Sei MCP Server (Rust)

A Model Context Protocol (MCP) server providing tools to interact with Sei EVM and Cosmos networks. It exposes wallet management, balances, faucet, transactions, contract utilities, token (ERC20/721/1155) helpers, and observability via SeiStream.

Quickstart

1) Installation (script)

curl -fsSL https://raw.githubusercontent.com/0xnvoid/seiyn-mcp/main/scripts/install.sh | GITHUB_REPO=0xnvoid/seiyn-mcp bash

Ensure your shell PATH includes ~/.local/bin so seiyn_mcp is discoverable:

echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.bashrc && source ~/.bashrc
# or zsh
echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.zshrc && source ~/.zshrc

2) Configure your MCP client (copiable)

Create or edit your mcp.json and add this entry:

{
  "mcpServers": {
    "sei-mcp": {
      "command": "seiyn_mcp",
      "args": ["--mcp"],
      "env": {
        "CHAIN_RPC_URLS": "{\"sei-evm-testnet\":\"https://evm-rpc-testnet.sei-apis.com\",\"atlantic-2\":\"https://rpc-testnet.sei-apis.com\",\"sei-evm-mainnet\":\"https://evm-rpc.sei-apis.com\",\"pacific-1\":\"https://sei-rpc.polkachu.com\"}",
        "FAUCET_API_URL": "https://sei-mcp.onrender.com",
        "DISCORD_API_URL": "https://sei-mcp-tdj3.onrender.com"
      }
    }
  }
}

Notes:

CHAIN_RPC_URLS is a JSON string map of chain_id -> rpc_url.
FAUCET_API_URL points to the optional faucet microservice in faucet-api/.
DISCORD_API_URL points to the optional Discord microservice (used by the post_discord_message tool). If unset, Discord-related tools will be unavailable.
You can also run locally without installing: set command to your built binary path and add cwd if needed.

Repository Structure

.
├── mcp-server/         # Rust MCP server and HTTP API
│   ├── src/
│   └── README.md       # Server-specific setup and tools
├── faucet-api/         # TypeScript faucet microservice (optional external service)
│   ├── src/
│   └── README.md       # Faucet endpoints, env, deploy
├── scripts/
│   └── install.sh      # Optional helper installer
└── README.md           # You are here (top-level overview)

Features

Wallets 👛

This category includes tools for creating, importing, and securely managing user wallets.

create_wallet: Generates a new EVM-compatible wallet, providing a new address, private key, and mnemonic phrase.
import_wallet: Imports an existing EVM wallet using a private key, returning the wallet's address and public key.
register_wallet: Encrypts a private key with a master password and saves it locally under a user-provided name for secure storage.
list_wallets: Lists the names of all wallets that have been securely registered. Requires the master password to view.
transfer_from_wallet: Executes a token transfer from a securely stored wallet. It requires the wallet's name and the master password to decrypt the private key for the transaction.

Balances & Faucet 💧

These tools are for checking account balances and acquiring testnet tokens.

get_balance: Fetches the native coin balance (e.g., SEI) for a given address on a specified chain.
request_faucet: Sends a request to a configured faucet to receive testnet tokens for a specific address.

Transfers 💸

This group of functions handles the movement of assets, from native coins to various token types.

transfer_evm: Sends a specified amount of the native EVM coin from one address to another using a provided private key.
transfer_sei: Executes a native Cosmos-based bank transfer for moving usei between Sei addresses.
transfer_nft_evm: Transfers a specific ERC-721 token from a sender to a receiver.
transfer_token: Transfers a specified amount of an ERC20 token to a recipient address.
transfer_erc1155: Transfers a specified amount of an ERC1155 token from one address to another.

Contracts 📜

These tools provide functionalities for interacting with and inspecting smart contracts.

get_contract: Retrieves general on-chain details about a smart contract from the SeiStream indexing service.
get_contract_code: Fetches the deployed bytecode for a smart contract at a given address.
get_contract_transactions: Obtains a history of transactions associated with a specific smart contract from SeiStream.
is_contract: Checks if a given address has smart contract code deployed to it, differentiating it from a standard wallet address.
read_contract: Performs a read-only call to a smart contract function without creating a transaction, using the contract's ABI to format the request.
write_contract: Creates and sends a signed transaction to execute a state-changing function on a smart contract, using its ABI.

Tokens 🪙

This section covers a wide range of tools for interacting with ERC20, ERC721, and ERC1155 token standards.

ERC20

get_token_info: Fetches standard metadata for an ERC20 token, such as its name, symbol, and decimal precision.
get_token_balance: Checks the balance of a specific ERC20 token held by a wallet address.
get_token_allowance: Checks the amount of an ERC20 token that a "spender" address is authorized to withdraw from an owner's address.
approve_token_spending: Grants a "spender" address permission to transfer a specified amount of an ERC20 token on the owner's behalf.

ERC721

get_nft_info: Retrieves the metadata URI (tokenURI) for a specific ERC-721 non-fungible token (NFT).
check_nft_ownership: Verifies the current owner of a specific ERC-721 token by its token ID.
get_nft_balance: Counts the total number of ERC-721 tokens from a specific contract that a wallet address owns.
get_nft_metadata: Fetches metadata for all ERC-721 items within a given contract from the SeiStream service.

ERC1155

get_erc1155_token_uri: Gets the metadata URI for a specific ERC1155 token ID.
get_erc1155_balance: Checks an address's balance of a specific token ID within an ERC1155 contract.

