/hmac"
-	"crypto/sha1"
 	"crypto/ed25519"
+	"crypto/hmac"
 	"crypto/rand"
+	"crypto/sha1" //nolint:gosec // G505: SHA1 required by RFC 6238 TOTP (HMAC-SHA1)
 	"encoding/binary"
 	"encoding/json"
 	"fmt"
@@ -23,6 +23,7 @@ import (
 	"git.wntrmute.dev/kyle/mcias/internal/config"
 	"git.wntrmute.dev/kyle/mcias/internal/db"
 	"git.wntrmute.dev/kyle/mcias/internal/model"
+	"git.wntrmute.dev/kyle/mcias/internal/policy"
 	"git.wntrmute.dev/kyle/mcias/internal/token"
 	"git.wntrmute.dev/kyle/mcias/internal/vault"
 )
@@ -972,3 +973,149 @@ func TestTOTPMissingDoesNotIncrementLockout(t *testing.T) {
 		t.Error("account was locked after TOTP-missing login — lockout counter was incorrectly incremented (PEN-06)")
 	}
 }
+
+// issueSystemToken creates a system account, issues a JWT with the given roles,
+// tracks it in the database, and returns the token string and account.
+func issueSystemToken(t *testing.T, srv *Server, priv ed25519.PrivateKey, username string, roles []string) (string, *model.Account) {
+	t.Helper()
+	acct, err := srv.db.CreateAccount(username, model.AccountTypeSystem, "")
+	if err != nil {
+		t.Fatalf("create system account: %v", err)
+	}
+	tokenStr, claims, err := token.IssueToken(priv, testIssuer, acct.UUID, roles, time.Hour)
+	if err != nil {
+		t.Fatalf("issue token: %v", err)
+	}
+	if err := srv.db.TrackToken(claims.JTI, acct.ID, claims.IssuedAt, claims.ExpiresAt); err != nil {
+		t.Fatalf("track token: %v", err)
+	}
+	return tokenStr, acct
+}
+
+// TestPolicyEnforcement verifies that the policy engine gates access:
+//   - Admin role is always allowed (built-in wildcard rule).
+//   - Unauthenticated requests are rejected.
+//   - Non-admin accounts are denied by default.
+//   - A non-admin account gains access once an operator policy rule is created.
+//   - Deleting the rule reverts to denial.
+func TestPolicyEnforcement(t *testing.T) {
+	srv, _, priv, _ := newTestServer(t)
+	handler := srv.Handler()
+
+	adminToken, _ := issueAdminToken(t, srv, priv, "admin-pol")
+
+	// 1. Admin can list accounts (built-in wildcard rule -1).
+	rr := doRequest(t, handler, "GET", "/v1/accounts", nil, adminToken)
+	if rr.Code != http.StatusOK {
+		t.Errorf("admin list accounts status = %d, want 200; body: %s", rr.Code, rr.Body.String())
+	}
+
+	// 2. Unauthenticated request is rejected.
+	rr = doRequest(t, handler, "GET", "/v1/accounts", nil, "")
+	if rr.Code != http.StatusUnauthorized {
+		t.Errorf("unauth list accounts status = %d, want 401", rr.Code)
+	}
+
+	// 3. System account with no operator rules is denied by default.
+	svcToken, svcAcct := issueSystemToken(t, srv, priv, "metacrypt", []string{"user"})
+	rr = doRequest(t, handler, "GET", "/v1/accounts", nil, svcToken)
+	if rr.Code != http.StatusForbidden {
+		t.Errorf("system account (no policy) list accounts status = %d, want 403; body: %s", rr.Code, rr.Body.String())
+	}
+
+	// 4. Create an operator policy rule granting the system account accounts:list.
+	rule := createPolicyRuleRequest{
+		Description: "allow metacrypt to list accounts",
+		Priority:    50,
+		Rule: policy.RuleBody{
+			SubjectUUID:  svcAcct.UUID,
+			AccountTypes: []string{"system"},
+			Actions:      []policy.Action{policy.ActionListAccounts},
+			Effect:       policy.Allow,
+		},
+	}
+	rr = doRequest(t, handler, "POST", "/v1/policy/rules", rule, adminToken)
+	if rr.Code != http.StatusCreated {
+		t.Fatalf("create policy rule status = %d, want 201; body: %s", rr.Code, rr.Body.String())
+	}
+	var created policyRuleResponse
+	if err := json.Unmarshal(rr.Body.Bytes(), &created); err != nil {
+		t.Fatalf("unmarshal created rule: %v", err)
+	}
+
+	// 5. The same system account can now list accounts.
+	rr = doRequest(t, handler, "GET", "/v1/accounts", nil, svcToken)
+	if rr.Code != http.StatusOK {
+		t.Errorf("system account (with policy) list accounts status = %d, want 200; body: %s", rr.Code, rr.Body.String())
+	}
+
+	// 6. The system account is still denied other actions (accounts:read).
+	rr = doRequest(t, handler, "POST", "/v1/accounts", map[string]string{
+		"username": "newuser", "password": "newpassword123", "account_type": "human",
+	}, svcToken)
+	if rr.Code != http.StatusForbidden {
+		t.Errorf("system account (list-only policy) create account status = %d, want 403", rr.Code)
+	}
+
+	// 7. Delete the rule and verify the account is denied again.
+	rr = doRequest(t, handler, "DELETE", fmt.Sprintf("/v1/policy/rules/%d", created.ID), nil, adminToken)
+	if rr.Code != http.StatusNoContent {
+		t.Fatalf("delete policy rule status = %d, want 204; body: %s", rr.Code, rr.Body.String())
+	}
+	rr = doRequest(t, handler, "GET", "/v1/accounts", nil, svcToken)
+	if rr.Code != http.StatusForbidden {
+		t.Errorf("system account (rule deleted) list accounts status = %d, want 403", rr.Code)
+	}
+}
+
+// TestPolicyDenyRule verifies that an explicit Deny rule blocks access even
+// when an Allow rule would otherwise permit it.
+func TestPolicyDenyRule(t *testing.T) {
+	srv, _, priv, _ := newTestServer(t)
+	handler := srv.Handler()
+
+	adminToken, _ := issueAdminToken(t, srv, priv, "admin-deny")
+
+	// Create an Allow rule for the system account.
+	svcToken, svcAcct := issueSystemToken(t, srv, priv, "svc-deny", []string{"user"})
+	allow := createPolicyRuleRequest{
+		Description: "allow svc-deny to list accounts",
+		Priority:    50,
+		Rule: policy.RuleBody{
+			SubjectUUID: svcAcct.UUID,
+			Actions:     []policy.Action{policy.ActionListAccounts},
+			Effect:      policy.Allow,
+		},
+	}
+	rr := doRequest(t, handler, "POST", "/v1/policy/rules", allow, adminToken)
+	if rr.Code != http.StatusCreated {
+		t.Fatalf("create allow rule status = %d; body: %s", rr.Code, rr.Body.String())
+	}
+
+	// Verify access is granted.
+	rr = doRequest(t, handler, "GET", "/v1/accounts", nil, svcToken)
+	if rr.Code != http.StatusOK {
+		t.Fatalf("with allow rule, list accounts status = %d, want 200", rr.Code)
+	}
+
+	// Add a higher-priority Deny rule for the same account.
+	deny := createPolicyRuleRequest{
+		Description: "deny svc-deny accounts:list",
+		Priority:    10, // lower number = higher precedence
+		Rule: policy.RuleBody{
+			SubjectUUID: svcAcct.UUID,
+			Actions:     []policy.Action{policy.ActionListAccounts},
+			Effect:      policy.Deny,
+		},
+	}
+	rr = doRequest(t, handler, "POST", "/v1/policy/rules", deny, adminToken)
+	if rr.Code != http.StatusCreated {
+		t.Fatalf("create deny rule status = %d; body: %s", rr.Code, rr.Body.String())
+	}
+
+	// Deny-wins: access must now be blocked despite the Allow rule.
+	rr = doRequest(t, handler, "GET", "/v1/accounts", nil, svcToken)
+	if rr.Code != http.StatusForbidden {
+		t.Errorf("deny-wins: list accounts status = %d, want 403", rr.Code)
+	}
+}

