API Documentation

Use the Similar Companies API to programmatically find competitors and lookalike companies for any domain, powered by AI.

Enterprise plan required. API access is available on the Enterprise plan ($100/month). Generate an API key from Account Settings → API Keys.

Authentication

All API requests require a Bearer token in the Authorization header.

Authorization: Bearer sk_live_your_api_key_here

Generate API keys from your account settings. Keys are prefixed with sk_live_ and shown only once at creation.

Errors

The API returns standard HTTP status codes. Error responses include an error field.

Status	Meaning
200	Success
400	Bad request — missing or invalid parameters
401	Unauthorized — invalid or missing API key
402	Insufficient credits
429	Rate limit exceeded
500	Server error

Search Competitors

POST /api/competitors

Find similar companies and competitors for a domain using one or more AI models.

Request Body

Parameter	Type	Description
domain required	string	Domain to search (e.g. `stripe.com`)

Example Request

curl -X POST https://similariq.com/api/competitors \
  -H "Authorization: Bearer sk-live-..." \
  -H "Content-Type: application/json" \
  -d '{"domain": "stripe.com"}'

Response

{
  "domain": "stripe.com",
  "total": 100,
  "elapsedSeconds": 4.2,
  "competitors": [
    {
      "rank": 1,
      "domain": "braintreepayments.com",
      "company": "Braintree",
      "competitorScore": 97,
      "competitorType": "Direct",
      "confidenceScore": 98,
      "confidence": "high",
      "likelyCompetitor": true
    }
  ],
  "access": {
    "plan": "growth",
    "canDownload": true
  }
}

Search History

GET /api/history

Returns your recent searches.

Parameter	Type	Description
limit optional	number	Max results (default 20, max 100)
offset optional	number	Pagination offset

Credits

GET /api/credits/balance

Returns your current credit balance.

GET /api/credits/transactions

Returns your credit transaction history.

Response Fields

Field	Type	Description
domain	string	The domain that was searched
total	number	Total competitors returned (always 100)
elapsedSeconds	number	Time taken to complete the search
competitors[].rank	number	Rank by competitive threat (1 = highest)
competitors[].domain	string	Competitor domain
competitors[].company	string	Competitor company name
competitors[].competitorScore	number	Overall score 0–100
competitors[].competitorType	string	Direct · Indirect · Emerging · Adjacent
competitors[].confidenceScore	number	AI confidence 0–100
competitors[].confidence	string	high · medium · low
competitors[].likelyCompetitor	boolean	Whether flagged as a strong match

Rate Limits

The API is rate limited per API key:

Limit	Window
60 requests	Per minute
1,000 requests	Per day

Rate limit headers are returned with each response: X-RateLimit-Remaining, X-RateLimit-Reset.