fix(custom-model): wait for a freshly launched session to go idle before applying

Root cause of every 'Session is busy' apply failure reported from live
testing: a just-launched CLI reports itself 'busy' for its own startup
(boot spinner, workspace-trust check) well before runCustomModelEntry's
apply call could reach it, and the apply route's isBusy() guard correctly
cannot tell that apart from a real turn in progress — it exists precisely
to refuse restarting a session mid-turn, and a fresh boot looks exactly
like one from the outside. Confirmed live: replaying the identical apply
call by hand against the same session, once it had settled, succeeded
immediately.

Fixed by waiting on the session's own readiness signal before applying:
GET /api/sessions/:id/wait?until=idle&timeout=20000, one GET already built
for exactly this ('Agent wait primitives', CLAUDE.md) rather than inventing
a client-side poll loop. A timeout there is a normal 200 per that
endpoint's own contract, never an error, so a session still busy after 20s
just reaches the apply call anyway and gets the route's own honest error —
now visible, since the previous commit made error toasts sticky and
stopped discarding the real error text.

Tests: new case in custom-model-run-menu-ui.test.ts pins the ordering (the
wait call happens, and strictly before the apply call) and its exact query
string.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RqZeHrRS6DYcGcGX2p9EwG

CLAUDE.md

@@ -227,7 +227,7 @@ Codeman is a Claude Code session manager with web interface and autonomous Ralph
 
 **DeepSeek web UI** (`POST`/`GET`/`DELETE /api/deepseek/web`, `deepseek-web-server.ts`): the Run menu's "DeepSeek web UI..." entry supervises ONE background `dsh web` child process, deliberately **NOT a shell session**. The session version worked and was still wrong in use: it put a terminal tab on screen next to the web tab the user actually asked for, every single time, and nothing about a long-lived HTTP server needs to be a tab. ⚠️ What a session gave for free now has to be paid for explicitly, and every piece is load-bearing: **exactly one** server (a second click REUSES it rather than racing it for a port, which two sessions structurally could not do), **restarted when the browser authority changes** (`--trusted-host` fences dsh's `/api` against the browser authority, and a Codeman reachable at both loopback and a tailnet name has two, so whoever asks last wins: the asker is by definition the origin about to load the page), **killed on shutdown** (`stopDeepSeekWeb()` in the server teardown, because the child is detached so its whole plugin tree can be signalled at once, which also means it would OUTLIVE Codeman and hold its port against the next start), and **failures returned to the caller**, since with no tab there is nowhere for a stack trace to land. ⚠️ The port search starts at dsh's own default 3080 and walks 40, never fixed: that default is precisely the port most likely to be taken already by the user's own `dsh web`, and hardcoding it killed this feature with EADDRINUSE once. Free-port detection BINDS rather than connects (a connect probe cannot tell "free" from "listening but not answering yet"), so it is racy by nature and the caller still waits for the server to really answer before reporting success. ⚠️ Both `POST` and `DELETE` sit at the **same privilege bar as the profile installer** (`canUsernameRunPrivilegedCommands`) even though the action reads as "open a page": booting a dsh profile executes the plugin code in it, and the server is a single shared instance, so stopping it in multi-user mode takes it out from under other users' tabs.
 