internal/ui/handlers_accounts.go

@@ -182,17 +182,35 @@ func (u *UIServer) handleAccountDetail(w http.ResponseWriter, r *http.Request) {
 		tags = nil
 	}
 
+	// For system accounts, load token issue delegates and the full account
+	// list so admins can add new ones.
+	var tokenDelegates []*model.ServiceAccountDelegate
+	var delegatableAccounts []*model.Account
+	if acct.AccountType == model.AccountTypeSystem && isAdmin(r) {
+		tokenDelegates, err = u.db.ListTokenIssueDelegates(acct.ID)
+		if err != nil {
+			u.logger.Warn("list token issue delegates", "error", err)
+		}
+		delegatableAccounts, err = u.db.ListAccounts()
+		if err != nil {
+			u.logger.Warn("list accounts for delegate dropdown", "error", err)
+		}
+	}
+
 	u.render(w, "account_detail", AccountDetailData{
-		PageData:          PageData{CSRFToken: csrfToken, ActorName: u.actorName(r), IsAdmin: isAdmin(r)},
-		Account:           acct,
-		Roles:             roles,
-		AllRoles:          knownRoles,
-		Tokens:            tokens,
-		PGCred:            pgCred,
-		PGCredGrants:      pgCredGrants,
-		GrantableAccounts: grantableAccounts,
-		ActorID:           actorID,
-		Tags:              tags,
+		PageData:            PageData{CSRFToken: csrfToken, ActorName: u.actorName(r), IsAdmin: isAdmin(r)},
+		Account:             acct,
+		Roles:               roles,
+		AllRoles:            knownRoles,
+		Tokens:              tokens,
+		PGCred:              pgCred,
+		PGCredGrants:        pgCredGrants,
+		GrantableAccounts:   grantableAccounts,
+		ActorID:             actorID,
+		Tags:                tags,
+		TokenDelegates:      tokenDelegates,
+		DelegatableAccounts: delegatableAccounts,
+		CanIssueToken:       true, // account_detail is admin-only, so admin can always issue
 	})
 }
 
