From 7b1990cf111a83ffe45d2eb7430390e0e9ff1312 Mon Sep 17 00:00:00 2001
From: Steve Cliff <steve@devcloud.guru>
Date: Mon, 4 May 2026 10:57:28 +0100
Subject: [PATCH] agent+server: P2R-11 pre/post hook execution for backup jobs
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Agent: new runner.BackupHooks struct + runHook helper invoked via
/bin/sh -c (cmd.exe /C on Windows). pre_hook non-zero exit aborts
the backup; post_hook always runs with RM_JOB_STATUS=succeeded|failed
in env. Output streamed as 'hook(<phase>): …' log.stream lines.
Hooks only run for kind=backup (other kinds skip both phases).

Server: resolveBackupHooks resolves group → host default → empty,
decrypts via crypto.AEAD with per-slot ad bytes, plumbs plaintext
into CommandRunPayload for both schedule.fire and per-group
Run-now dispatch sites. Decrypt failures degrade silently to no
hook so a malformed blob can't poison every backup.
---
 cmd/agent/main.go                     |   3 +-
 internal/agent/runner/hooks.go        | 106 ++++++++++++++++++++++++++
 internal/agent/runner/hooks_test.go   |  90 ++++++++++++++++++++++
 internal/agent/runner/runner.go       |  39 +++++++++-
 internal/server/http/hooks_resolve.go |  75 ++++++++++++++++++
 internal/server/http/run_group.go     |   9 +++
 internal/server/http/schedule_push.go |  14 ++++
 internal/store/hooks_test.go          |  30 ++++----
 internal/store/hosts.go               |  18 +++--
 internal/store/sources.go             |  24 +++---
 internal/store/types.go               |  23 +++---
 11 files changed, 379 insertions(+), 52 deletions(-)
 create mode 100644 internal/agent/runner/hooks.go
 create mode 100644 internal/agent/runner/hooks_test.go
 create mode 100644 internal/server/http/hooks_resolve.go

