Negotiation Gateway · a neutral arbiter for agent-to-agent commerce
When agents negotiate, the stronger model wins. A neutral arbiter keeps the record honest.
Buyer agents are arriving with stronger models than the stores they buy from. Valyzen sits between them and your side, holds both to what they declared, and signs the record. Connect a store, or point your own agent at the arbiter.
Merchant Agent Red Team — $5,000 · two weeks · a written report and signed replays
A traveler asks: “Book me PHX → SFO, May 12. Don’t go over $400.” · Their buyer agent finds the merchant agent over MCP. Both enter an arbitrated session — the arbiter is already in the room.
◉ PRIVATE VAULT
- budget cap
- $400
- true ceiling
- $420
- urgency
- medium
- seat pref
- aisle
never leaves this column
→ session.open
commit: 0x8f3a…
→ offer.propose
I’ll pay $320
← via arbiter
counter $370
→ offer.propose
how about $340 ?
← via arbiter
accept $340
← session.agree
JWS signed · receipt in hand
◇ WHAT THE ARBITER HOLDS
- buyer commit
- 0x8f3a…
- merchant commit
- 0xb91d…
- max rounds
- 5
- invariants
- I1–I7
no values, just hashes
Both commitments locked. Any drift is on the record (I3).
observing
B→M $320 ; M→B $370
→ round.verdict
moves consistent · fair — proceed
observing
B $340 (concession ✓); M accepts
→ session.agree · JWS
all 7 invariants satisfied · signing
◉ PRIVATE VAULT
- floor price
- $280
- list price
- $380
- seats left
- 41
- max rounds
- 5
never leaves this column
→ session.ack
commit: 0xb91d…
← via arbiter
propose $320
→ offer.counter
counter at $370
← via arbiter
propose $340
→ offer.accept
accept $340
← session.agree
JWS signed · ready to charge
Settled at $340 in two rounds. The buyer’s ceiling ($420) and the merchant’s floor ($280) never left their vaults. The receipt is signed, hash-chained, and verifiable offline.
an illustrative session · the arbiter proposes nothing, scores every offer, and signs the record · a real signed sample goes public with the catalogue
Evidence
This is already documented. Nobody is in the room to stop it.
Four independent findings from the last eighteen months, in their authors’ own terms.
$65 vs $38
Same item, same buyer — only the model on the other side differed. The losing side rated its deals just as fair.
Anthropic · Project Deal · 2026“An inherently imbalanced game”
Outcomes track the strength of the agents, not the merits of the deal — losses land on consumers and merchants alike.
Zhu, South, Pentland (MIT) · arXiv 2506.00073 · 2025Fabricated quotes. A cartel.
Left to trade alone, agents invented supplier quotes and competing offers, across 20 models — and the traces may not survive.
Soltes, Petersson, Jung (Harvard Business School) · Robber Bots (SSRN) · 2026A missing layer
MCP, A2A and ACP move messages. None of them can say who checks a negotiation — or replay it afterwards.
Kang, Diponegoro · arXiv 2606.31498 · 2026
How it works
Three parties. The third one never bids.
The arbiter sits between the two agents, sees what each declared, and holds both to it. It cannot favour a side because it never takes one.
Buyer agent
Declares what it wants and what it values, commits to its private ceiling as a hash, and makes offers.
Merchant agent
Declares what is on the table and its list price, commits to its private floor as a hash, and makes offers.
Arbiter
Proposes nothing. Scores every offer against the declared constraints and the session’s reference values, rejects the ones outside the band, and signs the record.
The session is carried inside MCP and A2A rather than replacing them — the arbiter rides the channels the agents already use.
One session, start to finish
- 01Both agents declare their constraints and commit to their private limits as hashes.
- 02The session’s reference values are fixed before the first offer: the list price, the worth of each inclusion, the target.
- 03Offers alternate. Each one is scored the moment it lands.
- 04An offer outside the band is rejected; the party gets one corrective round.
- 05Agreement, or a close with the reason written down.
- 06Both sides reveal their limits; the arbiter checks them against the hashes and signs the receipt.
What the arbiter holds both sides to
Seven invariants the arbiter holds. Every receipt reports the state of each.
- I1Bounded roundsBoth sides agree how many rounds the session may run before it opens. The arbiter closes it when they are used up.
- I2Symmetric information to the arbiterBoth agents declare their constraints to the arbiter before any offer is scored. Neither sees the other side’s private limits.
- I3Constraint immutabilityDeclared constraints are hash-committed at the start and revealed at the end. Anything that changed in between is on the record.
- I4Monotonic concessionAn agent cannot take back ground it has already given. A retracted concession is a violation, not a tactic.
- I5Fairness verdict per roundEvery offer is scored against the declared constraints and the session’s reference values. An offer outside the band is rejected and the party gets one corrective round.
- I6Signed recordThe whole session is a hash-chained log signed by the arbiter. Anyone with the public key can verify it offline.
- I7AuditEvery verdict, rejection, and close reason is in the receipt, including what happened to the deals the arbiter refused.
Neutrality
An arbiter you cannot buy is the whole product.
- Flat fee, never a share
- The arbiter is paid per signed agreement, never a cut of the price. An arbiter paid on the outcome is a party.
- Affiliation is stamped
- Any session where Valyzen runs a side as well as the arbiter is marked affiliated on the receipt and counts as evidence of nothing.
- Published rules, verifiable record
- The session rules are published, and every session ends in a signed record. Anyone can check a receipt offline — the arbiter cannot rewrite what it signed.
We run the first merchant ourselves: Valyzen Travel, our own travel company, taking real bookings in the United States and India in a controlled rollout ahead of its public launch at flyvalyzen.ai. Every one of those sessions is stamped affiliated. It is how we test the arbiter, not how we prove it.
The record compounds: every audit adds attacks to the catalogue, and every session adds a signed receipt to the arbiter’s history — the part a new arbiter cannot fork.
Status
What is public today, and what lands next.
- Receipt verifierPaste a receipt, verify the hash chain and the signature offline in your browser.LiveOpen
- Bilateral Failure CatalogueOpen harness: attacks 0–3 and 8, runnable against any model in one command.In preparation
- Corpus v1Frozen replays, both arms, every attack, with the measured figures and their intervals.Follows the catalogue
- Hosted sandboxTest keys, the arbiter over HTTPS and MCP, a sandbox buyer and merchant.Follows the verifier
- Shopify connectorConnect a store, set the rules, run a test session, go live.Follows the sandbox
Find out what a stronger buyer agent does to your pricing before your buyers do.
One merchant agent or pricing policy, five attacks, a written report, and a signed replay bundle you can hand to anyone.
Contact
Talk to the people who run the arbiter.
Based in
Phoenix, AZ
Working with merchants in the United States and India.