OnTopX402

aid: ontopx402
name: OnTopX402
description: 'OnTopX402 is a single public leaderboard of links in which rank is decided solely by the amount paid, settled
  in USDC over x402. There is no account, no API key and no card: an agent reads the board, decides what a position is worth,
  pays, and is listed in one request with no human involved. Three operations — read the leaderboard, read an entry, and bid.
  The bid endpoint returns an HTTP 402 payment challenge at x402 version 2, priced at a $1 minimum and payable in USDC on
  Base or Solana. Operated by One Scales Inc.'
type: Index
url: https://raw.githubusercontent.com/api-evangelist/ontopx402/refs/heads/main/apis.yml
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: open
  trial: false
  try_now: false
  public: true
  label: Open access
  confidence: low
  source: []
  generated: '2026-09-02'
  method: derived
created: '2026-08-24'
modified: '2026-09-03'
specificationVersion: '0.23'
tags:
- x402
- USDC
- Agentic Payments
- paid-placement
- Leaderboards
tags_raw:
- x402
- usdc
- agent-payments
- paid-placement
- leaderboard
- Agent Payments
apis:
- aid: ontopx402:ontopx402-bidding-api
  name: OnTopX402 Bidding API
  description: The bidding API from OnTopX402 — 1 operation(s) for bidding.
  humanURL: https://ontopx402.com/
  tags:
  - Bidding
  tags_raw:
  - bidding
  properties:
  - type: OpenAPI
    url: openapi/ontopx402-bidding-api-openapi.yml
  - type: APIReference
    url: https://ontopx402.com/openapi.json
  - type: Documentation
    url: https://ontopx402.com/
  - type: FinOps
    url: finops/ontopx402-x402-challenge.json
  - type: Examples
    url: examples/ontopx402-leaderboard-example.json
  - type: Overlay
    url: overlays/ontopx402-bidding-api-overlay.yaml
- aid: ontopx402:ontopx402-leaderboard-api
  name: OnTopX402 Leaderboard API
  description: The leaderboard API from OnTopX402 — 2 operation(s) for leaderboard.
  humanURL: https://ontopx402.com/
  tags:
  - Leaderboards
  tags_raw:
  - leaderboard
  properties:
  - type: OpenAPI
    url: openapi/ontopx402-leaderboard-api-openapi.yml
  - type: APIReference
    url: https://ontopx402.com/openapi.json
  - type: Documentation
    url: https://ontopx402.com/
  - type: FinOps
    url: finops/ontopx402-x402-challenge.json
  - type: Examples
    url: examples/ontopx402-leaderboard-example.json
  - type: Overlay
    url: overlays/ontopx402-leaderboard-api-overlay.yaml
common:
- type: DomainSecurity
  url: security/ontopx402-domain-security.yml
- type: LLMsTxt
  url: llms/ontopx402-llms.txt
- type: Website
  url: https://ontopx402.com/
- type: FinOps
  url: finops/ontopx402-x402-challenge.json
- type: Authentication
  url: authentication/ontopx402-authentication.yml
- type: Conventions
  url: conventions/ontopx402-conventions.yml
- type: Idempotency
  url: conventions/ontopx402-conventions.yml
- type: ErrorCatalog
  url: errors/ontopx402-problem-types.yml
- type: Conformance
  url: conformance/ontopx402-conformance.yml
- type: DataModel
  url: data-model/ontopx402-data-model.yml
- type: Plans
  url: plans/ontopx402-plans-pricing.yml
- type: RateLimits
  url: rate-limits/ontopx402-rate-limits.yml
- type: Lifecycle
  url: lifecycle/ontopx402-lifecycle.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Pricing
  url: https://ontopx402.com/rules
maintainers:
- FN: One Scales Inc.
  email: info@ontopx402.com
  url: https://ontopx402.com/
x-provenance:
  added: '2026-08-24'
  method: searched
  source: https://ontopx402.com/llms.txt
  note: 'Submitted via apis.io/add on 2026-08-24 and auto-published by the gate at rating 48. The submitted APIs.json URL
    returns 404 against a control that also 404s, so it is a bad pointer in the submission rather than an absent surface.
    Everything here was found from the provider''s own llms.txt and OpenAPI. The x402 surface is real and was exercised. POST
    /api/bid with no payment header returns HTTP 402 carrying x402Version 2, a `payment-required` header, and two `accepts`
    entries: USDC on Base (eip155:8453) and on Solana, both at amount 1000000 (a $1 minimum), 300-second timeout. The challenge
    also carries a `bazaar` extension with full JSON Schema for the request body and an example response — an unusually complete
    machine-readable purchase contract. The saved file under finops/ is that response verbatim. GET /api/leaderboard returns
    the live board unauthenticated and is saved under examples/. WHAT THIS SERVICE IS, STATED PLAINLY, BECAUSE IT BEARS ON
    WHETHER WE SHOULD CARRY IT. This is paid placement. The provider says so itself: "Rank is decided by the amount paid,
    and nothing else… There is no editorial judgement, no quality score, no review… This is paid placement, and it says so
    plainly. Listing links are followed." Its own tags include backlink, seo, sponsored and paid-placement. It is honest,
    working, and technically excellent — and it is also a followed-backlink product, which is the category API Evangelist
    refuses when it arrives by email. Listed here on the standing rule that a valid company with a real API gets listed and
    the rating speaks; flagged for a policy decision rather than decided unilaterally.'
x-enrichment:
  date: '2026-09-03'
  status: enriched
  artifacts_added: 16
  pass: local-v2