@@ -1009,6 +1027,13 @@ func (u *UIServer) handleAdminResetPassword(w http.ResponseWriter, r *http.Reque
 }
 
 // handleIssueSystemToken issues a long-lived service token for a system account.
+// Accessible to admins and to accounts that have been granted delegate access
+// for this specific service account via service_account_delegates.
+//
+// Security: authorization is checked server-side against the JWT claims stored
+// in the request context — it cannot be bypassed by client-side manipulation.
+// After issuance the token string is stored in a short-lived single-use
+// download nonce so the operator can retrieve it exactly once as a file.
 func (u *UIServer) handleIssueSystemToken(w http.ResponseWriter, r *http.Request) {
 	id := r.PathValue("id")
 	acct, err := u.db.GetAccountByUUID(id)
@@ -1021,6 +1046,32 @@ func (u *UIServer) handleIssueSystemToken(w http.ResponseWriter, r *http.Request
 		return
 	}
 
+	// Security: require admin role OR an explicit delegate grant for this account.
+	actorClaims := claimsFromContext(r.Context())
+	var actorID *int64
+	if !isAdmin(r) {
+		if actorClaims == nil {
+			u.renderError(w, r, http.StatusForbidden, "access denied")
+			return
+		}
+		actor, err := u.db.GetAccountByUUID(actorClaims.Subject)
+		if err != nil {
+			u.renderError(w, r, http.StatusForbidden, "access denied")
+			return
+		}
+		actorID = &actor.ID
+		hasAccess, err := u.db.HasTokenIssueAccess(acct.ID, actor.ID)
+		if err != nil || !hasAccess {
+			u.renderError(w, r, http.StatusForbidden, "not authorized to issue tokens for this service account")
+			return
+		}
+	} else if actorClaims != nil {
+		actor, err := u.db.GetAccountByUUID(actorClaims.Subject)
+		if err == nil {
+			actorID = &actor.ID
+		}
+	}
+
 	roles, err := u.db.GetRoles(acct.ID)
 	if err != nil {
 		u.renderError(w, r, http.StatusInternalServerError, "failed to load roles")
@@ -1054,17 +1105,18 @@ func (u *UIServer) handleIssueSystemToken(w http.ResponseWriter, r *http.Request
 		u.logger.Warn("set system token record", "error", err)
 	}
 
-	actorClaims := claimsFromContext(r.Context())
-	var actorID *int64
-	if actorClaims != nil {
-		actor, err := u.db.GetAccountByUUID(actorClaims.Subject)
-		if err == nil {
-			actorID = &actor.ID
-		}
-	}
 	u.writeAudit(r, model.EventTokenIssued, actorID, &acct.ID,
 		fmt.Sprintf(`{"jti":%q,"via":"ui_system_token"}`, claims.JTI))
 
+	// Store the raw token in the short-lived download cache so the operator
+	// can retrieve it exactly once via the download endpoint.
+	downloadNonce, err := u.storeTokenDownload(tokenStr, acct.UUID)
+	if err != nil {
+		u.logger.Error("store token download nonce", "error", err)
+		// Non-fatal: fall back to showing the token in the flash message.
+		downloadNonce = ""
+	}
+
 	// Re-fetch token list including the new token.
 	tokens, err := u.db.ListTokensForAccount(acct.ID)
 	if err != nil {
@@ -1077,13 +1129,209 @@ func (u *UIServer) handleIssueSystemToken(w http.ResponseWriter, r *http.Request
 		csrfToken = ""
 	}
 
