# Certificate Transparency Lookup (crt.sh): Certs by Domain (`lepidata/crt-sh`) Actor

Look up issued TLS certificates for a domain in public Certificate Transparency logs via crt.sh: names, issuer, validity dates and serial. One polite request at a time.

- **URL**: https://apify.com/lepidata/crt-sh.md
- **Developed by:** [Lepi Data](https://apify.com/lepidata) (community)
- **Categories:** Developer tools, Other
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $0.10 / 1,000 certificates

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.
Since this Actor supports Apify Store discounts, the price gets lower the higher subscription plan you have.

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

## Certificate Transparency Lookup (crt.sh): Certs by Domain

**What it does.** A certificate transparency lookup: for each domain, lists the publicly logged TLS certificates found on crt.sh, with the names on each certificate, the issuing CA, validity dates and serial number. Useful for certificate inventory, renewal tracking and checking which CA issued certificates for your domains.

**Input** (from `.actor/input_schema.json`)

- `domains`: up to 10 per run
- `includeSubdomains` (default off), `excludeExpired` (default on)
- `maxItems`: up to 5,000 rows

**Output fields**
`domain`, `certId`, `commonName`, `names`, `issuerName`, `issuerCaId`, `notBefore`, `notAfter`, `serialNumber`, `expired`, `crtShUrl`
Free status rows (not charged): `no-results`, `invalid-input`, `api-error`, `free-plan-limit`, `charge-limit-reached`.

**Example** (the build's prefill)
Input: `{"domains":["example.com"],"excludeExpired":true,"maxItems":100}`

**Data source and compliance**

- Source: crt.sh, a free public Certificate Transparency search service operated by Sectigo, over public CT logs. This is an independent Lepi Data tool, **not affiliated with or endorsed by Sectigo or crt.sh**.
- Polite by design: **one request at a time**, at least 3 seconds apart, each answer cached for the run, at most 10 domains and 5,000 rows per run. If crt.sh is busy you get a free `api-error` row; try again later.
- Certificates that carry e-mail addresses (personal S/MIME certificates) are left out.
- Free-plan accounts get up to 100 results per run.

**Pricing.** Pay per result, flat on every plan, no start fee. Free status rows are never charged.

# Actor input Schema

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

Domain names to look up in Certificate Transparency logs, up to 10 per run. Use domains you own or manage.

## `includeSubdomains` (type: `boolean`):

Also match certificates issued for names under the domain (crt.sh %.domain search). Large domains can return a lot; keep it off unless needed.

## `excludeExpired` (type: `boolean`):

Only return certificates that have not expired yet. Keeps answers small and fast.

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

Stop after this many certificate rows in total (up to 5,000).

## Actor input object example

```json
{
  "domains": [
    "example.com"
  ],
  "includeSubdomains": false,
  "excludeExpired": true,
  "maxItems": 100
}
```

# Actor output Schema

## `items` (type: `string`):

All rows from this run.

# 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"
    ],
    "maxItems": 100
};

// Run the Actor and wait for it to finish
const run = await client.actor("lepidata/crt-sh").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"],
    "maxItems": 100,
}

# Run the Actor and wait for it to finish
run = client.actor("lepidata/crt-sh").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"
  ],
  "maxItems": 100
}' |
apify call lepidata/crt-sh --silent --output-dataset

```

## MCP server setup

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

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/cIOQsathdeupdZ48H/builds/SwteWZtheHEvOTiJT/openapi.json