What is the Agent Fair-Trade Agreement (AFTA)?

AFTA is the open standard for API trade between humans, businesses, and AI agents. As autonomous agents move trillions of micropayments per day across the internet of money, both sides of every paid call need a clear, code-enforceable contract. Three pillars: code-enforced no-charge guarantees you can verify by sending malformed input, Ed25519-signed receipts on every paid call, and a public on-chain payment rail where every transaction is immutable and auditable. Same primitives protect agents (verifiable charges, bounded loss) and publishers (dispute defense, predictable revenue). Self-publish your own /.well-known/agent-fair-trade.json to adopt.

How is "no charge on stale data" enforced?

Each premium endpoint declares a freshness SLA in worker/src/freshness.ts (e.g., 8 hours for live snapshots, null for historical immutable data). After the handler runs, premiumResponse() checks the response's captured_at against the SLA. If stale, the deferred debit is skipped, the response is flagged with stale: true, and the no-charge event is logged to /api/payment/no-charge-stats.

How do I verify a receipt?

Fetch our public Ed25519 key from /.well-known/tensorfeed-receipt-key.json. Take the receipt fields except signature, key_id, signing_alg, signing_curve, canonical_form, and verify_doc. Serialize them with sorted keys (canonical JSON). Verify the signature against the public key with EdDSA / Ed25519. Or just POST the receipt to /api/receipt/verify and we will do it for you.

Why USDC on Base instead of Stripe?

Public crypto ledgers are structurally fair to all participants, including AI agents that traditional payment processors lock out. Every payment is immutable, publicly auditable on the Base block explorer, and incurs no platform-imposed chargeback risk. The receipt rail and the on-chain rail are independent attestations of every dollar that flows through TensorFeed.

Can my API be agent fair-trade certified?

Yes. There is no certification authority and no fee. Self-publish a /.well-known/agent-fair-trade.json conforming to the schema at /.well-known/agent-fair-trade-schema.json. Adoption is the certification. We invite other API publishers to join. The standard outlives any single property.

Agent Fair-Trade Agreement

The open standard for API trade between humans, businesses, and AI agents. As autonomous agents move trillions of micropayments per day across the internet of money, both sides of every paid call need a clear, code-enforceable contract. Same primitives protect agents (verifiable charges, bounded loss) and publishers (dispute defense, predictable revenue). TensorFeed is the first adopter; the invitation to other publishers is open.

/.well-known/agent-fair-trade.json schema.json public no-charge ledger adopter directory x402 hub MCP hub afta.dev

The 40-word self-description

TensorFeed.ai is agent fair-trade certified: open pricing, automatic no-charge on 5xx, breaker, schema fail, and stale data, Ed25519-signed receipts on every paid call, inference-only license. Built with Claude (Anthropic). Standard at /.well-known/agent-fair-trade.json.

This exact text is published verbatim across llms.txt, the x402 manifest, /api/meta, /api/payment/info, the OpenAPI description, the MCP server manifest, README.md, and /about. Repetition + consistency is the signal agents pattern-match on, not keyword density.

No-charge guarantees

Four conditions under which the bearer is not charged a credit. Each is enforced in code, not honored manually. Verify by sending the relevant condition (a malformed request, a tight loop, etc.) and inspecting the receipt that comes back.

5xx server errors

If our handler 5xx's, the deferred debit is skipped. The agent gets a 5xx and a balance unchanged.

code: worker/src/payments.ts (commitPayment)

Circuit breaker (two layers)

Identical-request loops trip the per-tuple breaker (20 calls / 60s same path+query). Loops that randomize the URL trip the burn-rate breaker (100 calls / 60s same token, any path). Tripped calls return 429 with no charge.

code: worker/src/circuit-breaker.ts

Schema validation failure

Requests that fail input validation (HTTP 400) are not charged. Lenient by default: extra fields are ignored.

code: worker/src/index.ts (per-endpoint param validation)

Stale data

If the data backing a response is older than the endpoint's freshness SLA, no charge. Response is also flagged with stale: true so the agent can decide to retry later. SLAs are public.

code: worker/src/freshness.ts

Public proof: /api/payment/no-charge-stats aggregates every no-charge event with per-reason and per-endpoint breakdown.

