Free data, no key, no signup
Every week is published as static files. The URL of a week never changes, and latest always points to the newest week.
Free under CC BY 4.0 · estimates, no warranty · use means you accept the Terms of Use. Step-by-step examples: free resale price API guide.
Endpoints
| File | What it is |
|---|---|
/data/latest/items.json | One flat row per item: price, type (SOLD/ASK), sample size, retail, premium, weekly change, per-source medians, best place to sell. |
/data/latest/items.csv | The same rows as CSV, for spreadsheets. |
/data/latest/full.json | Everything behind the pages: size tables, condition medians, ranges, payouts. |
/data/2026-W45/… | The same files frozen for one ISO week (kept forever). |
/data/fees.json | The fee rules we use, with source links and check date. |
Quick start
# Python
import requests
items = requests.get("https://www.aiplannermail.com/data/latest/items.json").json()["items"]
cheap = [i for i in items if i["premiumPct"] is not None and i["premiumPct"] < 0]
# JavaScript
const {items} = await (await fetch("https://www.aiplannermail.com/data/latest/items.json")).json();Fields
price, priceType | The headline price and whether it is SOLD (finished sales) or ASK (current listings). |
basis, sampleSize | Exactly how the price was computed and from how many data points. |
premiumPct | Price vs retail in %, when retail is known. |
changePct | Change vs last week's price of the same type (null in the first week). |
bestTrackedPlatform, bestTrackedNetPayout, trackedPlatforms | Of the platforms we have real prices for (count in trackedPlatforms), the one that leaves the seller the most after fees, and how much. |
updated, staleSource, lowSample | When the data behind the price was collected; whether it is an older week's data because this week's fetch failed; whether fewer than 10 data points sit behind it. |
Use it from an AI agent
The scrapers behind this site are public Apify Actors with an MCP endpoint, so Claude, ChatGPT or Cursor can pull fresh prices for any item, not only the ones listed here:
https://mcp.apify.com/?tools=malek_oweis/resale-price-checkerActors: Resale Price Checker, GOAT, Mercari sold listings, Chrono24. A larger sample dataset lives on Hugging Face, and every weekly file is also on Kaggle.
License and terms
Our derived statistics are free under CC BY 4.0: use them for anything, credit "SoldSignal (https://www.aiplannermail.com)". We do not republish listings, photos or seller details, and we claim no rights in the marketplaces' own data.
The data is an estimate, provided as is and without warranty. Using the files or API means you accept the Terms of Use, including the limitation of liability.