# Subdomain Finder - Certificate Transparency Search (`pushbuild/subdomain-finder`) Actor

Find subdomains of any domain from public Certificate Transparency logs: every hostname seen on an SSL certificate, first-seen date, certificate count and issuer, plus which names still resolve in DNS and their IPs. Passive: nothing touches the target.

- **URL**: https://apify.com/pushbuild/subdomain-finder.md
- **Developed by:** [Pushbuild Data](https://apify.com/pushbuild) (community)
- **Categories:** Developer tools, Lead generation, Automation
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

$0.30 / 1,000 subdomains

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For examples already wired to this Actor's own input schema, see the [API](#api) section below.

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).

# README

## Subdomain Finder - Certificate Transparency Search

Find the subdomains of any domain from public Certificate Transparency logs. Every publicly trusted SSL certificate is logged, so the hostnames on them map out a company's sites, apps, staging servers and services. Passive: nothing is sent to the target domain.

### Inputs

One or more root domains. Optionally check DNS, keep only names that resolve, or keep wildcard entries.

### Returns

Subdomain, certificate count, first-seen date, latest certificate expiry, issuing certificate authorities, whether the name resolves in DNS today and its IP addresses.

### Uses

Attack-surface mapping and security reviews of your own domains, bug-bounty reconnaissance within programme scope, finding a company's products and tools for sales research, brand and phishing monitoring, and domain due diligence. Pay per subdomain.

# Actor input Schema

## `domains` (type: `array`):

Root domains to search, one per line (up to 20).

## `resolve` (type: `boolean`):

Check which subdomains resolve today and return their IPs.

## `onlyResolving` (type: `boolean`):

Drop subdomains with no DNS record today.

## `includeWildcards` (type: `boolean`):

Return \*.name entries as their own rows.

## `maxItems` (type: `integer`):

Maximum subdomains to return.

## Actor input object example

```json
{
  "domains": [
    "example.com"
  ],
  "resolve": true,
  "onlyResolving": false,
  "includeWildcards": false,
  "maxItems": 1000
}
```

# Actor output Schema

## `results` (type: `string`):

No description

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "domains": [
        "example.com"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("pushbuild/subdomain-finder").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = { "domains": ["example.com"] }

# Run the Actor and wait for it to finish
run = client.actor("pushbuild/subdomain-finder").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "domains": [
    "example.com"
  ]
}' |
apify call pushbuild/subdomain-finder --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,pushbuild/subdomain-finder"
        }
    }
}
```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/5aKUCZtOvMsckgxJy/builds/r7aNJA9f6QoLDKkyL/openapi.json