Module extensions 

Extension subsystem — spawn-per-event subprocess hooks.

See docs/superpowers/specs/2026-05-21-capo-v0.7-design.md for the design rationale (spawn-per-event vs long-lived; codex-style; minimal scope).

Module structure mirrors mcp/: manifest.rs — TOML schema + parsing wire.rs — Event / Action serde types (JSONL line shape) registry.rs — validated, indexed view of loaded extensions dispatcher.rs — spawn-and-await; chain semantics; timeout diagnostic.rs — surfaced via /extensions slash command

Re-exports

pub use diagnostic::DiagnosticSeverity;

pub use diagnostic::ExtensionDiagnostic;

pub use manifest::parse_str;

pub use manifest::ExtensionEntry;

pub use manifest::ExtensionManifestFile;

pub use registry::ExtensionRegistry;

pub use registry::RegisteredExtension;

pub use wire::Action;

pub use wire::Event;

pub use wire::EventName;

Modules

diagnostic

Diagnostic surface for the extension subsystem — load-time issues (missing fields, duplicates, built-in conflicts) and runtime spawn failures collect here and are surfaced via /extensions.

dispatcher

Spawn-per-event dispatcher.

manifest

TOML manifest schema and parser. Implemented in Task 2.

registry

Validated, indexed runtime view of loaded extensions.

wire

Event/Action wire types — the single JSON line over stdio. Implemented in Task 4.

Functions

load_extensions_manifest

Load the manifest at path (missing-file = empty registry, no error) and validate it. Returns the registry and any diagnostics collected.