Harness Implementations Compared
A living comparison of major AI agent harness implementations. Last updated: April 2026.
Overview
| Project |
Stars |
License |
Model Support |
Memory Model |
Architecture |
| OpenClaw |
355K |
Apache-2.0 |
Any model |
User-owned files |
Thin harness + skills |
| Claude Code |
— |
Proprietary |
Claude only |
Platform-managed |
Monolithic |
| Codex |
— |
Proprietary |
GPT only |
Encrypted summaries |
Cloud HaaS |
| Cline |
~60K |
Apache-2.0 |
Multi-model |
Session-based |
VS Code extension |
| Aider |
~43K |
Apache-2.0 |
Multi-model |
Git-based |
CLI tool |
| Hermes Agent |
70K |
MIT |
Multi-model |
Configurable |
Multi-agent framework |
| Nexu |
2.3K |
MIT |
Any model |
User-owned files |
Desktop client + harness |
Detailed Breakdown
Context Management
| Project |
Max Context |
Overflow Strategy |
Context Prioritization |
| OpenClaw |
Model limit |
Summarization + sliding |
Configurable |
| Claude Code |
200K |
Built-in compaction |
Automatic |
| Codex |
Model limit |
Cloud-managed |
Automatic |
| Cline |
Model limit |
Truncation |
Manual |
| Aider |
Model limit |
Repository map |
Automatic |
Memory Persistence
| Project |
Memory Type |
Cross-session |
Exportable |
Editable |
| OpenClaw |
MEMORY.md + daily files |
✅ |
✅ |
✅ |
| Claude Code |
CLAUDE.md + platform |
✅ |
❌ |
Partial |
| Codex |
Encrypted summaries |
✅ |
❌ |
❌ |
| Cline |
.cline/ directory |
✅ |
✅ |
✅ |
| Aider |
Git history |
✅ |
✅ |
✅ |
| Nexu |
MEMORY.md + wiki/ |
✅ |
✅ |
✅ |
| Project |
Skill Model |
Community Skills |
Install Method |
| OpenClaw |
SKILL.md based |
5,400+ |
openclaw skill install |
| Claude Code |
Built-in + MCP |
Limited |
MCP config |
| Codex |
Built-in |
No |
— |
| Cline |
MCP integration |
Via MCP |
MCP config |
| Aider |
Built-in |
Limited |
— |
| Nexu |
OpenClaw skills |
5,400+ |
GUI or CLI |
Multi-Agent Support
| Project |
Multi-agent |
Coordination |
Observability |
| OpenClaw |
Sub-agents + sessions |
Hub-and-spoke |
Session logs |
| Claude Code |
Limited (tool use) |
Sequential |
— |
| Codex |
Codex tasks |
Parallel tasks |
Dashboard |
| Hermes Agent |
Native multi-agent |
Configurable |
Built-in |
| Nexu |
Sub-agents + ACP |
Hub-and-spoke |
Dashboard |
This comparison is community-maintained. If you spot inaccuracies, please open an issue.