-**Custom Model Endpoint Profiles** (opt-in, `customModelEndpointsEnabled`, SYNCED, default OFF; `docs/custom-model-endpoints.md`, design doc `docs/custom-model-endpoints-plan.md`; full stack — settings-panel CRUD + the Run-menu picker, on top of the backend below): points a session at a user-configured custom OpenAI-compatible endpoint — local (llama.cpp, DGX Spark, Strix Halo) or cloud (Azure AI Foundry, OpenRouter) — instead of its harness's native cloud backend. Endpoints are a read/write-array store (`custom-model-hosts.ts`, `~/.codeman/custom-model-hosts.json`) discovered via `GET <baseUrl>/v1/models`; `CustomModelHost.authStyle` is `'bearer'` (default, `Authorization: Bearer`) or `'api-key'` (Azure's convention) — **never both**, live-tested against a real server: sending both headers on one request reliably hangs it indefinitely, reproduced 3×. ⚠️ The actual per-CLI redirect is `capabilities.customModelInjection` on the CLI registry (four kinds: `env` for claude/gemini/deepseek, `configContentEnv` reusing opencode's existing `OPENCODE_CONFIG_CONTENT`, `configDir` for codex/pi/grok/omp — writes an isolated per-session config file, NEVER the user's real `~/.codex`/`~/.pi`/`~/.omp`/grok config — and `unsupported` for antigravity, which has no known mechanism), computed by the pure `custom-model-injection.ts` (mirrors `session-cli-builder.ts`'s no-IO discipline). ⚠️ `PI_CONFIG_DIR` does NOTHING for pi or omp (grepped pi's entire bundled JS source — the string appears nowhere); both hardcode `~/.pi/agent/models.json` / `~/.omp/agent/models.yml` with no dedicated override, so the real redirect for both is the child process's own **`HOME`**, and both need `models` as an ARRAY of `{id}` objects (an object keyed by id silently loads zero models). Grok's real mechanism turned out to be a `config.toml` `[model.<name>]` block redirected via `GROK_HOME` — its original env-var-based recipe was flat-out wrong (produced "Not signed in" against a real binary), not just unverified. ⚠️ Applying a selection **restarts the session's CLI process in place** via `Session.restartCli()` — a de-restricted `reattachRemote()` reusing the same `respawn-pane -k` primitive local/remote respawns already share — because every one of these harnesses reads its endpoint config at process start, never per-turn, so there is no live hot-swap; `Session.setCustomModel()` undoes the PREVIOUS selection's env keys (and deletes its old `configDir`) before merging the new ones in, so switching endpoints or clearing back to native cloud never leaves a stale key behind. ⚠️ Deleting a key from `_envOverrides` is NOT enough on its own: `tmux setenv` persists at the tmux-session level and is inherited by `respawn-pane` (measured: `setenv FOO bar` survived two successive `respawn-pane -k`), so the retired keys are queued (`_pendingEnvUnsets`) and ride `RespawnPaneOptions.unsetEnvKeys` into `applyEnvOverrides()`, which `setenv -u`s them BEFORE re-applying the live overrides. ⚠️ `restartCli()` kills a WORKING pane, so a CLI whose launch declares a `fallback` chain (claude) gets the live conversation id pinned as `resumeSessionId` for that one respawn: `--session-id <id>` refuses an id that already has a transcript (`Session ID ... is already in use`), and without the `--resume <id> || --session-id <id>` shape the docker/remote pane commands already use, applying a model killed the pane and lost the session. ⚠️ pi, omp and grok need the config file AND a `model` launch param (`custom/<id>` for pi/omp, grok's `[model.codeman-custom]` block name): that is the registry's `customModelInjection.launchModel` template, applied onto the respawn options through `legacyConfigField` by `_withCustomModelLaunchModel()`, never by id, and a model id the CLI's `model` token pattern cannot carry is refused with a 400 rather than silently dropped by the argv engine. ⚠️ Remote (SSH) and Docker sessions are REFUSED (400): their `restartCli()` reattaches a durable tmux rather than restarting the agent and the env lands on the local pane, so they used to report `restarted:true` and change nothing. The selection survives a Codeman restart as the disk-only `__customModel` (bookkeeping: env KEYS, config dir, launch model; never the values, which carry the API key and are re-derived from the endpoint store on recovery), the config dir is removed with the session, and every secret-bearing file (`custom-model-hosts.json`, the per-session config dir) is written 0600. ⚠️ **Security**: every env var this feature can redirect (`ANTHROPIC_BASE_URL`, `GOOGLE_GEMINI_BASE_URL`, `CODEX_HOME`, `GROK_HOME`, `HOME` for pi/omp, `OPENCODE_CONFIG_CONTENT`, etc.) is in that CLI's `privilegedEnvKeys` — several of these were reachable via the generic `envOverrides` field's prefix allowlist BEFORE this feature existed (the env allowlist is global and prefix-based, not per-CLI-scoped), so building this surfaced and closed a pre-existing gap ratherLine truncated
