MCP Server

Archer Protocol exposes its tools via a Model Context Protocol (MCP) server, allowing AI coding assistants and autonomous agents to interact with Web3 directly from their terminal or IDE.

What is MCP?

The Model Context Protocol is an open standard that enables AI tools to connect to external services. When you connect Claude Code, Cursor, or another MCP-compatible client to Archer's MCP server, the AI gains access to Archer's full suite of Web3 tools — token lookups, price checks, swap quotes, bridge quotes, and transaction execution — all without leaving your development environment.

What Can You Do?

With Archer's MCP server connected, you can ask your AI assistant to:

• Check token prices — "What's the current price of ETH?"

• Look up tokens — "Find the contract address for USDC on Arbitrum"

• Get swap quotes — "Quote swapping 100 USDC to ETH on Base"

• Get bridge quotes — "How much would it cost to bridge 0.5 ETH from Ethereum to Arbitrum?"

• Check balances — "What are my token balances across all chains?"

• Prepare transactions — "Swap 50 USDC to ETH on Base" (creates a transaction for you to approve in the webapp)

How It Works

Archer supports two connection models depending on the client:

Stdio Bridge (Claude Code, Claude Desktop)

Claude Code and Claude Desktop use a lightweight npm package that bridges stdio to Archer's remote server:

Your AI Assistant (Claude Code, Claude Desktop)
  |
  | stdio (stdin/stdout)
  |
  v
@archerprotocol/mcp-client (npm package, runs locally)
  |
  | Streamable HTTP (authenticated via API key)
  |
  v
Archer MCP Server (api.archerprotocol.com/mcp)
  |
  | Calls Archer's tools (resolve_token, get_token_price, get_swap_quote, etc.)
  |
  v
Archer Backend (intent parsing, multi-chain execution)
  |
  | If transaction needed:
  v
Webapp Approval Queue  -->  You sign in the browser  -->  Transaction submitted

Direct HTTP/SSE (Cursor, VS Code, Windsurf, etc.)

Most IDE-based clients connect directly to the remote endpoint:

Your AI Assistant (Cursor, VS Code, etc.)
  |
  | MCP Protocol (HTTP with x-api-key header)
  |
  v
Archer MCP Server (api.archerprotocol.com/mcp)
  |
  v
(same flow as above)

Why Two Models?

Claude Code's MCP client requires OAuth 2.1 for its internal auth state machine to transition to "authenticated" when using type: "http" or type: "sse" transports. Static API key headers authenticate at the HTTP layer but don't satisfy Claude Code's auth state tracking. The stdio bridge solves this cleanly — Claude Code launches the bridge as a subprocess (like any stdio MCP server) and the bridge handles authentication with Archer's API. This is the same pattern used by Stripe, Supabase, Neon, and other production MCP providers.

Transaction Approval Flow

When your AI assistant initiates a transaction (swap, bridge, or send):

1. The MCP server prepares the unsigned transaction and creates a Pending Approval

2. Your Archer webapp shows a notification with the transaction details

3. You review and Approve or Reject the transaction in the browser

4. If approved, the transaction is signed with your Privy embedded wallet and submitted on-chain

5. The MCP server receives the result and reports back to your AI assistant

This human-in-the-loop model ensures you always have full control over your funds. No transaction is ever submitted without your explicit consent.

Supported Tools

Tool	Description	Requires Approval
resolve_token	Look up token metadata (address, decimals, chain)	No
get_token_price	Get current USD price for any token	No
get_user_balances	Fetch your balances across all chains	No
get_chain_capabilities	List supported chains and their configs	No
get_swap_quote	Get a swap quote without executing	No
get_bridge_quote	Get a bridge quote without executing	No
check_feasibility	Validate balance + chain compatibility	No
check_approval_status	Check status of a pending transaction approval	No
prepare_swap_tx	Build a swap transaction for signing	Yes
prepare_bridge_tx	Build a bridge transaction for signing	Yes
prepare_send_tx	Build a send/transfer transaction for signing	Yes

Getting Started

1. Create an API Key in the Archer webapp

2. Connect your client (Claude Code, Cursor, VS Code, etc.)

3. Start prompting your AI assistant with Web3 queries

Compute Units (CU)

Every MCP tool call consumes Compute Units (CU). Your account includes a free monthly CU allowance. Read-only operations (price checks, token lookups) cost fewer CUs than transaction operations (swaps, bridges).

See the Developer Portal for usage tracking and billing details.