agents tool-use claude-api patterns implementation

Agent loops replace frameworks—ship in fifty lines

An AI agent is one synchronous loop: send conversation to model, run requested tools, feed results back, repeat until answered—no framework required.

June 5, 2026

Summary

Developers spend cycles evaluating agent frameworks when the core pattern fits in a single code block. Understanding this cuts through abstraction overhead and makes tool-use agents debuggable and portable.

Why it matters

Implementation verdict

Replaces opaque agent SDKs with transparent control flow. Requires Claude API access and basic async handling. Ready now—copy the loop, add your tools, deploy.

Sources

1.an agent is one loop: Send the conversation to the model. If it asks to use a tool, run the tool. Feed the result back. Repeat until it answers.
2.That's it. Tool use is just: the model emits a tool_use block, you run the matching function, you hand back a tool_result.
3.you can read every line of an agent in one sitting

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