Merge pull request 'feat(#194): Phase 1 — Merkle Call Stack protocol + CAS layer' (#199) from feat/194-merkle-call-stack-phase1 into main

packages/cli-workflow/__tests__/gc-cli.test.ts

@@ -45,8 +45,8 @@ describe("gc cli and garbageCollectCas", () => {
       {
         name: "demo",
         hash: bundleHash,
-
         depth: 0,
+        parentState: null,
       },
       promptHash,
     );
@@ -100,8 +100,8 @@ describe("gc cli and garbageCollectCas", () => {
       {
         name: "demo",
         hash: bundleHash,
-
         depth: 0,
+        parentState: null,
       },
       promptHash,
     );
@@ -135,8 +135,8 @@ describe("gc cli and garbageCollectCas", () => {
       {
         name: "demo",
         hash: bundleHash,
-
         depth: 0,
+        parentState: null,
       },
       promptHash,
     );

packages/workflow-cas/__tests__/collect-refs.test.ts

@@ -14,6 +14,7 @@ function payload(
     ancestors: partial.ancestors ?? [],
     compact: partial.compact ?? null,
     timestamp: partial.timestamp ?? 0,
+    childThread: partial.childThread ?? null,
   };
 }
 
@@ -62,4 +63,32 @@ describe("collectRefs", () => {
     );
     expect(refs).toEqual(["S2", "C2"]);
   });
+
+  test("includes childThread hash when childThread is non-null", () => {
+    const refs = collectRefs(
+      payload({
+        role: "developer",
+        start: "S3",
+        content: "C3",
+        ancestors: ["A3"],
+        compact: null,
+        childThread: "CHILDEND000000000000001",
+      }),
+    );
+    expect(refs).toEqual(["S3", "C3", "A3", "CHILDEND000000000000001"]);
+  });
+
+  test("does not include childThread when childThread is null", () => {
+    const refs = collectRefs(
+      payload({
+        role: "developer",
+        start: "S4",
+        content: "C4",
+        ancestors: [],
+        compact: null,
+        childThread: null,
+      }),
+    );
+    expect(refs).toEqual(["S4", "C4"]);
+  });
 });

