Thesaurus API

GET

Suggest relevant synonyms for any word your users write.

Thesaurus finds synonyms and alternative terms for any word. Supply a single target word to receive an array of matching synonyms.

Try it — live request, no key required

Request

GETapi.apiverve.com/v1/thesaurus?word=big

Query parameters

wordstring

Verification

Format

No key required to try it. Get a key to use it in your app.

Example

{
  "status": "ok",
  "error": null,
  "data": {
    "word": "big",
    "similarCount": 50,
    "similarWords": [
      "large",
      "ample",
      "sizable",
      "sizeable",
      "astronomic",
      "astronomical",
      "galactic",
      "bigger",
      "larger",
      "biggest",
      "greatest",
      "largest",
      "biggish",
      "largish",
      "blown-up",
      "enlarged",
      "bouffant",
      "puffy",
      "bulky",
      "capacious",
      "colossal",
      "prodigious",
      "stupendous",
      "cosmic",
      "deep",
      "double",
      "elephantine",
      "gargantuan",
      "giant",
      "jumbo",
      "enormous",
      "tremendous",
      "epic",
      "heroic",
      "larger-than-life",
      "extensive",
      "extended",
      "gigantic",
      "mammoth",
      "great",
      "hulking",
      "hulky",
      "huge",
      "immense",
      "vast",
      "Brobdingnagian",
      "humongous",
      "banging",
      "thumping",
      "whopping"
    ]
  }
}

About the Thesaurus API

Pass a target word as a query parameter to retrieve a list of related synonyms as an array of strings. Responses repeat the queried word with the matching vocabulary entries. Paid plans also include the total count of similar words found.

What people use it for

Text Editor Word Suggestions: When authors double-click repetitive phrases in an online editor, display the list of returned synonyms in an inline replacement menu.
Vocabulary Flashcard Apps: Language learning platforms generate supplementary study cards by pairing each target vocabulary word with its matching synonym list.
Search Query Expansion: Broaden catalog product searches by appending synonyms to buyer queries so shoppers find relevant items described with different terms.
Ad Copy Variation: Marketing automation tools suggest synonym replacements for overused adjectives to help copywriters test fresh variations of headline text.

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
GraphQL: Query language
MCP: For AI agents

View all integrations →

Other ways to use Thesaurus

Same data, same APIVerve account, same credit balance — one key works on all of them.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.on VerveKit Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.on VerveSheets Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.on VerveContext

Questions.

Common questions about the Thesaurus API.

Read the docs →

Can I look up multi-word phrases or full sentences?

No. The API accepts a single word string per request. If you are analyzing full sentences or paragraphs in a writing tool, your application must split the text and look up individual words separately.

Can I filter the synonyms by relevance or length?

No. The endpoint takes only the target word and returns all matching synonyms found in its database as a single array. If your interface requires filtering by character count, letter pattern, or frequency, you must apply those filters in your client code.

Do I get the total synonym count on the Free plan?

No. The total count of similar words is a premium field reserved for paid subscriptions. Free plan responses include the word queried and the array of synonyms, while any paid plan adds the total count metric.

What would 20,000 word lookups a month cost me?

That volume requires 40,000 credits, using 20% of the credits on the Starter plan, which covers up to 100,000 lookups each month. On Starter, lookups work out to about $0.30 per 1,000 calls (or $0.0003 per call). For small projects and evaluation, the Free plan gives you 100 lookups each month at no cost.

Can I use the returned synonyms in a commercial writing tool?

Yes, commercial use is permitted on any paid plan, starting with Starter. You can display synonyms inside your own writing assistants, text editors, or SEO platforms, but you may not resell or redistribute the raw thesaurus data.

Request parameters — GET /v1/thesaurus

Sent in the query string. 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

Parameter	Type	Example	Description
`word`Required	string	`big`	The word for which you want to get synonyms

Example request

1
2

curl "https://api.apiverve.com/v1/thesaurus?word=big" \
  -H "x-api-key: YOUR_API_KEY"

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.

