# Lemlist Usage Detector · Spot Companies Using Lemlist (`corent1robert/lemlist-tracking-domain-detector`) Actor Find out if a company uses Lemlist for their outreach. Detects Lemlist tracking domains via DNS — one clear yes/no per domain. - **URL**: https://apify.com/corent1robert/lemlist-tracking-domain-detector.md - **Developed by:** [Corentin Robert](https://apify.com/corent1robert) (community) - **Categories:** Developer tools, Automation, Lead generation - **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, NaN bookmarks - **User rating**: No ratings yet ## Pricing from $11.10 / 1,000 results This Actor is paid per event and usage. You are charged both the fixed price for specific events and for Apify platform usage. 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 ## Lemlist Usage Detector · Spot companies using Lemlist **Bulk-check which companies appear to run Lemlist for outreach.** Each domain you paste comes back as **one clear row: YES or NO** — a **strong buying / intent-style signal** for **sales, growth, and competitive research**. Export **CSV** or **JSON** and plug into Sheets, your CRM, or sequencing tools. The deliverable SDRs and growth teams care about is **`answer`** and **`answerDetail`** — not a DNS report. This is **not** an official Lemlist product. It does **not** mean “this specific rep uses Lemlist” — only that the **company’s domain** shows **public** infrastructure consistent with **Lemlist-style link tracking** ([custom tracking domain](https://help.lemlist.com/)). Only use domains you’re **allowed** to check. --- ### Table of contents - [Why use this?](#why-use-this) - [How it works (short)](#how-it-works-short) - [Quick start on Apify](#quick-start-on-apify) - [What you get in the dataset](#what-you-get-in-the-dataset) - [Proxy and blocked HTTPS](#proxy-and-blocked-https) - [Input](#input) - [Output (dataset & stores)](#output-dataset--stores) - [Example inputs](#example-inputs) - [Logs during a run](#logs-during-a-run) - [Limits](#limits) - [Support & contact](#support--contact) - [Developers: local run, tests, deploy](#developers-local-run-tests-deploy) --- ### Why use this? | Without this | With this Actor | |----------------|-----------------| | No scalable way to **prioritize accounts** that likely use Lemlist-style outbound | **Automated YES/NO** per company domain — **intent-style signal** for prospecting | | Manual guesswork on tracking subdomains | One **explainable line** per prospect (`answerDetail`) | | One-off checks | **Hundreds of domains in one run** (see [Limits](#limits)) | **Who it’s for** - **SDRs / AEs** — enrich account lists, prioritize outreach, tailor messaging. - **Growth / RevOps** — map the competitive landscape (“who runs this stack on their domain?”). - **Agencies** — quick due diligence on prospect or client domains you’re entitled to review. **Reality check:** **`YES`** = we saw a **strong public signal** on that domain (see below). It’s **not** a contract with Lemlist — use it as **one signal among many**. --- ### How it works (short) 1. You paste **website URLs or domains** (one per line); we normalize to the **company domain** (e.g. `www.shop.com` → `shop.com`). 2. We look for **Lemlist-style tracking setup** using **public DNS** and (by default) **HTTPS**, plus optional discovery from **public SSL certificate logs**. 3. **Strong match** → **`answer: YES`**; otherwise **`NO`** with a short reason. Technical options (extra proof rows, overview row, proxy, limits) → [`AGENTS.md`](AGENTS.md). --- ### Quick start on Apify 1. Open the Actor in the **Apify Console**. 2. Paste **domains** — **one per line** (`https://…` or `company.com`). 3. Click **Start**. 4. Open **Dataset** → tab **Results** for **`answer`** / **`answerDetail`**, or **All fields** for full JSON. If **HTTPS** fails from the cloud, set **`LEMLIST_RESIDENTIAL_PROXY=1`** under **Actor → Settings → Environment variables** (see [Proxy and blocked HTTPS](#proxy-and-blocked-https)). --- ### What you get in the dataset **Default:** **one row per company** (`apex_summary`). | Field | For sales / ops | |--------|------------------| | **`answer`** | **`YES`** or **`NO`** — treat as your **Lemlist-usage signal** for that domain. | | **`answerDetail`** | One line you can **read or forward** (what matched, or how many checks ran). | | **`apexDomain`** | Normalized company domain. | | **`usesLemlist`** | Same as YES/NO for filters in Sheets or code. | | **`evidenceHostname`** | When **YES**, where the signal showed up (if useful for your pitch). | | **`inputSource`** | What you pasted. | | **`checkedAt`** | Timestamp. | **Optional:** **`LEMLIST_RUN_OVERVIEW=1`** — one extra row with totals + list of all domains. **`LEMLIST_INCLUDE_HOSTNAME_PROBES=1`** — technical rows per subdomain (for audits). **`hostname_probe`** details: [`AGENTS.md`](AGENTS.md). --- ### Proxy and blocked HTTPS No proxy field in **Input**. By default, HTTPS runs **direct** from Apify. If sites **block** datacenter IPs, set **`LEMLIST_RESIDENTIAL_PROXY=1`** in **Environment variables** and ensure **residential** proxy is allowed on your plan. **Locally:** **`apify login`**. --- ### Input | Field | Required | Description | |--------|----------|-------------| | **domains** | Yes | Company **website URL or domain** — one per line. | **Common environment