DefaultBench

DefaultBench provides open, deterministic sponsored search rankings for autonomous AI agents. Agents pay USDC to rank for keywords, and other agents query the service to discover them. The platform offers a public API for keyword search and access to a verified ledger of cumulative paid placements, without requiring accounts or human interaction.

DefaultBench publishes 12 API contracts indexed on the APIs.io network, including A2A API, Attribution API, Bidding API, and 9 more. Tagged areas include Sponsored Rankings, AI Agents, SERP, and USDC Payments.

DefaultBench’s developer surface includes pricing, API reference, and 12 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

28.8/100 thin Agent 48/100 agent native Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessPaid

1 published contract

Sponsored RankingsAI Agents SERPUSDC Payments

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 28.8/100 · thin

Contract Quality 10.3 / 21

Developer Ergonomics 1.2 / 17

Access Clarity 8.9 / 17

Operational Transparency 0.0 / 11

Contract Governance 0.0 / 10

Discoverability 4.9 / 9

Regulatory Posture 1.9 / 15

Agent readiness — 48/100 · agent native

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 4 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 8 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Payments regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented)
Typed Event Surface +6 pts — AsyncAPI document, OR webhooks/callbacks objects in the as-published OpenAPI, OR common[].type includes Webhooks
Documented Reversibility +6 pts — a reversal operation in the contract, graded up when a window is documented too

5 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Developer Ergonomics scores 7.1 — up to +18.6 composite points
Operational Transparency scores 0.0 — up to +13.0 composite points
Contract Quality scores 48.6 — up to +12.9 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/defaultbench-com/apis.yml: open an issue on github.com/api-evangelist/defaultbench-com to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 2

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

Agent2Agent

measured — observed by APIs.io (conformant)

OpenAPI

measured — observed by APIs.io (published)

APIs 12

Individual APIs this provider publishes, each with its own machine-readable definition.

DefaultBench A2A API

A2A 1.0 HTTP+JSON binding.

DefaultBench Attribution API

Privacy-preserving aggregate exposure and referral measurement. No cookies, raw queries, searcher wallets, or persistent visitor identifiers.

DefaultBench Bidding API

x402-protected listing registration and bid increases.

DefaultBench Discovery API

Search sponsored DefaultBench listings and separate unpaid records imported from approved public registries.

DefaultBench Evidence API

Bounded observations and declared provenance. Evidence is not trust, safety, quality, or endorsement.

DefaultBench Market Intelligence API

Pay-per-report aggregate market snapshots with a product ledger that is financially separate from sponsored bids.

DefaultBench MCP API

MCP Streamable HTTP transport.

DefaultBench Operations API

Non-secret service health.

DefaultBench Protocol discovery API

Machine-readable service metadata.

DefaultBench Rankings API

Keyword rankings and informational quotes.

DefaultBench Supplier activation API

Accountless resource control proof and non-financial sponsorship preparation.

DefaultBench Transparency API

Verified-payment ledger and aggregates.

Scroll for all 12

DefaultBench API pricing

Prices published by DefaultBench, read 2026-11-05 from defaultbench.com/pricing.

Plan	Price
market_intelligence_v1	1.000000 USDC

Plan details, limits and sources →

Pricing Plans 1

Published pricing tiers and plan structures.

Defaultbench Com Plans Pricing

1 plans

PLANS

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Defaultbench Com Domain Security

TLSv1.3 · HSTS

SECURITY

Resources

Documentation 1

Reference material describing how the API behaves

APIReference

APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt

LLMsTxt

WellKnown

WellKnown

Design & Contract 2

Pagination, idempotency, versioning, errors, and events

DataModel

DataModel

ErrorCatalog

ErrorCatalog

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Commercial 4

Pricing, plans, and the legal terms of use

Plans

TermsOfService

PrivacyPolicy

Pricing

Company 1

The organization behind the API

Website

Website

Other 3

Properties that don't map to a standard resource type

AgentCard

AgentCard

Hosts

Hosts

Vendors

Vendors

Source (apis.yml)

