# How To Add a Vendor

## When to add a vendor

Add a vendor descriptor when the integration is the canonical API or
first-party model service for that provider.

Typical vendor cases:

- a direct OpenAI-compatible API with its own auth/base URL contract;
- a first-party model-serving endpoint that owns its own catalog;
- a vendor that should be selectable directly rather than only through a
  gateway.

Use a gateway descriptor instead when the route primarily hosts, proxies, or
aggregates models behind a separate endpoint contract.

## Step-by-step

1. Pick the descriptor file path.
   Use `src/integrations/vendors/<id>.ts`.
2. Choose the transport family.
   Common direct vendors use `transportConfig.kind: 'openai-compatible'`.
   Gemini-native and Anthropic-native routes keep their own transport kinds.
3. Define setup/auth metadata.
   Fill `setup.requiresAuth`, `setup.authMode`, and
   `setup.credentialEnvVars`.
4. Set the route defaults.
   Add `defaultBaseUrl`, `defaultModel`, and any required env vars or
   validation metadata.
5. For OpenAI-compatible vendors, set the `/provider` UI capability flags in
   `transportConfig.openaiShim`.
   Use `supportsApiFormatSelection` for API mode editing and
   `supportsAuthHeaders` for auth/header editing.
6. Add a catalog if the vendor exposes models directly.
   Put the vendor's offered model subset on the vendor descriptor itself. Use
   `modelDescriptorId` when an entry should inherit shared model metadata.
7. Add usage metadata if the vendor has real `/usage` support.
   If `/usage` is still unsupported, keep that explicit with
   `usage: { supported: false }`.
8. If the vendor should appear in preset-driven `/provider` flows, add a
   `preset` block on the descriptor.
9. Run `bun run integrations:generate` so the generated loader and preset
   manifest stay in sync.

## Authoring rules

Normal vendor descriptor files should:

- use `defineVendor` and `defineCatalog`;
- default-export the descriptor;
- keep registration out of the file;
- avoid direct `registerVendor(...)` calls;
- avoid extra `import type` boilerplate in contributor-facing patterns unless a
  real type import is unavoidable.

Registration is loader-owned through the generated artifacts consumed by
`src/integrations/index.ts`.

## Generated loader and preset manifest

Normal vendor onboarding is additive now:

1. add or edit the descriptor file;
2. add a `preset` block only if the vendor should be user-facing in preset
   flows;
3. run `bun run integrations:generate`;
4. let `src/integrations/generated/integrationArtifacts.generated.ts` feed the
   loader, compatibility mapping, preset typing, and provider UI metadata.

Preset ordering is derived automatically: `anthropic` is pinned first, middle
entries sort by preset description using standard alphanumeric sorting, and
`custom` is pinned last by the generated manifest. This ordering is not
configurable from descriptor files.

## Example: standard API-key vendor with direct OpenAI-compatible routing

This is the common "direct hosted vendor" shape.

```ts
import { defineCatalog, defineVendor } from '../define.js'

const catalog = defineCatalog({
  source: 'static',
  models: [
    {
      id: 'acme-chat',
      apiName: 'acme-chat',
      label: 'Acme Chat',
      modelDescriptorId: 'acme-chat',
    },
  ],
})

export default defineVendor({
  id: 'acme',
  label: 'Acme AI',
  classification: 'openai-compatible',
  defaultBaseUrl: 'https://api.acme.example/v1',
  defaultModel: 'acme-chat',
  requiredEnvVars: ['ACME_API_KEY'],
  setup: {
    requiresAuth: true,
    authMode: 'api-key',
    credentialEnvVars: ['ACME_API_KEY'],
    setupPrompt: 'Paste your Acme API key.',
  },
  transportConfig: {
    kind: 'openai-compatible',
    openaiShim: {
      supportsApiFormatSelection: false,
      supportsAuthHeaders: false,
    },
  },
  preset: {
    id: 'acme',
    description: 'Acme AI API',
    apiKeyEnvVars: ['ACME_API_KEY'],
  },
  catalog,
  usage: {
    supported: false,
  },
})
```

Why this is the right shape:

- the route is first-party and direct, so it is a vendor, not a gateway;
- `transportConfig.kind` owns the transport choice;
- `supportsApiFormatSelection: false` means `/provider` should not expose API
  mode editing for this fixed direct-vendor route;
- `supportsAuthHeaders: false` means `/provider` should only ask for the API
  key, not custom auth-header fields;
- the vendor owns its own catalog because it exposes models directly;
- `defaultModel` on the vendor selects the default catalog entry;
- the file default-exports one typed descriptor and leaves registration to the
  loader.