diff --git a/cmd/agent/main.go b/cmd/agent/main.go
index d6c3d8b..0c2b691 100644
--- a/cmd/agent/main.go
+++ b/cmd/agent/main.go
@@ -359,8 +359,9 @@ func (d *dispatcher) runJob(ctx context.Context, p api.CommandRunPayload, tx wsc
 		}
 		slog.Info("agent: accepting backup job",
 			"job_id", p.JobID, "paths", paths, "excludes", p.Excludes, "tag", p.Tag)
+		hooks := runner.BackupHooks{Pre: p.PreHook, Post: p.PostHook}
 		go func() {
-			if err := r.RunBackup(ctx, p.JobID, paths, p.Excludes, tags); err != nil {
+			if err := r.RunBackup(ctx, p.JobID, paths, p.Excludes, tags, hooks); err != nil {
 				slog.Warn("agent: backup job failed", "job_id", p.JobID, "err", err)
 				return
 			}
diff --git a/internal/agent/runner/hooks.go b/internal/agent/runner/hooks.go
new file mode 100644
index 0000000..904b100
--- /dev/null
+++ b/internal/agent/runner/hooks.go
@@ -0,0 +1,106 @@
+// hooks.go — pre/post backup hooks for the agent runner (P2R-11).
+//
+// Hooks fire only for backup jobs (the runner's other kinds —
+// init/forget/prune/check/unlock — call shell scripts that touch
+// repo internals; running operator hooks for those would be
+// surprising). Hook bodies arrive plaintext on the wire (server
+// decrypted before the WS push). The agent never persists them
+// to disk; they live in memory for the lifetime of one job.
+//
+// Failure semantics:
+//   - pre_hook non-zero exit aborts the backup: the runner returns
+//     the error, the job is recorded as failed, and the actual
+//     restic invocation never runs.
+//   - post_hook non-zero exit is logged with a warning prefix in
+//     the job log but does NOT change the job status — the operator
+//     wants the backup result preserved even if the cleanup step
+//     misbehaved.
+//
+// Streaming: each line of the hook's stdout/stderr is shipped as a
+// log.stream envelope with payload prefixed `hook: ` so the live
+// log viewer can visually separate it from restic's own output.
+package runner
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"io"
+	"os/exec"
+	"runtime"
+	"sync/atomic"
+	"time"
+
+	"gitea.dcglab.co.uk/steve/restic-manager/internal/api"
+)
+
+// runHook executes script via the host shell. status is the value
+// passed as RM_JOB_STATUS in the env (empty for pre-hooks; the
+// final job status — "succeeded" or "failed" — for post-hooks).
+// Returns an error iff the hook exited non-zero. ctx cancellation
+// kills the subprocess.
+func (r *Runner) runHook(ctx context.Context, jobID, phase, script, status string, seq *atomic.Int64) error {
+	if script == "" {
+		return nil
+	}
+	shell, flag := defaultShell()
+	cmd := exec.CommandContext(ctx, shell, flag, script)
+	cmd.Env = []string{
+		"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+	}
+	if status != "" {
+		cmd.Env = append(cmd.Env, "RM_JOB_STATUS="+status)
+	}
+	cmd.Env = append(cmd.Env, "RM_JOB_ID="+jobID, "RM_HOOK_PHASE="+phase)
+
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		return fmt.Errorf("hook %s: stdout pipe: %w", phase, err)
+	}
+	stderr, err := cmd.StderrPipe()
+	if err != nil {
+		return fmt.Errorf("hook %s: stderr pipe: %w", phase, err)
+	}
+	if err := cmd.Start(); err != nil {
+		return fmt.Errorf("hook %s: start: %w", phase, err)
+	}
+	done := make(chan struct{}, 2)
+	go func() { r.pumpHookLines(stdout, "stdout", phase, jobID, seq); done <- struct{}{} }()
+	go func() { r.pumpHookLines(stderr, "stderr", phase, jobID, seq); done <- struct{}{} }()
+	<-done
+	<-done
+	if werr := cmd.Wait(); werr != nil {
+		return fmt.Errorf("hook %s exited non-zero: %w", phase, werr)
+	}
+	return nil
+}
+
+// pumpHookLines streams lines as log.stream envelopes prefixed with
+// "hook(<phase>): " so the live log can visually separate them.
+func (r *Runner) pumpHookLines(rd io.Reader, stream, phase, jobID string, seq *atomic.Int64) {
+	scanner := bufio.NewScanner(rd)
+	scanner.Buffer(make([]byte, 0, 64*1024), 256*1024)
+	for scanner.Scan() {
+		line := "hook(" + phase + "): " + scanner.Text()