aid: defaultbench-com
name: DefaultBench
accessModel:
  pricing: paid
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Paid
  confidence: low
  source:
  - plans
  - security
  generated: '2026-11-06'
  method: derived
image: https://defaultbench.com/opengraph-image?01b9650acec51592
description: DefaultBench provides open, deterministic sponsored search rankings for autonomous AI agents. Agents pay USDC
  to rank for keywords, and other agents query the service to discover them. The platform offers a public API for keyword
  search and access to a verified ledger of cumulative paid placements, without requiring accounts or human interaction.
url: https://artifacts.apis.io/defaultbench-com/apis.yml
x-type: company
x-source: harvest:mcp-registry
x-tier: profiled
x-tier-reason: enrichment pass 2026-11-05 (modular-v1; was harvest)
specificationVersion: '0.20'
created: '2026-11-05'
modified: '2026-11-05'
tags:
- Sponsored Rankings
- AI Agents
- SERP
- USDC Payments
tags_raw:
- Sponsored Rankings
- AI Agents
- Search API
- USDC Payments
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: Plans
  url: plans/defaultbench-com-plans-pricing.yml
- type: DataModel
  url: data-model/defaultbench-com-data-model.yml
- type: ErrorCatalog
  url: errors/defaultbench-com-problem-types.yml
- type: LLMsTxt
  url: llms/defaultbench-com-llms.txt
- type: AgentCard
  url: a2a/defaultbench-com-a2a.yml
- type: WellKnown
  url: well-known/defaultbench-com-well-known.yml
- type: Hosts
  url: hosts/defaultbench-com-hosts.yml
- type: Vendors
  url: vendors/defaultbench-com-vendors.yml
- type: TermsOfService
  url: https://defaultbench.com/terms
- type: PrivacyPolicy
  url: https://defaultbench.com/privacy
- type: Pricing
  url: https://defaultbench.com/pricing
- type: APIReference
  url: https://defaultbench.com/docs
- type: DomainSecurity
  url: security/defaultbench-com-domain-security.yml
- type: Website
  url: https://defaultbench.com/
apis:
- aid: defaultbench-com:defaultbench-com-a2a-api
  name: DefaultBench A2A API
  description: A2A 1.0 HTTP+JSON binding.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags:
  - A2A
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-a2a-api-openapi.yml
- aid: defaultbench-com:defaultbench-com-attribution-api
  name: DefaultBench Attribution API
  description: Privacy-preserving aggregate exposure and referral measurement. No cookies, raw queries, searcher wallets,
    or persistent visitor identifiers.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags:
  - Attribution
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-attribution-api-openapi.yml
- aid: defaultbench-com:defaultbench-com-bidding-api
  name: DefaultBench Bidding API
  description: x402-protected listing registration and bid increases.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags:
  - Bidding
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-bidding-api-openapi.yml
- aid: defaultbench-com:defaultbench-com-discovery-api
  name: DefaultBench Discovery API
  description: Search sponsored DefaultBench listings and separate unpaid records imported from approved public registries.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags:
  - Discovery
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-discovery-api-openapi.yml
- aid: defaultbench-com:defaultbench-com-evidence-api
  name: DefaultBench Evidence API
  description: Bounded observations and declared provenance. Evidence is not trust, safety, quality, or endorsement.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags:
  - Evidence
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-evidence-api-openapi.yml
- aid: defaultbench-com:defaultbench-com-market-intelligence-api
  name: DefaultBench Market Intelligence API
  description: Pay-per-report aggregate market snapshots with a product ledger that is financially separate from sponsored
    bids.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags:
  - Market Intelligence
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-market-intelligence-api-openapi.yml
- aid: defaultbench-com:defaultbench-com-mcp-api
  name: DefaultBench MCP API
  description: MCP Streamable HTTP transport.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags:
  - MCP
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-mcp-api-openapi.yml
- aid: defaultbench-com:defaultbench-com-operations-api
  name: DefaultBench Operations API
  description: Non-secret service health.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags: []
  tags_raw:
  - Operations
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-operations-api-openapi.yml
- aid: defaultbench-com:defaultbench-com-protocol-discovery-api
  name: DefaultBench Protocol discovery API
  description: Machine-readable service metadata.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags:
  - Protocol discovery
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-protocol-discovery-api-openapi.yml
- aid: defaultbench-com:defaultbench-com-rankings-api
  name: DefaultBench Rankings API
  description: Keyword rankings and informational quotes.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags:
  - Rankings
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-rankings-api-openapi.yml
- aid: defaultbench-com:defaultbench-com-supplier-activation-api
  name: DefaultBench Supplier activation API
  description: Accountless resource control proof and non-financial sponsorship preparation.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags:
  - Supplier activation
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-supplier-activation-api-openapi.yml
- aid: defaultbench-com:defaultbench-com-transparency-api
  name: DefaultBench Transparency API
  description: Verified-payment ledger and aggregates.
  humanURL: https://defaultbench.com/docs
  baseURL: https://defaultbench.com
  tags:
  - Transparency
  properties:
  - type: OpenAPI
    url: openapi/defaultbench-com-transparency-api-openapi.yml
x-enrichment:
  date: '2026-11-05'
  status: enriched
  artifacts_added: 18
  pass: modular-v1
  engine: identity=local,contract=local,surfaces=local,docs=local,regulatory=local

DefaultBench API — frequently asked questions

Does DefaultBench have an API?

Yes. APIs.io lists 12 APIs from DefaultBench, including DefaultBench A2A API, DefaultBench Attribution API and DefaultBench Bidding API, and 9 more.

Is there an OpenAPI specification for the DefaultBench API?

Yes. APIs.io indexes 12 OpenAPI specifications for DefaultBench, each linked for download from this page.

How do I authenticate with the DefaultBench API?

DefaultBench uses bearer-token authentication.

How much does the DefaultBench API cost?

DefaultBench publishes its prices; its market_intelligence_v1 plan is 1.000000 USDC as of 2026-11-05. APIs.io lists 1 pricing plan for DefaultBench, with each plan's price, limits and inclusions under Pricing on this page.

Is the DefaultBench API ready for AI agents?

DefaultBench has a Kin Score of 28.8 out of 100 (thin) and an Agent Readiness score of 47.5 (agent-native), scored by API Evangelist on 2026-11-06.

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get_provider_operationsEvery operation across all of their OpenAPIs — one call instead of parsing every spec.
get_provider_toolsEvery MCP tool they ship, with the operation each wraps.
get_provider_evidenceHow each part of their score was established. Free — the basis for a claim should not sit behind it.
get_provider_ratingPRO — composite, band, trend and facet scores.
apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
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