+**Custom Model Endpoint Profiles** (opt-in, `customModelEndpointsEnabled`, SYNCED, default OFF; `docs/custom-model-endpoints.md`, design doc `docs/custom-model-endpoints-plan.md`; full stack — settings-panel CRUD + the Run-menu picker, on top of the backend below): points a session at a user-configured custom OpenAI-compatible endpoint — local (llama.cpp, DGX Spark, Strix Halo) or cloud (Azure AI Foundry, OpenRouter) — instead of its harness's native cloud backend. Endpoints are a read/write-array store (`custom-model-hosts.ts`, `~/.codeman/custom-model-hosts.json`) discovered via `GET <baseUrl>/v1/models`; `CustomModelHost.authStyle` is `'bearer'` (default, `Authorization: Bearer`) or `'api-key'` (Azure's convention) — **never both**, live-tested against a real server: sending both headers on one request reliably hangs it indefinitely, reproduced 3×. ⚠️ The actual per-CLI redirect is `capabilities.customModelInjection` on the CLI registry (four kinds: `env` for claude/gemini/deepseek, `configContentEnv` reusing opencode's existing `OPENCODE_CONFIG_CONTENT`, `configDir` for codex/pi/grok/omp — writes an isolated per-session config file, NEVER the user's real `~/.codex`/`~/.pi`/`~/.omp`/grok config — and `unsupported` for antigravity, which has no known mechanism), computed by the pure `custom-model-injection.ts` (mirrors `session-cli-builder.ts`'s no-IO discipline). ⚠️ `PI_CONFIG_DIR` does NOTHING for pi or omp (grepped pi's entire bundled JS source — the string appears nowhere); both hardcode `~/.pi/agent/models.json` / `~/.omp/agent/models.yml` with no dedicated override, so the real redirect for both is the child process's own **`HOME`**, and both need `models` as an ARRAY of `{id}` objects (an object keyed by id silently loads zero models). Grok's real mechanism turned out to be a `config.toml` `[model.<name>]` block redirected via `GROK_HOME` — its original env-var-based recipe was flat-out wrong (produced "Not signed in" against a real binary), not just unverified. ⚠️ Applying a selection **restarts the session's CLI process in place** via `Session.restartCli()` — a de-restricted `reattachRemote()` reusing the same `respawn-pane -k` primitive local/remote respawns already share — because every one of these harnesses reads its endpoint config at process start, never per-turn, so there is no live hot-swap; `Session.setCustomModel()` undoes the PREVIOUS selection's env keys (and deletes its old `configDir`) before merging the new ones in, so switching endpoints or clearing back to native cloud never leaves a stale key behind. ⚠️ Deleting a key from `_envOverrides` is NOT enough on its own: `tmux setenv` persists at the tmux-session level and is inherited by `respawn-pane` (measured: `setenv FOO bar` survived two successive `respawn-pane -k`), so the retired keys are queued (`_pendingEnvUnsets`) and ride `RespawnPaneOptions.unsetEnvKeys` into `applyEnvOverrides()`, which `setenv -u`s them BEFORE re-applying the live overrides. ⚠️ `restartCli()` kills a WORKING pane, so a CLI whose launch declares a `fallback` chain (claude) gets the live conversation id pinned as `resumeSessionId` for that one respawn: `--session-id <id>` refuses an id that already has a transcript (`Session ID ... is already in use`), and without the `--resume <id> || --session-id <id>` shape the docker/remote pane commands already use, applying a model killed the pane and lost the session. ⚠️ pi, omp and grok need the config file AND a `model` launch param (`custom/<id>` for pi/omp, grok's `[model.codeman-custom]` block name): that is the registry's `customModelInjection.launchModel` template, applied onto the respawn options through `legacyConfigField` by `_withCustomModelLaunchModel()`, never by id, and a model id the CLI's `model` token pattern cannot carry is refused with a 400 rather than silently dropped by the argv engine. ⚠️ Remote (SSH) and Docker sessions are REFUSED (400): their `restartCli()` reattaches a durable tmux rather than restarting the agent and the env lands on the local pane, so they used to report `restarted:true` and change nothing. The selection survives a Codeman restart as the disk-only `__customModel` (bookkeeping: env KEYS, config dir, launch model; never the values, which carry the API key and are re-derived from the endpoint store on recovery), the config dir is removed with the session, and every secret-bearing file (`custom-model-hosts.json`, the per-session config dir) is written 0600. ⚠️ **Security**: every env var this feature can redirect (`ANTHROPIC_BASE_URL`, `GOOGLE_GEMINI_BASE_URL`, `CODEX_HOME`, `GROK_HOME`, `HOME` for pi/omp, `OPENCODE_CONFIG_CONTENT`, etc.) is in that CLI's `privilegedEnvKeys` — several of these were reachable via the generic `envOverrides` field's prefix allowlist BEFORE this feature existed (the env allowlist is global and prefix-based, not per-CLI-scoped), so building this surfaced and closed a pre-existing gap ratherLine truncated
 
