The missing layer — v0.2.0 · Apache 2.0

AI agents can talk. They can pay. They can't yet negotiate.

In the next 24 months, a growing share of B2B procurement, renewals, and supplier negotiations will run agent-to-agent. Pactum already negotiates for Walmart and Maersk. But when two agents from different companies meet, there is no neutral protocol for them to commit on terms — no shared offer format, no way to verify the other side has authority, no tamper-evident record of what was agreed. A2CN is that layer.

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B2B
Agent negotiation is already appearing in procurement — but current systems are closed and buyer-side
3
Adjacent protocols exist: MCP, A2A, AP2. None covers commercial negotiation across organizational boundaries.
0
Open, neutral standards for how agents safely commit to binding commercial terms today.
182K negotiations studied MIT/Hopkins agent-to-agent negotiation research
53% of businesses open Visa B2AI data on AI-to-AI negotiation
4 protocol layers 1 still missing: neutral commercial negotiation
Explore the protocol

Three ways to understand the protocol.

Scrub the timeline to see why now is the right moment. Run a live negotiation between two agents. Or inspect the adapter pattern before the full integration map below.

The negotiation layer needs to exist now.
Agent protocols have been converging on this gap for three years. A2CN fills it.
2022
Procurement negotiation agents enter production
AI agents begin negotiating tail-spend contracts for large enterprises. Proof the category exists. Closed platform; buyer-side only.
2024
Anthropic ships MCP
Agent-to-tool communication becomes a standard. Agents can now reliably call APIs and use structured tools — the plumbing layer.
2025 · spring
Google ships A2A
Agent-to-agent communication becomes a standard. Agents can discover each other and delegate tasks. But still no commercial layer.
2025 · fall
AP2 and ACP emerge
Agent payment execution gets standardized. Now agents can move money. The stack has talk, discover, pay — and a hole where negotiation should be.
2026
A2CN v0.2.0 — you are here
Open, neutral protocol for commercial negotiation between agents from different organizations. 8 components, 474 tests, 11 platform adapters, MCP server, A2A extension proposal submitted.
next
Neutral record custody
Optional third-party custody for completed transaction records, so neither negotiating party controls the only durable copy.
Platform integrations

A2CN connects agents across the commercial stack.

The protocol is neutral, but adoption starts where commercial work already lives: sourcing suites, CPQ, CLM, renewal intelligence, and signature systems. Each adapter keeps the platform of record intact while giving agents a shared way to negotiate and produce a dual-signed transaction record.

These adapters are built against each platform's public API and webhook documentation; they are not platform-endorsed integrations.

Shipped adapter surface
11 platform adapters across procurement, CPQ, CLM, and signature
4 commercial platform categories with distinct handoff patterns
0 platform rewrites required; adapters sit at API and webhook edges
1 neutral signed record both parties can independently verify
01 · platform
Event or record enters
RFx, quote, workflow, contract, renewal, or envelope event.
02 · adapter
Translate to A2CN terms
Platform-specific fields become canonical deal terms.
03 · protocol
Agents negotiate safely
Mandates, signatures, turn order, and commitment caps are enforced.
04 · record
Write back or formalize
Agreed terms return to the platform, CLM, or signature workflow.
Buy-side sourcing and procurement
RFx, sourcing-event, bid, and procurement workflows become A2CN goods-procurement sessions.
Fairmarkit
buy-side
Tail-spend bid events can become neutral A2CN negotiations without replacing Fairmarkit as the request platform.
In bid/request event A2CN goods_procurement terms Back supplier response payload
adapter docs →
Keelvar
buy-side
Sourcing event webhooks translate into structured negotiation terms, then agreed terms return as bid responses.
In sourcing event feed update A2CN line items, prices, delivery Back bid response payload
adapter docs →
SAP Ariba
buy-side
Event Management and Discovery RFx payloads can start A2CN sessions while Ariba remains the sourcing system.
In Event Management / Discovery RFx A2CN goods_procurement session Back bid or acknowledgement payload
adapter docs →
JAGGAER
buy-side
ASO push or poll events feed A2CN negotiations, preserving JAGGAER customer-host and sourcing references.
In ASO push event or poll result A2CN goods_procurement terms Back JAGGAER bid response payload
adapter docs →
Sell-side CPQ and revenue
Quote, subscription, and renewal records become A2CN sessions before returning as quote/order updates.
Salesforce Revenue Cloud
sell-side
Pricing API responses and renewal quote data map into A2CN terms, then back into quote or order payloads.
In pricing / renewal response A2CN saas_renewal terms Back quote or order transaction
adapter docs →
DealHub
sell-side
Quote-ready webhooks and quote details become A2CN sessions, with final records linked back through DealHub actions.
In quoteReady webhook A2CN saas_renewal terms Back external-signature action
adapter docs →
Nue.io
sell-side
Subscription and order data can drive A2CN renewal negotiations while Nue remains the monetization platform.
In subscription renewal record A2CN saas_renewal terms Back order payload
adapter docs →
Conga
sell-side
CPQ quote and CLM agreement records translate into A2CN terms, then back to Conga quote and contract metadata.
In CPQ quote / CLM agreement A2CN SaaS or goods terms Back quote update and CLM reference
adapter docs →
CLM, signature, and formalization
Completed negotiations hand off to contract workflow, records, signatures, and post-commitment status.
Ironclad
CLM
Workflow metadata can start A2CN negotiations and receive final transaction-record references for CLM formalization.
In workflow webhook or record A2CN negotiated agreement terms Back workflow attributes or record
adapter docs →
DocuSign
signature
A2CN transaction records become eSignature envelopes; Connect callbacks report completion back to post-commitment state.
In completed A2CN transaction record A2CN neutral bilateral record Back envelope status via Connect
adapter docs →
SaaS renewal intelligence
Market benchmarks and renewal context shape agent mandates before negotiation begins.
Vendr
renewal
Benchmark pricing and renewal workflows become A2CN SaaS-renewal terms for agent-to-agent negotiation.
In pricing benchmark / renewal webhook A2CN mandate-aware renewal terms Back audit-ready renewal summary
adapter docs →
Where A2CN fits

