# DefaultBench

**Canonical:** https://apis.io/providers/defaultbench-com/  
**Website:** https://defaultbench.com/  
**APIs profiled:** 1

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.

## Kin Score — 28.8 / 100 (thin)

Scored 2026-11-06 under rubric 0.27.0.

| Facet | Score |
|---|---|
| Discoverability | 57.1 |
| Contract Quality | 48.6 |
| Contract Governance | 0.0 |
| Operational Transparency | 0.0 |
| Developer Ergonomics | 7.1 |
| Access Clarity | 52.6 |

Regulatory layer — **Payments**: 12.5 (matched via tags).

## Agent readiness — 47.5 (agent-native)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | bearer |
| Idempotency | verified |
| Error Semantics | verified |
| OpenAPI Examples | verified |
| Rate Limit Signal | verified |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | yes |
| Consent Identity | no |
| Agent Card | conformant |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |
| Pagination Ratio | na |
| Operation Distinctiveness | distinct |
| MCP Tool Quality | na |

## Access

Paid — onboarding: unknown, pricing: paid, trial: no (confidence: low).

## APIs (12)

- **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.

## Security (1)

- **Defaultbench Com Domain Security** — TLSv1.3 · HSTS

## Plans (1)

- **Defaultbench Com Plans Pricing**

## Tags

Sponsored Rankings, AI Agents, SERP, USDC Payments

---

Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/defaultbench-com/). Scores are computed from the provider's own public artifacts under a published rubric.