timmy-tower/artifacts/api-server/src/lib/agent.ts

import { anthropic } from "@workspace/integrations-anthropic-ai";
import type Anthropic from "@anthropic-ai/sdk";

export interface EvalResult {
  accepted: boolean;
  reason: string;
}

export interface WorkResult {
  result: string;
}

export interface AgentConfig {
  evalModel?: string;
  workModel?: string;
}

export class AgentService {
  private readonly evalModel: string;
  private readonly workModel: string;

  constructor(config?: AgentConfig) {
    this.evalModel = config?.evalModel ?? "claude-haiku-4-5";
    this.workModel = config?.workModel ?? "claude-sonnet-4-6";
  }

  async evaluateRequest(requestText: string): Promise<EvalResult> {
    const message = await anthropic.messages.create({
      model: this.evalModel,
      max_tokens: 8192,
      system: `You are Timmy, an AI agent gatekeeper. Evaluate whether a request is acceptable to act on.
ACCEPT if the request is: clear enough to act on, ethical, lawful, and within the capability of a general-purpose AI.
REJECT if the request is: harmful, illegal, unethical, incoherent, or spam.
Respond ONLY with valid JSON: {"accepted": true, "reason": "..."} or {"accepted": false, "reason": "..."}`,
      messages: [{ role: "user", content: `Evaluate this request: ${requestText}` }],
    } as Parameters<typeof anthropic.messages.create>[0]);

    const block = message.content[0] as Anthropic.TextBlock;
    if (block.type !== "text") {
      throw new Error("Unexpected non-text response from eval model");
    }

    let parsed: { accepted: boolean; reason: string };
    try {
      const raw = block.text.replace(/^```(?:json)?\s*/i, "").replace(/\s*```$/, "").trim();
      parsed = JSON.parse(raw) as { accepted: boolean; reason: string };
    } catch {
      throw new Error(`Failed to parse eval JSON: ${block.text}`);
    }

    return { accepted: Boolean(parsed.accepted), reason: parsed.reason ?? "" };
  }

  async executeWork(requestText: string): Promise<WorkResult> {
    const message = await anthropic.messages.create({
      model: this.workModel,
      max_tokens: 8192,
      system: `You are Timmy, a capable AI agent. A user has paid for you to handle their request.
Fulfill it thoroughly and helpfully. Be concise yet complete.`,
      messages: [{ role: "user", content: requestText }],
    } as Parameters<typeof anthropic.messages.create>[0]);

    const block = message.content[0] as Anthropic.TextBlock;
    if (block.type !== "text") {
      throw new Error("Unexpected non-text response from work model");
    }

    return { result: block.text };
  }
}

export const agentService = new AgentService();