+		env, _ := api.Marshal(api.MsgLogStream, "", api.LogStreamLine{
+			JobID:   jobID,
+			Seq:     seq.Add(1),
+			TS:      time.Now().UTC(),
+			Stream:  api.LogStream(stream),
+			Payload: line,
+		})
+		_ = r.tx.Send(env)
+	}
+}
+
+// defaultShell returns the (binary, single-arg-flag) pair to use for
+// `<shell> <flag> "<script>"`. /bin/sh -c on Unix; cmd.exe /C on
+// Windows. The hook author writes whichever shell they prefer
+// inside the script body itself (PowerShell, bash, etc) — this is
+// just the bootstrap interpreter.
+func defaultShell() (string, string) {
+	if runtime.GOOS == "windows" {
+		return "cmd.exe", "/C"
+	}
+	return "/bin/sh", "-c"
+}
diff --git a/internal/agent/runner/hooks_test.go b/internal/agent/runner/hooks_test.go
new file mode 100644
index 0000000..af3a54b
--- /dev/null
+++ b/internal/agent/runner/hooks_test.go
@@ -0,0 +1,90 @@
+// hooks_test.go — pre/post backup hook semantics (P2R-11).
+package runner
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"gitea.dcglab.co.uk/steve/restic-manager/internal/api"
+)
+
+// TestPreHookFailureAbortsBackup: pre_hook exits 1 → restic never
+// runs, job is recorded failed with the hook's error.
+func TestPreHookFailureAbortsBackup(t *testing.T) {
+	t.Parallel()
+	// Restic script that records every invocation. If restic was
+	// called we'll see "restic-was-here" in the captured log.
+	bin := setupScript(t, `echo "restic-was-here"`)
+	tx := &fakeSender{}
+	r := New(Config{ResticBin: bin}, tx, 0)
+
+	err := r.RunBackup(context.Background(), "job-pre",
+		[]string{"/etc"}, nil, []string{"tag"},
+		BackupHooks{Pre: "exit 1"})
+	if err == nil {
+		t.Fatal("expected RunBackup to return an error from failed pre_hook")
+	}
+	if !strings.Contains(err.Error(), "pre_hook failed") {
+		t.Fatalf("error message: %q (want 'pre_hook failed')", err)
+	}
+	// job.finished arrived with status=failed.
+	finEnv := firstEnvOfType(t, tx.envs, api.MsgJobFinished)
+	var fin api.JobFinishedPayload
+	_ = finEnv.UnmarshalPayload(&fin)
+	if fin.Status != api.JobFailed {
+		t.Fatalf("status: %q, want failed", fin.Status)
+	}
+	// restic must NOT have run.
+	for _, env := range tx.envs {
+		if env.Type != api.MsgLogStream {
+			continue
+		}
+		var l api.LogStreamLine
+		_ = env.UnmarshalPayload(&l)
+		if strings.Contains(l.Payload, "restic-was-here") {
+			t.Fatal("restic was invoked despite pre_hook failure")
+		}
+	}
+}
+
+// TestPostHookRunsAfterBackup: post_hook fires after a successful
+// backup and receives RM_JOB_STATUS=succeeded in the env.
+func TestPostHookRunsAfterBackup(t *testing.T) {
+	t.Parallel()
+	bin := setupScript(t, `
+case "$1" in
+  backup)    echo '{"message_type":"summary","snapshot_id":"abc"}' ;;
+  snapshots) echo '[]' ;;
+  stats)     echo '{"total_size":0,"total_uncompressed_size":0,"snapshots_count":0,"total_file_count":0,"total_blob_count":0}' ;;
+  *)         exit 0 ;;
+esac
+`)
+	tx := &fakeSender{}
+	r := New(Config{ResticBin: bin}, tx, 0)
+
+	post := `echo "post-status=$RM_JOB_STATUS phase=$RM_HOOK_PHASE"`
+	if err := r.RunBackup(context.Background(), "job-post",
+		[]string{"/etc"}, nil, nil, BackupHooks{Post: post}); err != nil {
+		t.Fatalf("RunBackup: %v", err)
+	}
+
+	// Walk log.stream envelopes; one of them should be the post-hook
+	// line with the expected status.
+	var found bool
+	for _, env := range tx.envs {
+		if env.Type != api.MsgLogStream {
+			continue
+		}
+		var l api.LogStreamLine
+		_ = env.UnmarshalPayload(&l)
+		if strings.Contains(l.Payload, "post-status=succeeded") &&
+			strings.Contains(l.Payload, "phase=post") {
+			found = true
+			break
+		}
+	}
+	if !found {
+		t.Fatal("post_hook output not found in log.stream envelopes")
+	}
+}
diff --git a/internal/agent/runner/runner.go b/internal/agent/runner/runner.go
index 617c8a6..aae9882 100644
--- a/internal/agent/runner/runner.go
+++ b/internal/agent/runner/runner.go
@@ -116,15 +116,34 @@ func (r *Runner) sendFinished(jobID string, finishedAt time.Time, err error, sta
 	_ = r.tx.Send(finEnv)
 }
 
