Docs · Guide

Fireworks and Fireworks Nexus in Claude Code, Codex and other agents

Fireworks hosts open models, paid as you go; Fireworks Nexus is an account and plan of its own at nexus.fireworks.ai, where Nexus Auto picks the model. magpie has a preset for each: fireworks and fireworks-nexus.

Fireworks, pay as you go

Get a key.Make one at app.fireworks.ai under Settings → Users → API Keys.
Add it.Pick Fireworks in the app and paste the key into API key, or from the CLI:

Terminal

magpie provider add fireworks fw_…
magpie provider test fireworks
magpie claude fireworks/

The preset asks Chat Completions alone, at https://api.fireworks.ai/inference/v1, with models.dev's fireworks-ai for the list and prices. magpie translates Claude Code's Anthropic requests and Codex's Responses requests to Chat for Fireworks.

Fireworks Nexus

A Nexus key is made at nexus.fireworks.ai, not on the Fireworks platform. Its /inference endpoints speak Chat Completions, Responses and Anthropic Messages alike, so Codex's and Claude Code's requests go on their own APIs.

Terminal

magpie provider add fireworks-nexus fw_…
magpie codex fireworks-nexus/auto
magpie claude fireworks-nexus/auto

Pro and Team take only auto, Nexus Auto, and refuse an open model named directly with a 403, so auto is the preset's list. An Enterprise account's open models are typed in by id among the provider's models.

Claude and GPT in Nexus

Nexus Auto reaches Claude and GPT with your own keys, in the x-anthropic-api-key and x-openai-api-key headers, or with Provider Keys set up on the Nexus account. In magpie's provider editor, Headers offers both names to add, with the values yours to fill in; from the CLI:

Terminal

magpie provider set fireworks-nexus header.x-anthropic-api-key=sk-ant-…
magpie provider set fireworks-nexus header.x-openai-api-key=sk-…

A header of your own goes on every request. An empty value removes it.

Notes

Agents only reach magpie; they never hold the Fireworks key or its address.
Fireworks can share a routing group with other providers of the same open models: when one fails, the group's next member answers.
Nexus plans and limits are as Fireworks' own pages say; this page covers how magpie connects.

FAQ

Does magpie support Fireworks AI?

Yes. The fireworks preset takes a Fireworks API key and asks Chat Completions at api.fireworks.ai/inference/v1; a model id is fireworks/.

How is Fireworks Nexus different from Fireworks?

Nexus is an account and plan of its own, with keys made at nexus.fireworks.ai. Its endpoints speak Chat, Responses and Messages, Nexus Auto picks the model, and Pro and Team take only auto.

Why does Nexus list only auto?

Pro and Team refuse an open model named directly with a 403 and take only auto. An Enterprise account types its open models in by id.

How do I use Claude and GPT in Nexus?

Put your own Anthropic and OpenAI keys in the x-anthropic-api-key and x-openai-api-key headers, or set up Provider Keys on the Nexus account.