 **Run launch synchronization**: the Run entrypoint holds an in-flight lock and disables `#runBtn` for the whole launch (≥500ms), so a double click cannot create duplicate sessions with the same `w<n>-<case>` name. `_ensureCreatedSessionVisible()` runs before `selectSession()`, and `_onSessionCreated()` stays an idempotent upsert, so POST-first and SSE-first ordering both produce exactly one rendered tab. ⚠️ **Closing has the mirror-image race and one owner**: `closeSession()` reads `wasActive` BEFORE its `await` and announces the delete via `_closingSessions`, while `_onSessionDeleted` skips the active-session handoff for an id in that set. Both used to read `activeSessionId` after the fact, so the `session_deleted` broadcast for your own delete could null it first and closing the tab you were on landed on the welcome screen instead of the next session, on the same build, depending on timing. The fallback also picks the first order entry that is still in `sessions` (a dead id can linger in `sessionOrder`, same reason Alt+N indexes a live-filtered list). A delete from ANOTHER client still shows the welcome screen, which is the honest answer when what you were looking at was taken away. Tests: `test/session-close-fallback.test.ts`. → [architecture-invariants#run-launch-synchronization](docs/architecture-invariants.md#run-launch-synchronization)
 

docs/custom-model-endpoints.md

@@ -105,11 +105,21 @@ the point of asking is letting one launch deliberately differ from the
 saved default, not just confirming it. Whichever way the model was decided,
 the launch itself runs a single session on that harness exactly the way its
 own Run-menu entry would (same case creation, env overrides, everything),
-then immediately applies the endpoint and model to it via the route below.
+then **waits for the new session to go idle** (`GET .../wait?until=idle`,
-It is a one-off "try this endpoint" action, not a sticky mode: the plain
+bounded at 20s — a normal 200 either way, never an error, per the wait
-Run button still means "this harness, native cloud" afterward. Entries are
+endpoint's own contract) before applying the endpoint and model to it via
-hidden entirely for a remote or Docker active case, since the apply route
+the route below. That wait exists because a freshly launched CLI reports
-refuses both (see the next section).
+itself as `busy` for its own startup (a boot spinner, a workspace-trust
+check) well before the apply call would otherwise reach it, and the apply
+route correctly refuses to restart a session mid-turn — a fresh boot looks
+exactly like one from the outside. A session still busy after the wait
+reaches the apply call anyway and gets that route's own honest
+`SESSION_BUSY` error, now visible as a sticky toast with a close button
+rather than a generic message that vanished in three seconds. It is a
+one-off "try this endpoint" action, not a sticky mode: the plain Run button
+still means "this harness, native cloud" afterward. Entries are hidden
+entirely for a remote or Docker active case, since the apply route refuses
+both (see the next section).
 
 ## Applying a model to a session
 

docs/wiki/Custom-Model-Endpoints.md

@@ -48,6 +48,14 @@ conversation where the harness supports resuming one, fresh environment. That re
 necessary, not incidental: every supported harness reads its endpoint config at process
 start, never per turn, so there is no live hot-swap while a turn is running.
 
