This is a comment left during a code review.
Path: extensions/xai/model-definitions.ts
Line: 7

Comment:
**Undocumented behavior change: context window silently expanded 4x**

`XAI_DEFAULT_CONTEXT_WINDOW` was quietly changed from `256_000` to `1_000_000` — a 4× increase — affecting the advertised context window of `grok-4`, `grok-4-0709`, and the fallback resolver path. The PR description says scope is limited to image gen / TTS with no model-definition behavior changes, so this looks like an unintended or at least undocumented side effect. If Grok 4 genuinely supports 1M tokens, this should be explicitly called out in the PR description and changelog so reviewers can validate the value against xAI's published limits.

How can I resolve this? If you propose a fix, please make it concise.

---

This is a comment left during a code review.
Path: extensions/xai/model-definitions.ts
Line: 14-17

Comment:
**`XAI_DEFAULT_MODEL_REF` type changed from `string` to `object` in the public API surface**

Before this PR, `model-definitions.ts` exported `XAI_DEFAULT_MODEL_REF = \`xai/${XAI_DEFAULT_MODEL_ID}\`` (a `string`). Now it exports `{ provider: "xai", model: "grok-4" }` (an object). Since `api.ts` re-exports `XAI_DEFAULT_MODEL_REF` from `model-definitions.ts`, any consumer of the xAI plugin's public `api.ts` barrel will now receive an object where they previously received a string — a breaking type-contract change.

`onboard.ts` still independently exports its own `XAI_DEFAULT_MODEL_REF` as a string (`\`xai/${XAI_DEFAULT_MODEL_ID}\``), so the two files now carry the same export name with different types. `index.ts` correctly imports the string from `onboard.js`, but the naming collision is fragile and will silently give callers the wrong type if they import via `api.ts`.

If the structured format is genuinely needed, it should use a distinct name (e.g. `XAI_DEFAULT_MODEL_REF_STRUCTURED`) to avoid shadowing the existing string export.

How can I resolve this? If you propose a fix, please make it concise.

---

This is a comment left during a code review.
Path: extensions/xai/speech-provider.ts
Line: 562-571

Comment:
**Unused `baseUrl` parameter accepted but never read**

The first parameter `baseUrl: string` is declared and passed at the call site (`config.baseUrl`), but the function body only branches on `target` and `configuredFormat` — `baseUrl` is never referenced. If it was intended for custom-endpoint format selection (like `tts.ts`'s `isCustomXaiEndpoint`), the logic is missing. If it's not needed, drop the parameter and the corresponding argument to avoid dead code and a likely lint warning.

```suggestion
function resolveSpeechResponseFormat(
  target: "audio-file" | "voice-note",
  configuredFormat?: XaiSpeechResponseFormat,
): XaiSpeechResponseFormat {
```

How can I resolve this? If you propose a fix, please make it concise.

---

This is a comment left during a code review.
Path: extensions/xai/index.ts
Line: 13

Comment:
**Duplicate import from the same module**

`buildXaiImageGenerationProvider` is imported in a separate statement rather than being merged into the existing `import { resolveXaiModelCompatPatch, ... } from "./api.js"` block above. This leaves two `import … from "./api.js"` declarations in the same file, which is redundant and may trigger the linter.

```suggestion
import {
  applyXaiModelCompat,
  buildXaiImageGenerationProvider,
  normalizeXaiModelId,
  resolveXaiTransport,
  resolveXaiModelCompatPatch,
  shouldContributeXaiCompat,
} from "./api.js";
```

How can I resolve this? If you propose a fix, please make it concise.

---

This is a comment left during a code review.
Path: extensions/xai/tts.ts
Line: 893

Comment:
**`XAI_BASE_URL` duplicated; already exported from `model-definitions.ts` via `api.ts`**

`model-definitions.ts` exports `XAI_BASE_URL = "https://api.x.ai/v1"` and that constant is re-exported through the public `api.ts` barrel. Re-declaring it here means the two values can drift if one is updated. `speech-provider.ts` already imports `XAI_BASE_URL` from `./tts.js`; consider importing from `./api.js` (or `./model-definitions.js`) to have a single source of truth.

How can I resolve this? If you propose a fix, please make it concise.

---

This is a comment left during a code review.
Path: extensions/xai/image-generation-provider.ts
Line: 422-424

Comment:
**`fileName` extension is always `.png` regardless of MIME type**

`fileName` is hardcoded to `image-${idx + 1}.png` even when `mimeType` is something other than `image/png` (e.g. `image/webp`, `image/jpeg`). The response type from xAI may vary. A small helper that maps the MIME type to the correct extension would keep the file name accurate.

```suggestion
              fileName: `image-${idx + 1}.${mimeType.split("/")[1] ?? "png"}`,
```

How can I resolve this? If you propose a fix, please make it concise.