Coding Agent Custom API Cheatsheet: Copy-Paste Configs to Cut Your Token Bill

Coding agents often require users to pay high fees due to hidden settings for swapping out the underlying model, which results in users sticking to default, costly models. This comprehensive guide addresses this issue by providing a clear reference to configure custom APIs for popular coding agents like Claude Code, OpenClaw, Codex, OpenCode, and Cursor, allowing users to redirect these agents to more affordable models. The guide highlights the two main protocol families of coding agents: Claude Code, which uses the Anthropic API, and others like OpenClaw and Codex, which use the OpenAI-compatible API. By understanding these distinctions and setting up the correct base URL, API key, and model ID, users can significantly reduce costs, as open-weight models are considerably cheaper than frontier models. The cheatsheet emphasizes the importance of using the right configuration to achieve savings of up to 70%, without altering the user's workflow, and suggests utilizing Atlas Cloud for a unified provider experience that simplifies budgeting and model management.