packages/workflow-cas/__tests__/nodes.test.ts

@@ -0,0 +1,161 @@
+import { afterEach, beforeEach, describe, expect, test } from "bun:test";
+import { mkdtemp, rm } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { stringify } from "yaml";
+
+import { createCasStore } from "../src/cas.js";
+import { parseCasThreadNode, putStartNode, putStateNode } from "../src/nodes.js";
+
+describe("putStartNode — parentState in refs", () => {
+  let dir: string;
+
+  beforeEach(async () => {
+    dir = await mkdtemp(join(tmpdir(), "wf-cas-nodes-"));
+  });
+
+  afterEach(async () => {
+    await rm(dir, { recursive: true, force: true });
+  });
+
+  test("refs contains only promptHash when parentState is null", async () => {
+    const cas = createCasStore(join(dir, "cas"));
+    const promptHash = await cas.put("hello");
+    const startHash = await putStartNode(
+      cas,
+      { name: "demo", hash: "BUNDLEAAAAAAAAA", depth: 0, parentState: null },
+      promptHash,
+    );
+
+    const blob = await cas.get(startHash);
+    expect(blob).not.toBeNull();
+    const parsed = parseCasThreadNode(blob ?? "");
+    expect(parsed).not.toBeNull();
+    expect(parsed?.kind).toBe("start");
+    if (parsed?.kind !== "start") return;
+
+    expect(parsed.node.refs).toEqual([promptHash]);
+    expect(parsed.node.payload.parentState).toBeNull();
+  });
+
+  test("refs contains [promptHash, parentStateHash] when parentState is set", async () => {
+    const cas = createCasStore(join(dir, "cas"));
+    const parentStateHash = await cas.put("fake-parent-state");
+    const promptHash = await cas.put("child-prompt");
+    const startHash = await putStartNode(
+      cas,
+      { name: "develop", hash: "BUNDLEBBBBBBBBB", depth: 1, parentState: parentStateHash },
+      promptHash,
+    );
+
+    const blob = await cas.get(startHash);
+    expect(blob).not.toBeNull();
+    const parsed = parseCasThreadNode(blob ?? "");
+    expect(parsed).not.toBeNull();
+    expect(parsed?.kind).toBe("start");
+    if (parsed?.kind !== "start") return;
+
+    expect(parsed.node.refs).toEqual([promptHash, parentStateHash]);
+    expect(parsed.node.payload.parentState).toBe(parentStateHash);
+  });
+});
+
+describe("putStateNode — childThread in refs", () => {
+  let dir: string;
+
+  beforeEach(async () => {
+    dir = await mkdtemp(join(tmpdir(), "wf-cas-nodes-state-"));
+  });
+
+  afterEach(async () => {
+    await rm(dir, { recursive: true, force: true });
+  });
+
+  test("refs does not include childThread when childThread is null", async () => {
+    const cas = createCasStore(join(dir, "cas"));
+    const startHash = await cas.put("start");
+    const contentHash = await cas.put("content");
+    const stateHash = await putStateNode(cas, {
+      role: "planner",
+      meta: {},
+      start: startHash,
+      content: contentHash,
+      ancestors: [],
+      compact: null,
+      timestamp: 1000,
+      childThread: null,
+    });
+
+    const blob = await cas.get(stateHash);
+    expect(blob).not.toBeNull();
+    const parsed = parseCasThreadNode(blob ?? "");
+    expect(parsed?.kind).toBe("state");
+    if (parsed?.kind !== "state") return;
+
+    expect(parsed.node.refs).not.toContain("anything-else");
+    expect(parsed.node.refs).toEqual([startHash, contentHash]);
+    expect(parsed.node.payload.childThread).toBeNull();
+  });
+
+  test("refs includes childThread hash when childThread is set", async () => {
+    const cas = createCasStore(join(dir, "cas"));
+    const startHash = await cas.put("start");
+    const contentHash = await cas.put("content");
+    const childEndHash = await cas.put("child-end-state");
+    const stateHash = await putStateNode(cas, {
+      role: "developer",
+      meta: { pr: 42 },
+      start: startHash,
+      content: contentHash,
+      ancestors: [],
+      compact: null,
+      timestamp: 2000,
+      childThread: childEndHash,
+    });
+
+    const blob = await cas.get(stateHash);
+    expect(blob).not.toBeNull();
+    const parsed = parseCasThreadNode(blob ?? "");
+    expect(parsed?.kind).toBe("state");
+    if (parsed?.kind !== "state") return;
+
+    expect(parsed.node.refs).toContain(childEndHash);
+    expect(parsed.node.payload.childThread).toBe(childEndHash);
+  });
+});
+
+describe("parseCasThreadNode — legacy node compatibility", () => {
+  test("start node without parentState field defaults to null", () => {
+    const yaml = stringify({
+      type: "start",
+      payload: { name: "demo", hash: "BUNDLEAAAAAAAAA", depth: 0 },
+      refs: ["PROMPTHASH00001"],
+    });
+    const parsed = parseCasThreadNode(yaml);
+    expect(parsed).not.toBeNull();
+    expect(parsed?.kind).toBe("start");
+    if (parsed?.kind !== "start") return;
+    expect(parsed.node.payload.parentState).toBeNull();
+  });
+
+  test("state node without childThread field defaults to null", () => {
+    const yaml = stringify({
+      type: "state",
+      payload: {
+        role: "planner",
+        meta: {},
+        start: "STARTHASH00001",
+        content: "CONTENTHASH0001",
+        ancestors: [],
+        compact: null,
+        timestamp: 1000,
+      },
+      refs: ["STARTHASH00001", "CONTENTHASH0001"],
+    });
+    const parsed = parseCasThreadNode(yaml);
+    expect(parsed).not.toBeNull();
+    expect(parsed?.kind).toBe("state");
+    if (parsed?.kind !== "state") return;
+    expect(parsed.node.payload.childThread).toBeNull();
+  });
+});

packages/workflow-cas/src/collect-refs.ts

@@ -9,5 +9,8 @@ export function collectRefs(payload: StateNode["payload"]): string[] {
   if (payload.compact !== null) {
     out.push(payload.compact);
   }
+  if (payload.childThread !== null) {
+    out.push(payload.childThread);
+  }
   return out;
 }

packages/workflow-cas/src/nodes.ts

@@ -18,6 +18,10 @@ function isStartPayload(value: unknown): value is StartNodePayload {
   if (!isRecord(value)) {
     return false;
   }
+  const parentState = value.parentState;
+  if (parentState !== undefined && parentState !== null && typeof parentState !== "string") {
+    return false;
+  }
   return (
     typeof value.name === "string" &&
     typeof value.hash === "string" &&
@@ -25,6 +29,16 @@ function isStartPayload(value: unknown): value is StartNodePayload {
   );
 }
 
