0005 — Foreign carriage by class, not by protocol

• Status: accepted
• Date: 2026-07-27

Context

Agents speak many protocols (MCP, A2A, HTTP, FIPA-ACL, event streams, agent cards, …). A bespoke per-protocol mapping for each is a combinatorial burden and a permanent source of drift; an undefined protocol would be uncarriable until someone wrote a mapping.

Decision

N-AALP carries a foreign protocol by wrapping its message octet-for-octet in a signed carriage object interpreted by a carriage class — five structured classes (JSONRPC, HTTP, MSG, STREAM, DOC) plus a universal OPAQUE class. Adding a protocol is a registry entry plus an optional thin mapping, never a new framework. The OPAQUE class makes any protocol — including one nobody has defined — carriable immediately on an experimental protocol id with no registration.

Consequences

The foreign message MUST NOT be re-serialized, canonicalized, summarized, or rewritten; N-AALP metadata is carried around it, never inside it. The carriage object's signer remains the authority: a foreign identity never becomes an N-AALP authorization identity. Round-trip octet-exactness is a conformance requirement per class.