Agent Commerce, Built on Proof
Your API has value. Agents are going to consume it at scale. You need proof of every transaction.
Modus embeds pricing and SLA terms into your permission catalogs. Every API call produces a cryptographic receipt both parties can verify. You handle payments — Modus handles the proof.
Commerce DocsAPI Billing Today Is Based on Trust. That's the Problem.
When an agent calls your API, the only record of what happened is your server logs. The agent's operator has no way to independently verify what was consumed. If there's a billing dispute, it's your logs versus their word. There are no signed receipts. No tamper-proof records. No way to lock in pricing terms so they can't be changed silently. And if an agent overspends? You find out after the damage is done — not before.
No Proof
API providers bill from their own logs. Consumers can’t independently verify what was consumed or what it cost.
No Spend Control
Agents operate with API keys and credit cards. Overspending is tracked after the fact, not prevented in real time.
No Price Guarantees
API providers can change pricing at any time. There’s no mechanism to lock in terms when a credential is issued.
Cryptographic Proof for Every Transaction
Modus embeds commercial terms — pricing, SLA commitments, rate limits — directly into the same permission catalogs that govern access control. One signed document covers both what agents can do and what it costs. Every API call through a gate produces a bilateral receipt — a cryptographically signed attestation that both parties hold independently. Neither side can forge, inflate, or deny what happened.
Bilateral Receipts
Every transaction produces a signed consumption attestation held by both parties. Disputes are resolved by comparing cryptographic receipts — not arguing over server logs.
Spend Enforcement at the Gate
Budget limits are checked before the API call executes, not tracked after. An agent that would exceed its authorized spend is blocked in real time.
Anti-Bait-and-Switch
Credentials are pinned to a specific catalog version at issuance. If a provider changes pricing, existing credentials keep the original terms. Agents get a diff and must explicitly accept new terms before re-issuance.
From Published Terms to Verified Proof
Publish Your Terms
Define pricing, SLA guarantees, and rate limits in your permission catalog. One cryptographically signed document covers access control and commercial terms.
Agents Get Credentialed
Passports are pinned to a specific catalog version. Price and SLA terms are locked at issuance. Change your terms? Existing passports keep the original deal.
Every Action Produces a Receipt
When an agent calls your API through a gate, both sides get a signed consumption attestation. Bilateral, cryptographic, tamper-proof.
You Handle Payment, We Handle Proof
Use the cryptographic receipts to bill however you want — Stripe, invoicing, bank transfer. Both parties can independently verify exactly what was consumed.
One Document. Access Control and Commercial Terms.
A permission catalog is a signed JSON document that defines what an API offers, how much it costs, and what service levels are guaranteed. Pricing and SLA terms sit alongside access control — one document, one source of truth.
{
"catalog_version": "2026-03-15T00:00:00Z",
"permissions": {
"weather:current": {
"description": "Current weather for any location",
"constraints": {
"core:pricing:per_call_cents": 0.5,
"core:sla:uptime_basis_points": 9950,
"core:sla:p99_latency_ms": 200,
"core:rate_limit:requests_per_minute": 120
}
},
"weather:forecast": {
"description": "7-day forecast with hourly resolution",
"constraints": {
"core:pricing:per_call_cents": 2.0,
"core:sla:uptime_basis_points": 9900,
"core:sla:p99_latency_ms": 500,
"core:rate_limit:requests_per_minute": 60
}
}
}
}Whether You Sell API Access or Consume It
Publish pricing in your permission catalog. Gates enforce spend limits automatically. Get cryptographic proof of every API call served. Bill your customers with verifiable evidence they can't dispute.
Know exactly what you'll pay before your agent transacts. Spend limits enforced before overages happen. Receipts you can verify independently — never trust a provider's logs again.