fix: dynamic frontmatter instruction from role schema (closes #389)

packages/workflow-agent-kit/__tests__/build-output-format-instruction.test.ts

@@ -2,13 +2,32 @@ import { describe, expect, test } from "vitest";
 
 import { buildOutputFormatInstruction } from "../src/build-output-format-instruction.js";
 
+const PLANNER_SCHEMA = {
+  type: "object",
+  properties: {
+    status: { type: "string", enum: ["ready", "insufficient_info"] },
+    plan: { type: "string" },
+  },
+  required: ["status"],
+  additionalProperties: false,
+};
+
+const REVIEWER_SCHEMA = {
+  type: "object",
+  properties: {
+    approved: { type: "boolean" },
+  },
+  required: ["approved"],
+  additionalProperties: false,
+};
+
 describe("buildOutputFormatInstruction", () => {
   test("always includes the frontmatter example block", () => {
     const result = buildOutputFormatInstruction({});
     expect(result).toContain("---");
-    expect(result).toContain("status: done");
-    expect(result).toContain("confidence:");
-    expect(result).toContain("scope: role");
+    expect(result).not.toContain("status: done");
+    expect(result).not.toContain("confidence:");
+    expect(result).not.toContain("scope: role");
   });
 
   test("always marks frontmatter as the primary deliverable", () => {
@@ -16,17 +35,36 @@ describe("buildOutputFormatInstruction", () => {
     expect(result).toContain("primary deliverable");
   });
 
-  test("lists fields from a flat object schema", () => {
+  test("generates planner-specific YAML example from schema", () => {
+    const result = buildOutputFormatInstruction(PLANNER_SCHEMA);
+    expect(result).toContain("status: ready  # required | ready | insufficient_info");
+    expect(result).toContain("plan: <string>");
+    expect(result).not.toContain("status: done");
+    expect(result).not.toContain("confidence:");
+    expect(result).not.toContain("artifacts:");
+  });
+
+  test("generates reviewer-specific YAML example from schema", () => {
+    const result = buildOutputFormatInstruction(REVIEWER_SCHEMA);
+    expect(result).toContain("approved: true  # required | true | false");
+    expect(result).not.toContain("status:");
+  });
+
+  test("lists fields from a flat object schema with required marker", () => {
     const schema = {
       type: "object",
       properties: {
         status: { type: "string" },
         confidence: { type: "number" },
       },
+      required: ["status"],
     };
     const result = buildOutputFormatInstruction(schema);
-    expect(result).toContain("`status`");
+    expect(result).toContain("`status` (required)");
     expect(result).toContain("`confidence`");
+    expect(result).not.toContain("`confidence` (required)");
+    expect(result).toContain("status: <string>  # required");
+    expect(result).toContain("confidence: <number>");
   });
 
   test("lists union of fields from an anyOf schema", () => {
@@ -45,6 +83,8 @@ describe("buildOutputFormatInstruction", () => {
     const result = buildOutputFormatInstruction(schema);
     expect(result).toContain("`alpha`");
     expect(result).toContain("`beta`");
+    expect(result).toContain("alpha: <string>");
+    expect(result).toContain("beta: <number>");
   });
 
   test("lists union of fields from a oneOf schema", () => {
@@ -63,6 +103,8 @@ describe("buildOutputFormatInstruction", () => {
     const result = buildOutputFormatInstruction(schema);
     expect(result).toContain("`foo`");
     expect(result).toContain("`bar`");
+    expect(result).toContain("foo: <string>");
+    expect(result).toContain("bar: true  # true | false");
   });
 
