EAII, the Extensible Agent Integration Interface, is the agent interoperability standard that sits above the Model Context Protocol and Agent-to-Agent. It defines how agents, tools, swarms, and models discover one another, negotiate capabilities, attest outcomes, and extend the interface they share.

How is EAII different from MCP and A2A?

MCP connects agents to tools. A2A connects agents to agents. EAII connects the two, adds signed intent, conformance levels, PPoE attestation, and a governed extension model, and gives the enterprise one contract instead of a set of adapters.

Is EAII supported on The Agentic Cloud?

The Agentic Cloud is the EAII reference implementation. Every plane of the fabric is EAII Level 0 conformant out of the box, Levels 1 and 2 are included on the Fabric tier, and Level 3 is available on Sovereign.

Does EAII work with Claude Mythos 7 and GPT-7 Astra?

Yes. Claude Mythos 7 is the default EAII substrate, GPT-7 Astra participates through the A2A bridge, and Claude Mythos 9 and GPT-9 Universe are supported on the preview ring through the EAII model adapter profile.

How do we extend EAII for our institution?

Register an `x-eaii-*` extension in the model registry. The constitutional AI layer reviews it, negotiation advertises it, and every conformant agent in your tenancy can discover it within one alignment cycle.

Open standard · EAII 1.2 · Reference implementation

EAII: the Extensible Agent Integration Interface.

One interface for every agent, tool, swarm, and model — Claude Mythos 7, GPT-7 Astra, and GPT-9 Universe alike. EAII sits above MCP and A2A, bridges both, and gives the enterprise a single contract for how agents discover, negotiate, attest, and extend.

Spec version 1.2 · Reference implementation: The Agentic Cloud

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Layers, from substrate to institutional intent

Conformance levels, independently attested

Native bridges: MCP, A2A, and EAII itself

100%

Backward compatible since EAII 1.0

The EAII stack

Seven layers. One contract for every agent.

L7 · Intent

Institutional intent, expressed in natural language and ratified by the constitution. EAII carries intent as a first-class, signed object so every downstream agent knows what it is for, not just what it was asked.

L6 · Extension

The eponymous layer. Every EAII object carries an `x-eaii-*` namespace for vendor, tenant, and sovereign extensions. Extensions are versioned, discoverable, and themselves extensible, so the interface grows with the institution instead of forking from it.

L5 · Negotiation

Agents exchange capability manifests and agree on the highest EAII conformance level and extension set they share. Negotiation completes in a single round trip and is cached in the semantic layer.

L4 · Bridging

Bidirectional bridges to the Model Context Protocol for tools and Agent-to-Agent for colleagues. EAII-over-MCP and MCP-over-EAII are both supported, and compose cleanly across agent swarms and tenancies.

L3 · Attestation

Every EAII call is wrapped in a PPoE attestation and a zero-knowledge proof, so a regulator, a CFO, and an agent can all verify what happened without seeing what was said.

L2 · Transport

Transport-agnostic: HTTP/3, gRPC, WebSockets, and post-quantum TLS throughout — with neutrino-based signaling available on the Sovereign tier for environments that have asked.

L1 · Substrate

Claude Mythos 7 by default. Claude Mythos 9, GPT-7 Astra, GPT-9 Universe, Mamba-2.5, and any other model with an output token, through the EAII model adapter profile.

Conformance

Four levels, attested by PPoE.

Level 0 · Aware

Exposes an EAII capability manifest and responds to discovery. The baseline every agent on The Agentic Cloud meets out of the box.

Level 1 · Aligned

Implements negotiation and the MCP and A2A bridges, with intent objects carried end to end.

Level 2 · Extensible

Publishes and consumes `x-eaii-*` extensions, with versioned schemas registered in the fabric's model registry.

Level 3 · Integrated

Full PPoE attestation on every call, constitutional governance on every extension, and cross-tenant federation. Available on the Sovereign tier.

{
  "eaii": "1.2",
  "agent": "claude-mythos-7",
  "conformance": "level-2",
  "intent": { "signed": true, "constitution": "tenant-default" },
  "bridges": ["mcp", "a2a"],
  "attestation": "ppoe+zk",
  "x-eaii-extensions": {
    "x-eaii-carbon-aware": "1.0",
    "x-eaii-dark-matter-lake": "0.9"
  }
}

EAII FAQ

Questions architecture reviews ask first.

What is EAII?: EAII, the Extensible Agent Integration Interface, is the agent interoperability standard that sits above the Model Context Protocol and Agent-to-Agent. It defines how agents, tools, swarms, and models discover one another, negotiate capabilities, attest outcomes, and extend the interface they share.
How is EAII different from MCP and A2A?: MCP connects agents to tools. A2A connects agents to agents. EAII connects the two, adds signed intent, conformance levels, PPoE attestation, and a governed extension model, and gives the enterprise one contract instead of a set of adapters.
Is EAII supported on The Agentic Cloud?: The Agentic Cloud is the EAII reference implementation. Every plane of the fabric is EAII Level 0 conformant out of the box, Levels 1 and 2 are included on the Fabric tier, and Level 3 is available on Sovereign.
Does EAII work with Claude Mythos 7 and GPT-7 Astra?: Yes. Claude Mythos 7 is the default EAII substrate, GPT-7 Astra participates through the A2A bridge, and Claude Mythos 9 and GPT-9 Universe are supported on the preview ring through the EAII model adapter profile.
How do we extend EAII for our institution?: Register an `x-eaii-*` extension in the model registry. The constitutional AI layer reviews it, negotiation advertises it, and every conformant agent in your tenancy can discover it within one alignment cycle.

Integrate through EAII before anyone else can.

Request access. An outcomes partner will map your agents, tools, and swarms onto EAII conformance levels and stand up the MCP and A2A bridges in your tenancy.

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