Create a Design Thinking session. The brief needs problem_space, target_segments, success_criteria, risk_tolerance, and may declare inputs (repo path, metrics/discussion/document files).

Advance the session to its next halt (gate, input, stop, or completion). Completed runs are finalized automatically: Dossier, then handoff specs.

Advance the session by at most one stage.

Stop the run (journaled human-initiated stop); the session stays resumable.

Where the session is and what blocks progress.

List sessions in the workspace.

Approve or reject the pending gate (rejection requires a reason).

Loop back to an earlier stage (test->define, test->empathize, define->empathize).

Answer the session's pending Founder-mode question, then run_session again.

Read ledger events with the same filters and canonical form as the CLI.

Generate OpenSpec MVP specifications for the validated concept, ready to be ingested by a coding harness (refused for killed concepts).

Generate the Session Dossier and return the export paths.