Module protocol 

Gate wire protocol — versioned, env-var-keyed.

Design: [docs/design.md §3.3, §7]. The schema version is held in the KLASP_GATE_SCHEMA environment variable exported by the generated hook script, not in the JSON stdin payload — this defends against a malicious agent that crafts a tool_input field claiming an arbitrary schema version.

Versioning is independent of klasp’s semver: most binary releases will not bump the schema. Bumping is reserved for genuine wire-format changes (renamed fields, required-field additions, exit-code semantics).

Structs

GateInput

The Claude Code PreToolUse payload klasp consumes from stdin.

GateProtocol

ToolInput

The subset of Claude Code’s tool_input klasp inspects. Only the Bash tool’s command field matters in v0.1; future fields can be added behind #[serde(default)] without bumping the schema.

Enums

GateError

Constants

GATE_SCHEMA_VERSION

Wire-protocol schema version. Bump only when the JSON shape, exit-code semantics, or env-var contract changes — never for cosmetic releases.

KLASP_OUTPUT_SCHEMA

klasp gate --format json output schema version.

PLUGIN_PROTOCOL_VERSION

Plugin subprocess protocol version. Separate from GATE_SCHEMA_VERSION so plugin upgrades and gate upgrades evolve independently.