Build and test a session store adapter

A SQLite SessionStore for the Python Agent SDK that implements all six methods of the protocol, plus a two-process demo in which a second "host" with an empty config folder resumes the session from the store alone. One unique rule, on the entry's uuid within its session and subpath, makes retried batches harmless.

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Before you start

Before you start:Install Claude Code Python with uv Get an OpenRouter key OpenRouter or a local model?Local models with Ollama

This exercise calls a model. Run it either way

Any model through OpenRouterOne key for Claude, GPT, Gemini, Llama and more. Pay per token, with a credit limit.A local open-source modelFree and private with Ollama. Weaker on hard tasks.

Which should I pick? →

The adapter is a table of transcript entries in commit order plus a small summary sidecar, wrapped in the six methods of the SDK's SessionStore protocol. Everything that matters is in the table design: an autoincrement id gives the order, and UNIQUE (project_key, session_id, subpath, uuid) with INSERT OR IGNORE turns the SDK's retries into no-ops while still appending entries that have no uuid. The resume demo then runs the real Agent SDK twice, in two processes with separate CLAUDE_CONFIG_DIRs, deleting the first host's local files in between.

Answers Lesson 5: State, sessions and checkpoints

Step-by-step answer

Core 75 min6 steps