Build a research harness

import { pathToFileURL } from "node:url";
import { defineTool, openai, type ModelProvider } from "@agentium/core";
import { agentDriver, HarnessRuntime, research } from "@agentium/harness";
import { z } from "zod";

export async function runResearch(model: ModelProvider) {
  const sources = {
    delivery: { text: "Standard delivery takes 3–5 business days.", uri: "policy:delivery" },
    refunds: { text: "Unopened items can be returned within 30 days.", uri: "policy:refunds" },
  };
  const lookup = defineTool({
    name: "lookup_policy",
    description: "Read the delivery or refunds policy. Cite the returned URI.",
    parameters: z.object({ topic: z.enum(["delivery", "refunds"]) }),
    execute: async ({ topic }) => JSON.stringify(sources[topic]),
  });
  const runtime = new HarnessRuntime({
    definition: research({
      id: "policy-research",
      text: {
        id: "scope",
        entries: [{ id: "catalog", text: "Available policy topics: delivery, refunds." }],
      },
      tools: [lookup],
    }),
    driver: agentDriver({
      name: "policy-researcher", model,
      instructions: "Use lookup_policy for policy facts. Cite its URI. If evidence is missing, say so.",
      maxToolRoundtrips: 3,
    }),
    grants: { toolIds: ["lookup_policy"], modelRoles: ["main"] },
    budgets: { maxModelCalls: 4, maxToolCalls: 3, maxTokens: 8000 },
  });
  // In a service, derive this identity from authenticated application state.
  const identity = { tenantId: "demo", userId: "reader" };
  const sessionId = "policy-research";
  try {
    const handle = runtime.start("How long does delivery take? Cite the policy.", { identity, sessionId });
    for await (const event of handle.events()) {
      if (event.payload.type === "tool.complete") {
        console.log("tool:", event.payload.toolName, "denied:", event.payload.denied);
      }
    }
    const result = await handle.result();
    if (result.status !== "completed") {
      throw new Error(`Research ended: ${result.status} (${result.reason?.code ?? "no reason"})`);
    }
    console.log(result.text);
    return result;
  } finally {
    const diagnostics = await runtime.resources.closeSession(identity, sessionId);
    if (diagnostics.length) throw new Error(`Session cleanup failed: ${diagnostics.join(", ")}`);
  }
}

if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
  await runResearch(openai(process.env.OPENAI_MODEL ?? "gpt-6.1-sol"));
}