-	// Flash the raw token once at the top so the operator can copy it.
+	var flash string
+	if downloadNonce == "" {
+		// Fallback: show token in flash when download nonce could not be stored.
+		flash = fmt.Sprintf("Token issued. Copy now — it will not be shown again: %s", tokenStr)
+	} else {
+		flash = "Token issued. Download it now — it will not be available again."
+	}
+
 	u.render(w, "token_list", AccountDetailData{
-		PageData: PageData{
-			CSRFToken: csrfToken,
-			Flash:     fmt.Sprintf("Token issued. Copy now — it will not be shown again: %s", tokenStr),
-		},
-		Account: acct,
-		Tokens:  tokens,
+		PageData:      PageData{CSRFToken: csrfToken, Flash: flash},
+		Account:       acct,
+		Tokens:        tokens,
+		DownloadNonce: downloadNonce,
+	})
+}
+
+// handleDownloadToken serves the just-issued service token as a file
+// attachment.  The nonce is single-use and expires after tokenDownloadTTL.
+//
+// Security: the nonce was generated with crypto/rand (128 bits) at issuance
+// time and is deleted from the in-memory store on first retrieval, preventing
+// replay.  The response sets Content-Disposition: attachment so the browser
+// saves the file rather than rendering it, reducing the risk of an XSS vector
+// if the token were displayed inline.
+func (u *UIServer) handleDownloadToken(w http.ResponseWriter, r *http.Request) {
+	nonce := r.PathValue("nonce")
+	if nonce == "" {
+		http.Error(w, "missing nonce", http.StatusBadRequest)
+		return
+	}
+
+	tokenStr, accountID, ok := u.consumeTokenDownload(nonce)
+	if !ok {
+		http.Error(w, "download link expired or already used", http.StatusGone)
+		return
+	}
+
+	filename := "service-account-" + accountID + ".token"
+	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
+	w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, filename))
+	// Security: Content-Type is text/plain and Content-Disposition is attachment,
+	// so the browser will save the file rather than render it, mitigating XSS risk.
+	_, _ = fmt.Fprint(w, tokenStr) //nolint:gosec // G705: token served as attachment, not rendered by browser
+}
+
+// handleGrantTokenDelegate adds a delegate who may issue tokens for a system
+// account.  Only admins may call this endpoint.
+//
+// Security: the target system account and grantee are looked up by UUID so the
+// URL/form fields cannot reference arbitrary row IDs.  Audit event
+// EventTokenDelegateGranted is recorded on success.
+func (u *UIServer) handleGrantTokenDelegate(w http.ResponseWriter, r *http.Request) {
+	r.Body = http.MaxBytesReader(w, r.Body, maxFormBytes)
+	if err := r.ParseForm(); err != nil {
+		u.renderError(w, r, http.StatusBadRequest, "invalid form")
+		return
+	}
+
+	id := r.PathValue("id")
+	acct, err := u.db.GetAccountByUUID(id)
+	if err != nil {
+		u.renderError(w, r, http.StatusNotFound, "service account not found")
+		return
+	}
+	if acct.AccountType != model.AccountTypeSystem {
+		u.renderError(w, r, http.StatusBadRequest, "token issue delegates are only supported for system accounts")
+		return
+	}
+
+	granteeUUID := strings.TrimSpace(r.FormValue("grantee_uuid"))
+	if granteeUUID == "" {
+		u.renderError(w, r, http.StatusBadRequest, "grantee is required")
+		return
+	}
+	grantee, err := u.db.GetAccountByUUID(granteeUUID)
+	if err != nil {
+		u.renderError(w, r, http.StatusNotFound, "grantee account not found")
+		return
+	}
+
+	actorClaims := claimsFromContext(r.Context())
+	var actorID *int64
+	if actorClaims != nil {
+		actor, err := u.db.GetAccountByUUID(actorClaims.Subject)
+		if err == nil {
+			actorID = &actor.ID
+		}
+	}
+
+	if err := u.db.GrantTokenIssueAccess(acct.ID, grantee.ID, actorID); err != nil {
+		u.logger.Error("grant token issue access", "error", err)
+		u.renderError(w, r, http.StatusInternalServerError, "failed to grant access")
+		return
+	}
+
+	u.writeAudit(r, model.EventTokenDelegateGranted, actorID, &acct.ID,
+		fmt.Sprintf(`{"grantee":%q}`, grantee.UUID))
+
+	delegates, err := u.db.ListTokenIssueDelegates(acct.ID)
+	if err != nil {
+		u.logger.Warn("list token issue delegates after grant", "error", err)
+	}
+	allAccounts, err := u.db.ListAccounts()
+	if err != nil {
+		u.logger.Warn("list accounts for delegate grant", "error", err)
+	}
+	csrfToken, err := u.setCSRFCookies(w)
+	if err != nil {
+		csrfToken = ""
+	}
+	u.render(w, "token_delegates", AccountDetailData{
+		PageData:            PageData{CSRFToken: csrfToken},
+		Account:             acct,
+		TokenDelegates:      delegates,
+		DelegatableAccounts: allAccounts,
+	})
+}
+
+// handleRevokeTokenDelegate removes a delegate's permission to issue tokens for
+// a system account.  Only admins may call this endpoint.
+//
+// Security: grantee looked up by UUID from the URL path.  Audit event
+// EventTokenDelegateRevoked recorded on success.
+func (u *UIServer) handleRevokeTokenDelegate(w http.ResponseWriter, r *http.Request) {
+	id := r.PathValue("id")
+	acct, err := u.db.GetAccountByUUID(id)
+	if err != nil {
+		u.renderError(w, r, http.StatusNotFound, "service account not found")
+		return
+	}
+
+	granteeUUID := r.PathValue("grantee")
+	grantee, err := u.db.GetAccountByUUID(granteeUUID)
+	if err != nil {
+		u.renderError(w, r, http.StatusNotFound, "grantee not found")
+		return
+	}
+
+	if err := u.db.RevokeTokenIssueAccess(acct.ID, grantee.ID); err != nil {
+		u.renderError(w, r, http.StatusInternalServerError, "failed to revoke access")
+		return
+	}
+
+	actorClaims := claimsFromContext(r.Context())
+	var actorID *int64
+	if actorClaims != nil {
+		actor, err := u.db.GetAccountByUUID(actorClaims.Subject)
+		if err == nil {
+			actorID = &actor.ID
+		}
+	}
+	u.writeAudit(r, model.EventTokenDelegateRevoked, actorID, &acct.ID,
+		fmt.Sprintf(`{"grantee":%q}`, grantee.UUID))
+
+	delegates, err := u.db.ListTokenIssueDelegates(acct.ID)
+	if err != nil {
+		u.logger.Warn("list token issue delegates after revoke", "error", err)
+	}
+	allAccounts, err := u.db.ListAccounts()
+	if err != nil {
+		u.logger.Warn("list accounts for delegate dropdown", "error", err)
+	}
+	csrfToken, err := u.setCSRFCookies(w)
+	if err != nil {
+		csrfToken = ""
+	}
+	u.render(w, "token_delegates", AccountDetailData{
+		PageData:            PageData{CSRFToken: csrfToken},
+		Account:             acct,
+		TokenDelegates:      delegates,
+		DelegatableAccounts: allAccounts,
+	})
+}
+
+// handleServiceAccountsPage renders the /service-accounts page showing all
+// system accounts the current user has delegate access to, along with the
+// ability to issue and download tokens for them.
+func (u *UIServer) handleServiceAccountsPage(w http.ResponseWriter, r *http.Request) {
+	csrfToken, err := u.setCSRFCookies(w)
+	if err != nil {
+		http.Error(w, "internal error", http.StatusInternalServerError)
+		return
+	}
+
+	claims := claimsFromContext(r.Context())
+	if claims == nil {
+		u.redirectToLogin(w, r)
+		return
+	}
+	actor, err := u.db.GetAccountByUUID(claims.Subject)
+	if err != nil {
+		u.renderError(w, r, http.StatusInternalServerError, "could not resolve actor")
+		return
+	}
+
+	accounts, err := u.db.ListDelegatedServiceAccounts(actor.ID)
+	if err != nil {
+		u.renderError(w, r, http.StatusInternalServerError, "failed to load service accounts")
+		return
+	}
+
+	u.render(w, "service_accounts", ServiceAccountsData{
+		PageData: PageData{CSRFToken: csrfToken, ActorName: u.actorName(r), IsAdmin: isAdmin(r)},
+		Accounts: accounts,
 	})
 }

