Double Holo Seller API: Manage Pokemon Card Listings and Orders With Code

Who can use the Seller API

An API is a way for software to work with your Double Holo account directly. To use the Seller API you need all of these:

• An approved seller account.
• A Stripe payout account that is set up.
• A verified phone number.
• Seller Level 2 or higher. See how seller levels work.
• Accepted Seller API terms.

Buying, bids, offers on other sellers' listings, store credit, and payouts are not part of the Seller API.

How to enroll

1. Open Settings, then Seller API.
2. Read and accept the terms.
3. Create a key and copy it right away, because it is shown once.
4. You can have up to 2 active keys.

Authentication

Send two headers with every request: Authorization: Bearer <your API key> and X-DH-User-Id: <your user ID>. Your API key is dh_sk_live_ followed by 40 lowercase hex characters (0 to 9 and a to f). Your user ID is shown in Seller API settings. Keep your key on a server you control. The API does not accept calls made from a web browser, so a key placed in a web page will not work and could leak.

curl https://api.doubleholo.com/api/v1/seller-api/me \
  -H "Authorization: Bearer $DH_API_KEY" \
  -H "X-DH-User-Id: $DH_USER_ID"

async function main() {
  const res = await fetch('https://api.doubleholo.com/api/v1/seller-api/me', {
    headers: {
      Authorization: `Bearer ${process.env.DH_API_KEY}`,
      'X-DH-User-Id': process.env.DH_USER_ID,
    },
  })
  if (!res.ok) throw new Error(`Seller API error ${res.status}`)
  console.log(await res.json())
}

main()

import os
import requests

resp = requests.get(
    "https://api.doubleholo.com/api/v1/seller-api/me",
    headers={
        "Authorization": f"Bearer {os.environ['DH_API_KEY']}",
        "X-DH-User-Id": os.environ["DH_USER_ID"],
    },
    timeout=30,
)
resp.raise_for_status()
print(resp.json())

Every response carries Cache-Control: no-store. A wrong key, a wrong user ID, and a revoked key all return the same 401 invalid_credentials answer, so the response never says which part was wrong. Twenty failed sign-ins from one network in 10 minutes block requests without a valid key from that network for an hour, with a 429 rate_limited answer.

Endpoint reference

Download the OpenAPI file

PATCH /asks/{id} edits an ask that is active or partially filled. Editing an expired ask also relists it, which puts it back on sale. A relist follows the same checks as any ask call, and your phone number must be verified.

Money is in integer cents (price_cents, amount_cents). The marketplace is US dollars only. Send JSON; use multipart form data only to upload photos. A JSON body can be up to 1 MB and a photo upload up to 105 MB. A body larger than its limit, or a chunked body sent without a length, answers 413. A field an endpoint does not take answers 422 unknown_parameter. Languages are lowercase keys such as english, japanese, and chinese_traditional.

Rate limits and daily caps

• Limits depend on your seller level.
• Daily caps reset at midnight UTC.
• Daily caps count Seller API calls only. Anything you do on the website or app is not counted.
• A request over a rate limit gets 429 rate_limited with a Retry-After header.
• A capped action over its daily cap gets 429 daily_limit_reached with the action, the cap, what you used, and when it resets.
• Responses to authenticated requests carry X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset.
• The 429 for too many failed sign-ins and the 413 for a body that is too large are refused before the API reads the request, so they carry no rate limit headers.
• A cancel counts its refund toward the refunded dollars cap.
• A refund larger than the whole daily refund limit is refused with 422 validation_failed (field amount_cents, with the limit). A cancel whose refund alone is larger than that limit is refused with invalid_state.
• A request that is refused before anything changes does not use up a cap.

Errors

Every error uses one shape: { "error": { "code": "...", "message": "..." } }.

If Double Holo pauses the Seller API, requests answer 503 seller_api_unavailable until it reopens. Retry a 503 upstream_unavailable after the Retry-After time.

Idempotency

These calls need an Idempotency-Key header and answer 400 idempotency_key_required without one: POST /asks (create an ask), POST /asks/bulk (create up to 50 asks), POST /orders/{id}/cancel (cancel an order), POST /orders/{id}/refunds (refund an order), POST /orders/{id}/shipping/label (buy a label), and DELETE /orders/{id}/shipping/label (void a label).

These calls accept one but do not need it: PATCH /asks/{id}, POST /asks/bulk-price, DELETE /asks/{id}, PUT /asks/{ask_id}/photos/order, DELETE /asks/{ask_id}/photos/{id}, and POST /orders/{id}/ship. Every other call, including the photo upload, does not take one and ignores the header (the Idempotency-Key column above shows this as Not accepted).