+// BackupHooks bundles the optional pre/post shell snippets that fire
+// around a backup. Empty fields skip that phase. Resolved server-side
+// (group → host default) before dispatch; the agent just executes
+// whatever arrives in the payload.
+type BackupHooks struct {
+	Pre  string
+	Post string
+}
+
 // RunBackup executes a backup job and reports back via the sender.
 // Returns nil on a clean (or "incomplete-but-snapshot-created") finish.
-func (r *Runner) RunBackup(ctx context.Context, jobID string, paths, excludes, tags []string) error {
+func (r *Runner) RunBackup(ctx context.Context, jobID string, paths, excludes, tags []string, hooks BackupHooks) error {
 	startedAt := time.Now().UTC()
 	r.sendStarted(jobID, api.JobBackup, startedAt)
 
-	env := r.resticEnv()
-
 	var seq atomic.Int64
+
+	// pre_hook: non-zero exit aborts the backup. The job is recorded
+	// as failed with the hook's error and restic never runs.
+	if hooks.Pre != "" {
+		if err := r.runHook(ctx, jobID, "pre", hooks.Pre, "", &seq); err != nil {
+			finishedAt := time.Now().UTC()
+			r.sendFinished(jobID, finishedAt, err, nil)
+			return fmt.Errorf("pre_hook failed: %w", err)
+		}
+	}
+
+	env := r.resticEnv()
 	lastProgress := time.Now()
 
 	handle := func(stream string, line string, ev any) {
@@ -173,6 +192,20 @@ func (r *Runner) RunBackup(ctx context.Context, jobID string, paths, excludes, t
 	if summary != nil {
 		statsBlob, _ = json.Marshal(summary)
 	}
+
+	// post_hook: always runs regardless of backup outcome. Receives
+	// RM_JOB_STATUS=succeeded|failed in env. Non-zero exit is logged
+	// but does not change the recorded job status.
+	if hooks.Post != "" {
+		status := "succeeded"
+		if err != nil {
+			status = "failed"
+		}
+		if perr := r.runHook(ctx, jobID, "post", hooks.Post, status, &seq); perr != nil {
+			slog.Warn("runner: post_hook exited non-zero", "job_id", jobID, "err", perr)
+		}
+	}
+
 	r.sendFinished(jobID, finishedAt, err, statsBlob)
 