internal/ui/ui.go

@@ -54,15 +54,31 @@ type pendingLogin struct {
 	accountID int64
 }
 
+// tokenDownload is a short-lived record that holds a just-issued service token
+// string so the operator can download it as a file.  It is single-use and
+// expires after tokenDownloadTTL.
+//
+// Security: the token string is stored only for tokenDownloadTTL after
+// issuance.  The nonce is random (128 bits) and single-use: it is deleted from
+// the map on first retrieval so it cannot be replayed.
+type tokenDownload struct {
+	expiresAt time.Time
+	token     string
+	accountID string // service account UUID (for the filename)
+}
+
+const tokenDownloadTTL = 5 * time.Minute
+
 // UIServer serves the HTMX-based management UI.
 type UIServer struct {
-	pendingLogins sync.Map                      // nonce (string) → *pendingLogin
-	tmpls         map[string]*template.Template // page name → template set
-	db            *db.DB
-	cfg           *config.Config
-	logger        *slog.Logger
-	csrf          *CSRFManager
-	vault         *vault.Vault
+	tmpls          map[string]*template.Template // page name → template set
+	db             *db.DB
+	cfg            *config.Config
+	logger         *slog.Logger
+	csrf           *CSRFManager
+	vault          *vault.Vault
+	pendingLogins  sync.Map // nonce (string) → *pendingLogin
+	tokenDownloads sync.Map // nonce (string) → *tokenDownload
 }
 
