feat(session): flip DefaultAgent to hermes

CHANGELOG.md

@@ -38,6 +38,12 @@ generated notes plus the signed checksums — see
 
 ### Changed
 
+- **Default agent flipped from `codex` to `hermes`.** `ctm new` / `ctm yolo`
+  without an explicit `--agent` flag now spawn Hermes Agent. Existing sessions
+  on disk keep whatever agent they were created with — only NEW sessions
+  default to hermes. Legacy `claude` rows continue to migrate to `codex` (not
+  the new default) in both `state.go` Save and NormalizeAgent, so the flip
+  cannot silently retarget historical conversations.
 - `internal/config/config.go` schema bumped to v2. Existing
   `config.json` files with `required_in_path: ["claude", …]` are
   migrated to `["codex", …]` on next `ctm` invocation. User

README.md

@@ -27,7 +27,8 @@ Download the prebuilt binary for your platform (no Go toolchain needed):
 curl -LO https://github.com/RandomCodeSpace/ctm/releases/latest/download/ctm-$(curl -s https://api.github.com/repos/RandomCodeSpace/ctm/releases/latest | jq -r .tag_name)-linux-amd64.tar.gz
 tar xzf ctm-*-linux-amd64.tar.gz && sudo mv ctm-*/ctm /usr/local/bin/
 