 	// On a successful backup, refresh the server's snapshot projection.
diff --git a/internal/server/http/hooks_resolve.go b/internal/server/http/hooks_resolve.go
new file mode 100644
index 0000000..7b5cadd
--- /dev/null
+++ b/internal/server/http/hooks_resolve.go
@@ -0,0 +1,75 @@
+// hooks_resolve.go — server-side resolution of pre/post hooks for a
+// backup dispatch (P2R-11). The agent receives plaintext hook bodies
+// in CommandRunPayload; this file is where the AEAD blob on the
+// source group (or the host's default) gets decrypted into the
+// strings the wire payload carries.
+//
+// Resolution order:
+//  1. source_group.<phase>_hook  (per-group override)
+//  2. host.<phase>_hook_default  (host-wide default)
+//  3. ""                          (no hook → agent skips that phase)
+//
+// Decrypt errors are logged and treated as "no hook configured" so
+// a malformed blob can't poison every backup. The audit trail
+// captures the underlying state regardless.
+package http
+
+import (
+	"log/slog"
+
+	"gitea.dcglab.co.uk/steve/restic-manager/internal/store"
+)
+
+// resolveBackupHooks returns the (pre, post) plaintext hook strings
+// the agent should run around the backup. Both are empty when no
+// hook is configured at either level.
+func (s *Server) resolveBackupHooks(host *store.Host, g *store.SourceGroup) (pre, post string) {
+	if s.deps.AEAD == nil {
+		return "", ""
+	}
+	pre = s.decryptHookOrFallback(g.PreHook, host.PreHookDefault, host.ID, "pre")
+	post = s.decryptHookOrFallback(g.PostHook, host.PostHookDefault, host.ID, "post")
+	return pre, post
+}
+
+// decryptHookOrFallback returns the per-group hook decrypted, or
+// (when that's empty) the host default decrypted, or "" if neither
+// is configured. Decrypt failures log and degrade to empty.
+func (s *Server) decryptHookOrFallback(group, hostDefault, hostID, phase string) string {
+	tryDecrypt := func(blob, slot string) (string, bool) {
+		if blob == "" {
+			return "", false
+		}
+		plain, err := s.deps.AEAD.Decrypt(blob, []byte("hook:"+hostID+":"+slot+":"+phase))
+		if err != nil {
+			slog.Error("decrypt hook", "host_id", hostID, "phase", phase, "slot", slot, "err", err)
+			return "", false
+		}
+		return string(plain), true
+	}
+	if v, ok := tryDecrypt(group, "group"); ok {
+		return v
+	}
+	if v, ok := tryDecrypt(hostDefault, "host"); ok {
+		return v
+	}
+	return ""
+}
+
+// EncryptHookForGroup encrypts a hook body for storage on a source
+// group. Caller passes the plaintext from a UI form; an empty body
+// returns "" so the store persists NULL (cleared).
+func (s *Server) EncryptHookForGroup(hostID, phase, body string) (string, error) {
+	if body == "" {
+		return "", nil
+	}
+	return s.deps.AEAD.Encrypt([]byte(body), []byte("hook:"+hostID+":group:"+phase))
+}
+
+// EncryptHookForHost is the host-default twin of EncryptHookForGroup.
+func (s *Server) EncryptHookForHost(hostID, phase, body string) (string, error) {
+	if body == "" {
+		return "", nil
+	}
+	return s.deps.AEAD.Encrypt([]byte(body), []byte("hook:"+hostID+":host:"+phase))
+}
diff --git a/internal/server/http/run_group.go b/internal/server/http/run_group.go
index 2b8d952..1ac33db 100644
--- a/internal/server/http/run_group.go
+++ b/internal/server/http/run_group.go
@@ -79,6 +79,13 @@ func (s *Server) handleRunSourceGroup(w stdhttp.ResponseWriter, r *stdhttp.Reque
 		return
 	}
 
+	// Resolve hooks (group → host default → empty). Best-effort host
+	// lookup; failure proceeds with no hook rather than block the run.
+	var preHook, postHook string
+	if host, herr := s.deps.Store.GetHost(r.Context(), hostID); herr == nil {
+		preHook, postHook = s.resolveBackupHooks(host, g)
+	}
+
 	// Backup invocations don't consume RetentionPolicy — that lives on
 	// forget. Sending the resolved set here would just be dead weight.
 	res, status, code, msg := s.dispatchJobWithPayload(r.Context(), user, hostID, api.JobBackup,
@@ -88,6 +95,8 @@ func (s *Server) handleRunSourceGroup(w stdhttp.ResponseWriter, r *stdhttp.Reque
 			Tag:               g.Name,
 			BandwidthUpKBps:   upOverride,
 			BandwidthDownKBps: downOverride,
+			PreHook:           preHook,
+			PostHook:          postHook,
 		})
 	if code != "" {
 		s.runGroupError(w, r, status, code, msg)
diff --git a/internal/server/http/schedule_push.go b/internal/server/http/schedule_push.go
index 6bcffb6..3c453ad 100644
--- a/internal/server/http/schedule_push.go
+++ b/internal/server/http/schedule_push.go
@@ -192,6 +192,18 @@ func (s *Server) dispatchBackupForGroupCore(ctx context.Context, conn *ws.Conn,
 			"schedule_id", scheduleID, "group", g.Name, "err", err)
 		return "", err
 	}
+	// Resolve pre/post hooks (group → host default → empty) so they
+	// ride on the backup payload as plaintext. The host lookup is
+	// cheap; failure here is non-fatal (we proceed without hooks
+	// rather than block the backup).
+	var preHook, postHook string
+	if host, herr := s.deps.Store.GetHost(ctx, hostID); herr == nil {
+		preHook, postHook = s.resolveBackupHooks(host, g)
+	} else {
+		slog.Warn("schedule.fire: load host for hook resolve",
+			"host_id", hostID, "err", herr)
+	}
+
 	// Backup ignores RetentionPolicy — the forget cadence lives on
 	// host_repo_maintenance and is driven by the server-side ticker
 	// (P2R-06). Don't ship the field on backup dispatches.
@@ -201,6 +213,8 @@ func (s *Server) dispatchBackupForGroupCore(ctx context.Context, conn *ws.Conn,
 		Includes: g.Includes,
 		Excludes: g.Excludes,
 		Tag:      g.Name,
+		PreHook:  preHook,
+		PostHook: postHook,
 	})
 	if err != nil {
 		slog.Warn("schedule.fire: marshal command.run",
diff --git a/internal/store/hooks_test.go b/internal/store/hooks_test.go
index 18a7864..15424bc 100644
--- a/internal/store/hooks_test.go
+++ b/internal/store/hooks_test.go
@@ -42,8 +42,8 @@ func TestSourceGroupHooksRoundTrip(t *testing.T) {
 
