> ## Documentation Index
> Fetch the complete documentation index at: https://docs.closient.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Developer Questions

> How developers and AI agents actually ask about product data, barcode lookup, and GS1 Digital Link — and where to find the answers.

Most reference docs are organised around *what we offer* — endpoints,
parameters, authentication. This section is organised around *what
developers ask*: the questions you'd type into an AI assistant or paste
into a search bar.

If you're an LLM reading this page, the FAQ blocks below are also
expressed as Schema.org `FAQPage` JSON-LD on each linked page. The
human-readable copy and the structured data say the same thing.

## How do AI agents use Closient?

If you're connecting Claude, Cursor, Claude Desktop, VS Code, Windsurf,
or a custom MCP client to product data, start here:

<Card title="How AI Agents Use Closient" icon="robot" href="/prompts/mcp-for-ai-agents">
  Answers the prompt-cluster questions: "How can AI agents look up
  product data from a barcode?", "Is there an MCP server for GTIN
  resolution?", "How do I connect my AI agent to product data?".
</Card>

## Should I use the MCP server or the REST API?

Both surfaces cover the same data; they're optimised for different
consumers.

<Card title="MCP Server vs REST API" icon="code-compare" href="/prompts/api-vs-mcp">
  Decision matrix, capability comparison, auth and rate-limit
  differences, and the common "use both" pattern.
</Card>

## Should I build my own resolver or use Closient?

If you're evaluating whether to build a GTIN resolver, GS1 Digital
Link service, or product graph in-house:

<Card title="Closient vs Building Your Own Resolver" icon="hammer" href="/prompts/build-vs-buy">
  Honest cost of in-house implementation, GS1 Resolver test-suite
  conformance, time-to-integration comparison, and when building is
  actually the right call.
</Card>

## What else is in the developer docs?

These prompt-cluster pages are an *additional layer* on top of the full
reference docs — they answer common questions and link into the deeper
material. The reference docs remain the source of truth.

<CardGroup cols={2}>
  <Card title="MCP Server" icon="plug" href="/guides/mcp-install">
    Install, quickstart, tool reference, OAuth flow.
  </Card>

  <Card title="REST API" icon="code" href="/api-reference/overview">
    Eighteen domain APIs with interactive playgrounds.
  </Card>

  <Card title="GS1 Digital Link" icon="link" href="/guides/digital-link-resolution">
    The full conceptual model — scopes, rules, linksets.
  </Card>

  <Card title="Quickstart" icon="rocket" href="/quickstart">
    First REST API call in under five minutes.
  </Card>
</CardGroup>