-ctm                    # launches tmux + codex; drop SSH, reattach anytime
+ctm                    # launches tmux + hermes (default agent); drop SSH, reattach anytime
+ctm new --agent codex  # opt back into codex per-session
 ctm last               # one-word reconnect from your phone
 ```
 
@@ -57,7 +58,7 @@ codex 0.130.0  ~/projects/ctm  ●
 - **YOLO mode.** Auto-commits a git checkpoint before launching with `codex --sandbox danger-full-access`, so you can always roll back.
 - **Preflight health checks.** Env vars, PATH, workdir, tmux session, codex process — cached for 60 s to keep mobile reconnects snappy.
 - **Tight lifecycle coupling.** When codex exits, the tmux session dies. No stuck bash shells, no zombie tabs.
-- **Multi-agent.** Codex is the default; pass `--agent hermes` to `ctm new` or `ctm yolo` to spawn [Hermes Agent](https://hermes-agent.dev) instead. New agents plug in via `internal/agent.Register` without touching call sites.
+- **Multi-agent.** [Hermes Agent](https://hermes-agent.dev) is the default; pass `--agent codex` to `ctm new` or `ctm yolo` to spawn codex instead. New agents plug in via `internal/agent.Register` without touching call sites.
 - **Crash-safe state.** Atomic writes, flock-based locking, strict JSON decode with self-healing strip-to-.bak, `schema_version` + startup migrations on `sessions.json` / `config.json`.
 - **Zero non-tmux runtime deps.** Pure Go throughout. No `jq`, `pgrep`, `grep`, or `uuidgen` required.
 
@@ -92,7 +93,7 @@ go install github.com/RandomCodeSpace/ctm@latest
 
 ### Post-install
 
-No extra setup step is required — the first time you run any codex-launching command (`ctm`, `ctm <name>`, `ctm new`, `ctm yolo`), ctm bootstraps `~/.config/ctm/` with sensible defaults, regenerates `tmux.conf` on every launch, and injects shell aliases into `~/.bashrc` / `~/.zshrc` if they exist.
+No extra setup step is required — the first time you run any agent-launching command (`ctm`, `ctm <name>`, `ctm new`, `ctm yolo`), ctm bootstraps `~/.config/ctm/` with sensible defaults, regenerates `tmux.conf` on every launch, and injects shell aliases into `~/.bashrc` / `~/.zshrc` if they exist.
 
 If you prefer an explicit setup step (or want the cc-session migration to run), `ctm install` still does the same work upfront.
 
@@ -172,7 +173,7 @@ Completion is aware of subcommands, flags, and (for `ctm attach`, `ctm kill`, `c
 
 | Command | Description |
 |---|---|
-| `ctm` | Attach to the default session (`codex`). Creates it if missing. |
+| `ctm` | Attach to the default session (`hermes`). Creates it if missing. |
 | `ctm <name>` | Attach to a named session, or create it. |
 | `ctm cc` | Shorthand for attaching to `cc`. |
 | `ctm new <name>` | Create a new session in a specific workdir. |

cmd/yolo_helpers_test.go

@@ -159,8 +159,8 @@ func TestResolveSimpleName(t *testing.T) {
 		args []string
 		want string
 	}{
-		{"no args → default 'codex'", nil, "codex"},
-		{"empty slice → default 'codex'", []string{}, "codex"},
+		{"no args → DefaultAgent", nil, session.DefaultAgent},
+		{"empty slice → DefaultAgent", []string{}, session.DefaultAgent},
 		{"single arg → that name", []string{"my-sess"}, "my-sess"},
 		{"extra args ignored — first wins", []string{"first", "ignored"}, "first"},
 	}
@@ -235,8 +235,8 @@ func TestResolveModeTargetDefaultName(t *testing.T) {
 	if err != nil {
 		t.Fatalf("resolveModeTarget: %v", err)
 	}
-	if name != "codex" {
-		t.Errorf("default name = %q, want codex", name)
+	if name != session.DefaultAgent {
+		t.Errorf("default name = %q, want %q", name, session.DefaultAgent)
 	}
 }
 

internal/session/spawn_discovery_test.go

@@ -6,7 +6,8 @@ import (
 	"testing"
 	"time"
 
-	_ "github.com/RandomCodeSpace/ctm/internal/agent/codex" // register codex
+	_ "github.com/RandomCodeSpace/ctm/internal/agent/codex"  // register codex
+	_ "github.com/RandomCodeSpace/ctm/internal/agent/hermes" // register hermes (DefaultAgent)
 	"github.com/RandomCodeSpace/ctm/internal/session"
 )
 
@@ -59,6 +60,7 @@ func TestYolo_DiscoveryStampsAgentSessionID(t *testing.T) {
 	sess, err := session.Yolo(session.SpawnOpts{
 		Name:                "discsess",
 		Workdir:             wd,
+		Agent:               "codex", // this test exercises codex rollout-file discovery specifically
 		Tmux:                tmux,
 		Store:               store,
 		OnDiscoveryComplete: func() { close(done) },
@@ -110,6 +112,7 @@ func TestYolo_DiscoveryTimeoutLeavesStoreRowEmpty(t *testing.T) {
 	if _, err := session.Yolo(session.SpawnOpts{
 		Name:                "timeoutsess",
 		Workdir:             wd,
+		Agent:               "codex", // this test exercises the codex no-rollout/timeout path
 		Tmux:                tmux,
 		Store:               store,
 		OnDiscoveryComplete: func() { close(done) },

internal/session/spawn_test.go

@@ -6,7 +6,8 @@ import (
 	"path/filepath"
 	"testing"
 
-	_ "github.com/RandomCodeSpace/ctm/internal/agent/codex" // register codex via init
+	_ "github.com/RandomCodeSpace/ctm/internal/agent/codex"  // register codex via init
+	_ "github.com/RandomCodeSpace/ctm/internal/agent/hermes" // register hermes (DefaultAgent) via init
 	"github.com/RandomCodeSpace/ctm/internal/session"
 )
 

internal/session/state.go

@@ -28,7 +28,13 @@ const SchemaVersion = 3
 // field set. Exposed as a constant so cmd/* code branching on the
 // default doesn't drift from the migration / Save / NormalizeAgent
 // codepaths.
-const DefaultAgent = "codex"
+//
+// Note on the legacy "claude" remap: Save and NormalizeAgent map
+// legacy "claude" values to "codex" (the v2→v3 migration target) —
+// not DefaultAgent — so changing the default later doesn't silently
+// move historical claude sessions onto whatever the current default
+// happens to be.