 	g := &SourceGroup{
 		ID: ulid.Make().String(), HostID: hostID, Name: "etc",
-		PreHook:  []byte("ENC-PRE"),
-		PostHook: []byte("ENC-POST"),
+		PreHook:  "ENC-PRE",
+		PostHook: "ENC-POST",
 	}
 	if err := st.CreateSourceGroup(context.Background(), g); err != nil {
 		t.Fatalf("create: %v", err)
@@ -52,16 +52,16 @@ func TestSourceGroupHooksRoundTrip(t *testing.T) {
 	if err != nil {
 		t.Fatalf("get: %v", err)
 	}
-	if string(got.PreHook) != "ENC-PRE" {
+	if got.PreHook != "ENC-PRE" {
 		t.Fatalf("PreHook: got %q, want ENC-PRE", got.PreHook)
 	}
-	if string(got.PostHook) != "ENC-POST" {
+	if got.PostHook != "ENC-POST" {
 		t.Fatalf("PostHook: got %q, want ENC-POST", got.PostHook)
 	}
 
 	// Update: clear PreHook, change PostHook.
-	got.PreHook = nil
-	got.PostHook = []byte("ENC-POST-2")
+	got.PreHook = ""
+	got.PostHook = "ENC-POST-2"
 	if err := st.UpdateSourceGroup(context.Background(), got); err != nil {
 		t.Fatalf("update: %v", err)
 	}
@@ -69,10 +69,10 @@ func TestSourceGroupHooksRoundTrip(t *testing.T) {
 	if err != nil {
 		t.Fatalf("get: %v", err)
 	}
-	if got.PreHook != nil {
-		t.Fatalf("PreHook: want nil after clear, got %q", got.PreHook)
+	if got.PreHook != "" {
+		t.Fatalf("PreHook: want empty after clear, got %q", got.PreHook)
 	}
-	if string(got.PostHook) != "ENC-POST-2" {
+	if got.PostHook != "ENC-POST-2" {
 		t.Fatalf("PostHook: got %q, want ENC-POST-2", got.PostHook)
 	}
 }
@@ -82,25 +82,25 @@ func TestHostHookDefaultsRoundTrip(t *testing.T) {
 	st := newTestStore(t)
 	hostID := makeHostInStore(t, st, "host-hooks-host")
 
