# 1Lookup, Full Reference

> 1Lookup is a data verification and enrichment platform that AI agents and application code both call directly: over a REST API, or over a hosted MCP server at https://app.1lookup.io/api/mcp. It covers phone numbers, email addresses, IP addresses, domains, companies, contacts, and keywords, and is delivered as a REST API, a hosted MCP server, a web dashboard with batch CSV validation, and a suite of free, rate-limited browser tools. This document is a factual capability reference for AI and answer engines. It deliberately excludes promotional performance, accuracy, and savings figures; consult the live pages at https://www.1lookup.io for current numbers and pricing.

## Start here for AI agents (MCP)

If you are an AI agent, or building one, this is the connection path:

- Endpoint: https://app.1lookup.io/api/mcp
- Transport: streamable HTTP (SSE is disabled)
- Auth: OAuth 2.1. No API key. Dynamic client registration, PKCE (S256 required), and a browser consent screen. Discovery documents: https://app.1lookup.io/.well-known/oauth-protected-resource (RFC 9728) and https://app.1lookup.io/.well-known/oauth-authorization-server (RFC 8414).
- Machine-readable server card: https://www.1lookup.io/.well-known/mcp/server-card.json
- Tools exposed (5): validate_phone, verify_email, ip_lookup, bulk_verify, get_account
- Cost: tool calls spend the same credits as the REST API, one credit per phone, email, or IP lookup, and one credit per record for bulk_verify. get_account is free. There is no separate MCP fee.
- Requires a paid plan. Free-plan accounts receive HTTP 403 UPGRADE_REQUIRED on every tool call. A 7-day trial is available.
- Token lifetimes: access tokens 1 hour, refresh tokens 30 days, registered clients 90 days. Authorization codes are single-use and live 60 seconds.
- Verified clients: Claude and Cursor. Any client that supports remote MCP over streamable HTTP can add the same URL.
- Setup pages: https://www.1lookup.io/mcp/claude and https://www.1lookup.io/mcp/cursor
- Auth reference: https://www.1lookup.io/mcp/oauth
- Overview: https://www.1lookup.io/products/mcp

Everything beyond those five tools (40 data products covering company, B2B contact, SEO, social, property and transcription data) is available over the REST API at https://app.1lookup.io/api/v1, not over MCP.

## What 1Lookup does

1Lookup takes a phone number, email address, IP address, domain, company, contact, keyword, social handle or post URL, or audio/video URL and returns a structured set of verification or enrichment signals. The same engine backs four surfaces:

1. **REST API**, programmatic access with API keys and JSON responses (docs at https://app.1lookup.io/api).
2. **Hosted MCP server**, the agent-callable surface at https://app.1lookup.io/api/mcp: streamable HTTP, OAuth 2.1 instead of an API key, five tools (validate_phone, verify_email, ip_lookup, bulk_verify, get_account). Same credits as the REST API, paid plans only.
3. **Web dashboard**, single lookups, batch CSV uploads, and analytics at https://app.1lookup.io.
4. **Free tools**, public, rate-limited demos of the API that return a useful partial result and gate richer fields behind a free account (https://www.1lookup.io/tools).

## Phone validation

A phone lookup parses a number into E.164 format, confirms it follows its country's numbering plan, and returns network-level signals. Available fields include:

- Validity and reachability status
- Line type (mobile, landline, or VoIP)
- Carrier / network identification
- Country, region, and timezone
- Number portability (whether the number has been ported; LRN / port type)
- HLR (Home Location Register) live network status for mobile numbers
- DNC (Do Not Call) registry status
- Spam / scam reputation: spam probability, report count, and robocaller status
- Fraud score with a risk assessment

Related pages: /products/phone-validation, /products/carrier-lookup, /products/hlr-lookup, /products/phone-spam-check, /products/reverse-lookup.

