Add LLM Model

Use this workflow when adding or updating model support in stagewise.

Architecture First

Models are no longer a single global enabled/disabled list. Routing and model availability are scoped to entries in preferences.providerInstances.

• apps/browser/src/shared/available-models.ts is the curated metadata catalog.
• apps/browser/src/backend/agents/providers/ contains stateless provider-type implementations. registry.ts maps each ProviderInstanceTypeId to its type.
• apps/browser/src/backend/agents/model-provider.ts resolves a provider instance, then delegates ID conversion and model creation to its provider type.
• Each provider instance owns enabledModelIds, disabledModelIds, and discoveredModels.
• apps/browser/src/shared/flagship-models.ts curates newly discovered models per provider instance. Catalog models on official APIs are considered flagship. OpenRouter has its own prefixed-ID flagship set.

Read those files and the relevant provider implementation before deciding the change surface. Do not apply guidance written for the old global model list.

Required Checks

1. Research authoritative metadata.

   • Confirm the canonical ID, native provider ID, context window, modalities, tool support, reasoning support, and pricing.
   • Prefer provider documentation for native behavior and OpenRouter data for the Stagewise/OpenRouter route.
   • Keep still-supported sibling models unless removal was explicitly requested.

2. Add or update catalog metadata.

   • Edit apps/browser/src/shared/available-models.ts.
   • Match the field order and provider options of the nearest sibling.
   • Update apps/browser/src/shared/model-thinking-capabilities.ts when the model supports configurable thinking/reasoning.

3. Audit provider-instance routing.

   • Inspect apps/browser/src/backend/agents/providers/registry.ts and the relevant implementation in apps/browser/src/backend/agents/providers/.
   • Existing providers are normally model-agnostic; do not add a per-model branch unless the wire ID or API behavior genuinely differs.
   • Put canonical-to-wire ID conversion in the provider type's toWireModelId, not in new branches in the central model provider.
   • Stagewise routing prefixes canonical IDs for OpenRouter in providers/stagewise.ts.
   • Explicit custom endpoint modelIdMapping values must override defaults.

4. Curate discovery intentionally.

   • For OpenRouter, update OPENROUTER_FLAGSHIP_MODELS in apps/browser/src/shared/flagship-models.ts when the new model should be enabled on first discovery. IDs must include the OpenRouter vendor prefix.
   • Remove a superseded model from that set only if it should stop being a default for new discovery. Existing user choices are intentionally preserved by computeDisabledModelIdsAfterDiscovery.
   • Official-provider catalog entries are already treated as flagship; do not duplicate them in VENDOR_FLAGSHIP_DISCOVERED_MODELS.

5. Do not seed model deprecations in the legacy provider migration.

   • Never add a new model ID to the stagewise-default.disabledModelIds literal inside PreferencesService.migrateToProviderInstances.
   • That function runs only when providerInstances is empty. Such a change affects only users crossing the legacy migration and misses users whose instances already exist, creating inconsistent availability.
   • Do not patch the ID on every startup either; that would override a user's later decision to re-enable the model.
   • If product requirements call for changing existing users' model choices, ask first and implement an explicit, idempotent, versioned preference migration with tests. Define which provider-instance types are in scope and preserve choices after the migration has run once.
   • If the old model remains supported, keep it in the catalog and leave existing per-instance state untouched. Discovery flagship curation controls defaults for newly discovered provider models.

6. Keep credential validation cheap and broadly available.

   • Validation now belongs to the provider type's validateCredentials implementation, usually in providers/official-api.ts, rather than being hardcoded in central routing.
   • Do not switch validation to a new flagship/high-tier model by default. Prefer a cheap model broadly available to provider keys.
   • Legacy validate-api-keys.ts paths may still exist for compatibility; inspect callers before editing them.

7. Audit other product surfaces rather than editing mechanically.

   • Coding plans: apps/browser/src/shared/coding-plans.ts.
   • Homepage showcase: apps/website/src/app/(home)/_components/model-provider-showcase.tsx.
   • README files and localized variants.
   • Thinking tests, provider tests, and model-selector tests.
   • Historical benchmark/comparison copy must not be renamed without evidence.

8. Always verify subscription-plan base URLs.

   • Many providers use different API endpoints for subscription/token-plan keys vs. pay-as-you-go (BYOK) keys.
   • Example: GLM uses https://api.z.ai/api/paas/v4 for BYOK but https://api.z.ai/api/coding/paas/v4 for coding-plan subscriptions. Xiaomi MiMo uses https://api.xiaomimimo.com/v1 for BYOK but https://token-plan-cn.xiaomimimo.com/v1 for token-plan subscriptions.
   • The two key types are often non-interchangeable — a subscription key will be rejected by the BYOK endpoint and vice versa.
   • Before finalizing a coding-plan entry, always check the provider's official documentation to confirm:
     • Whether subscription tokens require a separate baseUrl / validationBaseUrl.
     • The correct cluster or region-specific URL (some providers offer multiple regional endpoints for subscriptions).
     • The API key format prefix (e.g. tp- for MiMo token plan vs sk- for BYOK).
   • Set baseUrl, validationBaseUrl, validationModelId, apiKeyPattern, and endpointHelpText on the coding-plan entry accordingly.
   • If the provider exposes documentation via llms.txt, fetch it — it links to raw markdown doc pages that contain the authoritative endpoint and auth details.
   • Update apiKeyUrl and helpText to point to the subscription management page (not the BYOK API keys page) when the two are separate.

Validation

After changes:

• Run targeted tests for catalog metadata, thinking capabilities, flagship discovery, provider routing, and any preference migration touched.
• Run browser typecheck and Biome on all edited files.
• Search for the new and superseded model IDs across browser and website code.
• Confirm Stagewise/OpenRouter and official-provider wire IDs independently.
• Confirm docs, coding-plan featuredModelIds, and showcase entries are intentionally aligned.
• If preference migration changed, test both empty and already-populated providerInstances, idempotence, and preservation of user choices.