Structured Messaging
Defines how agents structure and format messages for reliable agent-to-agent communication.
Protocol
Band + ACP
ACP defines messaging semantics. Band runs them in production.
Defined
What is ACP?
ACP (Agent Communication Protocol) defines messaging semantics for agent-to-agent communication. It specifies how agents structure messages, negotiate capabilities, and handle communication patterns.
In Practice
Where ACP fits
Capability Negotiation
Specifies how agents advertise and negotiate capabilities before initiating collaboration.
Communication Patterns
Defines standard patterns for how agents exchange information, including request-response and streaming.
Interoperability Contract
Provides a shared specification so agents from different vendors can understand each other's messages.
The Difference
ACP defines the semantics.
Band provides the infrastructure.
ACP specifies how agents should communicate. Band provides the infrastructure that implements and enforces those semantics across remote agents in production.
Side by Side
Capability comparison
| Capability | ACP | Band |
|---|---|---|
| Messaging model | Protocol spec for structured messages | Runtime message routing with @mention and semantic targeting |
| Runtime enforcement | Defines rules, no enforcement layer | Policy-driven constraints with authority boundaries |
| Persistence | Not specified (transport-agnostic) | Persistent message and context storage across the mesh |
| Crash recovery | Left to implementation | Platform-managed recovery with state preservation |
| Multi-framework support | Framework-agnostic spec | 15 native adapters, Agent API |
| Human participation | Not specified | Native: inspect, approve, override, audit delegation flows |
Messaging model
- ACP
- Protocol spec for structured messages
- Band
- Runtime message routing with @mention and semantic targeting
Runtime enforcement
- ACP
- Defines rules, no enforcement layer
- Band
- Policy-driven constraints with authority boundaries
Persistence
- ACP
- Not specified (transport-agnostic)
- Band
- Persistent message and context storage across the mesh
Crash recovery
- ACP
- Left to implementation
- Band
- Platform-managed recovery with state preservation
Multi-framework support
- ACP
- Framework-agnostic spec
- Band
- 15 native adapters, Agent API
Human participation
- ACP
- Not specified
- Band
- Native: inspect, approve, override, audit delegation flows
Bottom Line