castomAPI
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Web, search & AI · 7 operations

SERP API

Search results, keyword research, rivals, cannibalisation, mobile tests and element counts.

Utilities 5–60 tokens API key

Endpoints in SERP

POSTSearch a phrase and detect which of a site's own pages compete/v1/serp/cannibalizationPRO from 60 tokens POSTSearch a phrase and report the ranking position of your URL (and…/v1/serp/check-urlPRO from 60 tokens POSTRun a Google search and count the SERP feature blocks on the first…/v1/serp/count-elementsPRO from 60 tokens POSTSearch a phrase and extract SEO metadata + top keywords from each…/v1/serp/keyword-researchPRO from 60 tokens POSTRun a full Lighthouse audit (performance/v1/serp/mobile-opt-testPRO 5 tokens POSTRun a Google search and return the top competing (rival) domains…/v1/serp/rivalsPRO from 60 tokens POSTRun a live Google search/v1/serp/searchPRO from 60 tokens

Cost and limits

This operation costs 5–60 tokens. A call that fails is never billed. Every account gets 1000 free tokens a month; paid balances never expire.

Rate limits per minute

No key 10 · Free 60 · Pro 300 · Enterprise 1200 ·

OpenAPI

https://app.castomapi.com/docs/json

Web, search & AI

Scrape

One page, its images, its favicon, its Google reviews, a CEIDG record, a content moderation verdict, a site's stack.

Crawl

Whole sites: basic, deep, or every image — with limits you set and a structure you can index.

Trends

Interest over time and by region, suggestions, top charts and what is trending now.

Proxy

Safe fetch, stealth fetch, CORS, image transforms, RSS and XML to JSON, CSV streams, cache acceleration, an LLM relay, webhook relay.

AI

A UX audit of any URL: multi-viewport screenshots read by a vision model, with concrete suggestions.

Email

Read and send over the customer's own IMAP and SMTP — stateless, nothing stored.