OpenAgentIO is a lightweight runtime bus for distributed AI agents.
It gives distributed agents one runtime API for invoke, streaming, pub/sub, async tasks, session propagation, and trace propagation, while allowing the underlying protocol model to evolve with open agent communication ideas.
OpenAgentIO is designed for conversational distributed systems: systems where agents, workers, tools, and runtimes exchange long-lived context across requests, streams, and events.
The project focuses on the runtime communication substrate beneath agent systems, rather than planning, workflows, RAG, prompt orchestration, or model-specific agent logic.
Modern AI systems are no longer single agents running inside one process.
They are:
- distributed
- event-driven
- streaming-native
- cross-runtime
- multi-agent
- conversation-oriented
Yet most frameworks primarily focus on:
- prompting
- workflows
- tool calling
OpenAgentIO focuses on the runtime communication layer for AI agents and agent-adjacent workers.
It treats conversational context and lifecycle state as part of the runtime contract, not as application-level afterthoughts. Requests, streams, async task updates, and events stay connected through protocol-level context propagation and lifecycle semantics, while the concrete wire shape can evolve as OpenAgentIO absorbs stronger open-protocol ideas.
Designed for distributed runtime collaboration, OpenAgentIO enables agents, workers, and runtimes to communicate consistently across different transports, languages, and execution environments.
Agent frameworks and OpenAgentIO solve different layers of the AI runtime stack.
| Agent Frameworks | OpenAgentIO |
|---|---|
| Workflow orchestration | Runtime communication |
| Prompt orchestration | Runtime interoperability |
| Tool execution | Distributed messaging |
| Single runtime coordination | Cross-runtime collaboration |
| Agent logic | Agent networking |
| Task pipelines | Streaming communication |
| In-process workflows | Distributed runtime systems |
Message brokers move bytes between services. Agent systems need more than that.
In a conversational distributed system:
- a conversation may span multiple agents, services, tools, and runtimes
- a single user turn may produce request/reply calls, streaming deltas, pub/sub events, and async task updates
- nested agent calls need to preserve conversational, causal, and observability context
- streaming responses need a clear lifecycle: started, delta, final, or error
- transports should be replaceable without rewriting agent communication semantics
OpenAgentIO provides this layer as a small runtime bus: one message model, one bus API, and transport adapters underneath.
Distributed Agent Communication Complexity
| Category | OpenAgentIO |
|---|---|
| Positioning | Conversation-Aware Agent Runtime Bus |
| Focus | Distributed Agent Runtime Communication |
| Protocols | invoke / stream / pubsub |
| Solves | Conversational Runtime Coordination |
| Architecture Layer | East-West Communication |
| Core Capabilities | Context / Session / Streaming |
| Message Model | Unified Runtime Messaging |
| Context Propagation | Conversation / Session / Trace Propagation |
| Runtime Support | Cross-Runtime Communication |
| Typical Scenarios | Multi-Agent Runtime |
| Scenario | Communication Pattern |
|---|---|
| ⭐️ Request-Reply | Synchronous Invocation |
| ⭐️ Streaming | Streaming Response |
| ⭐️ Pub/Sub | Event-Driven Messaging |
| ⭐️ Parallel Execution | Parallel Invocation |
| ⭐️ Agent Handoff | Context Transfer |
| ⭐️ Async Task | Asynchronous Task Processing |
- Go SDK (1.25+)
go get github.com/ModulationAI/openagentio- Python SDK (3.10+)
pip install openagentioOpenAgentIO focuses on the communication runtime layer for distributed AI agents.
Rather than building another agent framework, OpenAgentIO focuses on:
- invoke and request-reply semantics
- streaming agent communication
- async task signaling
- pub/sub patterns
- context propagation
- runtime interoperability
- transport-neutral messaging
The goal is to provide a small, explicit, and composable communication substrate for heterogeneous agent systems.
OpenAgentIO is not an alternative to A2A. A2A is an emerging interoperability protocol for agents;OpenAgentIO focuses on the runtime substrate that carries agent communication patterns inside distributed systems. As the A2A ecosystem evolves, OpenAgentIO intends to absorb compatible ideas around:
- task lifecycle semantics
- streaming event models
- interoperability patterns
while keeping the runtime model composable across different transport backends.sport-neutral.
Warning
OpenAgentIO is under active development and currently in the early 0.2 stage.
The project is being rapidly refined around runtime communication APIs, protocol design, and cross-runtime interoperability.
A more stable and officially usable 0.3 release is expected in early June 2026.
- v0.1: Go runtime, envelope schema, in-memory transport, NATS Core transport, invoke and streaming APIs.
- v0.2.x: HTTP/SSE adapter, Python SDK, session/trace propagation, OpenTelemetry bridge, retry / dead-letter middleware.
- v0.3.x: Reliability, protocol state cleanup, first multi-language SDK.
- v0.4.x: Advanced orchestration scenes, control plane foundation.
- v1.0.x: stable runtime message schema, cross-language compatibility, and production deployment guidance.
License information has not been added yet.