Overview
The local runtime is the fastest way to test the database-MCP commit boundary. It runs in your environment, exposes semantic MCP tools over stdio, stores evidence/proposals/replay in local SQLite, and applies approved jobs through local Postgres/MySQL adapters.
No Synapsor Cloud account is required. The public demo command starts disposable Docker Postgres/MySQL databases, lists MCP tools, inspects rows, creates proposals, proves the source is unchanged before approval, applies guarded writeback, retries idempotently, and proves stale-row conflict.
Local mode is useful on its own. Cloud is an optional upgrade when you need team approvals, RBAC, managed policy, hosted replay search, and runner fleet visibility.
Developer notes
- Use the Docker demo before connecting a real database.
- Keep credentials in environment variables, not runner config files.
- Use review mode only when a separate write credential is available to the trusted runner.
- Use replay export to inspect what the model saw, proposed, and what the runner applied or refused.