fix: keep stdin open for can_use_tool permission responses#1106
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Echolonius wants to merge 1 commit into
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fix: keep stdin open for can_use_tool permission responses#1106Echolonius wants to merge 1 commit into
Echolonius wants to merge 1 commit into
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wait_for_result_and_end_input() kept stdin open until the first result only when SDK MCP servers or hooks were present. A can_use_tool callback also needs the control protocol: the CLI sends can_use_tool requests mid-turn and the SDK writes the permission response back over stdin. With only can_use_tool configured (the query() + AsyncIterable path its own ValueError directs users to), stdin closed as soon as the input stream was exhausted, so every permission request failed with "Tool permission request failed: Error: Stream closed" and the callback was never invoked. Include can_use_tool in the keep-stdin-open condition, matching the existing behavior for SDK MCP servers and hooks.
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Fixes #1105.
Problem
wait_for_result_and_end_input()keeps stdin open until the first result only when SDK MCP servers or hooks are present. Acan_use_toolcallback needs the same treatment: the CLI deliverscan_use_toolpermission requests over the control protocol mid-turn, and the SDK writes the permission response back over stdin.With only
can_use_toolconfigured (thequery()+AsyncIterablepath that the callback's ownValueErrordirects users to), stdin closed as soon as the input stream was exhausted. Every subsequent permission request then failed withTool permission request failed: Error: Stream closed, the callback was never invoked, and the model burned its turns retrying the tool.Fix
Add
self.can_use_toolto the keep-stdin-open condition — the same contract already applied for SDK MCP servers (#731) and hooks.Verification
can_use_toolonly, the callback never fired and every Write failed withStream closed; adding a no-op hook whose matcher never fires (which only flips this condition) made the same run succeed. After this fix, the no-hook case invokes the callback and completes:can_use_tool calls: ['Write'], file created.test_streaming_prompt_with_can_use_tool_waits_for_result: the mock transport enforces the real CLI contract — thecan_use_toolcontrol request arrives only after the input stream is exhausted, the result is not produced until the permission response has been written, and writes afterend_input()raise. Fails onmainwithRuntimeError: stdin closed; passes with the fix.pytest tests/test_query.py tests/test_tool_callbacks.py: 75 passed.ruff check/ruff format --checkclean.🤖 Generated with Claude Code
https://claude.ai/code/session_01YcMi8ny9DUBDf6y6m76HWk