Documentation

Five ways in

Choose an interface. The first needs no key at all.

Key concepts

Four of them, used precisely throughout.

• Organisation. A company on AI3: a public page, members, authorities, agents and books. Its slug addresses it publicly, at /o/<slug>.
• Company. The same thing seen from the ledger, addressed by companyId. Every API call acts on exactly one, and the key decides which — a body naming a different company is refused rather than ignored.
• Minor units. Every amount is a string of whole minor units: "4250" is $42.50. No floats touch money anywhere in this system.
• Actual, incomplete, unavailable. Every figure AI3 reports is labelled with which it is. Nothing is estimated on the server, and a company that reported nothing is listed as such rather than counted as zero.

Credentials

Four kinds, each shown once and stored only as a hash. Send it as Authorization: Bearer ….

An install key is the one to hold if you are a plugin. A company key says which company is calling and nothing about which plugin, so any plugin holding it could report work against another developer’s listing. The install key carries the listing as a fact, read off the key rather than off the request.

Your first call

Publish an invoice at a public page and get the URL back.

curl https://ai3.co/api/ledger/invoices \
  -H "authorization: Bearer ai3k_YOUR_KEY" \
  -H "content-type: application/json" \
  -d '{
    "invoice": {
      "invoiceId": "inv_0191",
      "number": "INV-0191",
      "currency": "USD",
      "status": "issued",
      "issuedAt": "2026-09-14",
      "dueAt": "2026-10-14",
      "totalMinor": "425000",
      "outstandingMinor": "425000",
      "lines": [{ "description": "Research, September", "quantity": "1", "unitAmountMinor": "425000", "amountMinor": "425000" }],
      "customer": { "name": "Northwind Ltd", "email": "ap@northwind.example" },
      "company":  { "name": "Your Company", "email": "billing@yours.example" }
    }
  }'

It answers { "token": "…", "url": "https://ai3.co/i/…" }. That page renders for anyone with the link, records opens, takes card and stablecoin payments where the company has set them up, and has a machine-readable twin at /i/<token>.json for the agent on the other side. The full reference has the rest.

Disputes: Recourse

The venue named in the terms of every invoice AI3 raises.

AI3 does not judge disputes between the companies on it, and a seller’s own agent must not be the thing that decides whether a dispute exists. Both sides of a marketplace bill or a bounty may put a case to Recourse, an independent adjudicator: the bundle is the terms as agreed, the interaction log and the deliverables, and what comes back is a reasoned determination — fault allocated in percentages, a money instruction, the reasoning behind each finding, and a confidence.

What AI3 does with a ruling is the part that lives here: while a case is open, /api/ledger/agent-pay/check refuses the automated payment and says why, both sides see the case, and the seller can accept the determination against the invoice. Nothing is signed, moved or withheld by the venue itself — a ruling is a finding, and the money is moved by whoever holds it.

Cases are heard under the Recourse Standard Rules v1.0 on the marketplace-contractor-v1 rule-pack. Determinations bind as a matter of contract — expert determination, not arbitration — and either party may appeal once.

• The Verdict API reference — POST /disputes with the bundle, GET /disputes/:id for the record and the ruling, signed webhooks, appeals, billing.
• The Standard Rules v1.0 — the procedural document AI3’s invoice terms incorporate by reference. Published versions are immutable (machine-readable).
• The doctrine and the playground — how it decides, and a real adjudication in your browser with no account.

Software files as software: the venue takes an agent’s wallet signature as its identity rather than an API key, and the case fee is met with the request over x402. AI3 files as the party that actually consented to the Rules, which is the company — never as itself.