+/** Normalizes a raw start payload, defaulting `parentState` to `null` for legacy nodes. */
+function normalizeStartPayload(raw: StartNodePayload): StartNodePayload {
+  return {
+    name: raw.name,
+    hash: raw.hash,
+    depth: raw.depth,
+    parentState: raw.parentState ?? null,
+  };
+}
+
 function isStatePayload(value: unknown): value is StateNodePayload {
   if (!isRecord(value)) {
     return false;
@@ -41,6 +55,10 @@ function isStatePayload(value: unknown): value is StateNodePayload {
   if (!isRecord(meta)) {
     return false;
   }
+  const childThread = value.childThread;
+  if (childThread !== undefined && childThread !== null && typeof childThread !== "string") {
+    return false;
+  }
   return (
     typeof value.role === "string" &&
     typeof value.start === "string" &&
@@ -49,6 +67,20 @@ function isStatePayload(value: unknown): value is StateNodePayload {
   );
 }
 
+/** Normalizes a raw state payload, defaulting `childThread` to `null` for legacy nodes. */
+function normalizeStatePayload(raw: StateNodePayload): StateNodePayload {
+  return {
+    role: raw.role,
+    meta: raw.meta,
+    start: raw.start,
+    content: raw.content,
+    ancestors: raw.ancestors,
+    compact: raw.compact,
+    timestamp: raw.timestamp,
+    childThread: raw.childThread ?? null,
+  };
+}
+
 /** Parses a YAML CAS blob into a typed RFC v3 thread node (or legacy content layout with `children`). */
 export function parseCasThreadNode(yamlText: string): ParsedCasThreadNode | null {
   let raw: unknown;
@@ -86,14 +118,14 @@ export function parseCasThreadNode(yamlText: string): ParsedCasThreadNode | null
     if (!isStartPayload(raw.payload)) {
       return null;
     }
-    const node: StartNode = { type: "start", payload: raw.payload, refs: [...refs] };
+    const node: StartNode = { type: "start", payload: normalizeStartPayload(raw.payload), refs: [...refs] };
     return { kind: "start", node };
   }
 
   if (!isStatePayload(raw.payload)) {
     return null;
   }
-  const node: StateNode = { type: "state", payload: raw.payload, refs: [...refs] };
+  const node: StateNode = { type: "state", payload: normalizeStatePayload(raw.payload), refs: [...refs] };
   return { kind: "state", node };
 }
 
@@ -143,10 +175,14 @@ export async function putStartNode(
   payload: StartNode["payload"],
   promptHash: string,
 ): Promise<string> {
+  const refs = [promptHash];
+  if (payload.parentState !== null) {
+    refs.push(payload.parentState);
+  }
   const node: StartNode = {
     type: "start",
     payload,
-    refs: [promptHash],
+    refs,
   };
   return store.put(serializeCasNode(node));
 }

packages/workflow-execute/__tests__/gc-mark-sweep.test.ts

@@ -46,6 +46,7 @@ describe("garbageCollectCas (mark-and-sweep)", () => {
         name: "demo",
         hash: bundleHash,
         depth: 0,
+        parentState: null,
       },
       promptHash,
     );
@@ -59,6 +60,7 @@ describe("garbageCollectCas (mark-and-sweep)", () => {
       ancestors: [],
       compact: null,
       timestamp: 1,
+      childThread: null,
     } satisfies StateNodePayload);
 
     const c2 = await putContentNodeWithRefs(cas, "c1", []);
@@ -70,6 +72,7 @@ describe("garbageCollectCas (mark-and-sweep)", () => {
       ancestors: [h1],
       compact: null,
       timestamp: 2,
+      childThread: null,
     } satisfies StateNodePayload);
 
