> ## 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.

# Access Methods

> Pick the right interface for your workload — REST, GraphQL, WebSocket, Kafka, SDK, CLI or MCP.

ChainStream exposes the same catalog of [data products](/en/docs/data-products/overview) through several different interfaces. Each one has a sweet spot — you will usually combine two or three in a single integration.

## Quick comparison

|                   | Best for                                         | Pattern          | Latency           | Auth                   | Where to start                                          |
| :---------------- | :----------------------------------------------- | :--------------- | :---------------- | :--------------------- | :------------------------------------------------------ |
| **REST API**      | On-demand lookups, dashboards, user queries      | Request/response | 50–200 ms         | API key / OAuth        | [REST API](/en/docs/access-methods/rest-api)            |
| **GraphQL**       | Analytical queries, aggregations, flexible joins | Request/response | 100–500 ms        | API key / OAuth        | [GraphQL](/en/docs/access-methods/graphql)              |
| **WebSocket**     | Live UIs, browser + mobile apps                  | Push (subscribe) | \<2 ms tick       | API key                | [WebSocket](/en/docs/access-methods/websocket)          |
| **Kafka Streams** | Trading engines, indexers, alert pipelines       | Stream (consume) | \<100 ms p99      | SASL / OAuth           | [Kafka](/en/docs/access-methods/kafka-streams/overview) |
| **SDKs**          | Typed access from TS / Python / Go / Rust        | Client library   | Matches transport | Inherits underlying    | [SDKs](/en/sdks/overview)                               |
| **CLI**           | Scripting, CI/CD, AI agents, pay-per-call        | Command line     | Matches transport | API key / OAuth / x402 | [CLI](/en/docs/access-methods/cli)                      |
| **MCP Server**    | AI agents (Claude, Cursor, ChatGPT, custom)      | Tool protocol    | Matches transport | API key / x402         | [MCP](/en/docs/ai-agents/mcp-server/introduction)       |

## Decision guide

<AccordionGroup>
  <Accordion title="I'm building a user-facing dashboard">
    Start with **REST** for lookups and charts, layer **WebSocket** for live
    updates. Use **GraphQL** if your screens need aggregated or pivoted data.
  </Accordion>

  <Accordion title="I'm building a trading / indexing backend">
    Use **Kafka Streams** for primary ingestion (exactly-once, horizontally
    scaled). Fall back to **REST** for cold lookups and **GraphQL** for
    analytical backfills.
  </Accordion>

  <Accordion title="I'm doing research or ad-hoc analysis">
    **GraphQL** gives you dimensional queries over the entire data cube without
    per-chain boilerplate. Export to notebooks via the **Python SDK**.
  </Accordion>

  <Accordion title="I'm building a browser / mobile app">
    **WebSocket** for live streams (prices, trades, balances). **REST** for
    anything that is fine with polling or happens on user action.
  </Accordion>

  <Accordion title="I'm building an AI agent">
    **MCP Server** exposes the catalog as typed tools for LLM agents. If your
    agent runs its own code, use **SDKs** directly; for pay-per-call semantics,
    use the **CLI** with x402/MPP.
  </Accordion>

  <Accordion title="I'm running compliance / KYT workflows">
    **REST** calls to the KYT endpoints fit most integration patterns. For high
    volume screening pipelines, use the **Kafka transfer topic** plus REST
    scoring side-by-side.
  </Accordion>
</AccordionGroup>

## Authentication at a glance

Every access method accepts the same credentials. Pick the one that matches your environment — you do not need separate credentials per transport.

<CardGroup cols={3}>
  <Card title="API Keys" icon="key" href="/en/docs/platform/authentication/api-keys-oauth">
    Quickest path. One header, works on REST / GraphQL / WebSocket / CLI / SDK.
  </Card>

  <Card title="OAuth 2.0" icon="shield-halved" href="/en/docs/platform/authentication/api-keys-oauth">
    For server-to-server production use — client-credentials JWT flow.
  </Card>

  <Card title="Wallet Sign-In (SIWX)" icon="wallet" href="/en/docs/platform/authentication/wallet-auth-siwx">
    Sign-In With X — let end-users authenticate with their wallet.
  </Card>
</CardGroup>

<Note>
  For AI agents and per-call micropayments see
  [x402 Payments](/en/docs/platform/billing-payments/x402-payments) and
  [MPP Payments](/en/docs/platform/billing-payments/mpp-payments).
</Note>

## Next

<CardGroup cols={2}>
  <Card title="REST API" icon="bolt" href="/en/docs/access-methods/rest-api">
    HTTP endpoints for tokens, wallets, trades, pools, compliance.
  </Card>

  <Card title="GraphQL" icon="diagram-project" href="/en/docs/access-methods/graphql">
    Flexible analytics across the normalized chain cube.
  </Card>

  <Card title="WebSocket" icon="tower-broadcast" href="/en/docs/access-methods/websocket">
    Live push for prices, trades, balances and pool events.
  </Card>

  <Card title="Kafka Streams" icon="bars-staggered" href="/en/docs/access-methods/kafka-streams/overview">
    Production streaming with exactly-once semantics.
  </Card>
</CardGroup>