## Example: vendor with custom static headers

For OpenAI-compatible vendors, put fixed request headers in
`transportConfig.openaiShim.headers`. Secrets still belong in credential env
vars or runtime auth handling.

```ts
import { defineVendor } from '../define.js'

export default defineVendor({
  id: 'acme-labs',
  label: 'Acme Labs',
  classification: 'openai-compatible',
  defaultBaseUrl: 'https://labs.acme.example/v1',
  defaultModel: 'acme-research',
  requiredEnvVars: ['ACME_LABS_API_KEY'],
  setup: {
    requiresAuth: true,
    authMode: 'api-key',
    credentialEnvVars: ['ACME_LABS_API_KEY'],
  },
  transportConfig: {
    kind: 'openai-compatible',
    openaiShim: {
      headers: {
        'X-Acme-Client': 'openclaude',
        'X-Acme-Protocol': 'labs-v1',
      },
      supportsApiFormatSelection: false,
      supportsAuthHeaders: false,
      maxTokensField: 'max_completion_tokens',
    },
  },
  usage: {
    supported: false,
  },
})
```

Use this pattern when:

- the provider requires fixed non-secret headers on every request;
- the route still speaks an OpenAI-compatible body shape;
- the token-field contract needs to be explicit;
- users should not edit API mode or auth/header fields for this fixed vendor
  route.

## Example: vendor that owns a first-party model catalog

This is the OpenAI/DeepSeek-style pattern where the vendor serves multiple
first-party models directly.

```ts
import { defineCatalog, defineVendor } from '../define.js'

const catalog = defineCatalog({
  source: 'static',
  models: [
    {
      id: 'acme-fast',
      apiName: 'acme-fast',
      label: 'Acme Fast',
      modelDescriptorId: 'acme-fast',
    },
    {
      id: 'acme-reasoner',
      apiName: 'acme-reasoner',
      label: 'Acme Reasoner',
      modelDescriptorId: 'acme-reasoner',
      capabilities: {
        supportsReasoning: true,
      },
      transportOverrides: {
        openaiShim: {
          preserveReasoningContent: true,
          requireReasoningContentOnAssistantMessages: true,
          reasoningContentFallback: '',
        },
      },
    },
  ],
})

export default defineVendor({
  id: 'acme-first-party',
  label: 'Acme First-Party',
  classification: 'openai-compatible',
  defaultBaseUrl: 'https://api.acme-first-party.example/v1',
  defaultModel: 'acme-fast',
  setup: {
    requiresAuth: true,
    authMode: 'api-key',
    credentialEnvVars: ['ACME_FIRST_PARTY_API_KEY'],
  },
  transportConfig: {
    kind: 'openai-compatible',
    openaiShim: {
      supportsApiFormatSelection: false,
      supportsAuthHeaders: false,
    },
  },
  catalog,
  usage: {
    supported: false,
  },
})
```

Use this when the vendor really is the route that serves the models. Do not
move route availability into the shared model index by default. Put reusable
context windows, output limits, and cross-route capability metadata in
`src/integrations/models/`, then point catalog entries at those descriptors
with `modelDescriptorId`.

## Reasoning controls

For direct vendors, record reasoning controls on the exact catalog model
entry or shared model descriptor only after the vendor API has been probed.
`capabilities.supportsReasoning` means the model can reason; it does not
mean `/effort` should send `reasoning_effort` or any other control field.

If the vendor catalog contains both controllable and non-controllable
reasoning models, annotate each model separately. See
`docs/integrations/reasoning-effort.md` for the metadata shape and audit
checklist.

## OpenAI-compatible UI capability flags

For OpenAI-compatible vendors, be explicit about the provider editor surface:

- `supportsApiFormatSelection: false`
  for fixed vendor APIs where OpenClaude should choose the API surface.
- `supportsApiFormatSelection: true`
  only when users should choose between compatible API modes such as chat
  completions and responses.
- `supportsAuthHeaders: false`
  when the route should only collect the configured credential env var/API key.
- `supportsAuthHeaders: true`
  only when users should be able to edit custom auth/header fields in
  `/provider add` and `/provider edit`.

Most direct vendors should set both flags to `false`. Broad custom routes are
the usual place where both are `true`.

## Presets and user-facing vendor onboarding

Most metadata-driven consumers now read generated descriptor-backed state, so a
normal vendor addition should not require broad switch editing.

Only add `preset` metadata when the vendor should appear as an explicit preset
or legacy-facing selectable route.

```ts
preset: {
  id: 'acme',
  description: 'Acme AI API',
  apiKeyEnvVars: ['ACME_API_KEY'],
}
```

Then regenerate:

```bash
bun run integrations:generate
```

That keeps `src/integrations/index.ts`, `src/integrations/compatibility.ts`,
`src/integrations/providerUiMetadata.ts`, and the generated preset-id type in
sync without hand-editing them.

## What not to do

Avoid these patterns in new vendor docs and examples:

- `registerVendor(...)` inside the descriptor file;
- direct registry mutation from contributor-authored descriptor files;
- inventing extra runtime routing fields when `transportConfig.kind` already
  expresses the transport family;
- pushing route-owned model availability into shared model files by default;
- treating the legacy word "provider" as precise when you really mean vendor,
  gateway, route, or model.

## Verification checklist

Before calling the vendor guide complete:

- the file lives under `src/integrations/vendors/`;
- the descriptor default-exports a `defineVendor(...)` result;
- any direct model-serving route owns the subset of models it actually exposes;
- the route default is declared once through `defaultModel`;
- the transport family is expressed through `transportConfig.kind`;
- OpenAI-compatible `/provider` UI capabilities are explicit through
  `openaiShim.supportsApiFormatSelection` and `openaiShim.supportsAuthHeaders`;
- auth/setup metadata and validation routing are explicit;
- user-facing preset participation is expressed through descriptor `preset`
  metadata and regenerated artifacts rather than handwritten follow-through.