## Email validation

An email lookup checks an address for syntax and deliverability and adds intelligence about its domain. Available fields include:

- Syntax and format validation
- Domain validation, DNS, and MX-record checks
- Deliverability assessment
- Disposable / temporary address detection
- Role-based address detection (e.g. sales@, admin@, support@)
- Domain intelligence (age, reputation)
- Fraud score with risk factors

Related page: /products/email-validation. Free tool: /tools/email-verifier.

## IP intelligence

An IP lookup returns geolocation and risk signals. Available fields include:

- Geolocation (continent, country, city, coordinates)
- ISP / organization and ASN
- Connection type (residential, commercial, mobile, datacenter)
- Timezone and currency
- VPN / proxy / Tor detection
- Hosting / datacenter detection
- Fraud score and threat level

Related page: /products/ip-lookup. Free tools: /tools/ip-address-lookup, /tools/what-is-my-ip, /tools/vpn-proxy-detection, /tools/ip-blacklist-check.

## Domain & SEO intelligence

Domain checks assess a domain's age, authority, reputation, and search footprint. Five products cover this space:

- **Domain SEO Intelligence** (/products/domain-seo-intelligence): aggregated third-party authority metrics: domain authority (DA), domain rating (DR), backlink counts, and estimated traffic.
- **Domain Authority** (/products/domain-authority): a domain's measured search footprint: a 0-100 authority score derived from Semrush rank, organic and paid keyword counts, estimated monthly organic traffic, and what that traffic would cost to buy.
- **Backlink Overview** (/products/backlink-overview): the link profile: Authority Score, total backlinks, referring domains, referring IPs, and the follow/nofollow split with a computed follow ratio.
- **Audience Intelligence** (/products/audience-intelligence): who visits a website: traffic by country, visitor age/gender/income demographics, traffic sources, and onward destinations.
- **Domain Age** (/products/domain-age): when a domain was first registered, read from the registry over RDAP: creation date, exact age in days and years, expiry date, days until expiry, registrar, registry status codes, nameservers, and a newly-registered flag for fraud rules. 2 credits, and nothing at all for an unregistered domain.

Related free tools: /tools/domain-authority-checker, /tools/domain-age-checker.

## Keyword & search intent data

- **Keyword Metrics** (/products/keyword-metrics): monthly search volume, CPC in USD, a 0-100 keyword difficulty with plain-language band, search intent classification, 12-month trend direction, SERP features (including AI Overview presence), and estimated monthly traffic value for any keyword.
- **SERP Scraper** (/products/search-intent-lookup): scrape Google search results for any query: organic listings, knowledge panels, People Also Ask, and related searches.

## Company & B2B contact intelligence

- **Prospect Search** (/products/prospect-search): find people by job title, seniority, location, and employer. Searches are flat-priced; each result row shows whether a work email is available before you pay to reveal it.
- **Account Search** (/products/account-search): find companies by headcount band, revenue range, HQ location, technology in use, and keywords, up to 100 matching companies per search. Each row returns the company name, domain, and location; pair it with Company Firmographics for full enrichment of the accounts that qualify.
- **Company Firmographics** (/products/company-firmographics): turn a company domain into a full profile: industry, SIC and NAICS codes, estimated headcount and growth, annual revenue, tech stack, and departmental head counts.
- **B2B Contact Append** (/products/b2b-contact-append): a verified work email with confidence rating, job title, normalized seniority, and department from a name plus company, an email address, or a LinkedIn URL.
- **Company Profile Lookup** (/products/company-profile-lookup): a company domain becomes a profile built from professional network data: industry, size bands, headquarters, founding year, follower count, specialties, and funding history (total raised, rounds, investors, IPO status). Only charged on a match.

## Business, social & property lookups

These lookups run a live deep fetch against the source, so a first result typically returns in seconds rather than milliseconds; repeat lookups within 7 days return instantly from cache. All are only charged on a match.

