Documentation
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Overview ¶
Command obsigna-hook is a short-lived hook binary invoked by agent runtimes (Claude Code, Codex, …) on PostToolUse and PreToolUse events. It reads a JSON frame from stdin, maps it to an emitter.Event, and forwards it to the agent-receipts daemon over a Unix-domain socket.
It is the primary hook entrypoint (ADR-0036). The legacy agent-receipts-hook binary is a thin deprecation shim that forwards here (see ../agent-receipts-hook), so existing runtime configs that invoke the hook by the old name keep working through the rename. Unlike the daemon/mcp/collector binaries, the hook gets no `obsigna hook run` launcher: it is a per-tool-call callback, and wrapping it would tax every event for no benefit (ADR-0034 decision 5).
Exit behaviour:
- stdin unreadable or runtime not recognised → silent exit 0 (not our concern)
- runtime identified, any subsequent failure → exit 1 + message to stderr
The strict-error exit-1 behaviour is intentional: once we know which runtime is calling us, a failure to record the receipt is a signal worth surfacing.
Source Files