RunAPI Flux MCP Server

Flux API access for AI agents: run image generation operations, poll asynchronous results, and check pricing through one focused MCP server.

_{Works with Claude Code, Codex, Cursor, Windsurf, VS Code, Roo Code, and any MCP-compatible host.}

Install | Tools | Models | Agent Prompts | Configuration | Links

Why This Package?

@runapi.ai/flux-mcp is a focused Model Context Protocol server for the Flux model line on RunAPI. It gives MCP-compatible assistants direct access to 2 endpoints and 3 model variants without loading the full RunAPI catalog.

Use this per-model server when an agent should stay scoped to Flux. Use @runapi.ai/mcp when one assistant should discover every RunAPI model line.

Install

Add it to Claude Code:

claude mcp add flux -s user -- npx -y @runapi.ai/flux-mcp

Use project scope when the server should be shared with a repository:

claude mcp add flux -s project -- npx -y @runapi.ai/flux-mcp

Codex, Cursor, Windsurf, VS Code, Roo Code, and other MCP hosts can use the same stdio command:

{
  "mcpServers": {
    "flux": {
      "command": "npx",
      "args": ["-y", "@runapi.ai/flux-mcp"]
    }
  }
}

check_pricing works before sign-in. For task creation and status polling, ask your assistant to call the login tool. It opens a browser login and saves credentials to ~/.config/runapi/config.json, the same file used by runapi login. Headless and CI hosts can still set RUNAPI_API_KEY before starting the MCP host.

Ready-made examples are in examples/ for Claude, Cursor, Windsurf, VS Code, and Roo Code.

Tools

Models

Flux covers 3 model variants across 2 endpoints. Each tool accepts the models listed for it:

Model availability can change between releases. Use check_pricing or the Flux model page for the current catalog view.

Agent Prompts

Ask your assistant in natural language; it can inspect pricing, create the task, and return the task id plus output URLs.

Create a task

Run a Flux remix image task with RunAPI.

The assistant can call check_pricing, then remix_image, and return the task id, status, and output URLs.

Submit without waiting

Create the task but don't wait for it to finish.

The assistant calls the create tool with wait: false and returns the task id. Check on it later with get_task.

Check pricing before creating

Check current Flux pricing, then create the task if it matches my request.

The assistant calls check_pricing and can link to the Flux model page for the canonical catalog entry.

Configuration

The server resolves auth in this order:

1. RUNAPI_API_KEY environment variable, useful for headless and CI hosts
2. ~/.config/runapi/config.json, created by the MCP login tool or runapi login
3. No key, which still allows check_pricing

The config file is normally managed by login. A pre-provisioned headless config can use:

{
  "apiKey": "your_runapi_key"
}

Do not commit real API keys.

Links

License

Licensed under the Apache License, Version 2.0.