Agent Adapter

Agent Adapter is a free, open-source (Apache-2.0) Python framework for developers building AI agents. The problem: a tool written for LangChain has to be rewritten for CrewAI, then again for Google ADK, and the safety rules (who approves a risky call, how much a run may spend) live in each framework's own format. With Agent Adapter you write the tool once as a plain Python function and attach it to any of 21 frameworks and engines with one line: LangChain, CrewAI, Google ADK, OpenAI Agents SDK, Pydantic AI, LlamaIndex, DSPy and more. Every call goes through one executor that adds argument checks, budgets, one-use human approvals, caching, retries, a cost ledger and traces. The same tools can be served over MCP or HTTP to 10 languages, and a local run viewer shows the flow graph, each tool call and its cost. pip install agent-adapter