Models / Providers

xAI

Genesis ships a bundled xai provider plugin for Grok models.

Getting started

Create an API key

Create an API key in the xAI console.

Set your API key

Set XAI_API_KEY, or run:

genesis onboard --auth-choice xai-api-key

Pick a model

{
  agents: { defaults: { model: { primary: "xai/grok-4" } } },
}

Built-in catalog

Genesis includes these xAI model families out of the box:

The plugin also forward-resolves newer grok-4* and grok-code-fast* ids when they follow the same API shape.

Genesis feature coverage

The bundled plugin maps xAI's current public API surface onto Genesis's shared provider and tool contracts. Capabilities that don't fit the shared contract (for example streaming TTS and realtime voice) are not exposed — see the table below.

Fast-mode mappings

/fast on or agents.defaults.models["xai/<model>"].params.fastMode: true rewrites native xAI requests as follows:

Legacy compatibility aliases

Legacy aliases still normalize to the canonical bundled ids:

Features

Web search

The bundled grok web-search provider uses XAI_API_KEY too:

genesis config set tools.web.search.provider grok

Video generation

The bundled xai plugin registers video generation through the shared video_generate tool.

• Default video model: xai/grok-imagine-video
• Modes: text-to-video, image-to-video, remote video edit, and remote video extension
• Aspect ratios: 1:1, 16:9, 9:16, 4:3, 3:4, 3:2, 2:3
• Resolutions: 480P, 720P
• Duration: 1-15 seconds for generation/image-to-video, 2-10 seconds for extension

To use xAI as the default video provider:

{
  agents: {
    defaults: {
      videoGenerationModel: {
        primary: "xai/grok-imagine-video",
      },
    },
  },
}

Image generation

The bundled xai plugin registers image generation through the shared image_generate tool.

• Default image model: xai/grok-imagine-image
• Additional model: xai/grok-imagine-image-pro
• Modes: text-to-image and reference-image edit
• Reference inputs: one image or up to five images
• Aspect ratios: 1:1, 16:9, 9:16, 4:3, 3:4, 2:3, 3:2
• Resolutions: 1K, 2K
• Count: up to 4 images

Genesis asks xAI for b64_json image responses so generated media can be stored and delivered through the normal channel attachment path. Local reference images are converted to data URLs; remote http(s) references are passed through.

To use xAI as the default image provider:

{
  agents: {
    defaults: {
      imageGenerationModel: {
        primary: "xai/grok-imagine-image",
      },
    },
  },
}

Text-to-speech

The bundled xai plugin registers text-to-speech through the shared tts provider surface.

• Voices: eve, ara, rex, sal, leo, una
• Default voice: eve
• Formats: mp3, wav, pcm, mulaw, alaw
• Language: BCP-47 code or auto
• Speed: provider-native speed override
• Native Opus voice-note format is not supported

To use xAI as the default TTS provider:

{
  messages: {
    tts: {
      provider: "xai",
      providers: {
        xai: {
          voiceId: "eve",
        },
      },
    },
  },
}

Speech-to-text

The bundled xai plugin registers batch speech-to-text through Genesis's media-understanding transcription surface.

• Default model: grok-stt
• Endpoint: xAI REST /v1/stt
• Input path: multipart audio file upload
• Supported by Genesis wherever inbound audio transcription uses tools.media.audio, including Discord voice-channel segments and channel audio attachments

To force xAI for inbound audio transcription:

{
  tools: {
    media: {
      audio: {
        models: [
          {
            type: "provider",
            provider: "xai",
            model: "grok-stt",
          },
        ],
      },
    },
  },
}

Language can be supplied through the shared audio media config or per-call transcription request. Prompt hints are accepted by the shared Genesis surface, but the xAI REST STT integration only forwards file, model, and language because those map cleanly to the current public xAI endpoint.

Streaming speech-to-text

The bundled xai plugin also registers a realtime transcription provider for live voice-call audio.