+Picking an entry that launches a **brand-new** session waits (up to 20 seconds) for it to
+finish its own startup before applying — a freshly started CLI reports itself as busy for its
+boot sequence, and applying to a genuinely busy session is refused so a real, in-progress
+turn is never interrupted out from under you. A session that is still busy after that wait
+(a very slow-starting CLI, or one you started typing into right away) surfaces that refusal
+as an ordinary error, which now stays on screen with a close button instead of vanishing
+after a few seconds — read it, it names the actual reason rather than a generic failure.
+
 Entries are hidden entirely for a session in a **remote (SSH) or Docker case** — support for
 redirecting those hasn't landed yet, see below. The picker also only appears in the desktop
 **Run** dropdown; the phone home screen builds its own run picker separately and does not

src/web/public/session-ui.js

@@ -721,6 +721,19 @@ Object.assign(CodemanApp.prototype, {
     const sessionId = this.activeSessionId;
     if (!sessionId || sessionId === before) return;
 
+    // A freshly launched CLI reports its OWN startup as 'busy' (spinner, the
+    // workspace-trust check, whatever else it does before its first prompt) —
+    // measured landing well before this line reliably reaches it — and the
+    // apply route's isBusy() guard correctly refuses to restart a session
+    // mid-turn, "mid-turn" included, which this fresh boot looks exactly
+    // like from the outside. Give it a bounded chance to settle first rather
+    // than raising a false "Session is busy" on every single launch. Per the
+    // wait contract a timeout here is a normal 200, never an error — a
+    // session still busy after 20s just reaches the apply call below and
+    // gets the route's own honest, now-visible SESSION_BUSY error instead of
+    // this guessing about it.
+    await this._apiJson(`/api/sessions/${sessionId}/wait?until=idle&timeout=20000`);
+
     // _apiJson() (used everywhere else in this file) unwraps a success body to
     // its `data`, but on failure it swallows the response entirely and returns
     // null — exactly the `error` text a caller needs to tell "the endpoint is

test/custom-model-run-menu-ui.test.ts

@@ -340,6 +340,37 @@ describe('Custom Model Endpoint Profiles: applying a picked entry', () => {
     expect(calls[0].body).toEqual({ endpointId: 'llama-box', modelId: 'qwen3' });
   });
 
+  it('waits for the freshly launched session to go idle before applying, so its own boot activity is never mistaken for a busy turn', async () => {
+    // Measured live: a just-launched CLI reports 'busy' for its own startup
+    // (spinner, workspace-trust check) well before the apply call could
+    // otherwise reach it, and the apply route's isBusy() guard correctly
+    // refuses to restart a session mid-turn — which a fresh boot looks
+    // exactly like from the outside. This pins the fix: wait for idle FIRST.
+    const { app } = bootApp({});
+    app.activeSessionId = 'old-session';
+    app.run = async () => {
+      app.activeSessionId = 'new-session';
+    };
+    const calls: string[] = [];
+    app._apiJson = async (path: string) => {
+      calls.push(path);
+      if (path === '/api/model-endpoints') return [];
+      return null; // the wait call's return value is unused — a timeout is a normal 200
+    };
+    app._api = async (path: string) => {
+      calls.push(path);
+      return { ok: true, json: async () => ({ success: true, data: {} }) };
+    };
+
+    await app.runCustomModelEntry('claude', 'llama-box', 'qwen3');
+
+    const waitIndex = calls.findIndex((p) => p.includes('/wait?'));
+    const applyIndex = calls.findIndex((p) => p.endsWith('/custom-model'));
+    expect(waitIndex).toBeGreaterThanOrEqual(0);
+    expect(calls[waitIndex]).toBe('/api/sessions/new-session/wait?until=idle&timeout=20000');
+    expect(applyIndex).toBeGreaterThan(waitIndex);
+  });
+
   it('surfaces the real server error in the toast on a failed apply, rather than a generic message', async () => {
     const { app } = bootApp({});
     app.activeSessionId = 'old-session';