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

# REST API

> Lookup, snapshot and analytical endpoints over plain HTTP — the default surface for most apps.

The REST API is the simplest way to pull data from ChainStream. Every [data product](/en/docs/data-products/overview) is exposed as a JSON endpoint, with the same authentication and error envelope.

## Base URL

```
https://api.chainstream.io
```

## Authentication

Include one of:

```bash theme={null}
-H "Authorization: Bearer $CHAINSTREAM_API_KEY"
# or OAuth token
-H "Authorization: Bearer $OAUTH_TOKEN"
# or x402 micropayment (see Platform / Billing)
-H "X-PAYMENT: <signed payload>"
```

See [Authentication](/en/api-reference/authentication/authenticate) for the full matrix.

## First request

```bash theme={null}
curl -H "Authorization: Bearer $CHAINSTREAM_API_KEY" \
  "https://api.chainstream.io/v2/token/search?chain=sol&keyword=USDC&limit=5"
```

## When to use

* Single lookups, snapshots, server-rendered pages
* Any workload where sub-second latency isn't critical
* Pairing with [WebSocket](/en/docs/access-methods/websocket) (REST for history, WS for live)
* Agent tool-calls where each invocation maps to one endpoint

When **not** to: high-frequency streaming workloads (use WebSocket or Kafka) and multi-product JOINs (use GraphQL).

## Conventions

* Pagination: `limit` + `cursor` (cursor-based) on list endpoints
* Rate limits: per-plan; see response headers `X-RateLimit-Remaining`, `X-RateLimit-Reset`
* Errors: RFC 7807-style JSON with `code`, `message`, `requestId`

## Next

<CardGroup cols={2}>
  <Card title="API Reference" icon="code" href="/en/api-reference/overview">
    Every REST endpoint with request/response examples.
  </Card>

  <Card title="SDKs" icon="box" href="/en/docs/access-methods/sdks">
    Typed REST wrappers for TS / Py / Go / Rust.
  </Card>

  <Card title="Rate limits" icon="gauge" href="/en/docs/platform/billing-payments/plans-and-units">
    Per-plan throughput and how to plan for it.
  </Card>

  <Card title="Authentication" icon="key" href="/en/api-reference/authentication/authenticate">
    API keys, OAuth, wallet-auth, x402.
  </Card>
</CardGroup>