feat(hooks): switch PreToolUse to JSON permissionDecision protocol#6
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HeinrichvH merged 1 commit intomainfrom Apr 22, 2026
Merged
feat(hooks): switch PreToolUse to JSON permissionDecision protocol#6HeinrichvH merged 1 commit intomainfrom
HeinrichvH merged 1 commit intomainfrom
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Replace the exit-2 + stderr pattern with the documented JSON protocol:
emit `{"hookSpecificOutput": {"permissionDecision": "deny",
"permissionDecisionReason": ...}}` on stdout and exit 0 for all three
blocking paths (cache hit, successful worker routing, strict-mode worker
failure).
Claude Code's current rendering treats both protocols as "hook blocking
error" in the transcript, so there is no user-visible UX change today.
The switch is a semantic correctness improvement: we are using the
documented hook-decision API rather than repurposing exit 2. If Anthropic
adds a true result-override primitive (e.g. `toolResultOverride`) or
changes the rendering for `deny`-with-reason, we inherit it for free.
Loose-mode fallback stays on exit 0 + stderr warning (unchanged).
post_tool_use still uses exit 2 — untouched in this pass.
Tests updated to parse JSON stdout and assert `permissionDecision: deny`
plus the reason text. All 43 pass.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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Replace the exit-2 + stderr pattern with the documented JSON protocol: emit
{"hookSpecificOutput": {"permissionDecision": "deny", "permissionDecisionReason": ...}}on stdout and exit 0 for all three blocking paths (cache hit, successful worker routing, strict-mode worker failure).Claude Code's current rendering treats both protocols as "hook blocking error" in the transcript, so there is no user-visible UX change today. The switch is a semantic correctness improvement: we are using the documented hook-decision API rather than repurposing exit 2. If Anthropic adds a true result-override primitive (e.g.
toolResultOverride) or changes the rendering fordeny-with-reason, we inherit it for free.Loose-mode fallback stays on exit 0 + stderr warning (unchanged). post_tool_use still uses exit 2 — untouched in this pass.
Tests updated to parse JSON stdout and assert
permissionDecision: denyplus the reason text. All 43 pass.