     const ec = await putContentNodeWithRefs(cas, "", []);
@@ -81,6 +84,7 @@ describe("garbageCollectCas (mark-and-sweep)", () => {
       ancestors: [h1],
       compact: null,
       timestamp: 3,
+      childThread: null,
     } satisfies StateNodePayload);
 
     await upsertThreadEntry(bundleDir, "THREAD_AAAAAAA", {

packages/workflow-execute/src/engine/engine.ts

@@ -112,6 +112,7 @@ async function appendStateForStep(params: {
     ancestors,
     compact: null,
     timestamp: params.timestamp,
+    childThread: null,
   };
   const stateHash = await putStateNode(params.cas, payload);
   return {
@@ -137,6 +138,7 @@ async function appendEndState(params: {
     ancestors,
     compact: null,
     timestamp: params.timestamp,
+    childThread: null,
   };
   return putStateNode(params.cas, payload);
 }
@@ -439,6 +441,7 @@ export async function executeThread(
         name: workflowName,
         hash: io.hash,
         depth: options.depth,
+        parentState: null,
       },
       promptHash,
     );

packages/workflow-execute/src/engine/fork-thread.ts

@@ -240,6 +240,7 @@ async function buildForkContinuation(params: {
     ancestors: ancestorsMarker,
     compact: null,
     timestamp: Date.now(),
+    childThread: null,
   };
   const markerHash = await putStateNode(cas, markerPayload);
 

packages/workflow-protocol/src/cas-types.ts

@@ -4,6 +4,8 @@ export type StartNodePayload = {
   name: string;
   hash: string;
   depth: number;
+  /** Parent thread's head state hash at spawn time. `null` for top-level workflows. */
+  parentState: string | null;
 };
 
 export type StartNode = {
@@ -20,6 +22,8 @@ export type StateNodePayload = {
   ancestors: string[];
   compact: string | null;
   timestamp: number;
+  /** Child thread's final state hash (workflow-as-agent). `null` when no child spawned. */
+  childThread: string | null;
 };
 
 export type StateNode = {

packages/workflow-runtime/__tests__/build-context.test.ts

@@ -27,7 +27,7 @@ describe("buildThreadContext", () => {
     const bundleHash = "BHAAAAAAAAAAA";
     const startHash = await putStartNode(
       cas,
-      { name: "demo", hash: bundleHash, depth: 2 },
+      { name: "demo", hash: bundleHash, depth: 2, parentState: null },
       promptHash,
     );
 
@@ -41,6 +41,7 @@ describe("buildThreadContext", () => {
       ancestors: [],
       compact: null,
       timestamp: 1000,
+      childThread: null,
     });
 
     const chCode = await putContentNodeWithRefs(cas, "code body", []);
@@ -52,6 +53,7 @@ describe("buildThreadContext", () => {
       ancestors: [statePlan],
       compact: null,
       timestamp: 2000,
+      childThread: null,
     });
 
     const ctx = await buildThreadContext(stateCode, cas);
@@ -71,7 +73,7 @@ describe("buildThreadContext", () => {
     const promptHash = await cas.put("only-prompt");
     const startHash = await putStartNode(
       cas,
-      { name: "solo", hash: "BHBBBBBBBBBBB", depth: 1 },
+      { name: "solo", hash: "BHBBBBBBBBBBB", depth: 1, parentState: null },
       promptHash,
     );
 
@@ -87,7 +89,7 @@ describe("buildThreadContext", () => {
     const bundleHash = "BHCCCCCCCCCCC";
     const startHash = await putStartNode(
       cas,
-      { name: "demo", hash: bundleHash, depth: 0 },
+      { name: "demo", hash: bundleHash, depth: 0, parentState: null },
       promptHash,
     );
 
@@ -100,6 +102,7 @@ describe("buildThreadContext", () => {
       ancestors: [],
       compact: null,
       timestamp: 500,
+      childThread: null,
     });
 
     const endContent = await putContentNodeWithRefs(cas, "finished", []);
@@ -111,6 +114,7 @@ describe("buildThreadContext", () => {
       ancestors: [state1],
       compact: null,
       timestamp: 600,
+      childThread: null,
     });
 
     const ctx = await buildThreadContext(endState, cas);