# Newsletter Sponsor Finder — Substack (`davidbenittah/newsletter-sponsor-finder`) Actor

Scan Substack newsletters and extract who sponsors them: advertiser name, domain, sponsorship format, frequency and where each sponsor appeared — the data ad-space sellers and sponsor-hunting brands can't get anywhere.

- **URL**: https://apify.com/davidbenittah/newsletter-sponsor-finder.md
- **Developed by:** [David](https://apify.com/davidbenittah) (community)
- **Categories:** Marketing, Lead generation
- **Stats:** 2 total users, 1 monthly users, 100.0% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $15.00 / 1,000 results

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

## Newsletter Sponsor Finder — Substack

Scan any list of Substack newsletters and extract **who sponsors them**: advertiser name and domain, sponsorship format, how often they appear, in which newsletters, and when they were last seen.

Newsletter scrapers give you posts. Nobody gives you the **sponsors** — yet that is the data two groups pay for:

- **Newsletter operators selling ad space**: every brand already sponsoring a newsletter in your niche is a warm prospect for yours — they have budget and proven intent.
- **Brands & media buyers**: see where competitors spend, which advertisers are active in a niche, and which newsletters actually run sponsorships before you pitch or buy.

### What it does

1. Scrapes the recent posts (full content) of the newsletters you list — works with `*.substack.com` and custom domains.
2. Detects sponsorship sections via editorial markers: *brought to you by*, *sponsored by*, *today's sponsor*, *presented by*, *in partnership with*, *together with*...
3. Extracts the advertiser behind each sponsorship (link + brand anchor), ignoring CDN assets, social links, self-links and reference sites, and bounding the sponsor section so editorial links don't pollute the data.
4. Aggregates everything into **one item per sponsor** across all scanned newsletters, sorted by activity.

### Input example

```json
{
  "newsletterUrls": [
    "https://newsletter.pragmaticengineer.com",
    "https://www.lennysnewsletter.com"
  ],
  "maxPostsPerNewsletter": 20
}
````

The defaults work as-is: just list the newsletters of your niche.

### Output example

```json
{
  "type": "sponsor",
  "sponsorName": "WorkOS",
  "sponsorDomain": "workos.com",
  "sponsorUrl": "https://workos.com/",
  "totalMentions": 7,
  "newslettersSponsored": 2,
  "newsletters": [
    { "newsletterUrl": "https://newsletter.pragmaticengineer.com", "publicationName": "The Pragmatic Engineer", "subscriberCount": "1,100,000", "mentions": 5, "lastSeenAt": "2026-07-01T16:57:46.499Z" },
    { "newsletterUrl": "https://www.lennysnewsletter.com", "publicationName": "Lenny's Newsletter", "subscriberCount": "1,000,000", "mentions": 2, "lastSeenAt": "2026-06-20T12:00:00.000Z" }
  ],
  "markers": ["brought to you by"],
  "firstSeenAt": "2026-04-02T16:00:00.000Z",
  "lastSeenAt": "2026-07-01T16:57:46.499Z",
  "sampleContext": "Antithesis is autonomous testing... WorkOS — auth for B2B SaaS..."
}
```

A `SUMMARY` record in the run's key-value store gives the counts: newsletters scanned, posts scanned, posts with sponsors, sponsors found.

### How to use it

- **Selling ad space**: scan the 5-10 newsletters closest to yours, sort sponsors by `lastSeenAt` — active advertisers first — and you have your outreach list, with proof of where they already spend.
- **Competitive intel**: scan the newsletters of your category monthly (schedule + `postedAfter`) and diff which sponsors appear and disappear.
- **Frequency = budget signal**: a sponsor with `totalMentions` 6+ across recent posts is running a campaign, not a one-off test.

### Fair use & data

- Uses only **public newsletter posts** (no login, paywalled content is not accessed).
- Outputs **company-level advertiser data only** — no author or reader personal data.
- Inputs are hard-capped (10 newsletters, 100 posts each) so runs stay bounded and predictable.

### FAQ

**Does it work on beehiiv/Ghost newsletters?** v1 covers Substack (including custom domains). Other platforms are on the roadmap.

**Can detection be wrong?** Sponsorship is editorial text, so heuristics apply. Each sponsor item includes `sampleContext` and per-post provenance so you can verify in one click.

**How far back can it look?** Up to 100 posts per newsletter, optionally bounded with `postedAfter`.

# Actor input Schema

## `newsletterUrls` (type: `array`):

Newsletters to scan for sponsors — homepage or custom-domain URLs (e.g. https://www.lennysnewsletter.com). Hard maximum: 10 per run.

## `maxPostsPerNewsletter` (type: `integer`):

How many recent posts to analyze per newsletter. More posts = better frequency data, higher cost. Hard maximum: 100.

