1Lookup is a self-serve data verification and enrichment platform for SMBs, exposing more than forty products through a single REST API and one universal credit balance. It validates phone numbers (line type, carrier, HLR reachability, number portability, DNC status, spam/scam reputation, fraud score), email addresses (syntax, MX, deliverability, disposable and role-based detection) and IP addresses (geolocation, VPN/proxy/Tor and datacenter detection), then extends into B2B company and contact data (firmographics, prospect and account search, contact append, skip trace), SEO and web intelligence (domain authority, backlinks, keyword metrics, audience reports, SERP and website scraping), social and media lookups, property data and audio transcription. The same engine powers a web dashboard with batch CSV validation, roughly twenty-five free rate-limited browser tools, and a first-party hosted MCP connector authorized with OAuth 2.1 that gives AI agents five of the core tools without an API key.
1Lookup is listed with 3 APIs on the APIs.io network. Tagged areas include Phone Validation, Email Verification, IP Intelligence, Fraud and Risk, and Data Enrichment.
The 1Lookup catalog on APIs.io includes 1 event-driven AsyncAPI specification.
1Lookup’s developer surface includes documentation, API reference, getting-started guide, engineering blog, support, pricing, signup flow, and 34 more developer resources.
Regulatory Posture applies to this provider. Its tags matched the
Horizontal (data, software, accessibility, platform) regime, so
Regulatory Posture carries 15 points of the composite.
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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):
A2A Agent Card+8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0
Documented Reversibility+6 pts — a reversal operation in the contract, graded up when a window is documented too
Agentic Commerce Well-Known Document+5 pts — a parsing /.well-known/ucp.json or acp.json declaring a version and at least one service, OR (0.27) a live x402 payment challenge from _data/x402-adoption.json — `self` when its endpoints are on the provider's own domain, `platform` when they are on a vendor's
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.
Machine-readable content indexes (llms.txt and llms-full.txt) for AI and answer engines, indexing the free tools, every product page, the comparison pages and the key site secti...
name: 1Lookup
description: 1Lookup is a self-serve data verification and enrichment platform for SMBs, exposing more than forty products
through a single REST API and one universal credit balance. It validates phone numbers (line type, carrier, HLR reachability,
number portability, DNC status, spam/scam reputation, fraud score), email addresses (syntax, MX, deliverability, disposable
and role-based detection) and IP addresses (geolocation, VPN/proxy/Tor and datacenter detection), then extends into B2B
company and contact data (firmographics, prospect and account search, contact append, skip trace), SEO and web intelligence
(domain authority, backlinks, keyword metrics, audience reports, SERP and website scraping), social and media lookups, property
data and audio transcription. The same engine powers a web dashboard with batch CSV validation, roughly twenty-five free
rate-limited browser tools, and a first-party hosted MCP connector authorized with OAuth 2.1 that gives AI agents five of
the core tools without an API key.
deliveryModel:
model: saas
open_source: false
commercial: true
callable_host: false
label: Hosted service · you call their endpoint
confidence: medium
source:
- pricing
generated: '2026-08-28'
method: derived
accessModel:
pricing: paid
onboarding: open
trial: false
try_now: false
public: true
gated: none
gated_source:
- onboarding
label: Paid · Open access
confidence: high
source:
- plans
- authentication
- scopes
- rate-limits
- security
- sandbox
generated: '2026-11-06'
method: derived
image: https://www.1lookup.io/images/featured/pages/homepage.png
url: https://raw.githubusercontent.com/api-evangelist/1lookup/refs/heads/main/apis.yml
created: '2026-08-08'
modified: '2026-08-14'
specificationVersion: '0.23'
tags:
- Phone Validation
- Email Verification
- IP Intelligence
- Fraud and Risk
- Data Enrichment
- B2B contact & company data
- SEO / web analytics
- Audio Transcription
- MCP / agent-native
- REST API
tags_raw:
- phone validation
- email validation
- IP intelligence
- fraud & risk
- data enrichment
- B2B contact & company data
- SEO / web analytics
- audio transcription
- MCP / agent-native
- REST API
- Email Validation
apis:
- name: 1Lookup REST API
description: RESTful API over HTTPS covering all 1Lookup products (phone/email/IP validation, fraud, enrichment, B2B data,
SEO intelligence). API-key Bearer auth (sk_live_ keys, organization-scoped), JSON bodies, one response envelope on every
product, and job-based bulk processing up to 100,000 rows with an Idempotency-Key contract and signed webhook callbacks.
