# Webcite API documentation

Verify claims, inspect their sources, and extract evidence from documents.

Documentation index: https://webcite.co/llms.txt
Canonical page: https://webcite.co/api-docs
API origin: https://api.webcite.co
Authentication: x-api-key header. Keep keys on your server.

## Make your first request

Create an [API key](/api-keys), set it as `WEBCITE_API_KEY` on your server, and follow the [quickstart](/api-docs/quickstart). You can also test a claim in the [playground](/playground).

The API origin is `https://api.webcite.co`. Operation paths include their version, such as `/api/v1/verify`. Do not add another `/api` prefix.

## Choose a workflow

- Check a claim against the web: [Verify a claim](/api-docs/verify) returns sources, stances, and a verdict.
- Check quotations against known sources: [Batch quote matching](/api-docs/batch) reports whether the text can be found.
- Read a document: [Upload](/api-docs/upload), then [extract text](/api-docs/extract) or [anchored chunks](/api-docs/chunks).
- Check numbers: [Compare figures](/api-docs/conflicts) or [verify arithmetic](/api-docs/numeric) with retained operands.
- Connect an agent: Use the [MCP setup guide](/api-docs/mcp).

## Read results before acting

A source match, a source stance, and a factual verdict answer different questions. Read the [evidence guide](/api-docs/evidence) before deciding what your application can publish. Keep partial, unknown, and failed states visible.

## Use the format you need

Every topic has a **Copy page** action and a Markdown link. Agents can start with the [documentation index](/llms.txt), read the [full documentation](/llms-full.txt), or use the [public OpenAPI file](/api-docs/openapi.json).