Harness framework for distributed, enterprise-grade agents.

AgentScope Java is the open-source agent framework for the JVM. ReAct reasoning, Harness engineering infrastructure, multi-agent orchestration, and MCP/A2A protocol support — from local prototype to enterprise-scale deployment.

Get started → GitHub

JDK 17+Maven CentralApache 2.0

import io.agentscope.harness.*;
var agent = HarnessAgent.builder()
    .name("coder")
    .model(new QwenConfig("qwen-plus"))
    .filesystem(new LocalFilesystemSpec("./workspace"))
    .session(new RedisSession(jedisPool))
    .build();
// Stateful · resumable · memory-persistent
agent.call(messages, RuntimeContext.builder()
    .sessionId("user-123").build()).block();

io.agentscope:agentscope-harness

JDK 17+minimum Java version

Reactivebuilt on Project Reactor

MCP · A2Aopen protocol support

Apache 2.0open-source license

Harness Engineering

Enterprise patterns, zero boilerplate.

The Harness module injects workspace management, memory persistence, and context compression into the reasoning loop via hooks — without modifying core inference logic.

Structured workspace as the single source of truth
Cross-session long-term memory with automatic consolidation
Context overflow protection with auto-compaction
Local disk → Docker sandbox → object storage, one line to switch

Learn about Harness →

workspace/

workspace/
├── AGENTS.md          # persona + system instructions
├── MEMORY.md         # long-term memory (auto-managed)
├── knowledge/        # domain knowledge + RAG index
├── skills/           # reusable skill files
├── subagents/        # sub-agent specifications
└── agents/coder/session-user-123/
    ├── chat-history.jsonl
    └── scratchpad/
$ each call → load → reason → write back memory

multi-agent runtime architecture

+------------------------------------------------------------+
|                 Supervisor (HarnessAgent)                  |
|  - plans tasks / dispatches agents / aggregates results    |
+---------------------------+--------------------------------+
                            |
          +-----------------+------------------+
          |                                    |
+---------v---------+                +---------v---------+
| researcher Agent  |                |   coder Agent     |
| - web_search      |                | - filesystem/tool |
| - read_file       |                | - code execution  |
+---------+---------+                +---------+---------+
          |                                    |
          +-----------------+------------------+
                            |
+---------------------------v--------------------------------+
|           Shared Runtime Infrastructure                    |
|  Session (Redis) · Workspace · Memory · MCP · A2A         |
+------------------------------------------------------------+

Multi-Agent

Orchestrate agents like microservices.

Declare sub-agent specs in Markdown files. The supervisor spawns sub-agents on demand at runtime, supporting both blocking and non-blocking delegation modes.

Declarative sub-agent definitions — no code changes needed
Synchronous blocking and async non-blocking delegation
A2A protocol for cross-process and cross-machine agent calls
Sub-agents can independently inherit or override Harness config

Learn about multi-agent →

Full-stack capabilities, production-hardened

From reasoning core to enterprise deployment, AgentScope Java covers the full agent development lifecycle.

ReAct Reasoning

Autonomous planning, tool calling, and result integration. Built-in safe interruption, graceful cancellation, and hook-based human-in-the-loop oversight.

Quick start →

Memory & RAG

Persistent cross-session memory with semantic search. Automatic background consolidation prevents context bloat. Multi-tenant isolation out of the box.

Learn about memory →

MCP Protocol

Connect to any MCP-compatible server — file systems, databases, browsers, code interpreters — instantly extending agent tool capabilities without custom integration code.

View MCP →

A2A Protocol

Register agents with Nacos or similar service registries. Other agents can discover and delegate tasks as naturally as calling a microservice.

View A2A →

Sandbox Isolation

Tool execution in isolated environments (local Unix, Docker, E2B). Sandbox state is fully preserved across multi-turn conversations with cross-session snapshot restore.

Learn about sandboxes →

Observability

Pluggable Tracer SPI with native OpenTelemetry support for distributed tracing. AgentScope Studio provides visual debugging and real-time monitoring dashboards.

View Studio →

Ready to build?

Run your first agent in minutes. Start with a basic ReActAgent, then layer in Harness engineering, multi-agent orchestration, and enterprise capabilities as you need them — the same API scales with you.

Start building →

Frequently Asked Questions

Still have questions? Ask on GitHub Discussions.