-	if err := st.SetHostHooks(context.Background(), hostID, []byte("PRE"), []byte("POST")); err != nil {
+	if err := st.SetHostHooks(context.Background(), hostID, "PRE", "POST"); err != nil {
 		t.Fatalf("set: %v", err)
 	}
 	h, err := st.GetHost(context.Background(), hostID)
 	if err != nil {
 		t.Fatalf("get: %v", err)
 	}
-	if string(h.PreHookDefault) != "PRE" || string(h.PostHookDefault) != "POST" {
+	if h.PreHookDefault != "PRE" || h.PostHookDefault != "POST" {
 		t.Fatalf("after set: pre=%q post=%q", h.PreHookDefault, h.PostHookDefault)
 	}
-	// Clear by passing nil.
-	if err := st.SetHostHooks(context.Background(), hostID, nil, nil); err != nil {
+	// Clear by passing empty strings.
+	if err := st.SetHostHooks(context.Background(), hostID, "", ""); err != nil {
 		t.Fatalf("clear: %v", err)
 	}
 	h, err = st.GetHost(context.Background(), hostID)
 	if err != nil {
 		t.Fatalf("get: %v", err)
 	}
-	if h.PreHookDefault != nil || h.PostHookDefault != nil {
-		t.Fatalf("after clear: pre=%v post=%v (want nil)", h.PreHookDefault, h.PostHookDefault)
+	if h.PreHookDefault != "" || h.PostHookDefault != "" {
+		t.Fatalf("after clear: pre=%q post=%q (want empty)", h.PreHookDefault, h.PostHookDefault)
 	}
 }
diff --git a/internal/store/hosts.go b/internal/store/hosts.go
index fc0b383..96f85aa 100644
--- a/internal/store/hosts.go
+++ b/internal/store/hosts.go
@@ -158,7 +158,7 @@ func scanHostRow(s hostScanner) (*Host, error) {
 		enrolled                     string
 		tags                         string
 		bwUp, bwDown                 sql.NullInt64
-		preHook, postHook            []byte
+		preHook, postHook            sql.NullString
 	)
 	err := s.Scan(&h.ID, &h.Name, &h.OS, &h.Arch,
 		&h.AgentVersion, &h.ResticVersion, &h.ProtocolVersion,
@@ -215,18 +215,22 @@ func scanHostRow(s hostScanner) (*Host, error) {
 		v := int(bwDown.Int64)
 		h.BandwidthDownKBps = &v
 	}
-	h.PreHookDefault = preHook
-	h.PostHookDefault = postHook
+	if preHook.Valid {
+		h.PreHookDefault = preHook.String
+	}
+	if postHook.Valid {
+		h.PostHookDefault = postHook.String
+	}
 	return &h, nil
 }
 