 // issueTOTPNonce creates a random single-use nonce for the TOTP step and
@@ -196,6 +212,7 @@ func New(database *db.DB, cfg *config.Config, v *vault.Vault, logger *slog.Logge
 		"templates/fragments/policy_form.html",
 		"templates/fragments/password_reset_form.html",
 		"templates/fragments/password_change_form.html",
+		"templates/fragments/token_delegates.html",
 	}
 	base, err := template.New("").Funcs(funcMap).ParseFS(web.TemplateFS, sharedFiles...)
 	if err != nil {
@@ -205,16 +222,17 @@ func New(database *db.DB, cfg *config.Config, v *vault.Vault, logger *slog.Logge
 	// Each page template defines "content" and "title" blocks; parsing them
 	// into separate clones prevents the last-defined block from winning.
 	pageFiles := map[string]string{
-		"login":          "templates/login.html",
-		"dashboard":      "templates/dashboard.html",
-		"accounts":       "templates/accounts.html",
-		"account_detail": "templates/account_detail.html",
-		"audit":          "templates/audit.html",
-		"audit_detail":   "templates/audit_detail.html",
-		"policies":       "templates/policies.html",
-		"pgcreds":        "templates/pgcreds.html",
-		"profile":        "templates/profile.html",
-		"unseal":         "templates/unseal.html",
+		"login":            "templates/login.html",
+		"dashboard":        "templates/dashboard.html",
+		"accounts":         "templates/accounts.html",
+		"account_detail":   "templates/account_detail.html",
+		"audit":            "templates/audit.html",
+		"audit_detail":     "templates/audit_detail.html",
+		"policies":         "templates/policies.html",
+		"pgcreds":          "templates/pgcreds.html",
+		"profile":          "templates/profile.html",
+		"unseal":           "templates/unseal.html",
+		"service_accounts": "templates/service_accounts.html",
 	}
 	tmpls := make(map[string]*template.Template, len(pageFiles))
 	for name, file := range pageFiles {
@@ -242,6 +260,7 @@ func New(database *db.DB, cfg *config.Config, v *vault.Vault, logger *slog.Logge
 	// entries abandoned by users who never complete step 2 would otherwise
 	// accumulate indefinitely, enabling a memory-exhaustion attack.
 	go srv.cleanupPendingLogins()
+	go srv.cleanupTokenDownloads()
 
 	return srv, nil
 }
@@ -264,6 +283,56 @@ func (u *UIServer) cleanupPendingLogins() {
 	}
 }
 
+// storeTokenDownload saves a just-issued token string in the short-lived
+// download store and returns a random single-use nonce the caller can include
+// in the response.  The download nonce expires after tokenDownloadTTL.
+func (u *UIServer) storeTokenDownload(tokenStr, accountID string) (string, error) {
+	raw := make([]byte, 16)
+	if _, err := rand.Read(raw); err != nil {
+		return "", fmt.Errorf("ui: generate download nonce: %w", err)
+	}
+	nonce := hex.EncodeToString(raw)
+	u.tokenDownloads.Store(nonce, &tokenDownload{
+		token:     tokenStr,
+		accountID: accountID,
+		expiresAt: time.Now().Add(tokenDownloadTTL),
+	})
+	return nonce, nil
+}
+
+// consumeTokenDownload looks up, validates, and deletes the download nonce.
+// Returns the token string and account UUID, or ("", "", false) if the nonce
+// is unknown or expired.
+//
+// Security: single-use deletion prevents replay; expiry bounds the window.
+func (u *UIServer) consumeTokenDownload(nonce string) (tokenStr, accountID string, ok bool) {
+	v, loaded := u.tokenDownloads.LoadAndDelete(nonce)
+	if !loaded {
+		return "", "", false
+	}
+	td, valid := v.(*tokenDownload)
+	if !valid || time.Now().After(td.expiresAt) {
+		return "", "", false
+	}
+	return td.token, td.accountID, true
+}
+
+// cleanupTokenDownloads periodically evicts expired entries from tokenDownloads.
+func (u *UIServer) cleanupTokenDownloads() {
+	ticker := time.NewTicker(5 * time.Minute)
+	defer ticker.Stop()
+	for range ticker.C {
+		now := time.Now()
+		u.tokenDownloads.Range(func(key, value any) bool {
+			td, ok := value.(*tokenDownload)
+			if !ok || now.After(td.expiresAt) {
+				u.tokenDownloads.Delete(key)
+			}
+			return true
+		})
+	}
+}
+
 // Register attaches all UI routes to mux, wrapped with security headers.
 // All UI responses (pages, fragments, redirects, static assets) carry the
 // headers added by securityHeaders.
@@ -333,7 +402,14 @@ func (u *UIServer) Register(mux *http.ServeMux) {
 	uiMux.Handle("GET /accounts/{id}/roles/edit", adminGet(u.handleRolesEditForm))
 	uiMux.Handle("PUT /accounts/{id}/roles", admin(u.handleSetRoles))
 	uiMux.Handle("DELETE /token/{jti}", admin(u.handleRevokeToken))
-	uiMux.Handle("POST /accounts/{id}/token", admin(u.handleIssueSystemToken))
+	// Token issuance is accessible to both admins and delegates; the handler
+	// enforces the admin-or-delegate check internally.
+	uiMux.Handle("POST /accounts/{id}/token", authed(u.requireCSRF(http.HandlerFunc(u.handleIssueSystemToken))))
+	// Token download uses a one-time nonce issued at token-issuance time.
+	uiMux.Handle("GET /token/download/{nonce}", authed(http.HandlerFunc(u.handleDownloadToken)))
+	// Token issue delegate management — admin only.
+	uiMux.Handle("POST /accounts/{id}/token/delegates", admin(u.handleGrantTokenDelegate))
+	uiMux.Handle("DELETE /accounts/{id}/token/delegates/{grantee}", admin(u.handleRevokeTokenDelegate))
 	uiMux.Handle("PUT /accounts/{id}/pgcreds", admin(u.handleSetPGCreds))
 	uiMux.Handle("POST /accounts/{id}/pgcreds/access", admin(u.handleGrantPGCredAccess))
 	uiMux.Handle("DELETE /accounts/{id}/pgcreds/access/{grantee}", admin(u.handleRevokePGCredAccess))
@@ -349,6 +425,10 @@ func (u *UIServer) Register(mux *http.ServeMux) {
 	uiMux.Handle("PUT /accounts/{id}/tags", admin(u.handleSetAccountTags))
 	uiMux.Handle("PUT /accounts/{id}/password", admin(u.handleAdminResetPassword))
 
