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For Developers

Build on the world's product graph.

Resolve any GTIN in milliseconds. Access structured product data, GS1 Digital Link resolution, EPCIS 2.0 event capture, and AI-ready integrations — all through simple, standards-based APIs.

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The problems you're dealing with

Building product-aware applications shouldn't require stitching together unreliable data sources.

No reliable product data API

Most product databases are paywalled, stale, or incomplete. You end up scraping, deduplicating, and maintaining your own product catalog just to get basic GTIN lookups.

GS1 Digital Link resolution is complex

Implementing a conformant resolver from scratch requires deep GS1 knowledge, URI parsing, link-type negotiation, and ongoing spec compliance work.

AI agents need product context

LLM-powered shopping assistants, inventory agents, and recommendation engines need structured product data they can query — not HTML pages to scrape.

EPCIS integration is painful

Implementing EPCIS 2.0 from scratch is a multi-month project. Capture events, query histories, and maintain compliance — or let an API handle it.

What you can build with

APIs and tools designed for software engineers, integration architects, and AI/ML practitioners.

REST API

Query product data, manage trade items, and access the full product graph through a well-documented REST API with OpenAPI specs.

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GS1 Digital Link Resolver API

Resolve any GTIN to structured product data via a conformant GS1 Digital Link resolver. Supports AI qualifiers including lot, serial, and expiry.

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MCP Server & AI Agent Integration Coming soon

Connect AI agents to the product graph via Model Context Protocol. Give LLMs structured access to product data, availability, and safety information.

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EPCIS 2.0 API

Capture and query supply chain events with a standards-compliant EPCIS 2.0 implementation. Track products from manufacture to shelf.

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CLI & SDKs Coming soon

Manage your product data from the command line or integrate directly with client libraries for Python, JavaScript, and more.

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Why build on Closient

Standards-based

Built on GS1 Digital Link and EPCIS 2.0 — open standards, not proprietary formats. Your integrations are portable and future-proof.

Transparent pricing

Every price is published. No sales calls required. Free tier available with generous limits for development and small projects.

Fast resolution

Resolve any GTIN in milliseconds. Low-latency API responses designed for real-time applications, scanning workflows, and agentic pipelines.

Open data

Product data should be accessible, not locked behind paywalls. We believe in open access to the basic product information the world needs.

Frequently asked questions

The REST API returns JSON by default. The GS1 Digital Link resolver supports content negotiation including JSON, JSON-LD, and GS1 linkset formats. The EPCIS 2.0 API supports both JSON and JSON-LD as specified by the GS1 EPCIS standard.

Yes. The free tier includes generous limits for development and small projects — including trade item lookups, batch tracking, and API access. No credit card required to get started.

Create a free account, then generate an API key from your account dashboard. Keys use the format csb__ and are passed via the X-API-Key header.

The Model Context Protocol (MCP) server lets AI agents and LLMs query the Closient product graph as a tool. This enables shopping assistants, inventory agents, and other AI-powered applications to access structured product data programmatically. This feature is coming soon.

Start building today

Explore the API documentation or create a free account to get your API key. No credit card required.

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