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AssetDiscovery
Get API key

Subdomain API

Every known subdomain of a domain, from one API call.

Query a dataset of 6.5B+ subdomains with a single key. Get JSON with timestamps, a compact list or plain text back.

curl https://api.assetdiscovery.io/api/domain/example.com \
  -H 'Api-Key: YOUR_API_KEY'

200 OK · application/json

{
  "domain": "example.com",
  "total": 4521,
  "subdomains": [
    "api.example.com",
    "auth.example.com",
    "cdn.example.com",
    "dev.api.example.com",
    "mail.example.com",
    …
  ]
}

Getting started

From sign-up to first response

  1. Step 1

    Create a free account

    Sign up with email, GitHub or Google. Verify your email to activate the key.

  2. Step 2

    Copy your API key

    Your key is shown once at creation. Store it in your secret manager or shell profile.

  3. Step 3

    Query any domain

    Send GET /api/domain/{domain} with the Api-Key header and read the subdomains back.

Formats

Choose the response shape that fits your pipeline

JSONdefault
A flat array of hostnames with the total. Drop-in for existing recon scripts.
Plain text?format=txt
One host per line. Pipe it straight into httpx, dnsx or nuclei.
Full records?format=full
Each host with first_seen and last_seen timestamps, plus total and pagination cursor.

6.5B+subdomains indexed

Millisecondstypical query time, reported in every response

Built for bug bounty recon, attack surface monitoring and asset inventories.

Pricing

Start free, upgrade when you need every result

Monthly plans. Cancel any time.

Compare plans in detail

FAQ

Questions