+	// Service accounts page — accessible to any authenticated user; shows only
+	// the service accounts for which the current user is a token-issue delegate.
+	uiMux.Handle("GET /service-accounts", authed(http.HandlerFunc(u.handleServiceAccountsPage)))
+
 	// Profile routes — accessible to any authenticated user (not admin-only).
 	uiMux.Handle("GET /profile", authed(http.HandlerFunc(u.handleProfilePage)))
 	uiMux.Handle("PUT /profile/password", authed(u.requireCSRF(http.HandlerFunc(u.handleSelfChangePassword))))
@@ -678,11 +758,38 @@ type AccountDetailData struct {
 	// ActorID is the DB id of the currently logged-in user; used in templates
 	// to decide whether to show the owner-only management controls.
 	ActorID *int64
+	// TokenDelegates lists accounts that may issue tokens for this service account.
+	// Only populated for system accounts when viewed by an admin.
+	TokenDelegates []*model.ServiceAccountDelegate
+	// DelegatableAccounts is the list of human accounts available for the
+	// "add delegate" dropdown.  Only populated for admins.
+	DelegatableAccounts []*model.Account
+	// DownloadNonce is a one-time nonce for downloading the just-issued token.
+	// Populated by handleIssueSystemToken; empty otherwise.
+	DownloadNonce string
 	PageData
 	Roles    []string
 	AllRoles []string
 	Tags     []string
 	Tokens   []*model.TokenRecord
+	// CanIssueToken is true when the viewing actor may issue tokens for this
+	// system account (admin role or explicit delegate grant).
+	// Placed last to minimise GC scan area.
+	CanIssueToken bool
+}
+
+// ServiceAccountsData is the view model for the /service-accounts page.
+// It shows the system accounts for which the current user has delegate access,
+// plus the just-issued token download nonce (if a token was just issued).
+type ServiceAccountsData struct {
+	// Accounts is the list of system accounts the actor may issue tokens for.
+	Accounts []*model.Account
+	// DownloadNonce is a one-time nonce for downloading the just-issued token.
+	// Non-empty immediately after a successful token issuance.
+	DownloadNonce string
+	// IssuedFor is the UUID of the account whose token was just issued.
+	IssuedFor string
+	PageData
 }
 
 // AuditData is the view model for the audit log page.

web/templates/account_detail.html

@@ -26,7 +26,7 @@
 <div class="card">
   <div class="d-flex align-center justify-between" style="margin-bottom:1rem">
     <h2 style="font-size:1rem;font-weight:600">Tokens</h2>
-    {{if eq (string .Account.AccountType) "system"}}
+    {{if and (eq (string .Account.AccountType) "system") .CanIssueToken}}
     <button class="btn btn-sm btn-secondary"
             hx-post="/accounts/{{.Account.UUID}}/token"
             hx-target="#token-list" hx-swap="outerHTML">Issue Token</button>
@@ -39,6 +39,10 @@
   <h2 style="font-size:1rem;font-weight:600;margin-bottom:1rem">Postgres Credentials</h2>
   {{template "pgcreds_form" .}}
 </div>
+<div class="card">
+  <h2 style="font-size:1rem;font-weight:600;margin-bottom:1rem">Token Issue Access</h2>
+  <div id="token-delegates-section">{{template "token_delegates" .}}</div>
+</div>
 {{end}}
 <div class="card">
   <h2 style="font-size:1rem;font-weight:600;margin-bottom:1rem">Tags</h2>

web/templates/base.html

@@ -15,7 +15,7 @@
       {{if .IsAdmin}}<li><a href="/accounts">Accounts</a></li>
       <li><a href="/audit">Audit</a></li>
       <li><a href="/policies">Policies</a></li>
-      <li><a href="/pgcreds">PG Creds</a></li>{{end}}
+      <li><a href="/pgcreds">PG Creds</a></li>{{else}}<li><a href="/service-accounts">Service Accounts</a></li>{{end}}
       {{if .ActorName}}<li><a href="/profile">{{.ActorName}}</a></li>{{end}}
       <li><form method="POST" action="/logout" style="margin:0"><button class="btn btn-sm btn-secondary" type="submit">Logout</button></form></li>
     </ul>

