Full deep dive: OpenHands Architecture Breakdown
OpenHands (formerly OpenDevin) is the leading open-source autonomous coding agent — 77.6% on SWE-bench Verified, 64K+ GitHub stars, MIT licence. Its V1 SDK uses an event-sourced, stateless architecture split into four packages (SDK, Tools, Workspace, Server), with Docker-sandboxed execution, multi-agent delegation, model-agnostic LLM routing via litellm, and LLM-based context condensation for efficient long conversations.
Architecture Overview
OpenHands V1 is built on three core ideas:
- Event sourcing — all interactions are immutable events in an append-only log, enabling deterministic replay and crash recovery
- Stateless agents — configuration loaded at instantiation, never mutated; the
stepfunction processes state and returns the next action - Four-package SDK — SDK (core), Tools (implementations), Workspace (Docker/local/remote), Server (REST/WebSocket API)
Key Design Decisions
| Decision | Detail |
|---|---|
| Event-sourced state | Immutable event log enables crash recovery, auditability, and replay — critical when running 100+ parallel agents |
| CodeAct paradigm | Executable code as the unified action space — more flexible than structured JSON actions |
| Docker sandboxing | Kernel-level isolation (cap-drop ALL, seccomp, namespaces) — stronger than application-level permissions |
| Context condensation | LLM summarization of older events transforms quadratic cost scaling into linear — up to 2x cost reduction |
| Model agnosticism | litellm routes to any provider (Claude, GPT, Gemini, Ollama) with function-call fallback for less capable models |
| Multi-agent delegation | AgentDelegateAction spawns sub-agents with fresh context for parallel task processing |
Why It's in Trial
OpenHands is the answer to "can we get autonomous coding agent capabilities without proprietary SaaS pricing?" Its 77.6% SWE-bench score rivals commercial agents, the event-sourced SDK is production-grade, and the Docker sandbox provides real security isolation. The AMD partnership enables fully on-premises deployment for regulated industries. See the full deep dive for architecture diagrams, SDK package breakdown, and comparisons with Claude Code and Devin.
Key Characteristics
| Property | Value |
|---|---|
| Company | All Hands AI (community) |
| Language | Python (backend), React (frontend) |
| SWE-bench Verified | 77.6% (Claude Sonnet 4.5) |
| Key innovations | Event-sourced SDK, CodeAct paradigm, context condensation, Docker sandboxing |
| License | MIT (GitHub) |
| Sources | OpenHands, SDK Paper, GitHub |