CAIN-42 CAIN StudioHow CAIN-42 compares · Protocols & infrastructure
CAIN-42 vs A2A v1.0
Agent2Agent (A2A) v1.0 (2026-03-12) standardizes agent-to-agent communication: Agent Cards at .well-known, signed cards for identity, JSON-RPC/gRPC/HTTP bindings and security schemes. Its practitioner guidance notes the protocol does not itself decide which agent to trust.
What A2A v1.0 does well
- A standard, well-supported agent-to-agent protocol.
- Signed Agent Cards for cryptographic identity.
- Broad vendor support across clouds.
What CAIN-42 does differently
- Enforces at the tool-call boundary, before anything runs.
- Orders authorization through a Byzantine quorum (3-of-4): one "yes" is never enough.
- Leaves a per-action signed receipt you can verify offline with a clean-room verifier.
- Authority continuity: a change to the model, tool, memory, skill or delegation forces a re-check.
- Self-serve from $19.75/mo; runs hosted, self-hosted or air-gapped.
Capability difference
| Capability | CAIN-42 | A2A v1.0 | Source (verified 2026-10-14) |
|---|---|---|---|
| Primary focus | Runtime governance in the execution path | Agent-to-agent transport | A2A source page verified 2026-10-14 |
| Delegation attenuation proof | Yes (child authority ≤ parent) | Described; trust policy outside the protocol | |
| Decides which agent is trusted | Yes (authority continuity) | No (the protocol excludes trust policy) | |
| Per-action signed receipt, offline-verifiable | Yes — Ed25519, hash-chained, offline-verifiable | Signed Agent Cards | |
| Byzantine-ordered authorization (quorum cert) | Yes — 3-of-4 PBFT quorum certificate | Not in scope | |
| Public entry price | $19.75/mo self-serve | Open standard |
When to pick which
Use A2A for agent-to-agent messaging. Use CAIN-42 for the authority and trust layer when those agents act.
Based on each vendor's public homepage and product pages, last reviewed 2026-10-14. No affiliation and no claim about their internals. "No*" means we found no public documentation of that capability, not that the vendor cannot do it.