Header	When	Value
`x-api-key`Required	Every request	Your API key. Header names are case-insensitive, so `X-API-Key` is the same header.
`Authorization`Alternate	Instead of the above	`Bearer <key>` — for clients that only expose bearer auth. Resolves to the same account and the same billing.

401 is the only auth verdict

A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.

Response — GET /v1/thesaurus

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.

Sample response

{
  "status": "ok",
  "error": null,
  "data": {
    "word": "big",
    "similarCount": 50,
    "similarWords": [
      "large",
      "ample",
      "sizable",
      "sizeable",
      "astronomic",
      "astronomical",
      "galactic",
      "bigger",
      "larger",
      "biggest",
      "greatest",
      "largest",
      "biggish",
      "largish",
      "blown-up",
      "enlarged",
      "bouffant",
      "puffy",
      "bulky",
      "capacious",
      "colossal",
      "prodigious",
      "stupendous",
      "cosmic",
      "deep",
      "double",
      "elephantine",
      "gargantuan",
      "giant",
      "jumbo",
      "enormous",
      "tremendous",
      "epic",
      "heroic",
      "larger-than-life",
      "extensive",
      "extended",
      "gigantic",
      "mammoth",
      "great",
      "hulking",
      "hulky",
      "huge",
      "immense",
      "vast",
      "Brobdingnagian",
      "humongous",
      "banging",
      "thumping",
      "whopping"
    ]
  }
}

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.

Field	Type	Example	Description
`word`	string	`"big"`	The word queried for synonyms
`similarCount`Premium	number	`50`	Total count of similar words found in thesaurus
`similarWords`	array	`[large, ...]`	Array of synonym strings for the queried word

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.

Header	What it carries
`x-api-remaining-credits`	Credits left in the current cycle
`x-api-credits-used`	Credits spent in the current cycle
`x-api-max-credits`	The allowance for the cycle
`x-api-version`	Version of the endpoint that answered

Errors

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

Status	Meaning	What to do
`400`	Input was rejected	Read `error`; it names the parameter that has to change.
`401`	Key missing or invalid	Check the header name and the key value.
`403`	Key valid, but not permitted here	A key restriction or an IP allow-list — never a bad key.
`429`	Rate limited, or out of credits	Read `error` to tell them apart, then back off or top up.

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.

Plan	Per month	Credits	Thesaurus calls	Per 1,000 calls
Free	Free	200	100	Free
Starter	$29.99	200,000	100,000	$0.30
Pro	$99.99	1,000,000	500,000	$0.20
Mega	$299.99	4,000,000	2,000,000	$0.15

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.

Compare all pricing tiers →

Call it from cURL — GET /v1/thesaurus

No SDK to install — this is a plain HTTPS call to /v1/thesaurus with your key in the x-api-key header. Swap in a real key and it runs as-is.

cURL

1
2

curl "https://api.apiverve.com/v1/thesaurus" \
  -H "x-api-key: YOUR_API_KEY"

Resources

GitHubapiverve/thesaurus-apiSource, issues and the examples this page is built from.ReferenceThesaurus API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/thesaurusnpm apiverve-thesaurusPyPI APIVerve.API.ThesaurusNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Node.js — GET /v1/thesaurus

Install the Node.js SDK, then call the Thesaurus API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — npm

npm install @apiverve/thesaurus

Node.js

const res = await fetch("https://api.apiverve.com/v1/thesaurus", {
  headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);

Resources

npm@apiverve/thesaurusThe published Node.js client, versioned and signed.GitHubapiverve/thesaurus-apiSource, issues and the examples this page is built from.ReferenceThesaurus API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

apiverve-thesaurusPyPI APIVerve.API.ThesaurusNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Python — GET /v1/thesaurus

Install the Python SDK, then call the Thesaurus API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — PyPI

pip install apiverve-thesaurus

Python

import requests

res = requests.get(
    "https://api.apiverve.com/v1/thesaurus",
    headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])