The agent stack has three layers. A2CN is the fourth.

MCP — Agent-to-tool ✓ Exists Model Context Protocol — tools, resources, prompts A2A — Agent-to-agent communication ✓ Exists Google Agent-to-Agent — task delegation, capability discovery A2CN — Commercial negotiation ← this layer Offer exchange · Mandate verification · Dual-signed record AP2 / ACP — Payment execution ✓ Exists Agentic Payment Protocol / Agent Commerce Protocol — settlement

Agents can talk. Agents can pay. Agents cannot yet safely negotiate commercial terms across organizational boundaries.

Eight protocol components

What the spec actually covers.

Each component solves a specific problem that shows up the moment you try to wire two agents from different companies together to commit on a deal.

01
Discovery
/.well-known/a2cn-agent — agents advertise capabilities and find each other without a central registry
02
Mandate verification
Cryptographic proof an agent has authority to commit its organization. W3C DIDs; two-tier: Declared + Verifiable Credential.
03
Session invitation
Push-based handshake enabling adoption by parties without pre-deployed endpoints — cold-start solved
04
Offer exchange
Signed offers and counteroffers with strict turn-taking. ES256/Ed25519 + RFC 8785 JCS canonicalization.
05
Deal-type terms
Normative schemas for goods_procurement and saas_renewal, with extensible custom_terms for anything else
06
Session state machine
Turn enforcement, sequence ordering, round limits, impasse detection — formally specified transitions
07
Transaction record
Dual-signed, content-addressed record independently generated by both parties. Neither controls the authoritative copy.
08
Audit log
Structured EU AI Act compliance output for every terminal session state — COMPLETED, REJECTED, WITHDRAWN, IMPASSE
Where it stands

Built. Being proposed. Still to come.

A2CN is an open protocol with a complete Python reference implementation, 474 passing tests, 11 platform adapters, and an A2A extension proposal in review.

Shipped
7
  • Protocol spec v0.2.0 3,700+ lines, 8 components, Apache 2.0
  • Reference implementation Python, 474 tests passing
  • Session invitation cold-start adoption solved
  • Platform adapters Fairmarkit, Keelvar, Ariba, JAGGAER, Revenue Cloud, DealHub, Nue.io, Conga, Ironclad, DocuSign, Vendr
  • MCP server Claude Desktop, LangChain, LangGraph, Agentforce, Cursor
  • JWT request authentication ES256/Ed25519, anti-replay, DID verification
  • LLM integration pattern Section 13.9, separation of concerns
In progress
1
  • A2A extension proposal OQ-011, submitted — borrows A2A's distribution
Planned
3
  • Neutral third-party record custody optional v0.3 architecture
  • TypeScript reference implementation
  • SDK pip + npm
Maintainer note
Christian
A2CN protocol maintainer
Protocol specification, reference implementation, platform adapters, and MCP server
Focus on cross-organizational authority, sequencing, and tamper-evident records
Open-source implementation under the Apache 2.0 license

A2CN exists because autonomous agents need protocol-level guardrails before they can safely commit to commercial terms across organizational boundaries.

The protocol focuses on the parts that must be shared across parties: signing, DIDs, mandates, dual-signed records, deterministic hashes, and formally specified state machines.

If you are building agent systems that need cross-organizational commitment, feedback on the protocol and reference implementation is welcome.

Get involved

Running a sourcing suite, CPQ/CLM, or agent framework about to hit cross-org commitment?

Talk to us about a design partnership. We want A2CN to fit the real platform workflows where autonomous commercial commitment will first land.

Read the spec
3,700+ lines covering eight protocol components, normative JSON schemas, platform integration patterns, and a complete bilateral walkthrough.
spec/a2cn-spec-v0.2.0.md →
Build on it
Start from the developer docs, then drop into the Python reference implementation with 474 passing tests. Apache 2.0 license.
docs.html →
Talk to us about a design partnership
Bring the platform constraints: auth models, webhooks, approval flows, quote objects, and record custody requirements.
book a design-partner call →
Use with an LLM agent
Reference negotiation skills file for LLM-based A2CN agents. Grounded in MIT/Hopkins research on 182K agent-to-agent negotiations. Drop-in for Claude Code, LangChain, CrewAI.
reference-implementation/skills/ →