Text Similarity API

About the Text Similarity API

Text Similarity works by comparing the two texts and calculating the similarity score based on various factors. It returns the similarity score in a structured format.

What people use it for

Plagiarism Screening

Educators check student assignment submissions against reference essays to catch paraphrased or near-identical passages using case-insensitive similarity scores.

Catalog Deduplication

To merge duplicate inventory listings, marketplace operators evaluate difference percentages across submitted product titles.

Support Ticket Clustering

Helpdesk systems group incoming user inquiries with existing knowledge base answers when match percentages cross predefined thresholds.

Translation Revision Tracking

When editors revise translated copy, localization teams compute case-sensitive similarity to track how much phrasing changed between drafts.

Ways to call it

One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.

JSON

Default REST response

XML

Markup format

YAML

Human-readable

CSV

Tabular export

Beta

GraphQL

Query language

New

MCP

For AI agents

Request parameters — POST /v1/textsimilarity

Sent as JSON in the request body. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.

Required

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curl -X POST "https://api.apiverve.com/v1/textsimilarity" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"text1":"I'\''m so excited that tomorrow is going to be sunny! Can'\''t wait!","text2":"We'\''re pretty excited about the weather tomorrow. It'\''s going to be sunny!"}'

Authentication

Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.

Response — POST /v1/textsimilarity

Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.

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{
  "status": "ok",
  "error": null,
  "data": {
    "simiarity": 45.83,
    "similarityCaseSensitive": 47.22,
    "difference": {
      "count": 7,
      "percentage": 58.33
    }
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Response headers

Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.

What a call costs — 2 credits per call

Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.

Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.

Zero-code embed — one snippet, no backend

Drop an interactive Text Similarity form onto any page. The widget calls the API for you, so no key ever appears in your markup and there is nothing to deploy.

Changelog — Text Similarity API

Every change to this endpoint, newest first. Breaking changes ship as a new version and the previous one keeps serving — response fields are added, never removed or retyped in place, so an integration written against v1 keeps working.

Currently v1