Username Inspector

Check whether ONE username or store name is available on reselling platforms: eBay, eBay Store, Poshmark, Grailed, Vinted, Whatnot, Bonanza, and Chairish are looked up directly, but several of them (often eBay, Grailed, Whatnot, and Chairish) block automated lookups and then come back as unverified with a link; Poshmark, Vinted, and Bonanza most reliably return a live answer. Depop, Etsy, Mercari, and Ruby Lane cannot be checked automatically, so a link to the profile page is returned instead. Each platform status is "available" (no profile found), "taken" (a profile exists), "unverified" (open check_url to verify), or "error" (timed out or blocked). Usernames are 3 to 50 characters: letters, numbers, hyphens, and underscores. Each call checks one name. Results are cached for 5 minutes and repeated calls are rate-limited.

{
  "type": "object",
  "properties": {
    "username": {
      "type": "string",
      "pattern": "^[a-zA-Z0-9-_]{3,50}$",
      "description": "The username or store name to check, without an @ and without spaces."
    },
    "platforms": {
      "description": "Platform ids to check. Omit to check all of them: ebay, ebaystore, poshmark, grailed, vinted, whatnot, bonanza, chairish, depop, etsy, mercari, rubylane.",
      "minItems": 1,
      "maxItems": 12,
      "type": "array",
      "items": {
        "type": "string",
        "enum": [
          "ebay",
          "ebaystore",
          "poshmark",
          "grailed",
          "vinted",
          "whatnot",
          "bonanza",
          "chairish",
          "depop",
          "etsy",
          "mercari",
          "rubylane"
        ]
      }
    }
  },
  "required": [
    "username"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}

Compare what a sale pays out after marketplace fees on eBay, Poshmark, Mercari, Depop, Etsy, Grailed, and Vinted (US sellers). Takes the sale price in USD and, optionally, the shipping charged to the buyer, the item cost, the seller's own shipping cost, and an eBay promoted listing rate; with costs it also returns profit, margin, and ROI. Results are sorted best first. Sales tax is not included. Rates are approximate and carry the date each was last verified.

{
  "type": "object",
  "properties": {
    "price": {
      "type": "number",
      "exclusiveMinimum": 0,
      "maximum": 100000,
      "description": "Sale price in USD, before shipping."
    },
    "shipping_charged": {
      "description": "Shipping the buyer pays you in USD. eBay, Etsy, Depop, and Mercari charge fees on it. Ignored for Poshmark and Vinted. Leave out for free shipping.",
      "type": "number",
      "minimum": 0,
      "maximum": 100000
    },
    "item_cost": {
      "description": "What you paid for the item in USD. Adds profit, margin, and ROI.",
      "type": "number",
      "minimum": 0,
      "maximum": 100000
    },
    "shipping_cost": {
      "description": "What you pay for postage in USD. Not used for Poshmark or Vinted, where the buyer pays the label.",
      "type": "number",
      "minimum": 0,
      "maximum": 100000
    },
    "ebay_promoted_rate_percent": {
      "description": "eBay Promoted Listings ad rate as a percent of price plus shipping. Only affects eBay.",
      "type": "number",
      "minimum": 0,
      "maximum": 100
    }
  },
  "required": [
    "price"
  ],
  "$schema": "http://json-schema.org/draft-07/schema#"
}