variables** (Actor → **Settings** → **Environment variables**): | Variable | When to use | |----------|-------------| | **`LEMLIST_RESIDENTIAL_PROXY=1`** | HTTPS timeouts or blocks. | | **`LEMLIST_SKIP_CT=1`** | Faster runs (fewer subdomains checked). | | **`LEMLIST_DNS_ONLY=1`** | DNS-only (faster; fewer signals). | | **`LEMLIST_INCLUDE_HOSTNAME_PROBES=1`** | Add technical proof rows. | | **`LEMLIST_RUN_OVERVIEW=1`** | Add one aggregate summary row. | **Power user / tuning:** [`AGENTS.md`](AGENTS.md). --- ### Output (dataset & stores) - **Default:** **`apex_summary`** only — **YES/NO** per domain. - **Key-value store:** **`RUN_LOG`** (progress text). - **Console:** **Results** + **All fields**; **Output** tab → dataset API + **`RUN_LOG`**. --- ### Example inputs ```json { "domains": [ "https://www.acme.com", "https://partner.io/blog", "otherbrand.com" ] } ```` *** ### Logs during a run Short by default (summary + per-domain YES/NO line + final counts). **`LEMLIST_VERBOSE=1`** for detail. The **dataset** is the source of truth. *** ### Limits - **150** unique company domains per run; **2,500** planned checks max per run (usually less thanks to early exit). - Certificate-based discovery ≠ every DNS name in the world. - **Compliance:** only domains you may probe. *** ### Support & contact **Questions or issues?** [Corentin Robert](mailto:corentin@outreacher.fr). *** ### Developers: local run, tests, deploy ```bash npm install npm run apify:run npm run test:unit && npm run test:smoke npm test apify push ``` Use **`npm run apify:run`** (or **`apify run --input-file=input.json`**) so local **`INPUT.json`** isn’t empty after purge. Bump **`.actor/actor.json`** **`version`** (`MAJOR.MINOR`) when you publish. Maintainer notes: **[`AGENTS.md`](AGENTS.md)**. # Actor input Schema ## `domains` (type: `array`): Examples: `https://www.company.com` or `company.com`. ## Actor input object example ```json { "domains": [ "https://lemlist.com" ] } ``` # Actor output Schema ## `dataset` (type: `string`): All items — same as **All fields** in the Console. ## `resultsView` (type: `string`): Table with **answer**, **answerDetail**, etc. ## `apiRun` (type: `string`): Apify **GET** for run metadata. `Authorization: Bearer YOUR_API_TOKEN`. ## `runLog` (type: `string`): Progress during the 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 '' with your token const client = new ApifyClient({ token: '', }); // Prepare Actor input const input = { "domains": [ "https://lemlist.com" ] }; // Run the Actor and wait for it to finish const run = await client.actor("corent1robert/lemlist-tracking-domain-detector").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 = { "domains": ["https://lemlist.com"] } # Run the Actor and wait for it to finish run = client.actor("corent1robert/lemlist-tracking-domain-detector").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 '{ "domains": [ "https://lemlist.com" ] }' | apify call corent1robert/lemlist-tracking-domain-detector --silent --output-dataset ``` ## MCP server setup ```json { "mcpServers": { "apify": { "command": "npx", "args": [ "mcp-remote", "https://mcp.apify.com/?tools=corent1robert/lemlist-tracking-domain-detector", "--header", "Authorization: Bearer " ] } } } ``` ## OpenAPI specification ```json { "openapi": "3.0.1", "info": { "title": "Lemlist Usage Detector · Spot Companies Using Lemlist", "description": "Find out if a company uses Lemlist for their outreach. \nDetects Lemlist tracking domains via DNS — one clear yes/no per domain.", "version": "2.3", "x-build-id": "qZAcK5WPZIDV65l4v" }, "servers": [ { "url": "https://api.apify.com/v2" } ], "paths": { "/acts/corent1robert~lemlist-tracking-domain-detector/run-sync-get-dataset-items": { "post": { "operationId": "run-sync-get-dataset-items-corent1robert-lemlist-tracking-domain-detector", "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": { "$ref": "#/components/schemas/inputSchema" } } } }, "parameters": [ { "name": "token", "in": "query", "required": true, "schema": { "type": "string" }, "description": "Enter your Apify token here" } ], "responses": { "200": { "description": "OK" } } } }, "/acts/corent1robert~lemlist-tracking-domain-detector/runs": { "post": { "operationId": "runs-sync-corent1robert-lemlist-tracking-domain-detector", "x-openai-isConsequential": false, "summary": "Executes an Actor and returns information about the initiated run in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$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": { "$ref": "#/components/schemas/runsResponseSchema" } } } } } } }, "/acts/corent1robert~lemlist-tracking-domain-detector/run-sync": { "post": { "operationId": "run-sync-corent1robert-lemlist-tracking-domain-detector", "x-openai-isConsequential": false, "summary": "Executes an Actor, waits for completion, and returns the OUTPUT from Key-value store in response.", "tags": [ "Run Actor" ], "requestBody": { "required": true, "content": { "application/json": { "schema": { "$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", "required": [ "domains" ], "properties": { "domains": { "title": "Company website or domain", "type": "array", "description": "Examples: `https://www.company.com` or `company.com`.", "items": { "type": "string" } } } }, "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 } } } } } } } } } } ```