How one dev team runs an autonomous agent using JSONL files and Git as a state layer

A development team has spent three months running an autonomous publishing agent that manages posts, replies, follows, and articles — storing all its state in append-only JSONL files committed to a Git repository instead of a traditional database. The approach provides a built-in audit trail, since every state change appears as a Git diff with a timestamp, making it easier to monitor and review the agent's decisions. Append-only file writes limit crash damage to at most the last line, and deduplication via external system identifiers ensures that duplicate cron runs or retried commands do not create duplicate records. The team enforces strict safeguards such as all-or-nothing batch validation and mechanical copying of identifiers to prevent subtle data corruption. A key advantage is that the test suite can directly load production ledger files to assert data invariants before any commit is accepted.