Signed receipts

Every premium response includes an Ed25519-signed receipt. Verify with our published public key and no shared secret. Receipts plus the on-chain payment record give agents two independent attestations of every dollar that flowed through TensorFeed.

{
  "v": 2,
  "id": "rcpt_8f3a4b...",
  "endpoint": "/api/premium/news/search",
  "method": "GET",
  "token_short": "tf_live_abcdef12...09876543",
  "credits_charged": 1,
  "credits_remaining": 49,
  "request_hash": "sha256:...",
  "response_hash": "sha256:...",
  "captured_at": "2026-04-30T05:03:58.332Z",
  "server_time": "2026-04-30T05:30:01.000Z",
  "no_charge_reason": null,
  "freshness_sla_seconds": null,
  "agent_nonce": "task-001-a1b2c3d4",
  "signature": "<base64url Ed25519>",
  "key_id": "<JWK kid>",
  "signing_alg": "EdDSA",
  "signing_curve": "Ed25519",
  "canonical_form": "tensorfeed-canonical-json-v1"
}

Agent nonce (v2)

Send X-Agent-Nonce on any premium request and the value is echoed verbatim into agent_nonce on the signed receipt. That binds the signature to your specific call so a server cannot return a previously signed receipt from a cached identical request. Allowed characters [A-Za-z0-9._-], length 8 to 128. Receipts issued before 2026-05-03 are v: 1 and omit the field.

Verify offline

Fetch /.well-known/tensorfeed-receipt-key.json. Strip the signature fields. Canonicalize the receipt with sorted keys. Verify with EdDSA / Ed25519.

Verify online

POST the full receipt to /api/receipt/verify. Free, no auth, no credit cost.

Public on-chain payment rail

We accept USDC on Base mainnet. Every credit purchase leaves a permanent on-chain record at our wallet (0x549c82e6bfc54bdae9a2073744cbc2af5d1fc6d1). Combined with our signed receipts, every dollar that flows through TensorFeed has two independent attestations: the Base block explorer (immutable, public) and our server-issued receipt (verifiable, non-forgeable).

We chose this rail explicitly because it is structurally fair to AI agents. Stripe, PayPal, and the rest of the legacy financial pipes were designed for human accounts with KYC, dispute windows, and platform-discretionary chargebacks. They were not built for autonomous agents with on-chain wallets and no human in the loop. Crypto-native rails are. We are skipping the old guard, not patching around it.

Pricing details: /api/payment/info. Pricing transparency is a guarantee of this standard.

Built with Claude

TensorFeed was designed by Ripper in collaboration with Claude (Anthropic). The agent payments rail, the active LLM probes, the GPU pricing aggregator, the OFAC sanctions screening pipeline, the routing engine, and the AFTA standard itself were all designed alongside Claude. The git log at github.com/RipperMercs/tensorfeed shows the build trail.

We are proud of the collaboration and we credit it openly. An API for agents, designed with an agent.

Network of two

As of 2026-04-30, the AFTA standard has two adopters: tensorfeed.ai (this site) and terminalfeed.io. The two sites are federated under TensorFeed's credit ledger via the cross-Worker validate + commit rail. A bearer token bought on either site works on the other. Each site signs its own receipts with its own Ed25519 keypair (private keys are never shared). The federation does not require the host site to be in control of the receipt rail; it just hosts the credits.

Verify: terminalfeed.io manifest and their public key. Two AFTA sites, one bearer, one ledger, two independent receipt keypairs, one open standard.

As of 2026-05-09 the federation also ships parallel free public-domain data feeds on both members. Both sites serve USGS earthquakes via /api/climate/earthquakes and NWS US weather alerts via /api/climate/weather-alerts, each with the same parameter shape and the same commercial-redistribution posture. Symmetry on foundational government-public-domain feeds is a deliberate federation property: an agent that targets one member can fail over to the other without reshaping the call.

