Reference

Live proof: Grok client extensions (2026-07-18T14:16:50.643Z)

Live proof: Grok client extensions (2026-07-18T14:16:50.643Z)

#Result: PASS

High-confidence live reproduction against real grok agent stdio via AcpClient on branch feat/grok-client-ext-methods.

Host callbacks (onAskUserQuestion / onExitPlanMode) return canned outcomes; the agent must still invoke the vendor extMethods and accept our JSON-RPC responses without Method not found.

#Checks

ScenarioStatusWire evidence
ask_user_question acceptedPASSrequest → answers: {"Pick a color?":"Red"} → tool UserAnswered completed
exit_plan_mode approvedPASSresponse {outcome:"approved"} → tool completed (EmptyPlan/PlanReady path)
exit_plan_mode rejectedPASSresponse {outcome:"rejected", comments:"…"} → tool completed with revise text
exit_plan_mode abandonedPASSresponse {outcome:"abandoned"} → tool completed with abandon text

failures: [] · eventCount: 63 · agent model: grok-4.5

#Artifacts

#How to re-run

Requires a working grok CLI on PATH (Grok Build agent).

pnpm exec tsx scripts/grok-ext-live-proof.mts
# writes into docs/proof-2026-07-18-grok-ext-methods/

#What this proves / does not prove

Proves: with this PR's AcpClient.extMethod handlers registered, Grok's live agent successfully completes _x.ai/ask_user_question and _x.ai/exit_plan_mode for all four host outcomes (accepted / approved / rejected / abandoned). No Method not found.

Does not prove: interactive TTY prompt UX (callbacks short-circuit the CLI prompts). Unit tests cover parsers/response builders; this run covers the live agent ↔ host callback path used by embedders.