Removes kilo, kimi, kimi-code, copilot, windsurf, augment, trae, qwen, hermes, cline, codebuddy and pi end to end: capability descriptors, installer branches and converters (bin/install.js 14.9k -> 11.2k lines), TypeScript converters, hook surfaces and runtime homes, review lanes qwen/kimi-code, the two pi migrations, Kimi payload normalization in the hook guards, dead hostBehaviors vocabulary, launcher home probes, fixtures, runtime-specific tests and the prose that presented them as supported. Installer output for the six kept runtimes is byte-identical to before the prune. The Kimi tool-vocabulary tests in workflow-guard, read-guard and read-injection-scanner are left in place pending a decision.
3.4 KiB
How to author a host-plugin for MSD
This guide is for external tool authors who want to embed MSD's orchestration loop (dispatch + hooks + model + state) into a new host — a CLI, IDE, or agent runtime MSD does not special-case — by writing a host-plugin against the published Host-Integration SDK, without modifying msd-core source.
The contract is the SDK entry (src/host-integration-sdk.cts →
msd-core/bin/lib/host-integration-sdk.cjs): import only from it. Everything it
re-exports is public and versioned (PROTOCOL_VERSION); everything else in
msd-core is internal and may change. A smoke test
(tests/sdk-smoke.test.cjs) proves a third-party host can be built from this
surface alone.
1. Decide your host's profile
Classify your host into one of three profiles (the SDK's profileOf does this
from your axes):
| Profile | Example hosts | Binding |
|---|---|---|
programmatic-cli |
OpenCode | imperative adapter (createImperativeAdapter) |
declarative-cli |
Antigravity, Codex | declarative adapter (createDeclarativeAdapter) |
ide |
VS Code | imperative adapter + engine-owned hook bus + active model + sandboxed state |
2. Declare your host's integration axes
Declare the nine negotiated axes (embeddingMode, commandSurface, dispatch,
modelMode, hookBus, stateIO, transport, runtime, effortSurface) from your host's
authoritative documentation — never infer. Where the docs are silent, use the
undocumented sentinel (the SDK degrades it fail-closed). See
docs/reference/host-integration-interface.md for the closed vocabulary.
3. Compose the engine adapters
const SDK = require('@golem15/msd-core/sdk'); // the published entry
// Engine-owned hook bus (for hosts with no event bus, e.g. VS Code):
const hookBus = SDK.createHookBus({ bus: 'engine' });
// Active model via a host provider (e.g. vscode.lm); or 'passive' for CLIs:
const model = SDK.createModelAdapter({ modelMode: 'active' }, { sendRequest: hostSendRequest });
// State IO — filesystem for CLIs, sandboxed-storage for IDEs/web:
const stateIO = SDK.createStateIO({ io: 'filesystem' });
// The engine-as-library adapter bound to your runtime id:
const adapter = SDK.createImperativeAdapter({ runtime: 'my-host' });
4. Negotiate capabilities (serialized, for out-of-process hosts)
If your host runs out-of-process (can't share object refs with the engine), use
the serialized handshake instead of the in-process negotiateHostCapabilities:
const req = SDK.buildHandshakeRequest({ ...myAxes });
const { effective, points, warnings } = SDK.handleHandshakeRequest(req);
The result is identical to the in-process negotiation for the same axes — that consistency is the contract.
5. Bind your host primitives + ship
Map the six interface points (command, dispatch, model, hooks, state, artifact) to your host's primitives (palette/chat, plugin API, provider calls, etc.). The reference host-plugins (OpenCode, Antigravity, VS Code — see Phase 5) are canonical examples to mirror. Your host-plugin is now a self-contained artifact; no msd-core source change is required.
See also
- Tutorial:
docs/tutorials/embed-msd-in-a-new-host.md— a complete end-to-end embedding. - Reference:
docs/reference/host-integration-interface.md— every axis, adapter, and the handshake. - Versioning:
docs/explanation/interface-versioning-policy.md— what evolves additively vs. breaking.