Resources

PyPIapiverve-thesaurusThe published Python client, versioned and signed.GitHubapiverve/thesaurus-apiSource, issues and the examples this page is built from.ReferenceThesaurus API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/thesaurusnpm APIVerve.API.ThesaurusNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from C# / .NET — GET /v1/thesaurus

Install the C# / .NET SDK, then call the Thesaurus API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — NuGet

dotnet add package APIVerve.API.Thesaurus

C# / .NET

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");

var json = await client.GetStringAsync("https://api.apiverve.com/v1/thesaurus");
Console.WriteLine(json);

Resources

NuGetAPIVerve.API.ThesaurusThe published C# / .NET client, versioned and signed.GitHubapiverve/thesaurus-apiSource, issues and the examples this page is built from.ReferenceThesaurus API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/thesaurusnpm apiverve-thesaurusPyPI

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Go — GET /v1/thesaurus

No SDK to install — this is a plain HTTPS call to /v1/thesaurus with your key in the x-api-key header. Swap in a real key and it runs as-is.

req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/thesaurus", nil)
req.Header.Set("x-api-key", "YOUR_API_KEY")

res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))

Resources

Also published for

@apiverve/thesaurusnpm apiverve-thesaurusPyPI APIVerve.API.ThesaurusNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from PHP — GET /v1/thesaurus

No SDK to install — this is a plain HTTPS call to /v1/thesaurus with your key in the x-api-key header. Swap in a real key and it runs as-is.

PHP

$ch = curl_init("https://api.apiverve.com/v1/thesaurus");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-api-key: YOUR_API_KEY"]);

$response = curl_exec($ch);
echo $response;

Resources

Also published for

@apiverve/thesaurusnpm apiverve-thesaurusPyPI APIVerve.API.ThesaurusNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Ruby — GET /v1/thesaurus

No SDK to install — this is a plain HTTPS call to /v1/thesaurus with your key in the x-api-key header. Swap in a real key and it runs as-is.

Ruby

require "net/http"

uri = URI("https://api.apiverve.com/v1/thesaurus")
req = Net::HTTP::Get.new(uri)
req["x-api-key"] = "YOUR_API_KEY"

res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |h| h.request(req) }
puts res.body

Resources

Also published for

@apiverve/thesaurusnpm apiverve-thesaurusPyPI APIVerve.API.ThesaurusNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

All articles →

The Timezone Bug That Cost Us a ClientA scheduled email went out at 3 AM instead of 9 AM. The client wasn't happy. Here's what went wrong.Read

Build a Lead Enrichment Pipeline That Actually WorksTurn email addresses into full customer profiles. Location, company, social links—automatically. Here's how to build it.Read

Weather APIs: Build a Dashboard That's Actually UsefulCurrent conditions, forecasts, air quality, sunrise times—here's how to build a weather dashboard users will love.Read

Thesaurus API

Try it — live request, no key required

About the Thesaurus API

What people use it for

Ways to call it

Other ways to use Thesaurus

Questions.

Request parameters — GET /v1/thesaurus

Required

Authentication

Response — GET /v1/thesaurus

Response fields

Response headers

Errors

What a call costs — 2 credits per call

Call it from cURL — GET /v1/thesaurus

Resources

Also published for

Call it from Node.js — GET /v1/thesaurus

Resources

Also published for

Call it from Python — GET /v1/thesaurus

Resources

Also published for

Call it from C# / .NET — GET /v1/thesaurus

Resources

Also published for

Call it from Go — GET /v1/thesaurus

Resources

Also published for

Call it from PHP — GET /v1/thesaurus

Resources

Also published for

Call it from Ruby — GET /v1/thesaurus

Resources

Also published for

Zero-code embed — one snippet, no backend

Changelog — Thesaurus API

Data Lookup

Related articles

Ready to build with Thesaurus? Start with 200 free credits — one key unlocks all 300+ APIs.

Explore the catalog