The Agent Harness Framework

Not another SDK. Build autonomous agents and powerful AI workflows with Flue's programmable TypeScript harness.

View Documentation
agents/triage.ts
import { createAgent, type AgentRouteHandler, type AgentWebSocketHandler } from '@flue/runtime';
import { local } from '@flue/runtime/node';
import triage from '../skills/triage/SKILL.md' with { type: 'skill' };
import verify from '../skills/verify/SKILL.md' with { type: 'skill' };
import * as githubTools from '../tools/github.ts';

// Give agents the context and autonomy to solve complex tasks:
const instructions = `
Triage a bug report end-to-end: reproduce the bug,
diagnose the root cause, verify whether the behavior is
intentional, and attempt a fix.

...`;

// Expose (and protect) your agents over HTTP and WebSockets:
export const route: AgentRouteHandler = async (_c, next) => next();
export const websocket: AgentWebSocketHandler = async (_c, next) => next();

// Compose the complete harness your agent needs to do real work,
// complete with virtual, local, or remote container sandbox.
export default createAgent(() => ({
  model:   'anthropic/claude-sonnet-4-6',
  tools:   [...githubTools],
  skills:  [triage, verify],
  sandbox: local(),
  instructions,
}));

The framework for building the next generation of agents.

The first agents were built with raw LLM API calls. This worked for simple chatbots and scripted tasks, but not much else.

Agents like Claude Code and Codex broke the mold. These were real agents. Autonomous. You give them a task — not a pre-defined series of steps — and trust them to complete it using the context and tools that you provide.

Flue unlocks this new architecture for agents. Its built-in TypeScript harness gives any model the context and environment it needs for truly autonomous work: sessions, tools, skills, instructions, filesystem access, and a secure sandbox to run in. Run your agents locally via CLI or deploy them to your hosted runtime of choice.

Universal Agent Architecture

04 / Filesystem read · write · grep · glob
03 / Sandbox bash · security · network
02 / Harness skills · memory · sessions
01 / Model tokens · tools · prompts