fix(custom-model): address PR #430 pre-merge review (Ark0N)

Four blockers from the 2026-09-18 review:

- PUT /api/model-endpoints/:id now merges modelContextLengths/
  modelSizesGB back in from the stored record instead of trusting the
  editor's body, so renaming an endpoint or changing its default model
  no longer silently drops the context-window floor check and
  CLAUDE_CODE_MAX_CONTEXT_TOKENS injection.
- custom-model:swapped-out is now session-scoped (added to
  SESSION_PREFIXES) instead of broadcasting to every connected client.
- The quick-start custom-model path now hands setCustomModel() only
  the endpoint's own injected env vars, not the full merged set,
  matching the restart-in-place path — the full set put
  CLAUDE_CODE_EFFORT_LEVEL back after the Session constructor had
  already stripped it.
- The quick-start launchModel override for pi/grok/omp is now applied
  generically via the registry's legacyConfigField, mirroring
  Session._withCustomModelLaunchModel, instead of three hardcoded
  mode === '<id>' branches a future CLI's injection recipe would miss.

Also scopes the sticky-toast default (item 5): reverted the blanket
"all error toasts are sticky" default, which had no container cap or
eviction, back to a flat 3s; the one message that needs a moment to
read (a failed custom-model apply) now passes an explicit
duration: 0 at its own call site.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ea59JhUmHBm1gRCsiYF33R

src/web/public/panels-ui.js

@@ -5485,19 +5485,19 @@ Object.assign(CodemanApp.prototype, {
   },
 
   /**
-   * `duration` defaults to 0 (sticky, no auto-dismiss) for `error` toasts and
+   * `duration` defaults to 3000ms for every toast type. A message worth
-   * 3000ms for everything else — an error worth a distinct visual style is
+   * reading rather than glancing at (e.g. "Session started on the native
-   * also worth reading before it vanishes, which a fixed 3s auto-dismiss
+   * backend — could not apply the custom endpoint: <the actual reason>")
-   * does not guarantee: "Session started on the native backend — could not
+   * passes an explicit `opts.duration: 0` at its own call site instead of
-   * apply the custom endpoint: <the actual reason>" is exactly the kind of
+   * widening the default: this used to default every `error` toast to
-   * message that needs a moment to read, not a glance. Every toast gets an
+   * sticky, and with no cap on `.toast-container` and no eviction, a
-   * explicit close button regardless of duration, since a sticky one with no
+   * repeatedly failing path (a flapping SSE reconnect, a poll loop) stacked
-   * way to dismiss it would just pile up. A caller can still override either
+   * sticky toasts off the bottom of the viewport where they could not be
-   * default via `opts.duration` (e.g. a deliberately brief success toast, or
+   * read or dismissed. Every toast still gets an explicit close button
-   * a non-error one that should also stay put).
+   * regardless of duration.
    */
   showToast(message, type = 'info', opts = {}) {
-    const { duration = type === 'error' ? 0 : 3000, action } = opts;
+    const { duration = 3000, action } = opts;
     const toast = document.createElement('div');
     toast.className = `toast toast-${type}`;
 

src/web/public/session-ui.js

@@ -962,7 +962,9 @@ Object.assign(CodemanApp.prototype, {
     if (!ok || !data || data.success === false) {
       switchingToast?.dismiss();
       const detail = data?.error ? `: ${data.error}` : res ? ` (HTTP ${res.status})` : ' (request failed)';
-      this.showToast(`Session started on the native backend — could not apply the custom endpoint${detail}`, 'error');
+      this.showToast(`Session started on the native backend — could not apply the custom endpoint${detail}`, 'error', {
+        duration: 0,
+      });
       return;
     }
 

src/web/routes/custom-model-routes.ts

@@ -108,6 +108,18 @@ function applyStoredApiKey(incoming: CustomModelHost, existing: CustomModelHost)
   return incoming.apiKey ? incoming : { ...incoming, apiKey: existing.apiKey };
 }
 
