fix(openai): harden realtime stt

docs/providers/openai.md

@@ -16,6 +16,21 @@ OpenAI provides developer APIs for GPT models. OpenClaw supports two auth routes
 
 OpenAI explicitly supports subscription OAuth usage in external tools and workflows like OpenClaw.
 
+## OpenClaw feature coverage
+
+| OpenAI capability         | OpenClaw surface                          | Status                                                 |
+| ------------------------- | ----------------------------------------- | ------------------------------------------------------ |
+| Chat / Responses          | `openai/<model>` model provider           | Yes                                                    |
+| Codex subscription models | `openai-codex/<model>` model provider     | Yes                                                    |
+| Server-side web search    | Native OpenAI Responses tool              | Yes, when web search is enabled and no provider pinned |
+| Images                    | `image_generate`                          | Yes                                                    |
+| Videos                    | `video_generate`                          | Yes                                                    |
+| Text-to-speech            | `messages.tts.provider: "openai"` / `tts` | Yes                                                    |
+| Batch speech-to-text      | `tools.media.audio` / media understanding | Yes                                                    |
+| Streaming speech-to-text  | Voice Call `streaming.provider: "openai"` | Yes                                                    |
+| Realtime voice            | Voice Call `realtime.provider: "openai"`  | Yes                                                    |
+| Embeddings                | memory embedding provider                 | Yes                                                    |
+
 ## Getting started
 
 Choose your preferred auth method and follow the setup steps.
@@ -299,18 +314,56 @@ Legacy `plugins.entries.openai.config.personality` is still read as a compatibil
 
   </Accordion>
 
+  <Accordion title="Speech-to-text">
+    The bundled `openai` plugin registers batch speech-to-text through
+    OpenClaw's media-understanding transcription surface.
+
+    - Default model: `gpt-4o-transcribe`
+    - Endpoint: OpenAI REST `/v1/audio/transcriptions`
+    - Input path: multipart audio file upload
+    - Supported by OpenClaw wherever inbound audio transcription uses
+      `tools.media.audio`, including Discord voice-channel segments and channel
+      audio attachments
+
+    To force OpenAI for inbound audio transcription:
+
+    ```json5
+    {
+      tools: {
+        media: {
+          audio: {
+            models: [
+              {
+                type: "provider",
+                provider: "openai",
+                model: "gpt-4o-transcribe",
+              },
+            ],
+          },
+        },
+      },
+    }
+    ```
+
+    Language and prompt hints are forwarded to OpenAI when supplied by the
+    shared audio media config or per-call transcription request.
+
+  </Accordion>
+
   <Accordion title="Realtime transcription">
     The bundled `openai` plugin registers realtime transcription for the Voice Call plugin.
 
     | Setting | Config path | Default |
     |---------|------------|---------|
     | Model | `plugins.entries.voice-call.config.streaming.providers.openai.model` | `gpt-4o-transcribe` |
+    | Language | `...openai.language` | (unset) |
+    | Prompt | `...openai.prompt` | (unset) |
     | Silence duration | `...openai.silenceDurationMs` | `800` |
     | VAD threshold | `...openai.vadThreshold` | `0.5` |
     | API key | `...openai.apiKey` | Falls back to `OPENAI_API_KEY` |
 
     <Note>
-    Uses a WebSocket connection to `wss://api.openai.com/v1/realtime` with G.711 u-law audio.
+    Uses a WebSocket connection to `wss://api.openai.com/v1/realtime` with G.711 u-law (`g711_ulaw` / `audio/pcmu`) audio. This streaming provider is for Voice Call's realtime transcription path; Discord voice currently records short segments and uses the batch `tools.media.audio` transcription path instead.
     </Note>
 
   </Accordion>

docs/tools/media-overview.md

@@ -51,10 +51,12 @@ Media understanding uses any vision-capable or audio-capable model registered in
 
 Video and music generation run as background tasks because provider processing typically takes 30 seconds to several minutes. When the agent calls `video_generate` or `music_generate`, OpenClaw submits the request to the provider, returns a task ID immediately, and tracks the job in the task ledger. The agent continues responding to other messages while the job runs. When the provider finishes, OpenClaw wakes the agent so it can post the finished media back into the original channel. Image generation and TTS are synchronous and complete inline with the reply.
 
-xAI currently maps to OpenClaw's image, video, search, code-execution, batch
-TTS, batch STT, and Voice Call streaming STT surfaces. xAI Realtime voice is
-an upstream capability, but it is not registered in OpenClaw until the shared
-realtime voice contract can represent it.
+OpenAI maps to OpenClaw's image, video, batch TTS, batch STT, Voice Call
+streaming STT, realtime voice, and memory embedding surfaces. xAI currently
+maps to OpenClaw's image, video, search, code-execution, batch TTS, batch STT,
+and Voice Call streaming STT surfaces. xAI Realtime voice is an upstream
+capability, but it is not registered in OpenClaw until the shared realtime
+voice contract can represent it.
 
 ## Quick links