- **Business Verify** (/products/business-verify): one check answering whether a business is real, open, and reachable. Blends live business-listing data (status, rating, review count, address) with 1Lookup's phone and email validation into a 0-100 verification score and a verdict (verified / partially verified / unverified / not found).
- **Business Lookup** (/products/business-lookup): business name and city in; address, phone, website, category, star rating, review count, hours, and open/closed status out, from live business-listing data.
- **Social Profile Check** (/products/social-profile-check): handle in on any of ten platforms (Instagram, TikTok, YouTube, X/Twitter, Facebook, Threads, Twitch, Snapchat, Bluesky, Truth Social); existence, followers, following, post count, verified, private, and business-account flags, bio, and engagement rate out, from public social profiles. Used for influencer vetting and fake-signup checks.
- **Property Lookup** (/products/property-lookup): US address in; beds, baths, square footage, home type, year built, listing status, list price, last sold date and price, and days on market out, from public real-estate listing data.

## Social media lookups

These lookups read public social pages and public transparency archives, never anything behind a login. A first lookup typically returns in a few seconds and can take up to about a minute; repeat lookups within 7 days return instantly from cache.

- **Social Post Lookup** (/products/social-post-lookup): post or video URL in (Instagram, TikTok, YouTube, X/Twitter, Facebook, Threads, Bluesky, Truth Social, Pinterest, LinkedIn); caption or title, author handle and display name, likes, comments, shares, views, and posted date out. Only charged on a match.
- **Video Transcript** (/products/video-transcript): public video URL in (TikTok, Instagram, YouTube, X, Facebook, LinkedIn, Reddit); the full spoken transcript out as text, with detected language and word count. Flat price per transcript regardless of length; only charged when a transcript is found.
- **Social Search** (/products/social-search): platform plus keyword in (Instagram, TikTok, YouTube, Threads, Pinterest, Reddit); one page of matching public profiles and content out, each row typed with handle or author, display name or caption, follower or view counts, and a direct URL. Searches that return nothing are free.
- **Ad Library Lookup** (/products/ad-library-lookup): company name or keyword in; the ads that advertiser is running out, from the public ad libraries of Meta/Facebook, TikTok, LinkedIn, and Google: per-ad creative text, media type, active/inactive status, start date, and landing URL, plus total and active ad counts. Only charged when ads are found.
- **TikTok Audience Demographics** (/products/audience-demographics): TikTok handle in; follower countries out as aggregate percentages, each with the country name, its ISO code, and its share of the audience. Country shares are the only breakdown returned: there is no gender and no age data. Premium lookup used to check where a creator's followers actually are before campaigns; only charged on a match.
- **Link-in-Bio Lookup** (/products/link-in-bio-lookup): Linktree, Komi, Pillar, Lnk.bio, or Linkme page URL in; page title, bio, avatar, every link with its label and destination, and connected social profiles out. Only charged on a match.

## Monitoring

- **Job Change Monitoring** (/products/job-change-monitoring): watch a list of contacts and receive an event when someone changes company or title. Contacts are rechecked weekly; unreachable profiles are not charged.

## Audio transcription

- **Audio Transcription** (/products/bulk-audio-transcription): transcribe any audio or video URL with word-level timestamps and speaker labels, billed per minute of audio. One https URL per API call; large backlogs are processed by looping calls.

## The free tools

Phone:
- /tools/phone-number-lookup, Validate any number and see line type, carrier and country.
- /tools/reverse-phone-lookup, Find the likely owner and location behind a phone number.
- /tools/carrier-lookup, Identify the carrier and network for any phone number.
- /tools/phone-line-type-lookup, Check if a number is mobile, landline or VoIP.
- /tools/spam-phone-checker, Look up any number's spam, scam and robocall reputation.
- /tools/hlr-lookup, Live HLR query: is a mobile number active and reachable?
- /tools/phone-portability-lookup, Check whether a mobile number has been ported.