+/**
+ * `modelContextLengths`/`modelSizesGB` are server-populated by discovery, never
+ * user-entered, and PUT replaces the whole record — so merge them back in from the
+ * stored host rather than trust whatever the editor's body carried (or omitted).
+ * The editor only ever sends `models`/`lastDiscoveredAt` verbatim from its cached
+ * copy; requiring it to also round-trip these two is exactly the kind of thing a
+ * future caller forgets, same class of bug `applyStoredApiKey` exists to prevent.
+ */
+function applyDiscoveredFields(incoming: CustomModelHost, existing: CustomModelHost): CustomModelHost {
+  return { ...incoming, modelContextLengths: existing.modelContextLengths, modelSizesGB: existing.modelSizesGB };
+}
+
 function authHeaders(host: Pick<CustomModelHost, 'apiKey' | 'authStyle'>): Record<string, string> {
   const headers: Record<string, string> = {};
   const apiKey = host.apiKey?.trim();
@@ -705,7 +717,7 @@ export function registerCustomModelRoutes(app: FastifyInstance): void {
     const hosts = await readCustomModelHosts(CODEMAN_CONFIG_DIR);
     const index = hosts.findIndex((item) => item.id === id);
     if (index === -1) return createErrorResponse(ApiErrorCode.NOT_FOUND, 'Model endpoint not found');
-    const host = applyStoredApiKey(incoming, hosts[index]);
+    const host = applyDiscoveredFields(applyStoredApiKey(incoming, hosts[index]), hosts[index]);
     const next = [...hosts];
     next[index] = host;
     await writeCustomModelHosts(CODEMAN_CONFIG_DIR, next);

src/web/routes/session-routes.ts

@@ -3576,6 +3576,12 @@ export function registerSessionRoutes(
     // a lighter version of them, since this is the same server-side authority reached a
     // different way, not a separate, less-checked path.
     let qsCustomModelEnvOverrides = qsGatedEnvOverrides;
+    // Only the INJECTED keys (never the caller's envOverrides merged in) — this is what
+    // setCustomModel() bookkeeping must be given below. The Session constructor already
+    // applies qsCustomModelEnvOverrides (the full merged set) directly; re-merging that
+    // full set into setCustomModel() would put CLAUDE_CODE_EFFORT_LEVEL back after the
+    // constructor stripped it (see setCustomModel()'s own doc comment in session.ts).
+    let qsCustomModelAppliedEnvOverrides: Record<string, string> | undefined;
     let qsCustomModelLaunchModel: string | undefined;
     let qsCustomModelSessionId: string | undefined;
     let qsCustomModelSwapInProgress = false;
@@ -3670,6 +3676,7 @@ export function registerSessionRoutes(
       }
 
       qsCustomModelEnvOverrides = { ...qsGatedEnvOverrides, ...cmApplied.envOverrides };
+      qsCustomModelAppliedEnvOverrides = cmApplied.envOverrides;
       qsCustomModelLaunchModel = cmApplied.launchModel;
       qsCustomModelBookkeeping = {
         endpointId: cmEndpoint.id,
@@ -3689,7 +3696,7 @@ export function registerSessionRoutes(
       }
     }
 
