---
title: "Use Claude Code with Your OpenAI Key — Keychain-Locked BYOK"
description: "Bring your own OpenAI key to Claude Code. ToolPiper injects it server-side from macOS Keychain — never in dotfiles, never in logs."
canonical: "https://modelpiper.com/recipes/claude-code-byok-openai/"
---

# Use Claude Code with Your OpenAI Key — Keychain-Locked BYOK

> Bring your own OpenAI key to Claude Code. ToolPiper injects it server-side from macOS Keychain — never in dotfiles, never in logs.

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BYOK · Keychain · Pro

# Claude Code with your own OpenAI key.

Use gpt-4o or gpt-4o-mini through Claude Code, billed against your OpenAI account, with the key locked in macOS Keychain. ToolPiper injects it server-side — your dotfiles, shell history, and screenshots stay clean.

## Before you start

-   OpenAI account with API access (an OPENAI\_API\_KEY at <a href="https://platform.openai.com/api-keys" target="\_blank" rel="noopener noreferrer" class="text-primary-400 hover:text-primary-300">platform.openai.com/api-keys</a>).
-   Claude Code installed.
-   ToolPiper installed and ToolPiper Pro activated (cloud-key proxying is a Pro feature).

## Setup

1.  1
    
    ### Add your OpenAI key to ToolPiper
    
    Open ToolPiper → Settings → Cloud Providers → OpenAI → _Add Key_. Paste the key. ToolPiper stores it in macOS Keychain (encrypted at rest, never written to disk in plaintext) and returns a Keychain reference. The actual key string is never available to JavaScript or to Claude Code.
    
2.  2
    
    ### Create an OpenAI endpoint
    
    In ToolPiper → Endpoints → Add Endpoint → **OpenAI (cloud)**. Pick a model — _gpt-4o-mini_ for cheap fast work, _gpt-4o_ for harder tasks. Save. The endpoint references your Keychain key by id, not by value.
    
3.  3
    
    ### Click "Configure for Claude Code"
    
    ToolPiper → Docs → Claude Code → _Configure for Claude Code_. We write `~/.claude/settings.json` with a ToolPiper dev token (not your OpenAI key) and add your OpenAI endpoint to Claude Code's `/model` picker.
    
4.  4
    
    ### Run Claude Code, pick OpenAI in /model
    
    Open any terminal.
    
    shell
    
    ```
    claude
    # /model → "OpenAI gpt-4o-mini (your key)"
    # Every prompt now bills against your OpenAI account.
    ```
    
5.  5
    
    ### Watch the bill from inside Claude Code
    
    Ask _"how much have I spent in this session?"_ — ToolPiper's LogPiper telemetry surfaces per-session token counts (pre-pricing rollup). For full billing, the OpenAI dashboard is the source of truth.
    

## Why this recipe

### Key never leaves Keychain

ToolPiper signs OpenAI requests server-side. Your dotfiles stay free of secrets, screenshots can't leak the key, and Claude Code never sees it.

### You own the bill

No marketplace markup, no token routing through us. ToolPiper Pro is a flat subscription; the per-token cost goes straight to OpenAI on your card.

### Same flow for any provider

Same recipe works for Anthropic Console, Gemini, Groq, DeepSeek, OpenRouter, Mistral, xAI, and Perplexity. One BYOK pattern; ten providers.

## Frequently asked

Why route through ToolPiper instead of pointing Claude Code straight at OpenAI?

Three reasons. (1) Your key stays in Keychain — Claude Code's default flow puts <code class="font-mono text-xs text-white/70">ANTHROPIC\_API\_KEY</code> in env vars and dotfiles. (2) You can switch providers mid-session ("use my local Qwen") without restarting. (3) ToolPiper's 147 MCP tools come along for free.

Does this work with Anthropic Claude API too?

Yes. Same recipe, but pick <strong>Anthropic (cloud)</strong> as the endpoint provider. Your Anthropic API key is BYOK, billed against your console account. Claude Code talks to ToolPiper, ToolPiper talks to Anthropic.

Can I limit which models the BYOK key can be used for?

Yes. Configure model-level permissions in ToolPiper → Settings → Cloud Providers. The OpenAI Responses API also supports key-level scoping; combine the two for defense in depth.

What if my OpenAI key gets compromised?

Revoke it on platform.openai.com and update ToolPiper's Keychain reference. No rebuild, no Claude Code restart needed — ToolPiper picks up the new key on the next request. Old key string never existed outside Keychain.

## Ready to try it?

ToolPiper is a free download. Configure once and Claude Code routes through your Mac.

[Download ToolPiper](https://modelpiper.com/download)[Open Setup Guide](/docs/toolpiper#claude-code)

## Other Claude Code recipes

[

### Apple Intelligence (free)

/claude-code-apple-intelligence](/recipes/claude-code-apple-intelligence)[

### Local Qwen via llama.cpp

/claude-code-local-qwen](/recipes/claude-code-local-qwen)[

### Switch providers in chat

/claude-code-cross-provider](/recipes/claude-code-cross-provider)