This landing page is built as a practical shortlist for tool-calling agents: APIs for finding information, controlling browsers, processing speech, translating text, sending messages, and storing state.
The strongest APIs for AI agents are the ones that make tool use predictable. That usually means straightforward documentation, stable request shapes, clean JSON responses, and enough coverage to support planning, retrieval, automation, and follow-up actions.
Use this page when you are designing a core agent stack for research assistants, workflow automations, support copilots, trading tools, or multi-step developer agents. The goal is not just breadth, but APIs that are realistic to call from prompts, chains, and tool routers.
From here, drill into narrower landing pages if you are solving a specific subproblem like OCR, browser automation, translation, search for RAG, or speech. This page is the broad canonical entry point for the most reusable free APIs in the directory.
