Substack Notes API

Request parameters

Code samples

curl -X POST 'https://api.everyinfra.com/api/v1/social' \
  -H "Authorization: Bearer $EVERYINFRA_API_KEY" \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "platform": "substack",
  "action": "notes",
  "params": {
    "username": "astralcodexten"
  }
}'

[OpenAPI definition (JSON)]Samples read the key from the EVERYINFRA_API_KEY environment variable; copied code never contains your key.

Response example

{
  "id": "req_…",
  "platform": "substack",
  "action": "notes",
  "results": [
    {
      "id": "p-（已隐去）",
      "kind": "restack",
      "author_username": "astralcodexten",
      "author_name": "（已隐去）",
      "posted_at": "2026-09-25T22:26:10.306000+00:00",
      "platform": "substack",
      "restacked_post": {
        "title": "Your Book Review: Lee Kuan Yew's Memoirs",
        "url": "https://www.astralcodexten.com/p/your-book-review-lee-kuan-yews-memoirs"
      }
    },
    {
      "id": "p-（已隐去）",
      "kind": "restack",
      "author_username": "astralcodexten",
      "author_name": "（已隐去）",
      "posted_at": "2026-09-25T06:06:18.720000+00:00",
      "platform": "substack",
      "restacked_post": {
        "title": "Fall Meetups 2026 - Call For Meetup Organizers",
        "url": "https://www.astralcodexten.com/p/fall-meetups-2026-call-for-meetup"
      }
    }
  ],
  "count": 25,
  "billing": { … },
  "quota": { … }
}

Response fields

Business data is in results. The table lists the fields a record can contain; values the source does not provide are never made up.

Errors and billing

401

Missing or invalid key. Authentication runs before parameter checks, so unauthenticated requests never see the parameter schema.

422

Wrong parameter name or value. The error lists the parameters and allowed values this capability accepts and the closest match; it happens before any charge.

402

Insufficient balance. Top up first.

429

Per-minute request limit reached. Wait for Retry-After and try again.

503

Could not complete right now. Any charge for the call goes back to your balance automatically, and the billing receipt in the response states the actual outcome, including when it is not yet known. Do not resend blindly.

200 empty

The request completed without data and is not charged (billing.reason = empty_result_refunded).

Official references

Used only to check objects and terms. They do not imply authorization or endorsement of EveryInfra by the platform.

• Substack: Definition of Notes and Restack ↗

  Substack defines Notes as short-form content activity and Restack as sharing content within Notes, distinguishing them from article-by-article newsletter dispatch. Official publishing, engagement, and revenue analytics capabilities on Substack do not mean this notes read endpoint supports those operations or metrics.

  Checked 2026-09-04