USACallerLookup

A free, read-only JSON REST API over US phone-numbering data and FTC robocall complaint records. No API key or signup required; access is throttled at 60 requests/minute per IP. Data is sourced from FTC Do Not Call complaints and the NANPA registry and dedicated to the public domain under CC0.

USACallerLookup publishes 1 API on the APIs.io network: Free Phone Lookup API. Tagged areas include Phone Lookup, Caller ID, robocall, FTC, and Telecom.

USACallerLookup’s developer surface includes authentication, documentation, API reference, engineering blog, support, and 18 more developer resources.

🌐 Visit website 📡 Source on GitHub
30.8/100 thin Agent 25/100 agent aware Full breakdown ↓
scored 2026-09-14 · rubric v0.22.0
1 APIs
Phone LookupCaller IDrobocallFTCTelecomOpen DataAnti-Fraud

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-09-14 · rubric v0.22.0
Composite quality — 30.8/100 · thin
Contract Quality 7.1 / 21
Developer Ergonomics 7.6 / 17
Access Clarity 1.8 / 17
Operational Transparency 2.9 / 11
Contract Governance 0.5 / 10
Discoverability 6.5 / 9
Regulatory Posture 4.4 / 15
Agent readiness — 25/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 0 / 10
Documented Reversibility 6 / 6
MCP Server 0 / 12
Machine-Readable Auth 10 / 10
Idempotency 9 / 9
Stable Error Semantics 8 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 5 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 4 / 4
Delegated User Identity 0 / 6
Protected Resource Metadata 0 / 5
Registration Without a Human 0 / 6
Agentic Commerce Well-Known Document 0 / 5
Regulatory Posture applies to this provider. Its tags matched the Telecommunications 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 does not apply to this provider. The published contracts declare no write operations, and a read-only API cannot create-or-update. The facet is excluded from this provider's denominator entirely — not scored zero. A reference or data API is not deficient for being unable to upsert.
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/.
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 github.com/api-evangelist/usacallerlookup: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 1

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

USACallerLookup Free Phone Lookup API

No-auth, read-only REST API with three GET endpoints: reverse phone number lookup, area-code aggregates, and dataset stats. Backed by a public OpenAPI 3.1.0 contract.

Pricing Plans 1

Published pricing tiers and plan structures.

Usacallerlookup Plans Pricing

0 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Usacallerlookup Rate Limits

1 limits

RATE LIMITS

Security Posture 2

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

Usacallerlookup Authentication

0 schemes

SECURITY

Usacallerlookup Domain Security

TLSv1.3 · DMARC

SECURITY

Resources

Documentation 3

Reference material describing how the API behaves

OpenAPI
OpenAPI
 Documentation
Documentation
 APIReference
APIReference

Agent Surfaces 2

MCP servers, agent skills, and machine-readable catalogs

LLMsTxt
LLMsTxt
 AgentSkill
AgentSkill

Design & Contract 5

Pagination, idempotency, versioning, errors, and events

ErrorCatalog
ErrorCatalog
 Conventions
Conventions
 DataModel
DataModel
 Conformance
Conformance
 Lifecycle
Lifecycle

Build 3

SDKs, sample code, and the tooling you integrate with

Packages
Packages
 SDKs
SDKs
 GitHubOrganization
GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

Authentication
Authentication
 DomainSecurity
DomainSecurity

Operate 3

Status, limits, changes, and where to get help

RateLimits
RateLimits
 Support
Support
 HelpCenter
HelpCenter

Commercial 2

Pricing, plans, and the legal terms of use

Plans
Plans
 TermsOfService
TermsOfService

Company 2

The organization behind the API

Website
Website
 Blog
Blog

Other 1

Properties that don't map to a standard resource type

Overlay
Overlay

Source (apis.yml)

