The commerceAPI for AI.

Give your assistant a catalogue of 284,000+ merchants — merchant-generated discounts at supported stores, scored public codes, delivery estimates and shopper history, through one REST API.

See it live →Read the API docs

Explore six integration recipes →

api.openstock.sh

Everlane · example request and response

POST /v1/merchants/codes

{"queries":[{
  "query_id":"everlane",
  "merchant_id":"01g4s5dc138qsnh4egsjys8g9c",
  "idempotency_key":"your-shopper-session-key",
  "limit":1
}]}

{
  "results": [{
    "query_id": "everlane",
    "partnered": true,
    "cashback": { "value_type": "percent", "value_amount": 3 },
    "activation_url": "https://api.openstock.sh/mr/01g4s5dc138qsnh4egsjys8g9c",
    "suppressed_code_count": 0,
    "items": [{
      "code": "EXAMPLE-NOT-REDEEMABLE",
      "source": "generated",
      "probability": 1,
      "single_use": true,
      "value_type": "fixed",
      "value_amount": 35,
      "currency": "USD",
      "conditions": ["minimum_subtotal"],
      "description": "$35 off orders of $175 or more",
      "redirect_url": "https://api.openstock.sh/mr/01g4s5dc138qsnh4egsjys8g9c?code=EXAMPLE-NOT-REDEEMABLE",
      "expires_at": null,
      "last_success": null,
      "apply_count": null,
      "success_count": null
    }]
  }]
}

Example values and links. Live availability and terms may change.

Inspect the contract, then run it live

A catalogue spanning 284,000+ merchants

284,000+

Indexed merchants

100M+

US shoppers in our network

3.4B+

Shopping data points

API key to reach them all

The new layer for agentic commerce

One API sits between every assistant and every store.

Models and apps shouldn’t integrate with 284,000 merchants one by one. They connect to Checkmate once to resolve the catalogue, inspect available offers and access supported merchant integrations.

Agents & models

AI assistants, shopping copilots and autonomous agents that need to find, recommend and transact on real products.

OpenStock

One REST API exposing merchants, live-minted codes, delivery estimates and shopper history across the whole network.

284,000+ merchants

A broad merchant catalogue with observed offers, delivery context and direct integrations for merchant-generated discounts.

The API

Everything an assistant needs to shop the network.

Three batched endpoints with typed, documented responses. Built to be read by a model and shown to a person.

POST /v1/merchants/codes

Real codes, minted live

At supported direct integrations, request a merchant-generated single-use code. The response identifies its source and terms; retries reuse the same code.

Generated · single use

EXAMPLE-NOT-REDEEMABLE

$35 offmin $175

{
  "code": "EXAMPLE-NOT-REDEEMABLE",
  "source": "generated",
  "probability": 1,
  "single_use": true,
  "value_type": "fixed",
  "value_amount": 35,
  "description": "$35 off orders of $175+"
}

Inspect a generated code

Built for builders

Drop it in. Start selling.

OpenStock is a plain REST API with an OpenAPI 3.1 spec, so it drops into any assistant, agent framework or backend in an afternoon. Batch up to 50 merchants in one call and get back JSON a model can reason over.

Plain HTTPS + bearer key — no SDK required
OpenAPI 3.1 spec with operationIds for every route
Batch up to 50 merchant searches or 20 offer queries
One credential for the merchant catalogue and supported capabilities
Served from Cloudflare’s edge in 300+ cities — the same network that fronts chatgpt.com
Designed for an assistant with a billion monthly users; every endpoint checked live at status.openstock.sh

quickstart.sh

$ curl https://api.openstock.sh/v1/merchants/search \
    -H "Authorization: Bearer $OPENSTOCK_API_KEY" \
    -H "Content-Type: application/json" \
    -d '{"queries":[{"query_id":"q1",
          "type":"domain","value":"everlane.com"}]}'

# → id, domains, estimated_shipping
# then POST /v1/merchants/codes with that id

Six complete recipes · requests, responses and live runs →

The Checkmate network

The world’s most trusted shopping network, built for internet-scale demand.

OpenStock is powered by Checkmate, a network spanning 100 million shoppers and 284,000+ merchants. Its batched API is designed to scale from launch partners to the world’s largest AI platforms—without rebuilding merchant connections one by one.

@joincheckmate @checkmatesavings

100 million

shoppers in network

1M+

Social followers

284k+

Indexed merchants

From the community

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