web/templates/fragments/token_delegates.html

@@ -0,0 +1,47 @@
+{{define "token_delegates"}}
+<div id="token-delegates-section">
+  <h3 style="font-size:.9rem;font-weight:600;margin-bottom:.5rem">Token Issue Delegates</h3>
+  <p class="text-muted text-small" style="margin-bottom:.75rem">
+    Delegates can issue and rotate tokens for this service account without holding the admin role.
+  </p>
+  {{if .TokenDelegates}}
+  <table class="table table-sm" style="font-size:.85rem;margin-bottom:.75rem">
+    <thead>
+      <tr><th>Account</th><th>Granted</th><th></th></tr>
+    </thead>
+    <tbody>
+      {{range .TokenDelegates}}
+      <tr>
+        <td>{{.GranteeName}}</td>
+        <td class="text-small text-muted">{{formatTime .GrantedAt}}</td>
+        <td>
+          <button class="btn btn-sm btn-danger"
+                  hx-delete="/accounts/{{$.Account.UUID}}/token/delegates/{{.GranteeUUID}}"
+                  hx-target="#token-delegates-section" hx-swap="outerHTML"
+                  hx-confirm="Remove delegate access for {{.GranteeName}}?">Remove</button>
+        </td>
+      </tr>
+      {{end}}
+    </tbody>
+  </table>
+  {{else}}
+  <p class="text-muted text-small" style="margin-bottom:.75rem">No delegates.</p>
+  {{end}}
+
+  {{if .DelegatableAccounts}}
+  <form hx-post="/accounts/{{.Account.UUID}}/token/delegates"
+        hx-target="#token-delegates-section" hx-swap="outerHTML"
+        style="display:flex;gap:.5rem;align-items:center">
+    <select class="form-control" name="grantee_uuid" required style="flex:1">
+      <option value="">— select account to add as delegate —</option>
+      {{range .DelegatableAccounts}}
+      {{if eq (string .AccountType) "human"}}
+      <option value="{{.UUID}}">{{.Username}}</option>
+      {{end}}
+      {{end}}
+    </select>
+    <button class="btn btn-sm btn-secondary" type="submit">Add Delegate</button>
+  </form>
+  {{end}}
+</div>
+{{end}}

web/templates/fragments/token_list.html

@@ -1,5 +1,16 @@
 {{define "token_list"}}
 <div id="token-list">
+  {{if .Flash}}
+  <div class="alert alert-success" role="alert" style="margin-bottom:1rem">
+    {{.Flash}}
+    {{if .DownloadNonce}}
+    <div style="margin-top:.5rem">
+      <a class="btn btn-sm btn-secondary"
+         href="/token/download/{{.DownloadNonce}}">Download token as file</a>
+    </div>
+    {{end}}
+  </div>
+  {{end}}
   {{if .Tokens}}
   <div class="table-wrapper">
     <table>

web/templates/service_accounts.html

@@ -0,0 +1,47 @@
+{{define "service_accounts"}}{{template "base" .}}{{end}}
+{{define "title"}}Service Accounts — MCIAS{{end}}
+{{define "content"}}
+<div class="page-header">
+  <h1>Service Accounts</h1>
+  <p class="text-muted text-small">Service accounts for which you have been granted token-issue access.</p>
+</div>
+{{if .DownloadNonce}}
+<div class="alert alert-success" role="alert" style="margin-bottom:1rem">
+  Token issued.
+  <a class="btn btn-sm btn-secondary" style="margin-left:.5rem"
+     href="/token/download/{{.DownloadNonce}}">Download token as file</a>
+</div>
+{{end}}
+{{if .Accounts}}
+<div class="card">
+  <table>
+    <thead>
+      <tr><th>Name</th><th>Status</th><th>Action</th></tr>
+    </thead>
+    <tbody>
+      {{range .Accounts}}
+      <tr>
+        <td>{{.Username}}</td>
+        <td><span class="badge badge-{{string .Status}}">{{string .Status}}</span></td>
+        <td>
+          <button class="btn btn-sm btn-secondary"
+                  hx-post="/accounts/{{.UUID}}/token"
+                  hx-target="#issue-result-{{.UUID}}"
+                  hx-swap="outerHTML">Issue Token</button>
+        </td>
+      </tr>
+      <tr>
+        <td colspan="3">
+          <div id="issue-result-{{.UUID}}"></div>
+        </td>
+      </tr>
+      {{end}}
+    </tbody>
+  </table>
+</div>
+{{else}}
+<div class="card">
+  <p class="text-muted text-small">You have not been granted access to any service accounts.</p>
+</div>
+{{end}}
+{{end}}