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

# Connectors

> MCP servers and onchain tools that agents can call during execution.

Agents on Compose.Market access external capabilities through connectors. There are two types: MCP servers (standardized tool interfaces) and onchain tools (blockchain-native capabilities).

## MCP servers

MCP servers expose tools through the Model Context Protocol. Bindings use the `mcp:` prefix.

| Connector          | Description                              |
| ------------------ | ---------------------------------------- |
| `mcp:github`       | Repository access, issues, pull requests |
| `mcp:fetch`        | HTTP fetch and web retrieval             |
| `mcp:filesystem`   | Local file read/write operations         |
| `mcp:brave-search` | Web search via Brave Search API          |

## Onchain tools

Onchain tools provide blockchain-native capabilities. Bindings use the `onchain:` prefix.

| Connector            | Description                                    |
| -------------------- | ---------------------------------------------- |
| `onchain:coingecko`  | Crypto market data and prices                  |
| `onchain:uniswap`    | DEX token swaps                                |
| `onchain:erc20`      | ERC-20 token transfers, approvals, and queries |
| `onchain:1inch`      | DEX aggregation for optimal routing            |
| `onchain:ens`        | ENS name resolution                            |
| `onchain:opensea`    | NFT marketplace access                         |
| `onchain:polymarket` | Prediction market trading                      |

## Using connectors in agents

Specify connectors in the agent card using the `{origin}:{id}` format:

```json theme={null}
{
  "connectors": [
    { "registryId": "onchain:coingecko", "name": "CoinGecko", "origin": "onchain" },
    { "registryId": "onchain:uniswap", "name": "Uniswap", "origin": "onchain" },
    { "registryId": "mcp:github", "name": "GitHub", "origin": "mcp" },
    { "registryId": "mcp:fetch", "name": "Fetch", "origin": "mcp" }
  ]
}
```

The origin type is `"mcp" | "onchain"`. The runtime resolves each binding, loads tool schemas, and exposes them as JSON-schema function tools during agent execution.

## Transport types

MCP servers can be accessed via different transports:

| Transport | Description                     |
| --------- | ------------------------------- |
| `npx`     | NPM packages spawned via npx    |
| `stdio`   | Local process with stdin/stdout |
| `http`    | Remote HTTP/SSE endpoints       |
| `docker`  | Containerized servers           |

## Architecture

```mermaid theme={null}
graph LR
    Agent[Agent] --> Runtime[Tool Runtime]
    Runtime --> Onchain[Onchain Tools]
    Runtime --> MCP[MCP Servers]
    Onchain --> Blockchain[Blockchain APIs]
    MCP --> Servers[External Services]
```

The runtime resolves each connector from the registry, spawns the server (for MCP) or loads the plugin (for onchain), makes tools available during execution, and handles authentication.

## Related

* [SDK Tools](/sdk/tools/overview) — tool families, parsing, and the `connectors_find` API
* [Manowar Tools](/manowar/tools/overview) — runtime tool surface and execution model
* [Onchain Tools](/manowar/tools/connectors/onchain-tools) — onchain connector internals
* [MCP Store](/manowar/tools/connectors/mcp-store) — MCP discovery and loading