Claude Code (manual setup) - Fireworks AI Docs

Prefer FireConnect. Run fireconnect claude on --model firerouter (v0.9.0+) instead of editing JSON by hand. See Claude Code and Models.

This page is only for manual ~/.claude/settings.json setup when you cannot use FireConnect.

Prerequisites

Claude Code installed
A Fireworks API key (fw_...)
An Anthropic API key if you need pass-through to Claude Opus 4.8. See Authentication.

Add one of the configs below to ~/.claude/settings.json (on Windows: %USERPROFILE%\.claude\settings.json), then restart Claude Code.

With a Claude subscription

You do not need to pass any access or API token. Use ANTHROPIC_CUSTOM_HEADERS to pass your Fireworks API key.

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://api.fireworks.ai/inference",
    "ANTHROPIC_MODEL": "firerouter[1m]",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "firerouter[1m]",
    "ANTHROPIC_DEFAULT_FABLE_MODEL": "glm-fast-latest[1m]",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "kimi-latest",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "deepseek-v4-flash",
    "CLAUDE_CODE_SUBAGENT_MODEL": "deepseek-v4-flash",
    "ANTHROPIC_CUSTOM_HEADERS": "x-fireworks-api-key: YOUR_FIREWORKS_API_KEY"
  }
}

With an Anthropic API key

Add ANTHROPIC_API_KEY for pass-through. You still need ANTHROPIC_CUSTOM_HEADERS for your Fireworks API key.

{
  "env": {
    "ANTHROPIC_BASE_URL": "https://api.fireworks.ai/inference",
    "ANTHROPIC_MODEL": "firerouter[1m]",
    "ANTHROPIC_DEFAULT_OPUS_MODEL": "firerouter[1m]",
    "ANTHROPIC_DEFAULT_FABLE_MODEL": "glm-fast-latest[1m]",
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "kimi-latest",
    "ANTHROPIC_DEFAULT_HAIKU_MODEL": "deepseek-v4-flash",
    "CLAUDE_CODE_SUBAGENT_MODEL": "deepseek-v4-flash",
    "ANTHROPIC_CUSTOM_HEADERS": "x-fireworks-api-key: YOUR_FIREWORKS_API_KEY",
    "ANTHROPIC_API_KEY": "YOUR_ANTHROPIC_API_KEY"
  }
}

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