Nano Cordis

Key features

• session.ts keeps an append-only list of events: turn/start, step/start, user/message, request/header, assistant/message, tool/call, tool/result, step/end, turn/end.
• Before each request the loop logs a request/header (model, system prompt, tool schemas) whenever it changed, and then builds the request from the last logged header plus the derived messages.
• A turn starts with the user's message and ends when the model answers without tool calls (completed), when the step limit is hit (max-steps), or on an error.
• tools.ts holds the definitions and runs every call through the same pipeline: tools/pre-execute (allow or deny) → the tool body → tools/post-execute (rewrite the result).
• append() is the only way to write (session.events is a frozen copy)