+const DefaultAgent = "hermes"
 
 // errFmtNotFound is the consistent shape returned by Get/Set/Delete/etc.
 // when a session name is unknown. Callers that distinguish "not found"
@@ -158,17 +164,22 @@ type Session struct {
 	AgentSessionID string `json:"agent_session_id,omitempty"`
 }
 
-// NormalizeAgent returns DefaultAgent ("codex") when s.Agent is empty,
-// else s.Agent verbatim. Cheap idempotent guard used by read paths
-// that handle pre-migration in-memory values without touching disk.
+// NormalizeAgent returns DefaultAgent when s.Agent is empty, else
+// s.Agent verbatim. Cheap idempotent guard used by read paths that
+// handle pre-migration in-memory values without touching disk.
 //
-// Legacy "claude" values that escaped the v2→v3 migration are also
-// remapped to "codex" so a stale in-memory Session never surfaces as
-// an agent.For miss at the call site.
+// Legacy "claude" values that escaped the v2→v3 migration are
+// remapped to "codex" (the on-disk migration target) — not
+// DefaultAgent — so a stale in-memory Session never surfaces as an
+// agent.For miss at the call site, and changing DefaultAgent doesn't
+// silently move historical claude sessions.
 func (s *Session) NormalizeAgent() string {
-	if s.Agent == "" || s.Agent == "claude" {
+	if s.Agent == "" {
 		return DefaultAgent
 	}
+	if s.Agent == "claude" {
+		return "codex"
+	}
 	return s.Agent
 }
 
@@ -314,12 +325,17 @@ func (s *Store) backupLocked() (string, error) {
 }
 
 // Save adds or updates a session. Empty sess.Agent is normalized to
-// DefaultAgent ("codex"). Legacy "claude" values are also rewritten —
-// the claude implementation was removed and a stray "claude" row
-// would fail at spawn-time agent.For lookup.
+// DefaultAgent. Legacy "claude" values are rewritten to "codex" (the
+// v2→v3 migration target) — not DefaultAgent — so changing the
+// default later doesn't silently retarget historical claude sessions.
+// A stray "claude" row would otherwise fail at spawn-time agent.For
+// lookup.
 func (s *Store) Save(sess *Session) error {
-	if sess.Agent == "" || sess.Agent == "claude" {
+	switch sess.Agent {
+	case "":
 		sess.Agent = DefaultAgent
+	case "claude":
+		sess.Agent = "codex"
 	}
 
 	lf, err := s.lock()

internal/session/state_migration_test.go

@@ -118,7 +118,7 @@ func TestMigration_V1ToV2_Idempotent(t *testing.T) {
 // TestSession_AgentFieldRoundTrip verifies that the Agent and
 // AgentSessionID fields survive a Save / Get cycle for non-default
 // agents. (The default agent path is covered by
-// TestSession_EmptyAgentDefaultsCodexOnSave.)
+// TestSession_EmptyAgentDefaultsToDefaultAgentOnSave.)
 func TestSession_AgentFieldRoundTrip(t *testing.T) {
 	dir := t.TempDir()
 	store := session.NewStore(filepath.Join(dir, "sessions.json"))
@@ -145,9 +145,11 @@ func TestSession_AgentFieldRoundTrip(t *testing.T) {
 	}
 }
 
-// TestSession_EmptyAgentDefaultsCodexOnSave verifies the read-side
-// guard: Save sets s.Agent = "codex" when empty.
-func TestSession_EmptyAgentDefaultsCodexOnSave(t *testing.T) {
+// TestSession_EmptyAgentDefaultsToDefaultAgentOnSave verifies the
+// write-side guard: Save sets s.Agent = DefaultAgent when empty.
+// Asserts on the constant (not a literal) so a future default flip
+// doesn't silently leave this test pinned to a stale value.
+func TestSession_EmptyAgentDefaultsToDefaultAgentOnSave(t *testing.T) {
 	dir := t.TempDir()
 	store := session.NewStore(filepath.Join(dir, "sessions.json"))
 	in := &session.Session{
@@ -161,8 +163,9 @@ func TestSession_EmptyAgentDefaultsCodexOnSave(t *testing.T) {
 		t.Fatalf("save: %v", err)
 	}
 	out, _ := store.Get("bar")
-	if out.Agent != "codex" {
-		t.Fatalf("empty Agent should default to \"codex\" on Save, got %q", out.Agent)
+	if out.Agent != session.DefaultAgent {
+		t.Fatalf("empty Agent should default to %q on Save, got %q",
+			session.DefaultAgent, out.Agent)
 	}
 }
 

internal/session/state_test.go

@@ -305,24 +305,29 @@ func TestMigrationPlan_MatchesSchemaVersion(t *testing.T) {
 	}
 }
 
-// TestNormalizeAgent_DefaultsCodex covers the read-side helper. Empty
-// values default to "codex" (the post-claude-removal default); legacy
-// "claude" values are also remapped to "codex" so a stale Session
-// never surfaces as an agent.For miss at the call site. Other agent
-// names pass through verbatim.
-func TestNormalizeAgent_DefaultsCodex(t *testing.T) {
+// TestNormalizeAgent covers the read-side helper. Empty values default
+// to DefaultAgent ("hermes" post-default-flip); legacy "claude" values
+// are remapped to "codex" (the v2→v3 on-disk migration target — NOT
+// DefaultAgent, by design, so the default flip doesn't silently
+// retarget historical claude sessions). Other agent names pass
+// through verbatim.
+func TestNormalizeAgent(t *testing.T) {
 	s := &session.Session{}
-	if got := s.NormalizeAgent(); got != "codex" {
-		t.Fatalf("NormalizeAgent on zero-value = %q, want codex", got)
+	if got := s.NormalizeAgent(); got != "hermes" {
+		t.Fatalf("NormalizeAgent on zero-value = %q, want hermes", got)
 	}
 	s.Agent = "claude"
 	if got := s.NormalizeAgent(); got != "codex" {
-		t.Fatalf("NormalizeAgent(claude) = %q, want codex (legacy remap)", got)
+		t.Fatalf("NormalizeAgent(claude) = %q, want codex (legacy remap, not DefaultAgent)", got)
 	}
 	s.Agent = "codex"
 	if got := s.NormalizeAgent(); got != "codex" {
 		t.Fatalf("NormalizeAgent(codex) = %q, want codex", got)
 	}
+	s.Agent = "hermes"
+	if got := s.NormalizeAgent(); got != "hermes" {
+		t.Fatalf("NormalizeAgent(hermes) = %q, want hermes", got)
+	}
 	s.Agent = "opencode"
 	if got := s.NormalizeAgent(); got != "opencode" {
 		t.Fatalf("NormalizeAgent(opencode) = %q, want opencode (forward-compat)", got)