   test("falls back gracefully for a non-object schema with no properties", () => {
@@ -80,6 +122,23 @@ describe("buildOutputFormatInstruction", () => {
     const result = buildOutputFormatInstruction(schema);
     const matches = [...result.matchAll(/`shared`/g)];
     expect(matches.length).toBe(1);
+    expect(result).toContain("shared: <string>");
+  });
+
+  test("marks required when any union variant requires the field", () => {
+    const schema = {
+      anyOf: [
+        {
+          type: "object",
+          properties: { shared: { type: "string" } },
+          required: ["shared"],
+        },
+        { type: "object", properties: { shared: { type: "number" } } },
+      ],
+    };
+    const result = buildOutputFormatInstruction(schema);
+    expect(result).toContain("`shared` (required)");
+    expect(result).toContain("shared: <string>  # required");
   });
 
   test("includes focus reminder about role scope", () => {

packages/workflow-agent-kit/src/build-output-format-instruction.ts

@@ -1,5 +1,11 @@
 import type { JSONSchema } from "@uncaged/json-cas";
 
+type SchemaProperty = {
+  name: string;
+  schema: JSONSchema;
+  required: boolean;
+};
+
 /**
  * Extract top-level property names from a JSON Schema object.
  *
@@ -10,8 +16,43 @@ import type { JSONSchema } from "@uncaged/json-cas";
  * Returns an empty array for schemas with no inspectable property definitions.
  */
 export function extractSchemaFields(schema: JSONSchema): string[] {
+  return extractSchemaProperties(schema).map((p) => p.name);
+}
+
+function extractSchemaProperties(schema: JSONSchema): SchemaProperty[] {
+  const objectSchemas = collectObjectSchemas(schema);
+  if (objectSchemas.length === 0) {
+    return [];
+  }
+
+  const byName = new Map<string, SchemaProperty>();
+
+  for (const objectSchema of objectSchemas) {
+    const requiredSet = new Set(
+      Array.isArray(objectSchema.required) ? (objectSchema.required as string[]) : [],
+    );
+    const properties = objectSchema.properties as Record<string, JSONSchema> | null | undefined;
+    if (typeof properties !== "object" || properties === null) {
+      continue;
+    }
+
+    for (const [name, propSchema] of Object.entries(properties)) {
+      const required = requiredSet.has(name);
+      const existing = byName.get(name);
+      if (existing === undefined) {
+        byName.set(name, { name, schema: propSchema, required });
+      } else if (required) {
+        byName.set(name, { ...existing, required: true });
+      }
+    }
+  }
+
+  return [...byName.values()];
+}
+
+function collectObjectSchemas(schema: JSONSchema): JSONSchema[] {
   if (typeof schema.properties === "object" && schema.properties !== null) {
-    return Object.keys(schema.properties as Record<string, unknown>);
+    return [schema];
   }
 
   const unionKey = Array.isArray(schema.anyOf)
@@ -20,18 +61,109 @@ export function extractSchemaFields(schema: JSONSchema): string[] {
       ? "oneOf"
       : null;
 
-  if (unionKey !== null) {
-    const variants = schema[unionKey] as JSONSchema[];
-    const fieldSet = new Set<string>();
-    for (const variant of variants) {
-      for (const field of extractSchemaFields(variant)) {
-        fieldSet.add(field);
-      }
-    }
-    return [...fieldSet];
+  if (unionKey === null) {
+    return [];
   }
 