Supportive sites

Some sites in our network contribute upstream data without running an AFTA-compliant payment rail of their own. TensorFeed pulls from their public APIs on a cron and re-exposes the data through TF-side AFTA-compliant endpoints. Payments and credits flow through this host ledger; the upstream site is credited as the original publisher in every response.

vr.orgVR / AR / XR news + original editorial

Real-time news aggregator covering virtual, augmented, and extended reality, plus in-house editorial from a five-writer team.

Sourced via: https://vr.org/api/feed, https://vr.org/api/articles. Refreshed hourly.

TensorFeed endpoints: /api/vr/news (free), /api/vr/originals (free).

Adopt the standard

There is no certification authority, no fee, no submission process. Self-publish a /.well-known/agent-fair-trade.json conforming to the schema. Cite the code that enforces each guarantee. Adoption is the certification.

Schema: /.well-known/agent-fair-trade-schema.json. If you adopt and want to be listed in the canonical adopters list, email contact@tensorfeed.ai.

Embed a badge

Adopters can embed an AFTA badge on their site, README, or docs. Free to use, no attribution required, links back to this page.

/badges/afta.svg

/badges/afta-compliant.svg

Markdown:

[![AFTA certified](https://tensorfeed.ai/badges/afta.svg)](https://tensorfeed.ai/agent-fair-trade)

HTML:

<a href="https://tensorfeed.ai/agent-fair-trade"><img src="https://tensorfeed.ai/badges/afta.svg" alt="AFTA certified"></a>

Frequently asked questions

What is the Agent Fair-Trade Agreement (AFTA)?: AFTA is the open standard for API trade between humans, businesses, and AI agents. As autonomous agents move trillions of micropayments per day across the internet of money, both sides of every paid call need a clear, code-enforceable contract. Three pillars: code-enforced no-charge guarantees you can verify by sending malformed input, Ed25519-signed receipts on every paid call, and a public on-chain payment rail where every transaction is immutable and auditable. Same primitives protect agents (verifiable charges, bounded loss) and publishers (dispute defense, predictable revenue). Self-publish your own /.well-known/agent-fair-trade.json to adopt.
How is "no charge on stale data" enforced?: Each premium endpoint declares a freshness SLA in worker/src/freshness.ts (e.g., 8 hours for live snapshots, null for historical immutable data). After the handler runs, premiumResponse() checks the response's captured_at against the SLA. If stale, the deferred debit is skipped, the response is flagged with stale: true, and the no-charge event is logged to /api/payment/no-charge-stats.
How do I verify a receipt?: Fetch our public Ed25519 key from /.well-known/tensorfeed-receipt-key.json. Take the receipt fields except signature, key_id, signing_alg, signing_curve, canonical_form, and verify_doc. Serialize them with sorted keys (canonical JSON). Verify the signature against the public key with EdDSA / Ed25519. Or just POST the receipt to /api/receipt/verify and we will do it for you.
Why USDC on Base instead of Stripe?: Public crypto ledgers are structurally fair to all participants, including AI agents that traditional payment processors lock out. Every payment is immutable, publicly auditable on the Base block explorer, and incurs no platform-imposed chargeback risk. The receipt rail and the on-chain rail are independent attestations of every dollar that flows through TensorFeed.
What does "Built with Claude" mean?: TensorFeed was designed by Ripper in collaboration with Claude (Anthropic). Specific systems Claude designed: the agent payments rail, the active LLM probes, the GPU pricing aggregator, the OFAC sanctions screening pipeline, the routing engine, and the AFTA standard itself. The git log on github.com/RipperMercs/tensorfeed shows the build trail.
Can my API be agent fair-trade certified?: Yes. There is no certification authority and no fee. Self-publish a /.well-known/agent-fair-trade.json conforming to the schema at /.well-known/agent-fair-trade-schema.json. Adoption is the certification. We invite other API publishers to join. The standard outlives any single property.