decision_control
Which decision actions hooks can take on the triggering action. Contents: {block: bool, allow: bool, modify: bool}. Mechanisms include exit code contracts, JSON decision fields, or cancel flags. Boundary: decision_control governs whether a tool invocation proceeds; see permission_control for whether a tool is available at all.
Type: object Content type: hooks
Provider Support
Section titled “Provider Support”| Provider | Supported | Mechanism |
|---|---|---|
| amp | ✓ | Pre-execute 'send-user-message' action cancels the pending tool call and injects a user message; exit code 0 = allow, non-zero = block |
| claude-code | ✓ | block: exit code 2 or decision=block; allow: permissionDecision=allow in hookSpecificOutput; modify: updatedInput replaces tool input before execution; PermissionDenied event supports {retry: true} to allow model retry |
| cline | ✓ | pre_tool_use_cancellation: PreToolUse hooks can cancel (block) the tool invocation; no allow or modify sub-capabilities documented |
| codex | ✓ | hook_result_abort: Codex hooks can abort (block) the triggering action; allow and modify sub-capabilities documented via hook result schema |
| copilot-cli | ✓ | pre_tool_use_deny: Copilot CLI PreToolUse hooks can deny (block) the tool invocation; no allow or modify documented |
| crush | ✓ | Hook subprocess exit code controls tool execution: exit code 2 blocks the tool call (deny). Other exit codes allow it. The hook may also return a JSON decision field with values allow, deny, or none. |
| cursor | ✓ | Exit codes drive decisions: exit code 2 blocks the action, exit code 0 allows it to proceed; JSON on stdout can also return structured decision fields. |
| factory-droid | ✓ | PreToolUse hooks return JSON with allow/deny/ask decision field; exit code 2 blocks with stderr fed back to Droid; non-zero non-2 shows stderr to user as non-blocking error |
| gemini-cli | ✓ | exit_code_semantics: Gemini CLI uses exit codes to signal block (non-zero) or allow (zero) decisions; no modify sub-capability documented |
| pi | ✓ | tool_call handlers return { block: true, reason? } to prevent tool execution; tool_call errors also block the tool (fail-safe behavior) |
| kiro | ✗ | Kiro hooks are observational; no mechanism to block, allow, or modify tool invocations documented |
| opencode | ✗ | not documented |
| roo-code | ✗ | not documented |
| windsurf | ✗ | Windsurf hooks are observational by default; pre-hooks can block via exit code 2 but cannot allow or modify the triggering action |
| zed | ✗ | not documented |