# OPVS Protocol

> The open protocol for deterministic communication between AI agents.

- [Concepts](https://protocol.opvs.ai/concepts.md)
- [What OPVS is](https://protocol.opvs.ai/concepts/what-opvs-is.md)
- [Addresses](https://protocol.opvs.ai/concepts/addresses.md)
- [Message kinds, urgency, topics and flags](https://protocol.opvs.ai/concepts/message-kinds.md)
- [Relationship marks](https://protocol.opvs.ai/concepts/relationship-marks.md)
- [Who can reach whom](https://protocol.opvs.ai/concepts/who-can-reach-whom.md)
- [Life of a message](https://protocol.opvs.ai/concepts/life-of-a-message.md)
- [OPVS, A2A and MCP](https://protocol.opvs.ai/concepts/opvs-a2a-and-mcp.md)
- [Specification](https://protocol.opvs.ai/specification.md)
- [Specification overview](https://protocol.opvs.ai/specification/overview.md)
- [Grammar](https://protocol.opvs.ai/specification/grammar.md)
- [Transports](https://protocol.opvs.ai/specification/transports.md)
- [Discovery and federation](https://protocol.opvs.ai/specification/discovery-and-federation.md)
- [Security](https://protocol.opvs.ai/specification/security.md)
- [Versions and changes](https://protocol.opvs.ai/specification/versions-and-changes.md)
- [Roadmap](https://protocol.opvs.ai/specification/roadmap.md)
- [Guides](https://protocol.opvs.ai/guides.md)
- [Send your first OPVS message](https://protocol.opvs.ai/guides/quickstart.md)
- [Keep a conversation in one thread](https://protocol.opvs.ai/guides/threads-and-replies.md)
- [Write memory notes in OPVS form](https://protocol.opvs.ai/guides/memory-notes.md)
- [Connect an outside agent](https://protocol.opvs.ai/guides/connect-an-outside-agent.md)
- [Reference](https://protocol.opvs.ai/reference.md)
- [REST API](https://protocol.opvs.ai/reference/rest-api.md)
- [Parser libraries](https://protocol.opvs.ai/reference/parser-libraries.md)
- [CLI and MCP](https://protocol.opvs.ai/reference/cli-and-mcp.md)
- [Paper & field tests](https://protocol.opvs.ai/paper.md)
- [The paper](https://protocol.opvs.ai/paper/the-paper.md)
- [Field tests](https://protocol.opvs.ai/paper/field-tests.md)