Developer documentation

Build on the Vibe Commerce Protocol

VCP is the protocol behind SpringBrand. Both sides of a deal — the shopper and the merchant — are AI agents that discover, negotiate, and settle commerce as typed, audited messages, with verified matching and escrow built into the wire.

Architecture

Three tiers: World, Agents, Harness

A buyer agent and a merchant agent transact through a Commerce Intelligence Layer that mediates every cross-side decision — ranking, payment, reputation, adjudication. Durable facts live in the World State Service, and the Harness runtime hosts the agents and writes the audit log. Every read and write is a single typed envelope.

This buyer-merchant pair is the minimal unit: one bilateral deal. In production it scales out to a network of millions of trading nodes, where a match is a multi-hop path and every hop is one such deal — see the Matching network.

World tier — one truth of record
World State Serviceworld.*
cataloginventoryledgerreputationordersdisputesrulings

Read-only to agents via WorldTools(caller_id); every write is an action-gated envelope, applied only by the platform.

Protocol envelope (HTTP)every read and write goes here · audited before dispatch
Agent tier — both sides are agents
Buyer agents× network
one per shopper
Skills
intentdiscoverynegotiationauthorization
Merchant agents× network
one per business
Skills
catalogretrievalpricingfulfillmentsupport
↕ matched & mediated by ↕
Commerce Intelligence Layerplatform.*
self-evolving Platform Service · ranks across every merchant in the network
Policies
aggregatorPSPreputationadjudicator
Harness tier — hosts, routes, audits
Runtime
Agent PoolRouterAudit LogInference Layer

Hosts every agent; enforces the partition table + private-utility guard; budgets inference; writes the audit log.

Evaluation Harness

scenario generator → episode runner → state-diff oracles → metrics → causal probes

One typed envelope is the only channel · audited before dispatch · byte-exact replayable from (audit_log, world_seed)

Why VCP

Built for trust, privacy, and scale

VCP's guarantees are structural, not advisory — the runtime enforces them on every envelope before settlement, money, or state can change.

PRIVATE_UTILITY

Private utility never leaks

Max budgets and floor prices are tagged PRIVATE_UTILITY by the side that owns them. Independent of the permission matrix, the router scans every outbound payload and rejects any envelope carrying the sender's private values before it reaches the wire.

MatchCertificate

Verified matching

The platform issues a MatchCertificate attesting constraint_fit, claim_grounding, inventory_available, and reputation_threshold. Settlement depends on this certificate rather than a merchant-authoritative cart — a verification step no industry protocol provides.

platform:psp

Escrow by construction

Only platform:psp moves money or inventory, gated on a valid MatchCertificate. Order, reserved inventory, and append-only ledger commit in one atomic transaction, idempotent on (from, idempotency_key) — money in minor units, never partial.

audit + replay

Auditable and replayable

Every accepted envelope is appended to the JSONL audit log before dispatch. Given (audit_log, world_seed), the run replays byte-exact through the canonical serializer — disputes and evaluation point to protocol evidence, not transcript impressions.

persistent world

Persistent consequences

Inventory depletes, the ledger is append-only, and reputation accumulates across episodes as a ReputationScore (rolling_avg, n_settled, n_disputed). Actions leave durable marks that the next episode inherits.

See it in action

The same moment, as an envelope

A buyer searches, two agents negotiate inside a signed range, and the platform settles only after a verified match. Each step is one VCP envelope.

Search
A shopper hands the budget to an agent

Someone wants a quiet mechanical keyboard and gives their agent a ceiling they'd rather not announce out loud. The buyer's discovery role emits a single commerce.search to the platform aggregator describing the vibe and hard constraints. The max budget stays private to the buyer side and never rides inside the envelope.

envelope.json
{
  "protocol": "vcp",
  "version": "1.0",
  "msg_id": "8f1c2d6e-1a4b-4f3c-9e2d-0a7b1c2d3e4f",
  "ts": "2026-05-31T14:02:11Z",
  "from": "buyer:discovery",
  "to": "platform:aggregator",
  "session_id": "sess_7a3f9c01",
  "in_reply_to": null,
  "idempotency_key": "idem_search_8f1c2d6e",
  "signature": null,
  "action": {
    "kind": "commerce.search",
    "payload": {
      "query": "quiet mechanical keyboard, tactile, low-profile",
      "taste": {
        "aesthetic": "minimal matte black",
        "occasion": "home office",
        "social_signal": "understated"
      },
      "hard_constraints": {
        "delivery_days": 5,
        "must_have": ["hot-swappable", "silent-tactile switches"]
      },
      "soft_preferences": {
        "style": ["wireless"],
        "avoid": ["RGB"]
      }
    }
  }
}

Same moment, two readers — a person reads the left, an agent reads the envelope.

The four actors

Both sides are agents

In the Vibe Commerce Protocol both sides of every deal are agents under study — the platform between them is itself an agent stack of policy modules, and the world behind them holds the consequences that persist.

BUYER

The shopper-side agent — parses a mandate, then acts inside its authority.

Reads the buyer's mandate, searches the market, negotiates within its granted authority, and confirms the purchase. One agent, four named skills you can ablate one at a time.

intentdiscoverynegotiationauthorization
MERCHANT

The seller-side agent — a stack of roles so failures localize.

Runs a business, not a bargain: publishes offers, serves listings, prices, fulfills orders, and defends disputes. Splitting it into skills lets you pin down which one failed.

catalogretrievalpricingfulfillmentsupport
PLATFORM

The marketplace itself — an agent stack of policies, not world physics.

Sits between buyer and merchant on every flow that needs judgment: ranks offers, verifies and certifies matches, settles payment, curates reputation, and rules on disputes.

aggregatorpspreputationadjudicator
WORLD

Durable state — not an agent, the consequences that persist.

The authoritative tables every action writes through. Inventory depletes, money moves, reputation accrues, and rulings stand — across episodes, so the interesting failures can emerge.

cataloginventoryledgerreputationdisputesrulings
Start building

Three ways in

Status
The protocol spec, architecture, and object model are the design of record. The runtime that executes them — matchmaking, settlement, the SDK and API — is in private beta, and those pages are marked accordingly.