apis.yml Raw ↑ 
name: USACallerLookup
description: A free, read-only JSON REST API over US phone-numbering data and FTC robocall complaint records. No API key or
  signup required; access is throttled at 60 requests/minute per IP. Data is sourced from FTC Do Not Call complaints and the
  NANPA registry and dedicated to the public domain under CC0.
url: https://raw.githubusercontent.com/api-evangelist/usacallerlookup/refs/heads/main/apis.yml
created: '2026-09-14'
modified: '2026-09-14'
specificationVersion: '0.21'
tags:
- Phone Lookup
- Caller ID
- robocall
- FTC
- Telecom
- Open Data
- Anti-Fraud
tags_raw:
- phone lookup
- caller ID
- robocall
- FTC
- telecom
- open data
- anti-fraud
apis:
- name: USACallerLookup Free Phone Lookup API
  description: 'No-auth, read-only REST API with three GET endpoints: reverse phone number lookup, area-code aggregates, and
    dataset stats. Backed by a public OpenAPI 3.1.0 contract.'
  humanURL: https://www.usacallerlookup.com/api/
  baseURL: https://www.usacallerlookup.com/wp-json/ucl/v1
  tags:
  - Phone Lookup
  - Caller ID
  - robocall
  - FTC
  - Telecom
  - Open Data
  - Anti-Fraud
  tags_raw:
  - phone lookup
  - caller ID
  - robocall
  - FTC
  - telecom
  - open data
  - anti-fraud
  properties:
  - type: OpenAPI
    url: https://www.usacallerlookup.com/wp-content/uploads/api/openapi.json
  - type: Documentation
    url: https://www.usacallerlookup.com/api/
  - type: LLMsTxt
    url: https://www.usacallerlookup.com/llms.txt
  image: https://www.usacallerlookup.com/favicon.ico
maintainers:
- FN: USACallerLookup
  url: https://www.usacallerlookup.com/
  email: contact@usacallerlookup.com
common:
- type: Website
  url: https://www.usacallerlookup.com/
- type: OpenAPI
  url: openapi/usacallerlookup-openapi.json
- type: LLMsTxt
  url: llms/usacallerlookup-llms.txt
- type: Packages
  url: packages/usacallerlookup-packages.yml
- type: SDKs
  url: packages/usacallerlookup-packages.yml
- type: Authentication
  url: authentication/usacallerlookup-authentication.yml
- type: RateLimits
  url: rate-limits/usacallerlookup-rate-limits.yml
- type: Plans
  url: plans/usacallerlookup-plans-pricing.yml
- type: ErrorCatalog
  url: errors/usacallerlookup-problem-types.yml
- type: Conventions
  url: conventions/usacallerlookup-conventions.yml
- type: DataModel
  url: data-model/usacallerlookup-data-model.yml
- type: Conformance
  url: conformance/usacallerlookup-conformance.yml
- type: Lifecycle
  url: lifecycle/usacallerlookup-lifecycle.yml
- type: DomainSecurity
  url: security/usacallerlookup-domain-security.yml
- type: AgentSkill
  url: skills/_index.yml
- type: Overlay
  url: overlays/usacallerlookup-openapi-overlay.yaml
- type: Documentation
  url: https://www.usacallerlookup.com/api/
- type: APIReference
  url: https://www.usacallerlookup.com/api/
- type: TermsOfService
  url: https://www.usacallerlookup.com/terms-conditions/
- type: Blog
  url: https://www.usacallerlookup.com/blog/
- type: Support
  url: https://www.usacallerlookup.com/contact-us/
- type: HelpCenter
  url: https://www.usacallerlookup.com/faq/
- type: GitHubOrganization
  url: https://github.com/usacallerlookup
x-enrichment:
  date: '2026-09-14'
  status: enriched
  artifacts_added: 16
  pass: local-v3
x-generated:
  by: apis.io/add
  model: claude-opus-4-8
  confidence: 95
  at: '2026-09-14T18:32:05.841Z'
image: https://www.usacallerlookup.com/favicon.ico

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