feat: add shadow LangGraph orchestrator runtime

2026-07-24 21:25:40 +08:00
parent 46ea22b342
commit 24336d0178
29 changed files with 3247 additions and 25 deletions
@@ -0,0 +1,128 @@
+import {
+  Annotation,
+  END,
+  START,
+  StateGraph,
+} from '@langchain/langgraph';
+import {
+  buildRunEvent,
+  normalizeRunSpec,
+} from './contracts.mjs';
+
+export const CODE_RUN_SHADOW_WORKFLOW = 'code-run-v1';
+
+const ShadowState = Annotation.Root({
+  spec: Annotation(),
+  status: Annotation({
+    reducer: (_current, update) => update,
+    default: () => 'queued',
+  }),
+  phase: Annotation({
+    reducer: (_current, update) => update,
+    default: () => 'accepted',
+  }),
+  plan: Annotation({
+    reducer: (_current, update) => update,
+    default: () => null,
+  }),
+  result: Annotation({
+    reducer: (_current, update) => update,
+    default: () => null,
+  }),
+  events: Annotation({
+    reducer: (current, update) => [...current, ...update],
+    default: () => [],
+  }),
+});
+
+function eventFor(state, type, data = null) {
+  return buildRunEvent({
+    runId: state.spec.runId,
+    sequence: state.events.length + 1,
+    type,
+    data,
+  });
+}
+
+function validateNode(state) {
+  const spec = normalizeRunSpec(state.spec);
+  if (spec.workflow.name !== CODE_RUN_SHADOW_WORKFLOW) {
+    const error = new Error(`Unsupported workflow: ${spec.workflow.name}`);
+    error.code = 'WORKFLOW_NOT_SUPPORTED';
+    throw error;
+  }
+  if (spec.policy.executionMode !== 'observe-only' || spec.policy.sideEffectsAllowed !== false) {
+    const error = new Error('Phase 2 LangGraph service accepts observe-only runs');
+    error.code = 'WORKFLOW_OBSERVE_ONLY_REQUIRED';
+    throw error;
+  }
+  return {
+    spec,
+    status: 'running',
+    phase: 'validated',
+    events: [eventFor(state, 'workflow_validated', {
+      workflow: spec.workflow,
+      executionMode: 'observe-only',
+    })],
+  };
+}
+
+function planNode(state) {
+  const taskType = String(state.spec.input?.taskType ?? '').trim() || 'code-change';
+  const instruction = String(state.spec.input?.instruction ?? '');
+  const plan = {
+    taskType,
+    executorAdapter: 'native-agent-run',
+    instructionCharacters: instruction.length,
+    steps: [
+      'accept_control_plane_run',
+      'project_executor_boundary',
+      'record_shadow_result',
+    ],
+  };
+  return {
+    phase: 'planned',
+    plan,
+    events: [eventFor(state, 'workflow_planned', {
+      taskType,
+      executorAdapter: plan.executorAdapter,
+      stepCount: plan.steps.length,
+    })],
+  };
+}
+
+function finalizeNode(state) {
+  const result = {
+    observed: true,
+    executed: false,
+    executorAdapter: state.plan.executorAdapter,
+    taskType: state.plan.taskType,
+  };
+  return {
+    status: 'succeeded',
+    phase: 'completed',
+    result,
+    events: [eventFor(state, 'workflow_completed', result)],
+  };
+}
+
+export function createCodeRunShadowGraph({ checkpointer } = {}) {
+  if (!checkpointer) throw new Error('Code run shadow graph requires a checkpointer');
+  return new StateGraph(ShadowState)
+    .addNode('validate_run', validateNode)
+    .addNode('build_plan', planNode)
+    .addNode('finalize_run', finalizeNode)
+    .addEdge(START, 'validate_run')
+    .addEdge('validate_run', 'build_plan')
+    .addEdge('build_plan', 'finalize_run')
+    .addEdge('finalize_run', END)
+    .compile({ checkpointer });
+}
+
+export const codeRunShadowGraphInternals = {
+  ShadowState,
+  eventFor,
+  validateNode,
+  planNode,
+  finalizeNode,
+};