-    const session = new Session({
+    const qsSessionOptions: ConstructorParameters<typeof Session>[0] = {
       id: qsCustomModelSessionId,
       workingDir: resolvedCasePath,
       name: sessionName ? sessionName.slice(0, MAX_SESSION_NAME_LENGTH) : '',
@@ -3705,23 +3712,10 @@ export function registerSessionRoutes(
       codexConfig: mode === 'codex' ? qsGatedCodexConfig : undefined,
       geminiConfig: mode === 'gemini' ? qsGatedGeminiConfig : undefined,
       antigravityConfig: mode === 'antigravity' ? qsGatedAntigravityConfig : undefined,
-      piConfig:
+      piConfig: mode === 'pi' ? qsGatedPiConfig : undefined,
-        mode === 'pi'
+      grokConfig: mode === 'grok' ? qsGatedGrokConfig : undefined,
-          ? qsCustomModelLaunchModel !== undefined
-            ? { ...(qsGatedPiConfig ?? {}), model: qsCustomModelLaunchModel }
-            : qsGatedPiConfig
-          : undefined,
-      grokConfig:
-        mode === 'grok'
-          ? qsCustomModelLaunchModel !== undefined
-            ? { ...(qsGatedGrokConfig ?? {}), model: qsCustomModelLaunchModel }
-            : qsGatedGrokConfig
-          : undefined,
       deepSeekConfig: mode === 'deepseek' ? qsGatedDeepSeekConfig : undefined,
-      ompConfig:
+      ompConfig: qsResolvedOmpConfig,
-        mode === 'omp' && qsCustomModelLaunchModel !== undefined
-          ? { ...(qsResolvedOmpConfig ?? {}), model: qsCustomModelLaunchModel }
-          : qsResolvedOmpConfig,
       envOverrides: qsCustomModelEnvOverrides,
       effort,
       remote,
@@ -3729,7 +3723,25 @@ export function registerSessionRoutes(
       resumeSessionId: dockerResumeId,
       tmuxHistoryLimit: qsTerminalHistoryConfig.tmuxHistoryLimit,
       parentSessionId: qsParentSessionId,
-    });
+    };
+    // Force the custom-model selection's launchModel (pi/omp `custom/<id>`, grok's
+    // `[model.<name>]` block name) onto whichever config field the registry says the
+    // CLI's `model` launch param lives in — mirrors Session._withCustomModelLaunchModel,
+    // which the restart-in-place path already uses, rather than a hardcoded per-CLI
+    // branch here that a CLI landing its injection recipe later would silently miss.
+    if (qsCustomModelLaunchModel !== undefined) {
+      const qsCustomModelField = getCli(mode)?.launch.legacyConfigField;
+      if (qsCustomModelField) {
+        const qsSessionOptionsBag = qsSessionOptions as unknown as Record<string, unknown>;
+        qsSessionOptionsBag[qsCustomModelField] = {
+          ...((qsSessionOptionsBag[qsCustomModelField] as Record<string, unknown>) ?? {}),
+          model: qsCustomModelLaunchModel,
+        };
+      } else {
+        qsSessionOptions.model = qsCustomModelLaunchModel;
+      }
+    }
+    const session = new Session(qsSessionOptions);
 
     // Records the selection for session.customModel/getCustomModelForPersist() and future
     // clear/switch calls — the actual env vars and launch-model config are already part of
@@ -3737,7 +3749,7 @@ export function registerSessionRoutes(
     // this is bookkeeping only, never a restart: setCustomModel() is synchronous state, no
     // tmux IO of its own (see its own doc comment in session.ts).
     if (qsCustomModelBookkeeping) {
-      session.setCustomModel(qsCustomModelBookkeeping, qsCustomModelEnvOverrides);
+      session.setCustomModel(qsCustomModelBookkeeping, qsCustomModelAppliedEnvOverrides);
     }
 
     // Auto-detect completion phrase from CLAUDE.md BEFORE broadcasting

src/web/server.ts

@@ -2373,6 +2373,7 @@ export class WebServer extends EventEmitter {
       'scheduled:',
       'team:',
       'case:',
+      'custom-model:',
     ];
     if (SESSION_PREFIXES.some((p) => event.startsWith(p))) {
       const d = (data ?? {}) as { sessionId?: string; id?: string; session?: { id?: string } };

test/cli-registry-no-id-branching.test.ts

@@ -80,8 +80,6 @@ const ALLOWED_BRANCHES: Record<string, string> = {
   "web/routes/session-routes.ts::mode === 'pi'": 'legacy <Mode>Config plumbing',
   "web/routes/session-routes.ts::mode === 'grok'": 'legacy <Mode>Config plumbing',
   "web/routes/session-routes.ts::mode === 'deepseek'": 'legacy <Mode>Config plumbing',
-  "web/routes/session-routes.ts::mode === 'omp'":
-    'legacy <Mode>Config plumbing (custom-model launchModel merge onto ompConfig, same selection resolveOmpConfigForCreate already makes internally)',
   "web/server.ts::mode === 'opencode'": 'legacy <Mode>Config plumbing (session recovery)',
   "web/server.ts::mode === 'codex'": 'legacy <Mode>Config plumbing (session recovery)',
   "web/server.ts::mode === 'gemini'": 'legacy <Mode>Config plumbing (session recovery)',