-  return [];
+  const variants = schema[unionKey] as JSONSchema[];
+  const result: JSONSchema[] = [];
+  for (const variant of variants) {
+    result.push(...collectObjectSchemas(variant));
+  }
+  return result;
+}
+
+function resolvePropertySchema(prop: JSONSchema): JSONSchema {
+  if (Array.isArray(prop.enum) && prop.enum.length > 0) {
+    return prop;
+  }
+
+  const unionKey = Array.isArray(prop.anyOf) ? "anyOf" : Array.isArray(prop.oneOf) ? "oneOf" : null;
+
+  if (unionKey !== null) {
+    const variants = prop[unionKey] as JSONSchema[];
+    const nonNull = variants.filter((v) => v.type !== "null");
+    if (nonNull.length === 1) {
+      return nonNull[0];
+    }
+  }
+
+  return prop;
+}
+
+function formatYamlScalar(value: unknown): string {
+  if (typeof value === "boolean") {
+    return String(value);
+  }
+  if (typeof value === "number") {
+    return String(value);
+  }
+  return String(value);
+}
+
+function buildPropertyComment(parts: string[]): string {
+  const filtered = parts.filter((p) => p.length > 0);
+  return filtered.length > 0 ? `  # ${filtered.join(" | ")}` : "";
+}
+
+function buildPropertyExampleLine(prop: SchemaProperty): string {
+  const resolved = resolvePropertySchema(prop.schema);
+  const commentParts: string[] = [];
+  if (prop.required) {
+    commentParts.push("required");
+  }
+
+  if (Array.isArray(resolved.enum) && resolved.enum.length > 0) {
+    const enumValues = resolved.enum.map((v) => String(v));
+    commentParts.push(...enumValues);
+    const first = resolved.enum[0];
+    return `${prop.name}: ${formatYamlScalar(first)}${buildPropertyComment(commentParts)}`;
+  }
+
+  if (resolved.type === "boolean") {
+    commentParts.push("true", "false");
+    return `${prop.name}: true${buildPropertyComment(commentParts)}`;
+  }
+
+  if (resolved.type === "string") {
+    return `${prop.name}: <string>${buildPropertyComment(commentParts)}`;
+  }
+
+  if (resolved.type === "number" || resolved.type === "integer") {
+    return `${prop.name}: <number>${buildPropertyComment(commentParts)}`;
+  }
+
+  if (resolved.type === "array") {
+    return `${prop.name}:\n  - <item>${buildPropertyComment(commentParts)}`;
+  }
+
+  if (resolved.type === "object") {
+    return `${prop.name}: <object>${buildPropertyComment(commentParts)}`;
+  }
+
+  return `${prop.name}: <value>${buildPropertyComment(commentParts)}`;
+}
+
+function buildYamlExampleBlock(properties: SchemaProperty[]): string {
+  if (properties.length === 0) {
+    return "---\n\n... your markdown work here ...";
+  }
+
+  const lines = properties.map((p) => buildPropertyExampleLine(p));
+  return `---\n${lines.join("\n")}\n---\n\n... your markdown work here ...`;
+}
+
+function buildFieldList(properties: SchemaProperty[]): string {
+  if (properties.length === 0) {
+    return "  (schema fields will be extracted automatically)";
+  }
+
+  return properties
+    .map((p) => {
+      const suffix = p.required ? " (required)" : "";
+      return `  - \`${p.name}\`${suffix}`;
+    })
+    .join("\n");
 }
 
 /**
@@ -42,28 +174,16 @@ export function extractSchemaFields(schema: JSONSchema): string[] {
  * system prompt so the deliverable format is the first thing the agent sees.
  */
 export function buildOutputFormatInstruction(schema: JSONSchema): string {
-  const fields = extractSchemaFields(schema);
-
-  const fieldList =
-    fields.length > 0
-      ? fields.map((f) => `  - \`${f}\``).join("\n")
-      : "  (schema fields will be extracted automatically)";
+  const properties = extractSchemaProperties(schema);
+  const yamlExample = buildYamlExampleBlock(properties);
+  const fieldList = buildFieldList(properties);
 
   return `## Deliverable Format
 
 Your response MUST begin with a YAML frontmatter block followed by your markdown work:
 
 \`\`\`
----
-status: done          # done | needs_input | in_progress | failed
-next: <role-name>     # suggested next role, or omit
-confidence: 0.9       # 0.0–1.0, your self-assessed confidence
-artifacts:            # list of file paths or CAS hashes you produced
-  - path/to/file.ts
-scope: role           # role | thread
----
-
-... your markdown work here ...
+${yamlExample}
 \`\`\`
 
 The frontmatter is the **primary deliverable** — the engine reads it directly.