Fix MCP elicitation detection and multi-resume hang - #126
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- Relax supportsManagedElicitation to only require form capability (not form AND url). Most MCP clients (including Claude Code) only advertise form support — they were incorrectly falling back to the pause/resume two-tool pattern. - When a UrlElicitation is triggered but the client lacks url support, fall back to a form elicitation with the URL in the message. - Fix resume hanging when an execution triggers multiple elicitations. The pause signal is now re-armable so resume races completion against a new pause, matching the executeWithPause pattern. Previously resume just awaited the completion promise which would never resolve if the execution paused again. - Update resume return type from ExecuteResult | null to ExecutionResult | null so callers can handle re-pauses.
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Replace raw Promise.race, mutable callbacks, and unsafe casts with idiomatic Effect primitives: - Deferred<PausedExecution> as the pause signal (swappable via Ref) - Deferred<ElicitationResponse> as the resume response channel - Fiber for the sandbox execution (stays alive across pause/resume) - Effect.race (non-interrupting) to await completion or next pause
RhysSullivan
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* Fix MCP elicitation detection and multi-elicitation resume hang - Relax supportsManagedElicitation to only require form capability (not form AND url). Most MCP clients (including Claude Code) only advertise form support — they were incorrectly falling back to the pause/resume two-tool pattern. - When a UrlElicitation is triggered but the client lacks url support, fall back to a form elicitation with the URL in the message. - Fix resume hanging when an execution triggers multiple elicitations. The pause signal is now re-armable so resume races completion against a new pause, matching the executeWithPause pattern. Previously resume just awaited the completion promise which would never resolve if the execution paused again. - Update resume return type from ExecuteResult | null to ExecutionResult | null so callers can handle re-pauses. * Refactor pause/resume engine to use Effect Deferred/Fiber/Ref Replace raw Promise.race, mutable callbacks, and unsafe casts with idiomatic Effect primitives: - Deferred<PausedExecution> as the pause signal (swappable via Ref) - Deferred<ElicitationResponse> as the resume response channel - Fiber for the sandbox execution (stays alive across pause/resume) - Effect.race (non-interrupting) to await completion or next pause * Fix type error: orDie on Fiber.join to eliminate unknown error channel
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Summary
supportsManagedElicitationto only requireformcapability — clients like Claude Code that advertise{ form: {} }now use inline elicitation instead of the pause/resume two-tool pathurlsupportresume()hanging when an execution triggers multiple elicitations (e.g. a loop calling multiple tools that each require approval) — the pause signal is now re-armable soresumeraces completion against a new pauseresumereturn type fromExecuteResult | nulltoExecutionResult | nullso callers can handle re-pausesTest plan