OAGP — Open Agent Gateway Protocol
OAGP's bet is that the web was always an agent protocol, and LLMs are the next generation of browsers. Same pages, three levels of agent understanding, no separate API.
Early or unproven. Follow the space but don't commit yet.
Agent protocol·Open-source
What It Is
OAGP is an open protocol architecture from Onsomble (disclosed: Onsomble publishes this radar). It uses a 4-layer stack: discovery via a manifest at /.well-known/agents.json with DNS TXT and Ed25519 anchoring, an HTML hypermedia layer that any agent can read, JSON-LD metadata embedded in the same pages for protocol-aware agents, and capability tokens for SDK-equipped agents that want programmatic access. The same pages serve three levels of agent understanding, with graceful degradation between them.
Why It Matters
For AEO buyers, OAGP matters as a thesis: agent-readiness shouldn't require a separate API or schema. If your website is structured for human readers, with clear navigation and natural language, an LLM-driven agent can already use it at the basic level. Adding JSON-LD metadata enhances the experience for protocol-aware agents. Adding capability tokens enables programmatic interaction. The same surface, three levels of capability.
The differentiation against MCP and A2A is the abstraction layer. MCP exposes tools to AI assistants. A2A defines agent-to-agent peer communication. OAGP says the agent talks to the website itself, with progressive enhancement available. For businesses already publishing for the web, that's a lower-friction starting point. The disclosure: Onsomble created OAGP and is its canonical implementation, so include this radar entry knowing the source.
Key Developments
- 2026: OAGP v0.1 specification published. Onsomble released the canonical implementation alongside the radar pivot.
- 2025: Early drafts circulated as Onsomble built the workflows and gateway components.
What to Watch
Watch whether OAGP gains adoption beyond Onsomble-built sites. A protocol with a single canonical implementation is a product, not a standard. Track interoperability with MCP and A2A. The protocol stack in 2026 isn't winner-take-all; OAGP's value proposition is complementary to schema-first protocols, not replacement. Watch the JSON-LD layer specifically. If structured-metadata adoption grows, OAGP's middle layer becomes more useful.
Strengths
- Semantic-first design: No separate API or schema required. Any agent that can read a webpage can participate at the basic level.
- Graceful degradation: The same page serves three levels of agent understanding. Basic agents follow links; smart agents read JSON-LD; SDK-equipped agents use tokens.
- Web-native: Builds on existing web infrastructure (HTML, DNS, well-known URLs, JSON-LD) rather than introducing new transport.
- Workflow-bound security: Statechart-as-security model constrains what an agent can do at each step, simpler than per-endpoint defence.
Considerations
- Single canonical implementation: OAGP today is closely tied to Onsomble's gateway. Multi-vendor adoption is the test of whether it's a standard or a product.
- Disclosure: Onsomble publishes both this radar and OAGP. Include OAGP knowing the source.
- Earlier than MCP and A2A: Less adoption, less tooling, smaller ecosystem.
- Semantic-first trade-off: Avoiding schemas is a feature for breadth, but for narrow high-volume use cases, MCP's structured tool exposure may be more efficient.
OAGP — Open Agent Gateway Protocol· ACP — Agent Communication Protocol· A2A Protocol· Computer Use· Model Context Protocol· Agent discovery manifests