46 documented operations, almost all POST, priced against a universal credit balance. No OpenAPI or other machine-readable
contract is published.
humanURL: https://app.1lookup.io/api
baseURL: https://app.1lookup.io/api/v1
tags:
- Phone Validation
- Email Verification
- IP Intelligence
- Fraud and Risk
- Data Enrichment
- B2B contact & company data
- SEO / web analytics
- Audio Transcription
- REST API
tags_raw:
- phone validation
- email validation
- IP intelligence
- fraud & risk
- data enrichment
- B2B contact & company data
- SEO / web analytics
- audio transcription
- REST API
- Email Validation
properties:
- type: Documentation
url: https://app.1lookup.io/api
- type: APIReference
url: https://app.1lookup.io/api#endpoints
- type: GettingStarted
url: https://app.1lookup.io/api#getting-started
- type: Authentication
url: authentication/1lookup-authentication.yml
- type: Conventions
url: conventions/1lookup-conventions.yml
- type: ErrorCatalog
url: errors/1lookup-problem-types.yml
- type: RateLimits
url: rate-limits/1lookup-rate-limits.yml
- type: Lifecycle
url: lifecycle/1lookup-lifecycle.yml
- type: Idempotency
url: conventions/1lookup-conventions.yml
- type: Webhooks
url: asyncapi/1lookup-webhooks.yml
- type: DataModel
url: data-model/1lookup-data-model.yml
- type: Examples
url: examples/1lookup-examples.yml
- name: 1Lookup MCP Server
description: First-party hosted/remote MCP connector with OAuth 2.1 auth (authorization code + PKCE, dynamic client registration,
single `lookup` scope) exposing 5 tools (validate_phone, verify_email, ip_lookup, bulk_verify, get_account) for Claude,
Cursor, ChatGPT, and any MCP client. Tool calls bill against the same plan credits as the REST API.
humanURL: https://www.1lookup.io/products/mcp
baseURL: https://app.1lookup.io/api/mcp
tags:
- MCP / agent-native
- Phone Validation
- Email Verification
- IP Intelligence
tags_raw:
- MCP / agent-native
- phone validation
- email validation
- IP intelligence
- Email Validation
properties:
- type: MCPServer
url: https://app.1lookup.io/api/mcp
- type: MCPServer
url: mcp/1lookup-mcp.yml
- type: ToolCrosswalk
url: mcp/1lookup-tool-crosswalk.yml
- type: Documentation
url: https://www.1lookup.io/products/mcp
- type: OAuthScopes
url: scopes/1lookup-scopes.yml
- type: WellKnown
url: https://www.1lookup.io/.well-known/mcp/server-card.json
- name: 1Lookup LLMs Index
description: Machine-readable content indexes (llms.txt and llms-full.txt) for AI and answer engines, indexing the free
tools, every product page, the comparison pages and the key site sections.
