# Subdomain Finder — CT Log Enumeration + Live DNS Check (`eliai/subdomain-finder`) Actor Input: a domain. Output: JSON records of subdomains found in public Certificate Transparency logs (crt.sh), each with a live DNS resolution check. Passive recon — no active scanning of the target. Cheap pay-per-result pricing: $0.03 per domain checked. - **URL**: https://apify.com/eliai/subdomain-finder.md - **Developed by:** [Anthony Snider](https://apify.com/eliai) (community) - **Categories:** Developer tools, Automation - **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks - **User rating**: No ratings yet ## Pricing $30.00 / 1,000 domain checkeds 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/platform/actors/running/actors-in-store#pay-per-event ## What's an Apify Actor? Actors are a software tools running on the Apify platform, for all kinds of web data extraction and automation use cases. 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. Actors are written with capital "A". ## 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. The best way to integrate Actors is as follows. In JavaScript/TypeScript projects, use official [JavaScript/TypeScript client](https://docs.apify.com/api/client/js.md): ```bash npm install apify-client ``` In Python projects, use official [Python client library](https://docs.apify.com/api/client/python.md): ```bash pip install apify-client ``` In shell scripts, use [Apify CLI](https://docs.apify.com/cli/docs.md): ````bash # MacOS / Linux curl -fsSL https://apify.com/install-cli.sh | bash # Windows irm https://apify.com/install-cli.ps1 | iex ```bash In AI frameworks, you might use the [Apify MCP server](https://docs.apify.com/platform/integrations/mcp.md). If your project is in a different language, use the [REST API](https://docs.apify.com/api/v2.md). For usage examples, see the [API](#api) section below. For more details, see Apify documentation as [Markdown index](https://docs.apify.com/llms.txt) and [Markdown full-text](https://docs.apify.com/llms-full.txt). # README ## Subdomain Finder (CT Logs) Discover every subdomain of any domain in seconds — straight from public Certificate Transparency logs. Passive recon, no port scanning, no noise, plus an optional live DNS check that tells you which subdomains actually resolve. **Live on the Apify Store — run it instantly, or call it as an agent tool via Apify MCP.** ### What you get - **Full subdomain inventory** from `crt.sh` Certificate Transparency logs (wildcards stripped, deduped, scoped to your domain). - **Live/dead status** per subdomain via real DNS resolution (A/AAAA, with CNAME fallback). - **Resolved IPs** for each live host — instant asset map for security recon, attack-surface review, or migration audits. - **Single or bulk** — one domain or a whole list in one run. - Fully passive: it never touches the target's servers, only public logs and DNS. ### Input ```json { "domain": "github.com", "resolve": true, "maxDomains": 25 } ```` | Field | Type | Default | Description | |-------|------|---------|-------------| | `domain` | string | — | A single domain (scheme/path/wildcards auto-stripped). | | `domains` | array | — | Multiple domains in one run. | | `resolve` | boolean | `true` | Resolve each subdomain via DNS to mark it live + collect IPs. | | `maxDomains` | integer | `25` | Cap on domains processed per run (max 100). | ### Output One dataset item per domain: ```json { "domain": "github.com", "subdomainCount": 3, "subdomains": [ { "name": "api.github.com", "resolves": true, "ips": ["140.82.112.6"] }, { "name": "gist.github.com", "resolves": true, "ips": ["140.82.113.4"] }, { "name": "old.github.com", "resolves": false, "ips": [] } ], "checkedAt": "2026-06-24T00:00:00.000Z" } ``` When `resolve` is `false`, each subdomain is returned with `resolves: null` and an empty `ips` array for a fast passive-only listing. # Actor input Schema ## `domain` (type: `string`): A single domain to find subdomains for (e.g. github.com). Scheme/path/wildcards are stripped automatically. ## `domains` (type: `array`): Multiple domains to scan in one run. ## `resolve` (type: `boolean`): Resolve each discovered subdomain to mark it live and collect IPs. Turn off for a faster passive-only listing. ## `maxDomains` (type: `integer`): Cap on how many domains to process per run. ## Actor input object example ```json { "domain": "github.com", "domains": [ "apify.com" ], "resolve": true, "maxDomains": 25 } ``` # 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 '' with your token const client = new ApifyClient({ token: '', }); // Prepare Actor input const input = { "domain": "github.com", "domains": [ "apify.com" ] }; // Run the Actor and wait for it to finish const run = await client.actor("eliai/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 '' with your token. client = ApifyClient("") # Prepare the Actor input run_input = { "domain": "github.com", "domains": ["apify.com"], } # Run the Actor and wait for it to finish run = client.actor("eliai/subdomain-finder").call(run_input=run_input) # Fetch and print Actor results from the run's dataset (if there are any) print("💾 Check your data here: https://console.apify.com/storage/datasets/" + run["defaultDatasetId"]) for item in client.dataset(run["defaultDatasetId"]).iterate_items(): print(item) # 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start ``` ## CLI example ```bash echo '{ "domain": "github.com", "domains": [ "apify.com" ] }' | apify call eliai/subdomain-finder --silent --output-dataset ``` ## MCP server setup ```json { "mcpServers": { "apify": { "command": "npx", "args": [ "mcp-remote", "https://mcp.apify.com/?tools=eliai/subdomain-finder", "--header", "Authorization: Bearer " ] } } } ``` ## OpenAPI specification ```json { "openapi": "3.0.1", "info": { "title": "Subdomain Finder — CT Log Enumeration + Live DNS Check", "description": "Input: a domain. Output: JSON records of subdomains found in public Certificate Transparency logs (crt.sh), each with a live DNS resolution check. Passive recon — no active scanning of the target. Cheap pay-per-result pricing: $0.03 per domain checked.", "version": "0.1", "x-build-id": "djGULVoPSuLUj4F4w" }, "servers": [ { "url": "https://api.apify.com/v2" } ], "paths": { "/acts/eliai~subdomain-finder/run-sync-get-dataset-items": { "post": { "operationId": "run-sync-get-dataset-items-eliai-subdomain-finder", "x-openai-isConsequential": false, "summary": "Executes an Actor, waits for its completion, and returns Actor's dataset items in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/inputSchema" } } } }, "parameters": [ { "name": "token", "in": "query", "required": true, "schema": { "type": "string" }, "description": "Enter your Apify token here" } ], "responses": { "200": { "description": "OK" } } } }, "/acts/eliai~subdomain-finder/runs": { "post": { "operationId": "runs-sync-eliai-subdomain-finder", "x-openai-isConsequential": false, "summary": "Executes an Actor and returns information about the initiated run in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/inputSchema" } } } }, "parameters": [ { "name": "token", "in": "query", "required": true, "schema": { "type": "string" }, "description": "Enter your Apify token here" } ], "responses": { "200": { "description": "OK", "content": { "application/json": { "schema": { "$ref": "#/components/schemas/runsResponseSchema" } } } } } } }, "/acts/eliai~subdomain-finder/run-sync": { "post": { "operationId": "run-sync-eliai-subdomain-finder", "x-openai-isConsequential": false, "summary": "Executes an Actor, waits for completion, and returns the OUTPUT from Key-value store in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$ref": "#/components/schemas/inputSchema" } } } }, "parameters": [ { "name": "token", "in": "query", "required": true, "schema": { "type": "string" }, "description": "Enter your Apify token here" } ], "responses": { "200": { "description": "OK" } } } } }, "components": { "schemas": { "inputSchema": { "type": "object", "properties": { "domain": { "title": "Domain", "type": "string", "description": "A single domain to find subdomains for (e.g. github.com). Scheme/path/wildcards are stripped automatically." }, "domains": { "title": "Domains (bulk)", "type": "array", "description": "Multiple domains to scan in one run.", "items": { "type": "string" } }, "resolve": { "title": "Resolve subdomains via DNS", "type": "boolean", "description": "Resolve each discovered subdomain to mark it live and collect IPs. Turn off for a faster passive-only listing.", "default": true }, "maxDomains": { "title": "Max domains", "minimum": 1, "maximum": 100, "type": "integer", "description": "Cap on how many domains to process per run.", "default": 25 } } }, "runsResponseSchema": { "type": "object", "properties": { "data": { "type": "object", "properties": { "id": { "type": "string" }, "actId": { "type": "string" }, "userId": { "type": "string" }, "startedAt": { "type": "string", "format": "date-time", "example": "2025-01-08T00:00:00.000Z" }, "finishedAt": { "type": "string", "format": "date-time", "example": "2025-01-08T00:00:00.000Z" }, "status": { "type": "string", "example": "READY" }, "meta": { "type": "object", "properties": { "origin": { "type": "string", "example": "API" }, "userAgent": { "type": "string" } } }, "stats": { "type": "object", "properties": { "inputBodyLen": { "type": "integer", "example": 2000 }, "rebootCount": { "type": "integer", "example": 0 }, "restartCount": { "type": "integer", "example": 0 }, "resurrectCount": { "type": "integer", "example": 0 }, "computeUnits": { "type": "integer", "example": 0 } } }, "options": { "type": "object", "properties": { "build": { "type": "string", "example": "latest" }, "timeoutSecs": { "type": "integer", "example": 300 }, "memoryMbytes": { "type": "integer", "example": 1024 }, "diskMbytes": { "type": "integer", "example": 2048 } } }, "buildId": { "type": "string" }, "defaultKeyValueStoreId": { "type": "string" }, "defaultDatasetId": { "type": "string" }, "defaultRequestQueueId": { "type": "string" }, "buildNumber": { "type": "string", "example": "1.0.0" }, "containerUrl": { "type": "string" }, "usage": { "type": "object", "properties": { "ACTOR_COMPUTE_UNITS": { "type": "integer", "example": 0 }, "DATASET_READS": { "type": "integer", "example": 0 }, "DATASET_WRITES": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_READS": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_WRITES": { "type": "integer", "example": 1 }, "KEY_VALUE_STORE_LISTS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_READS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_WRITES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_INTERNAL_GBYTES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_EXTERNAL_GBYTES": { "type": "integer", "example": 0 }, "PROXY_RESIDENTIAL_TRANSFER_GBYTES": { "type": "integer", "example": 0 }, "PROXY_SERPS": { "type": "integer", "example": 0 } } }, "usageTotalUsd": { "type": "number", "example": 0.00005 }, "usageUsd": { "type": "object", "properties": { "ACTOR_COMPUTE_UNITS": { "type": "integer", "example": 0 }, "DATASET_READS": { "type": "integer", "example": 0 }, "DATASET_WRITES": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_READS": { "type": "integer", "example": 0 }, "KEY_VALUE_STORE_WRITES": { "type": "number", "example": 0.00005 }, "KEY_VALUE_STORE_LISTS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_READS": { "type": "integer", "example": 0 }, "REQUEST_QUEUE_WRITES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_INTERNAL_GBYTES": { "type": "integer", "example": 0 }, "DATA_TRANSFER_EXTERNAL_GBYTES": { "type": "integer", "example": 0 }, "PROXY_RESIDENTIAL_TRANSFER_GBYTES": { "type": "integer", "example": 0 }, "PROXY_SERPS": { "type": "integer", "example": 0 } } } } } } } } } } ```