## `postedAfter` (type: `string`):

Optional YYYY-MM-DD date — ignore posts older than this (e.g. last quarter only).

## Actor input object example

```json
{
  "newsletterUrls": [
    "https://newsletter.pragmaticengineer.com",
    "https://www.lennysnewsletter.com"
  ],
  "maxPostsPerNewsletter": 20
}
```

# 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 = {
    "newsletterUrls": [
        "https://newsletter.pragmaticengineer.com",
        "https://www.lennysnewsletter.com"
    ]
};

// Run the Actor and wait for it to finish
const run = await client.actor("davidbenittah/newsletter-sponsor-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 = { "newsletterUrls": [
        "https://newsletter.pragmaticengineer.com",
        "https://www.lennysnewsletter.com",
    ] }

# Run the Actor and wait for it to finish
run = client.actor("davidbenittah/newsletter-sponsor-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 '{
  "newsletterUrls": [
    "https://newsletter.pragmaticengineer.com",
    "https://www.lennysnewsletter.com"
  ]
}' |
apify call davidbenittah/newsletter-sponsor-finder --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "command": "npx",
            "args": [
                "mcp-remote",
                "https://mcp.apify.com/?tools=davidbenittah/newsletter-sponsor-finder",
                "--header",
                "Authorization: Bearer <YOUR_API_TOKEN>"
            ]
        }
    }
}

```

## OpenAPI specification

```json
{
    "openapi": "3.0.1",
    "info": {
        "title": "Newsletter Sponsor Finder — Substack",
        "description": "Scan Substack newsletters and extract who sponsors them: advertiser name, domain, sponsorship format, frequency and where each sponsor appeared — the data ad-space sellers and sponsor-hunting brands can't get anywhere.",
        "version": "1.0",
        "x-build-id": "ThFQvJkSIdKJZqA3P"
    },
    "servers": [
        {
            "url": "https://api.apify.com/v2"
        }
    ],
    "paths": {
        "/acts/davidbenittah~newsletter-sponsor-finder/run-sync-get-dataset-items": {
            "post": {
                "operationId": "run-sync-get-dataset-items-davidbenittah-newsletter-sponsor-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": {
                                "$ref": "#/components/schemas/inputSchema"
                            }
                        }
                    }
                },
                "parameters": [
                    {
                        "name": "token",
                        "in": "query",
                        "required": true,
                        "schema": {
                            "type": "string"
                        },
                        "description": "Enter your Apify token here"
                    }
                ],
                "responses": {
                    "200": {
                        "description": "OK"
                    }
                }
            }
        },
        "/acts/davidbenittah~newsletter-sponsor-finder/runs": {
            "post": {
                "operationId": "runs-sync-davidbenittah-newsletter-sponsor-finder",
                "x-openai-isConsequential": false,
                "summary": "Executes an Actor and returns information about the initiated run in response.",
                "tags": [
                    "Run Actor"
                ],
                "requestBody": {
                    "required": true,
                    "content": {
                        "application/json": {
                            "schema": {
                                "$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": {
                                    "$ref": "#/components/schemas/runsResponseSchema"
                                }
                            }
                        }
                    }
                }
            }
        },
        "/acts/davidbenittah~newsletter-sponsor-finder/run-sync": {
            "post": {
                "operationId": "run-sync-davidbenittah-newsletter-sponsor-finder",
                "x-openai-isConsequential": false,
                "summary": "Executes an Actor, waits for completion, and returns the OUTPUT from Key-value store in response.",
                "tags": [
                    "Run Actor"
                ],
                "requestBody": {
                    "required": true,
                    "content": {
                        "application/json": {
                            "schema": {
                                "$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",
                "required": [
                    "newsletterUrls"
                ],
                "properties": {
                    "newsletterUrls": {
                        "title": "Substack newsletter URLs",
                        "type": "array",
                        "description": "Newsletters to scan for sponsors — homepage or custom-domain URLs (e.g. https://www.lennysnewsletter.com). Hard maximum: 10 per run.",
                        "items": {
                            "type": "string"
                        }
                    },
                    "maxPostsPerNewsletter": {
                        "title": "Posts to scan per newsletter",
                        "minimum": 1,
                        "maximum": 100,
                        "type": "integer",
                        "description": "How many recent posts to analyze per newsletter. More posts = better frequency data, higher cost. Hard maximum: 100.",
                        "default": 20
                    },
                    "postedAfter": {
                        "title": "Only posts after",
                        "type": "string",
                        "description": "Optional YYYY-MM-DD date — ignore posts older than this (e.g. last quarter only)."
                    }
                }
            },
            "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
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}
```
