Vox MCP

Multi-model AI gateway for MCP clients.

Why

MCP clients like Claude Code, Claude Desktop, and Cursor are locked to their host model. Vox gives them access to every other model — Gemini, GPT, Grok, DeepSeek, Kimi, or your local Ollama — through a single chat tool.

The design is deliberately minimal: prompts go to providers unmodified, responses come back unmodified. No system prompt injection. No response formatting. No behavioral directives. The only value Vox adds is routing and conversation memory — everything else is pure passthrough.

What it does

Send a prompt, optionally attach files or images, pick a model (or let the agent pick), and get back the model's raw response. Conversation threads persist in memory via continuation_id for multi-turn exchanges across any provider — start a thread with Gemini, continue it with GPT. Threads are shadow-persisted to disk as JSONL for durability and can be exported as Markdown.

3 tools:

10 providers:

These are preferences within each provider. With auto, the calling agent chooses an available model; if Vox must choose, its existing provider priority applies. An explicit model or configured default takes precedence. GPT-6 Sol/Luna, Grok 4.7, Claude Fable 5.1, Sonnet 5, and Haiku 4.5 remain selectable. Claude 3 Opus's pinned snapshot is preserved for accounts with access.

See model selections and verification sources for provider preferences, exact API IDs, and reasoning behavior.

Quick start

Published package

With uv installed, add Vox to your MCP client's configuration. For example, to use OpenAI:

{
  "mcpServers": {
    "vox-mcp": {
      "command": "uvx",
      "args": ["vox-mcp"],
      "env": {
        "OPENAI_API_KEY": "your-key-here"
      }
    }
  }
}

Use the environment variable for your preferred provider from the table above. Only one provider is required. Connect the server, then ask your agent to call listmodels to see the models available with your configuration.

For an exact release, use "args": ["vox-mcp@0.9.0"]. To refresh a cached installation, run uvx --refresh vox-mcp config show, then reconnect the MCP server. A version pinned in your client configuration must be updated there as well.

Source checkout

git clone https://github.com/linxule/vox-mcp.git
cd vox-mcp
cp .env.example .env
# Edit .env — add at least one API key
uv sync
uv run python server.py

MCP client configuration

Vox runs as a stdio MCP server. Each client needs to know how to launch it. The following examples use a source checkout; the published-package configuration above avoids cloning the repository. Replace /path/to/vox-mcp with the absolute path to your cloned repo.

Claude Code (CLI)

claude mcp add vox-mcp \
  -e GEMINI_API_KEY=your-key-here \
  -- uv run --directory /path/to/vox-mcp python server.py

Or add to .mcp.json in your project root:

{
  "mcpServers": {
    "vox-mcp": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/vox-mcp", "python", "server.py"],
      "env": {
        "GEMINI_API_KEY": "your-key-here"
      }
    }
  }
}

Claude Desktop

Add to claude_desktop_config.json:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "vox-mcp": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/vox-mcp", "python", "server.py"],
      "env": {
        "GEMINI_API_KEY": "your-key-here"
      }
    }
  }
}

Cursor

Add to .cursor/mcp.json (project) or ~/.cursor/mcp.json (global):

{
  "mcpServers": {
    "vox-mcp": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/vox-mcp", "python", "server.py"],
      "env": {
        "GEMINI_API_KEY": "your-key-here"
      }
    }
  }
}

Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{
  "mcpServers": {
    "vox-mcp": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/vox-mcp", "python", "server.py"],
      "env": {
        "GEMINI_API_KEY": "your-key-here"
      }
    }
  }
}

Any MCP client

The canonical stdio configuration:

{
  "mcpServers": {
    "vox-mcp": {
      "command": "uv",
      "args": ["run", "--directory", "/path/to/vox-mcp", "python", "server.py"],
      "env": {
        "GEMINI_API_KEY": "your-key-here"
      }
    }
  }
}

Tips:

• Paths must be absolute
• You only need one API key to start — add more providers later via .env
• The .env file in the vox-mcp directory is loaded automatically, so API keys can go there instead of in the client config
• Use VOX_FORCE_ENV_OVERRIDE=true in .env if client-passed env vars conflict with your .env values

Configuration

Set these values in your MCP client's Vox env object. For a source checkout, you can instead copy .env.example to .env:

• API keys — at least one provider key is required
• DEFAULT_MODEL — overrides the saved model preference; auto asks the agent to choose
• VOX_CONFIG_PATH — optional settings file path (default: ~/.vox/config.json)
• Model restrictions — GOOGLE_ALLOWED_MODELS, OPENAI_ALLOWED_MODELS, etc.
• CONVERSATION_TIMEOUT_HOURS — thread TTL (default: 24h)
• MAX_CONVERSATION_TURNS — thread length limit (default: 100)

See .env.example for the full reference.

Set your default model

Available since 0.8.0. You or your agent can save a default without editing MCP client configuration. For example, choose GPT-6 Astra:

uvx vox-mcp config set-default gpt-6-astra
uvx vox-mcp config show

Replace gpt-6-astra with any available model ID, such as kimi-k3, grok-4.6, claude-opus-5-5, claude-fable-5-1, deepseek-flash, or gemini-3.8-flash. To remove the saved preference, run uvx vox-mcp config reset-default.