• Endpoint: xAI WebSocket wss://api.x.ai/v1/stt
• Default encoding: mulaw
• Default sample rate: 8000
• Default endpointing: 800ms
• Interim transcripts: enabled by default

Voice Call's Twilio media stream sends G.711 µ-law audio frames, so the xAI provider can forward those frames directly without transcoding:

{
  plugins: {
    entries: {
      "voice-call": {
        config: {
          streaming: {
            enabled: true,
            provider: "xai",
            providers: {
              xai: {
                apiKey: "${XAI_API_KEY}",
                endpointingMs: 800,
                language: "en",
              },
            },
          },
        },
      },
    },
  },
}

Provider-owned config lives under plugins.entries.voice-call.config.streaming.providers.xai. Supported keys are apiKey, baseUrl, sampleRate, encoding (pcm, mulaw, or alaw), interimResults, endpointingMs, and language.

x_search configuration

The bundled xAI plugin exposes x_search as an Genesis tool for searching X (formerly Twitter) content via Grok.

Config path: plugins.entries.xai.config.xSearch

{
  plugins: {
    entries: {
      xai: {
        config: {
          xSearch: {
            enabled: true,
            model: "grok-4-1-fast",
            inlineCitations: true,
          },
        },
      },
    },
  },
}

Code execution configuration

The bundled xAI plugin exposes code_execution as an Genesis tool for remote code execution in xAI's sandbox environment.

Config path: plugins.entries.xai.config.codeExecution

{
  plugins: {
    entries: {
      xai: {
        config: {
          codeExecution: {
            enabled: true,
            model: "grok-4-1-fast",
          },
        },
      },
    },
  },
}

Known limits

• Auth is API-key only today. There is no xAI OAuth or device-code flow in Genesis yet.
• grok-4.20-multi-agent-experimental-beta-0304 is not supported on the normal xAI provider path because it requires a different upstream API surface than the standard Genesis xAI transport.
• xAI Realtime voice is not registered as an Genesis provider yet. It needs a different bidirectional voice session contract than batch STT or streaming transcription.
• xAI image quality, image mask, and extra native-only aspect ratios are not exposed until the shared image_generate tool has corresponding cross-provider controls.

Advanced notes

• Genesis applies xAI-specific tool-schema and tool-call compatibility fixes automatically on the shared runner path.
• Native xAI requests default tool_stream: true. Set agents.defaults.models["xai/<model>"].params.tool_stream to false to disable it.
• The bundled xAI wrapper strips unsupported strict tool-schema flags and reasoning payload keys before sending native xAI requests.
• web_search, x_search, and code_execution are exposed as Genesis tools. Genesis enables the specific xAI built-in it needs inside each tool request instead of attaching all native tools to every chat turn.
• x_search and code_execution are owned by the bundled xAI plugin rather than hardcoded into the core model runtime.
• code_execution is remote xAI sandbox execution, not local exec.

Live testing

The xAI media paths are covered by unit tests and opt-in live suites. The live commands load secrets from your login shell, including ~/.profile, before probing XAI_API_KEY.

pnpm test extensions/xai
GENESIS_LIVE_TEST=1 GENESIS_LIVE_TEST_QUIET=1 pnpm test:live -- extensions/xai/xai.live.test.ts
GENESIS_LIVE_TEST=1 GENESIS_LIVE_TEST_QUIET=1 GENESIS_LIVE_IMAGE_GENERATION_PROVIDERS=xai pnpm test:live -- test/image-generation.runtime.live.test.ts

The provider-specific live file synthesizes normal TTS, telephony-friendly PCM TTS, transcribes audio through xAI batch STT, streams the same PCM through xAI realtime STT, generates text-to-image output, and edits a reference image. The shared image live file verifies the same xAI provider through Genesis's runtime selection, fallback, normalization, and media attachment path.

Related

• Model selection Choosing providers, model refs, and failover behavior.

• Video generation Shared video tool parameters and provider selection.

• All providers The broader provider overview.

• Troubleshooting Common issues and fixes.