Module process_extension 

Process-hosted extension contract (roadmap phases 64, 95, and 97).

A process extension is a non-Rust child process that registers ordinary extension services (inference engines, event sinks, tool providers, subagent dispatchers, task executors) through a manifest and speaks newline-delimited JSON-RPC 2.0 over stdio. These DTOs are the canonical protocol: the Rust host serializes them as-is and child implementations (e.g. the Python POCs, the Cursor SDK TypeScript extension) must round-trip them without raw unowned JSON.

Method names (host -> child requests unless noted):

• extension/initialize
• inference/listModels
• inference/streamTurn
• inference/event (child -> host notification)
• subagents/definitions
• subagents/dispatch
• subagents/event (child -> host notification)
• subagents/cancel
• tasks/spec
• tasks/execute
• tasks/event (child -> host notification)
• tasks/cancel
• tools/call
• events/handle (host -> child notification)
• extension/event (child -> host notification)
• extension/shutdown

Structs

ProcessEventFilter

Prefix filter over canonical event kinds, e.g. ["turn.", "inference."].

ProcessEventsHandleNotification

events/handle notification payload (host -> child).

ProcessExtensionConfig

One [[process_extensions]] config entry. env is an explicit allowlist — the host never forwards its full environment.

ProcessExtensionManifest

The manifest TOML shipped next to a process extension.

ProcessExtensionOwnedEvent

extension/event notification payload (child -> host): a typed, extension-owned event. Payloads must already be redacted by the child; the host additionally enforces a size cap before re-emitting.

ProcessInferenceEventNotification

inference/event notification payload (child -> host). The host routes by stream_id and converts event into the runtime inference stream.

ProcessInitializeParams

extension/initialize params (host -> child).

ProcessInitializeResult

extension/initialize result (child -> host).

ProcessListModelsParams

inference/listModels params.

ProcessListModelsResult

ProcessStreamTurnAck

ProcessStreamTurnParams

inference/streamTurn params: a canonical request plus turn provenance.

ProcessSubagentCancelParams

subagents/cancel params (host -> child request; result is empty).

ProcessSubagentDefinitionsParams

subagents/definitions params (host -> child).

ProcessSubagentDefinitionsResult

subagents/definitions result (child -> host).

ProcessSubagentDispatchAck

ProcessSubagentDispatchParams

subagents/dispatch params: a canonical request plus parent provenance and a host-chosen dispatch id the child must echo and stream against.

ProcessSubagentEventNotification

subagents/event notification payload (child -> host). The host routes by dispatch_id; completed/failed are terminal.

ProcessTaskCancelParams

tasks/cancel params (host -> child request; result is empty).

ProcessTaskEventNotification

tasks/event notification payload (child -> host). The host routes by execution_id; completed/failed are terminal.

ProcessTaskExecuteAck

ProcessTaskExecuteParams

tasks/execute params: canonical task input plus execution provenance and a host-chosen execution id the child must echo and stream against.

ProcessTaskSpecParams

tasks/spec params (host -> child).

ProcessTaskSpecResult

tasks/spec result (child -> host).

ProcessToolCallParams

tools/call params (host -> child): one invocation of a tool the manifest declared under a tool_provider service.

ProcessToolCallResult

tools/call result (child -> host): the subset of the native crate::tools::ToolResult a child populates. content becomes the model-visible text, optional data carries a structured payload, and is_error marks a tool-level failure without failing the turn.

Enums

ProcessProvidedService

A manifest service declaration; mirrors ProvidedService variants the process host supports. Tool providers declare their ToolSpecs statically so the registry can be built deterministically without spawning the child.

ProcessSubagentEvent

ProcessTaskEvent

Constants

METHOD_EVENTS_HANDLE

METHOD_EXTENSION_EVENT

METHOD_INFERENCE_EVENT

METHOD_INITIALIZE

METHOD_LIST_MODELS

METHOD_SHUTDOWN

METHOD_STREAM_TURN

METHOD_SUBAGENTS_CANCEL

METHOD_SUBAGENTS_DEFINITIONS

METHOD_SUBAGENTS_DISPATCH

METHOD_SUBAGENTS_EVENT

METHOD_TASKS_CANCEL

METHOD_TASKS_EVENT

METHOD_TASKS_EXECUTE

METHOD_TASKS_SPEC

METHOD_TOOLS_CALL

PROCESS_EXTENSION_PROTOCOL_VERSION

Protocol version spoken by the host; children must echo a compatible version from extension/initialize. Bumped to 0.2.0 when subagent dispatcher, task executor (phase 95), and tool provider (phase 97) services were added.

Functions

manifest_checksum

FNV-1a 64-bit checksum (hex) of the manifest bytes. Not cryptographic — it only detects manifest drift between host config and child package.

validate_initialize_echo

Validates the child’s initialize echo against the configured manifest. Mismatches fail closed: the host refuses to register services from a child that disagrees about identity, API, or provided services.

validate_manifest

Validates the manifest against the host’s supported extension API.