Email:
- /tools/email-verifier, Check if an email is valid, deliverable and safe to send.
- /tools/dmarc-checker, See whether anyone can send email pretending to be your domain, read live from DNS.
- /tools/spf-record-checker, Validate an SPF record and expand every include to catch the RFC 7208 10-lookup limit.
- /tools/mx-record-lookup, See which mail servers accept a domain's email, by priority, and which provider runs them.

IP:
- /tools/ip-address-lookup, Geolocate any IP: city, ISP, ASN and connection type.
- /tools/what-is-my-ip, Instantly see your public IP, location and ISP.
- /tools/vpn-proxy-detection, Detect VPN, proxy, Tor and datacenter IPs.
- /tools/ip-blacklist-check, Check an IP's reputation and blocklist status.

Domain:
- /tools/domain-authority-checker, Check DA, DR, backlinks and estimated traffic.

Business and vehicle (free public registers, read directly):
- /tools/dot-number-lookup, Check a trucking company by USDOT number against the FMCSA motor carrier census.
- /tools/vin-decoder, Decode a 17-character VIN into year, make, model, body, engine and plant, from NHTSA vPIC.
- /tools/npi-lookup, Look up a healthcare provider by NPI in the CMS NPPES registry.

Social:
- /tools/social-username-checker, See whether a username is already taken on ten networks.
- /tools/instagram-profile-viewer, Followers, following, posts and verified status for any public Instagram account.
- /tools/video-transcript-generator, Paste a TikTok, YouTube, Instagram or X video link and read the spoken words.
- /tools/engagement-rate-calculator, Fetch a creator's follower count, add average likes and comments, and grade the rate by account size.
- /tools/facebook-ad-library-search, See the ads a brand is running on Facebook and Instagram.
- /tools/tiktok-ad-library-search, Look up the TikTok ads a brand is currently running.
- /tools/is-this-a-scam, Paste any message, email or offer and get a read on whether it is a scam, with the specific reasons.
- /tools/scam-text-message-checker, Check a suspicious SMS for the signs of a smishing scam.
- /tools/phishing-email-checker, Paste a suspicious email and see whether it is phishing, and why.
- /tools/is-this-website-legit, Check whether a site is a real business or a scam storefront, from its address.
- /tools/is-this-link-safe, Check where a link really goes, without opening it.
- /tools/who-called-me, Find out who is behind the number that just called you.
- /tools/whose-number-is-this, Identify the owner, carrier and location behind any US number.
- /tools/reverse-email-lookup, Find out who is behind an email address.
- /tools/area-code, Every US area code, the state and city it covers, and which prefixes are toll-free.

Each free tool is rate-limited and returns a partial result; full reports, batch processing, and API access require a free account.

## Who uses 1Lookup

Common use cases (see /use-cases): fraud prevention, lead-list cleaning, SMS deliverability, and onboarding verification. Industry pages (see /industries) cover call centers, debt collection, e-commerce, education, financial services, gaming, government, healthcare, insurance, lead generation, market research, marketing, real estate, SaaS, and travel.

## Access and integration

- Web dashboard: https://app.1lookup.io (single lookups, batch CSV, analytics, API keys)
- REST API docs: https://app.1lookup.io/api
- MCP server (hosted): https://app.1lookup.io/api/mcp over streamable HTTP with OAuth 2.1 and no API key. Five tools: validate_phone, verify_email, ip_lookup, bulk_verify, get_account. Same credits as the REST API, paid plans only. Setup: https://www.1lookup.io/mcp/claude, https://www.1lookup.io/mcp/cursor; auth reference: https://www.1lookup.io/mcp/oauth; overview: https://www.1lookup.io/products/mcp
- Free tools: https://www.1lookup.io/tools
- Pricing: https://www.1lookup.io/pricing (credit-based; per-lookup credit cost varies by product, and credits are shared across every product)

## Contact

- Support: support@1lookup.io
- Sales: sales@1lookup.io
- Partnerships: partners@1lookup.io
- Website: https://www.1lookup.io