For a source checkout, use uv run vox-mcp config .... Preferences are stored in ~/.vox/config.json; set VOX_CONFIG_PATH to use another file. This file contains model preferences, not API keys. Commands make no model requests and do not need provider credentials. Use listmodels in your connected MCP client to choose an available ID or alias. Explicit gateway routes such as vercel/google/gemini-3.1-pro-preview can also be saved. IDs are preserved exactly; saving a default does not verify your account's access to that model.

Restart or reconnect Vox after changing settings. config show prints the saved default, effective default, and its source for the command's launch environment. The running MCP client's environment may differ; listmodels reports the default that its server actually loaded.

Selection order is: explicit chat.model, the previous model for a continued thread, DEFAULT_MODEL from the server environment, the saved default, then auto. A saved default therefore changes new conversations; it does not switch existing threads. To override saved preferences for one MCP client, add "DEFAULT_MODEL": "your-model-id" to the Vox server's env object. Existing source checkout .env settings also retain their environment precedence. The automatically loaded .env belongs to the Vox installation, not the current directory; use the settings command or MCP client environment for uvx installations.

With auto, the agent is asked to select a model for each call. If a caller passes model: "auto", Vox uses its built-in provider priority and preferences; this is not a live comparison of all providers. Explicit model selections always remain available. An agent with terminal access can do this for you:

Use Vox listmodels to check that GPT-6 Astra is available. Save it as my Vox default with the config command, check whether DEFAULT_MODEL overrides it, and tell me how to reconnect Vox.

An agent with only Vox's three MCP tools can select a model for each call, but cannot persist a preference; saving settings requires terminal or file access.

Cloudflare and Vercel AI Gateway

Use an explicit gateway prefix in chat.model. Vox removes only that first prefix before sending the request and keeps it in conversation memory. A missing gateway configuration or disallowed model fails without falling through to OpenRouter or a native provider. Bare model names keep their existing routing behavior.

Cloudflare

CLOUDFLARE_API_TOKEN=your-cloudflare-token
CLOUDFLARE_ACCOUNT_ID=your-account-id
CLOUDFLARE_GATEWAY_ID=default
CLOUDFLARE_MODELS=openai/gpt-5.5

{"prompt": "Explain quorum consensus.", "model": "cloudflare/openai/gpt-5.5"}

Vox uses the Cloudflare account REST API at https://api.cloudflare.com/client/v4/accounts/<account>/ai/v1, authenticates with a bearer token, and sets cf-aig-gateway-id (default unless configured). The token needs Workers AI Read permission; an AI Gateway-only token is not sufficient. Third-party models use Cloudflare Unified Billing. Workers AI model IDs retain their @cf/ prefix, for example cloudflare/@cf/moonshotai/kimi-k2.6. Legacy /compat, provider-key forwarding, and dynamic/ routes are not supported by this adapter.

Vercel

VERCEL_AI_GATEWAY_API_KEY=your-vercel-gateway-key
VERCEL_MODELS=anthropic/claude-sonnet-4.6

{"prompt": "Explain quorum consensus.", "model": "vercel/anthropic/claude-sonnet-4.6"}

Vox uses Vercel's OpenAI-compatible API at https://ai-gateway.vercel.sh/v1. AI_GATEWAY_API_KEY is also accepted; VERCEL_AI_GATEWAY_API_KEY takes precedence when both are set.

Catalogs and limits

CLOUDFLARE_MODELS and VERCEL_MODELS are optional comma-separated upstream IDs for listmodels and agent discovery. They do not restrict access. Explicit gateway model IDs work without a catalog, including with the default DEFAULT_MODEL=auto; the caller must supply the gateway model. Use CLOUDFLARE_ALLOWED_MODELS or VERCEL_ALLOWED_MODELS to restrict access. Both upstream IDs and fully prefixed Vox routes are accepted in catalogs and allowlists. Use the exact model ID published by the gateway; native-provider and gateway IDs can differ.

Gateway requests currently support text only. Vox does not infer vision or thinking controls from a model name; explicit gateway thinking_mode requests are rejected before inference. Its 32,768-token context and 4,096-token output budgets are conservative local estimates, not advertised upstream limits; these numbers are not sent as generation parameters. Omitted temperature and reasoning settings use upstream defaults. No catalog or model availability request is made at startup. The adapters are covered by mocked HTTP tests; live inference requires a configured account and has not been exercised as part of the release checks.

Development

Dependencies are maintained in pyproject.toml and uv.lock; Dependabot updates the lock through its uv integration while respecting the supported version ranges. Changing those ranges requires a deliberate compatibility review. CI checks the lockfile, runs the offline test suite on Python 3.10 and 3.13, and audits locked packages with pip-audit. The supported SDK lines are MCP 2.x, OpenAI 2.x, and Anthropic 0.x. Provider major upgrades are kept separate from dependency maintenance.

uv sync
uv run python -c "import server"   # smoke test
uv run pytest                       # run tests

See CONTRIBUTING.md for code style, project structure, and how to add providers.

License

Apache 2.0 — see LICENSE and NOTICE.

Derived from pal-mcp-server by Beehive Innovations.