AI repos for API design
Open-source AI projects built around API design or genuinely useful if you work with it, each with what it does for you. 16 repos, most relevant first.
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litellm
Offers one OpenAI-format API across 100+ LLM providers, as a library or gateway.
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freellmapi
Expose 34 providers' free tiers behind one OpenAI-style /v1 endpoint with routing, failover and per-key rate tracking.
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cli-printing-press
Turns an API into agent-friendly commands with a local SQLite store and compact output.
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free-claude-code
Shows how a local proxy translates between agent API formats and many provider backends.
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CLIProxyAPI
A Go proxy translating between OpenAI, Gemini and Claude API formats across multiple accounts.
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open-notebook
Automate notebook content and transformations through the included REST API.
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cli
See a CLI that generates commands dynamically from Google's Discovery Service.
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9router
See a gateway that translates between provider API formats behind one endpoint.
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cli
Shows a layered CLI over a large API surface that both humans and agents can drive.
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presenton
Ships an API for generating decks programmatically from prompts or documents.
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honcho
A peer, session and message API model to study or self-host for agent memory.
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treg
Shows a proxy pattern for server-side credential injection and per-call pricing of API endpoints.
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agent-client-protocol
Versioned JSON Schema with capability negotiation is a worked example of protocol design.
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Switchyard
Offers a local proxy and gateway integrations for routing LLM requests.
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proof-sdk
Agent HTTP bridge with event polling shows a concrete API for agent document edits.
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Clodex
Reference for translating between Anthropic and Codex API formats in a proxy.