 // SetHostHooks replaces the host-wide pre/post hook defaults. Pass
-// nil/empty to clear that hook. Stored verbatim — caller is expected
-// to encrypt the bytes before they reach this layer.
-func (s *Store) SetHostHooks(ctx context.Context, hostID string, pre, post []byte) error {
+// the empty string to clear that hook. Stored verbatim — caller is
+// expected to encrypt before they reach this layer.
+func (s *Store) SetHostHooks(ctx context.Context, hostID string, pre, post string) error {
 	_, err := s.db.ExecContext(ctx,
 		`UPDATE hosts SET pre_hook_default = ?, post_hook_default = ? WHERE id = ?`,
-		nullableBytes(pre), nullableBytes(post), hostID)
+		nullableString(pre), nullableString(post), hostID)
 	if err != nil {
 		return fmt.Errorf("store: set host hooks: %w", err)
 	}
diff --git a/internal/store/sources.go b/internal/store/sources.go
index 164e893..bb2f6bc 100644
--- a/internal/store/sources.go
+++ b/internal/store/sources.go
@@ -52,7 +52,7 @@ func (st *Store) CreateSourceGroup(ctx context.Context, g *SourceGroup) error {
 		g.RetryMax, g.RetryBackoffSeconds,
 		nullableString(g.ConflictDimension),
 		now.Format(time.RFC3339Nano), now.Format(time.RFC3339Nano),
-		nullableBytes(g.PreHook), nullableBytes(g.PostHook),
+		nullableString(g.PreHook), nullableString(g.PostHook),
 	); err != nil {
 		return fmt.Errorf("store: create source group: %w", err)
 	}
@@ -96,7 +96,7 @@ func (st *Store) UpdateSourceGroup(ctx context.Context, g *SourceGroup) error {
 		g.RetryMax, g.RetryBackoffSeconds,
 		nullableString(g.ConflictDimension),
 		now.Format(time.RFC3339Nano),
-		nullableBytes(g.PreHook), nullableBytes(g.PostHook),
+		nullableString(g.PreHook), nullableString(g.PostHook),
 		g.ID, g.HostID,
 	)
 	if err != nil {
@@ -226,7 +226,7 @@ func scanSourceGroupRow(s sourceGroupScanner) (*SourceGroup, error) {
 		includes, excludes, retention string
 		conflict                      sql.NullString
 		createdAt, updatedAt          string
-		preHook, postHook             []byte
+		preHook, postHook             sql.NullString
 	)
 	err := s.Scan(&out.ID, &out.HostID, &out.Name,
 		&includes, &excludes, &retention,
@@ -235,8 +235,12 @@ func scanSourceGroupRow(s sourceGroupScanner) (*SourceGroup, error) {
 	if err != nil {
 		return nil, err
 	}
-	out.PreHook = preHook
-	out.PostHook = postHook
+	if preHook.Valid {
+		out.PreHook = preHook.String
+	}
+	if postHook.Valid {
+		out.PostHook = postHook.String
+	}
 	if includes != "" {
 		_ = json.Unmarshal([]byte(includes), &out.Includes)
 	}
@@ -264,13 +268,3 @@ func nullableString(s string) any {
 	}
 	return s
 }
-
-// nullableBytes returns nil for an empty/nil slice so SQL stores it
-// as NULL rather than an empty BLOB. The agent treats both the same
-// (no hook), but NULL is the canonical "absent" form on disk.
-func nullableBytes(b []byte) any {
-	if len(b) == 0 {
-		return nil
-	}
-	return b
-}
diff --git a/internal/store/types.go b/internal/store/types.go
index 4e52d91..c42bc89 100644
--- a/internal/store/types.go
+++ b/internal/store/types.go
@@ -67,11 +67,12 @@ type Host struct {
 	BandwidthUpKBps   *int
 	BandwidthDownKBps *int
 
-	// PreHookDefault / PostHookDefault are AEAD-encrypted host-wide
-	// hook bodies. Per source group hooks (SourceGroup.PreHook /
-	// PostHook) override these when set. nil = no default configured.
-	PreHookDefault  []byte
-	PostHookDefault []byte
+	// PreHookDefault / PostHookDefault are AEAD ciphertext (string
+	// blob produced by crypto.AEAD.Encrypt). Per source group hooks
+	// (SourceGroup.PreHook / PostHook) override these when set.
+	// Empty = no default configured.
+	PreHookDefault  string
+	PostHookDefault string
 }
 
 // Schedule is now intentionally slim: cron + which groups + enabled.
@@ -113,12 +114,12 @@ type SourceGroup struct {
 	CreatedAt         time.Time
 	UpdatedAt         time.Time
 
-	// PreHook / PostHook are AEAD-encrypted shell snippets (raw blob).
-	// nil means "no hook configured." Encryption/decryption happens at
-	// the HTTP layer (where AEAD lives); the store layer just persists
-	// the bytes verbatim.
-	PreHook  []byte
-	PostHook []byte
+	// PreHook / PostHook are AEAD ciphertext (string blob produced by
+	// crypto.AEAD.Encrypt). Empty means "no hook configured."
+	// Encryption/decryption happens at the HTTP layer (where AEAD
+	// lives); the store layer just persists the bytes verbatim.
+	PreHook  string
+	PostHook string
 }
 
 // RetentionPolicy is the typed view of `restic forget --keep-*`.