feat: add shadow LangGraph orchestrator runtime

services/orchestrator/checkpoint.mjs

@@ -0,0 +1,74 @@
+import { MemorySaver } from '@langchain/langgraph';
+import { PostgresSaver } from '@langchain/langgraph-checkpoint-postgres';
+
+const DEFAULT_POSTGRES_SCHEMA = 'memind_orchestrator';
+
+function normalizeMode(value) {
+  const mode = String(value ?? 'postgres').trim().toLowerCase();
+  if (mode === 'memory' || mode === 'postgres') return mode;
+  throw new Error(`Unsupported orchestrator checkpoint mode: ${value}`);
+}
+
+function normalizeSchema(value) {
+  const schema = String(value ?? DEFAULT_POSTGRES_SCHEMA).trim();
+  if (!/^[a-z_][a-z0-9_]{0,62}$/i.test(schema)) {
+    throw new Error('Invalid orchestrator PostgreSQL schema');
+  }
+  return schema;
+}
+
+export async function createOrchestratorCheckpoint({
+  mode = process.env.MEMIND_ORCHESTRATOR_CHECKPOINT_MODE,
+  connectionString = process.env.MEMIND_ORCHESTRATOR_DATABASE_URL,
+  schema = process.env.MEMIND_ORCHESTRATOR_DATABASE_SCHEMA,
+} = {}) {
+  const normalizedMode = normalizeMode(mode);
+  if (normalizedMode === 'memory') {
+    return {
+      kind: 'memory',
+      durable: false,
+      checkpointer: new MemorySaver(),
+      async probe() {
+        return true;
+      },
+      async close() {},
+    };
+  }
+
+  const normalizedConnectionString = String(connectionString ?? '').trim();
+  if (!normalizedConnectionString) {
+    const error = new Error(
+      'MEMIND_ORCHESTRATOR_DATABASE_URL is required when checkpoint mode is postgres',
+    );
+    error.code = 'ORCHESTRATOR_DATABASE_URL_REQUIRED';
+    throw error;
+  }
+
+  const checkpointer = PostgresSaver.fromConnString(normalizedConnectionString, {
+    schema: normalizeSchema(schema),
+  });
+  await checkpointer.setup();
+  return {
+    kind: 'postgres',
+    durable: true,
+    checkpointer,
+    async probe() {
+      await checkpointer.getTuple({
+        configurable: {
+          thread_id: '__orchestrator_readiness__',
+          checkpoint_ns: '',
+        },
+      });
+      return true;
+    },
+    async close() {
+      await checkpointer.end();
+    },
+  };
+}
+
+export const orchestratorCheckpointInternals = {
+  DEFAULT_POSTGRES_SCHEMA,
+  normalizeMode,
+  normalizeSchema,
+};