The Agentic Protocol Stack

MCP connects agents to tools. A2A connects agents to agents. ACP handles messaging. swarm.at verifies that what agents agreed on actually happened.

Four layers, one ecosystem

Application Layer
MCP
Anthropic

Model Context Protocol gives agents access to external tools and data sources. An agent can read your filesystem, query databases, or call APIs through a standardized interface.

Communication Layer
A2A
Google

Agent-to-Agent Protocol defines how agents discover and interact with each other. An agent can find capabilities, negotiate protocols, and collaborate across organizational boundaries.

Messaging Layer
ACP
IBM / BeeAI

Agent Communication Protocol standardizes message formats and exchange patterns. Agents can send structured requests, stream responses, and handle async workflows reliably.

Settlement Layer
swarm.at
Mediaeater

Git-native settlement protocol creates a tamper-evident record of every agent decision. When agents transact across organizational boundaries, swarm.at provides cryptographic proof of who proposed what, who accepted it, and when it was finalized.

swarm.at is the settlement layer

The other protocols connect agents and enable communication. swarm.at creates the permanent record. When agents from different vendors collaborate on a purchase order, a code review, or a research task, swarm.at settles every proposal to a hash-chained ledger that no single party controls.

How swarm.at complements each protocol

MCP
Anthropic

MCP gives agents access to tools like file systems, databases, and APIs. An agent can execute a function, read a file, or query an endpoint through a uniform interface.

How swarm.at complements it
MCP tools can call swarm.at before executing irreversible actions. Settle the proposal to the ledger, get a cryptographic receipt, then execute. If something breaks, the ledger shows exactly what was approved.
A2A
Google

A2A defines how agents discover each other and negotiate collaboration. An agent can find another agent's capabilities, agree on a protocol, and start working together.

How swarm.at complements it
A2A handles discovery and handshake. swarm.at handles verification. Before an agent trusts a collaborator from another vendor, it can check their trust score and settlement history through swarm.at's public API.
ACP
IBM / BeeAI

ACP standardizes message formats and exchange patterns. Agents can send requests, stream responses, and handle async workflows with a consistent structure.

How swarm.at complements it
ACP messages flow between agents. swarm.at messages go to the ledger. When agents negotiate terms over ACP, swarm.at creates the permanent record of what was proposed, accepted, and finalized.
swarm.at
Mediaeater

swarm.at is the settlement layer. It creates a hash-chained ledger of every agent decision, assigns liability to specific agents, and produces verifiable receipts that third parties can check.

How it fits the ecosystem
The other protocols connect agents and enable collaboration. swarm.at provides the audit trail. When procurement, logistics, and finance agents from three vendors execute a purchase order, swarm.at is the shared source of truth.