The key is a unique value you make for each action, such as a UUID. If a network error leaves you unsure whether the call worked, send it again with the same key and the same body: you get the first answer back instead of a second action. Keys are remembered for 48 hours. The same key with a different body returns 422 idempotency_key_reused, and a retry while the first call is still running returns 409 idempotency_in_progress.

Cancels, refunds, label purchases, label voids, and creating asks (single or bulk) never run twice for one key. They answer 409 idempotency_in_progress until the first request settles. If one of them fails with a server error (5xx), or the connection drops before you get an answer, check the order with GET /orders/{id} (or your asks with GET /asks) first and then use a new key, because the old key keeps its stored answer or stays in progress. Other writes that failed with a 5xx can be retried with the same key after 2 minutes.

# Make the key once per action. If you retry, send the same key again.
KEY=$(uuidgen)
curl -X POST https://api.doubleholo.com/api/v1/seller-api/asks \
  -H "Authorization: Bearer $DH_API_KEY" \
  -H "X-DH-User-Id: $DH_USER_ID" \
  -H "Idempotency-Key: $KEY" \
  -H "Content-Type: application/json" \
  -d '{"card_id":123,"price_cents":1250,"condition":"NM"}'

const crypto = require('node:crypto')

async function createAsk() {
  // Make the key once per action. If you retry, send the same key again.
  const key = crypto.randomUUID()
  const res = await fetch('https://api.doubleholo.com/api/v1/seller-api/asks', {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${process.env.DH_API_KEY}`,
      'X-DH-User-Id': process.env.DH_USER_ID,
      'Idempotency-Key': key,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({ card_id: 123, price_cents: 1250, condition: 'NM' }),
  })
  if (!res.ok) throw new Error(`Seller API error ${res.status}`)
  console.log(await res.json())
}

createAsk()

import os
import uuid
import requests

# Make the key once per action. If you retry, send the same key again.
key = str(uuid.uuid4())
resp = requests.post(
    "https://api.doubleholo.com/api/v1/seller-api/asks",
    headers={
        "Authorization": f"Bearer {os.environ['DH_API_KEY']}",
        "X-DH-User-Id": os.environ["DH_USER_ID"],
        "Idempotency-Key": key,
    },
    json={"card_id": 123, "price_cents": 1250, "condition": "NM"},
    timeout=30,
)
resp.raise_for_status()
print(resp.json())

The request body for each call is in the OpenAPI file.

Pagination

List calls return newest first, up to 100 items (limit, 1 to 100, default 50) and a next_cursor. Pass it back as cursor to get the next page, and stop when next_cursor is null. There are no webhooks yet: to find changes, call GET /orders or GET /asks with updated_since set to the time of your last check.

Listing photos

• Upload JPEG, PNG, or WebP photos, up to 10 MB each.
• A photo can be up to 50 megapixels (its width times its height in pixels). For example, 8,000 by 6,000 pixels is 48 megapixels.
• You can add up to 10 photos per listing.
• Listings of $250 and above need at least one photo, unless your account has a photo waiver.
• Send photos with POST /asks as multipart form data (photos[]).
• The bulk call takes no photos, so it cannot create a listing of $250 or more for an account without a waiver.
• You cannot delete the last photo of a listing of $250 and above, unless the ask is graded and has a cert number or cert images, or your account has a photo waiver.
• Photos are re-encoded, and location and camera details are removed before a photo is stored.
• Photo ids change after you reorder, so read them from the response.
• HEIC photos and importing a photo from a link are not supported.
• If photo processing is temporarily unavailable, the call answers 503 photo_processing_unavailable with a Retry-After header. Try again after that time.

Orders and shipping labels

The API only shows orders you sold. The buyer's name and shipping address appear only while an order is waiting to ship; buyer email, phone, and account details never appear. You can mark an order shipped with a tracking number, get label rates, buy a label, or void it. The cost of a label comes out of your payout for that order.

Each rate says whether it costs more than your payout for the order, and the API will not buy such a label (it answers label_cost_exceeds_payout); choose a cheaper rate or ship it yourself. A voided label keeps its cost unless the carrier accepts the label refund. On an order that is later cancelled or fully refunded, a kept cost becomes a debt that is taken from your later payouts. You can cancel an order that has not shipped, and refund all or part of an order that has not been paid out. Buyers get the same notifications they would get if you did these things on the website.

If your Stripe setup, seller approval, or seller level lapses, your keys still work for the orders and labels you already sold. A ban or a selling restriction revokes every key.

Changelog

• October 22, 2026: Version 1.0 of the Seller API docs published. Enrollment opens in stages.

Frequently asked questions

Related

• Seller fees calculator
• Best place to sell Pokemon cards in 2026
• How seller levels work
• Seller API terms