halt

treeship halt is the kill switch. It signs a halt.v1 receipt naming an actor (or *, every actor in the workspace), chains it onto the active session, and writes a marker that the enforcement points read. While the halt stands, the Claude Code plugin's PreToolUse gate refuses every tool call for that actor, before any card rule, and signs each refusal as a blocked.v1 receipt with reason_class: operator_revocation. Lifting it signs a second receipt and clears the marker. A verifier reading the sealed package sees when the switch was thrown, by whom, and when it was lifted.

treeship halt agent://claude-code --reason "off-task network calls"
treeship halt '*' --reason "incident 2026-09-18"
treeship halt list
treeship halt --lift agent://claude-code

What it reaches, and what it does not

A halt stops what the harness routes through hooks: every tool call the Claude Code plugin sees, and under TREESHIP_STRICT=1, calls through the MCP bridge. It does not reach a process an agent started outside those paths, a runtime with no hooks, or another machine. The coverage level says where that boundary is for each harness. A halt is an order the instrumented surface obeys, not a guarantee about the uninstrumented one.

Halting

✓ actor halted
  actor:      agent://claude-code
  halt:       art_9c1e…
  issued_at:  2026-09-18T16:29:15Z
  reason:     off-task network calls
   → every tool call the harness routes through hooks is now refused and signed as blocked.v1
   → treeship halt --lift agent://claude-code   to lift it

The actor must be a URI (agent://…, human://…) or *. A second halt on an actor already halted is refused until the first is lifted, so there is one halt to point at. When a session is active, the halt chains onto its head, inside the signature, so the sealed package shows it in order with the actions it stopped.

Lifting

✓ halt lifted
  actor:  agent://claude-code
  lift:   art_2b7a…
  halt:   art_9c1e…
  issued_at: 2026-09-18T16:41:02Z

The lift names the halt it ends in its signed payload and chains onto the session like the halt did.

Listing

treeship halt list
treeship halt list --format json

Each row shows the actor, the halt artifact, when it was issued, the reason, and whether it is honoured. A marker is honoured only when it names an artifact in this workspace's store signed by this workspace's key. A marker written by hand, or pointing at an artifact from elsewhere, is listed as ignored and the gate does not act on it.

Options

See also

• halt.v1, the predicate
• The Claude Code gate, where a halt is enforced
• blocked.v1, what each refusal is signed as