humanURL: https://www.1lookup.io
tags:
- MCP / agent-native
properties:
- type: LLMsTxt
url: https://www.1lookup.io/llms.txt
- type: LLMsTxt
url: https://www.1lookup.io/llms-full.txt
- type: LLMsTxt
url: llms/1lookup-llms.txt
maintainers:
- FN: 1Lookup
url: https://www.1lookup.io
email: support@1lookup.io
generated:
by: apis.io/add
model: claude-opus-4-8
confidence: 93
at: '2026-08-08T11:53:32.811Z'
common:
- type: DeveloperPortal
url: https://app.1lookup.io/api
- type: Documentation
url: https://app.1lookup.io/api
- type: APIReference
url: https://app.1lookup.io/api#endpoints
- type: GettingStarted
url: https://app.1lookup.io/api#getting-started
- type: Website
url: https://www.1lookup.io
- type: Blog
url: https://www.1lookup.io/blog
- type: Support
url: https://www.1lookup.io/contact
- type: Pricing
url: https://www.1lookup.io/pricing
- type: SignUp
url: https://app.1lookup.io/signup
- type: Login
url: https://app.1lookup.io/login
- type: TermsOfService
url: https://www.1lookup.io/terms
- type: PrivacyPolicy
url: https://www.1lookup.io/privacy
- type: FAQ
url: https://www.1lookup.io/faq
- type: Integrations
url: https://www.1lookup.io/integrations
- type: Glossary
url: https://www.1lookup.io/glossary
- type: LinkedIn
url: https://linkedin.com/company/1lookup
- type: Twitter
url: https://x.com/1LookupApp
- type: YouTube
url: https://www.youtube.com/@1LookupApp
- type: Authentication
url: authentication/1lookup-authentication.yml
- type: OAuthScopes
url: scopes/1lookup-scopes.yml
- type: Conventions
url: conventions/1lookup-conventions.yml
- type: ErrorCatalog
url: errors/1lookup-problem-types.yml
- type: RateLimits
url: rate-limits/1lookup-rate-limits.yml
- type: Plans
url: plans/1lookup-plans-pricing.yml
- type: Lifecycle
url: lifecycle/1lookup-lifecycle.yml
- type: Conformance
url: conformance/1lookup-conformance.yml
- type: Compliance
url: https://www.1lookup.io/security
- type: TrustCenter
url: security/1lookup-trust-center.yml
- type: Security
url: https://www.1lookup.io/security
- type: VulnerabilityDisclosure
url: security/1lookup-vulnerability-disclosure.yml
- type: DomainSecurity
url: security/1lookup-domain-security.yml
- type: WellKnown
url: well-known/1lookup-well-known.yml
- type: Packages
url: packages/1lookup-packages.yml
- type: Sandbox
url: sandbox/1lookup-sandbox.yml
- type: MCPServer
url: mcp/1lookup-mcp.yml
- type: ToolCrosswalk
url: mcp/1lookup-tool-crosswalk.yml
- type: LLMsTxt
url: llms/1lookup-llms.txt
- type: AgentSkill
url: skills/_index.yml
- type: Idempotency
url: conventions/1lookup-conventions.yml
- type: Webhooks
url: asyncapi/1lookup-webhooks.yml
- type: DataModel
url: data-model/1lookup-data-model.yml
- type: Examples
url: examples/1lookup-examples.yml
x-enrichment:
date: '2026-08-14'
status: enriched
artifacts_added: 5
artifacts_updated: 14
pass: local-v1
note: '1Lookup rewrote its API reference between 2026-08-09 and 2026-08-14: an Idempotency-Key contract on bulk jobs, a
signed webhook surface, a thirteen-code error registry, X-Request-Id, Retry-After, a four-tier rate-limit model, a versioning
policy, two new products, and a machine-readable MCP server card at www.1lookup.io/.well-known/mcp/server-card.json. Still
no OpenAPI and no A2A agent card.'
1Lookup API — frequently asked questions
Does 1Lookup have an API?
Yes. APIs.io lists 3 APIs from 1Lookup, including 1Lookup REST API, 1Lookup MCP Server and 1Lookup LLMs Index.
How do I authenticate with the 1Lookup API?
1Lookup documents its authentication (http/oauth2 · 2 schemes). The details are profiled on APIs.io as 1Lookup Authentication.
How much does the 1Lookup API cost?
1Lookup publishes its prices; its Starter plan is $99/mo as of 2026-10-28. APIs.io lists 5 pricing plans for 1Lookup, with each plan's price, limits and inclusions under Pricing on this page.
Does 1Lookup have an MCP server?
Yes. APIs.io lists 1 MCP server for 1Lookup.
Is the 1Lookup API ready for AI agents?
1Lookup has a Kin Score of 65.9 out of 100 (strong) and an Agent Readiness score of 55.4 (agent-native), scored by API Evangelist on 2026-11-06.
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