Chain & Tx ⛓️

These tools offer insights into the blockchain's status and transaction history.

get_chain_info: Retrieves general information about the blockchain from SeiStream, including the network name and latest block height.
get_transaction_info: Fetches detailed information about a single transaction using its unique hash from SeiStream.
get_transaction_history: Provides a list of past transactions for a given wallet address from SeiStream.
search_events: Queries the blockchain for specific log events emitted by smart contracts based on filters like address and topic.

Utilities 🛠️

This category contains miscellaneous helper tools.

discord_post_message: Sends a message to a pre-configured Discord channel via a webhook.
redirect_to_seidocs: Provides the URL for the official Sei documentation (https://docs.sei.io/).

Additional Installation Options

One-liner installer (adjust repo env if needed):

curl -fsSL https://raw.githubusercontent.com/0xnvoid/seiyn-mcp/main/scripts/install.sh | GITHUB_REPO=0xnvoid/seiyn-mcp bash

Or build locally:

cd mcp-server
cargo build --release

See mcp-server/README.md for detailed server usage and tool references.

Manual download and setup

If you prefer downloading a specific release asset (without the script):

# Set the tag you want
TAG=v0.1.0

# Pick the correct artifact for your OS/arch
# linux:   seiyn_mcp-linux-x86_64.tar.gz   or   seiyn_mcp-linux-arm64.tar.gz
# macOS:   seiyn_mcp-macos-x86_64.tar.gz   or   seiyn_mcp-macos-arm64.tar.gz
# windows: seiyn_mcp-windows-x86_64.zip    or   seiyn_mcp-windows-arm64.zip

ART=seiyn_mcp-linux-x86_64.tar.gz   # change to your OS/arch
curl -fsSL -o "$ART" "https://github.com/0xnvoid/seiyn-mcp/releases/download/${TAG}/${ART}"

# Extract and install (Linux/macOS)
tar -xzf "$ART"
install -m 0755 seiyn_mcp "$HOME/.local/bin/seiyn_mcp"

# Ensure PATH contains ~/.local/bin
case :$PATH: in
  *:"$HOME/.local/bin":*) ;; 
  *) echo 'export PATH="$HOME/.local/bin:$PATH"' >> "$HOME/.bashrc" ;;
esac

Note: Configure required env (e.g. CHAIN_RPC_URLS) in your MCP client entry.

Install via script (recommended)

The script downloads the latest release and installs the binary to ~/.local/bin.

curl -fsSL https://raw.githubusercontent.com/0xnvoid/seiyn-mcp/main/scripts/install.sh | GITHUB_REPO=0xnvoid/seiyn-mcp bash

Ensure your shell PATH includes ~/.local/bin:

echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.bashrc && source ~/.bashrc
# or for zsh:
echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.zshrc && source ~/.zshrc

After install, use the binary name seiyn_mcp in your MCP config (no absolute path needed if PATH is set).

Uninstall

To remove the MCP server installed via the script/manual steps, delete the binary:

rm -f "$HOME/.local/bin/seiyn_mcp"

If you added an entry in your MCP client config (e.g., mcp.json), you may also remove the sei-mcp entry there.

Configuration

Set chain RPC URLs in config (the server already loads from its internal config). Supported chain_id examples:

sei-evm-testnet
sei-evm-mainnet

Most tools accept chain_id or network (alias). If omitted, defaults to sei-evm-testnet.

MCP Tools (Highlights)

Below is a non-exhaustive list. See mcp-server/src/mcp/handler.rs for the canonical schemas.

get_balance
create_wallet, import_wallet
request_faucet
transfer_evm, transfer_sei
get_contract, get_contract_code, get_contract_transactions
get_chain_info, get_transaction_info, get_transaction_history
search_events
post_discord_message

Newly added token/contract tools:

get_token_info
get_token_balance
get_token_allowance
transfer_token
approve_token_spending
get_nft_info (ERC721 tokenURI)
check_nft_ownership (ERC721 ownerOf)
get_nft_balance (ERC721 balanceOf)
get_erc1155_token_uri
get_erc1155_balance
transfer_erc1155
is_contract
read_contract
write_contract

Usage (MCP Client)

Examples of tool calls (JSON-RPC-like payloads). Replace addresses and private keys accordingly.

ERC20 Info

{
  "method": "tools/call",
  "params": {"name": "get_token_info", "arguments": {"tokenAddress": "0x...", "chain_id": "sei-evm-testnet"}}
}

ERC20 Balance

{
  "method": "tools/call",
  "params": {"name": "get_token_balance", "arguments": {"tokenAddress": "0x...", "ownerAddress": "0x..."}}
}

ERC20 Allowance

{
  "method": "tools/call",
  "params": {"name": "get_token_allowance", "arguments": {"tokenAddress": "0x...", "ownerAddress": "0x...", "spenderAddress": "0x..."}}
}

ERC20 Transfer

{
  "method": "tools/call",
  "params": {"name": "transfer_token", "arguments": {"private_key": "<hex>", "tokenAddress": "0x...", "toAddress": "0x...", "amount": "1000000000000000000"}}
}

ERC20 Approve

{
  "method": "tools/call",
  "params": {"name": "approve_token_spending", "arguments": {"private_key": "<hex>", "tokenAddress": "0x...", "spenderAddress": "0x...", "amount": "115792089237316195423570985008687907853269984665640564039457584007913129639935"}}
}

The large amount above is 2^256 - 1 (max uint256), a common pattern for "infinite approval" so you don’t need to re-approve each transfer. Consider the security trade‑off: if the spender is compromised, it can spend up to that limit. Prefer smaller, purpose‑scoped allowances when appropriate.

ERC721 tokenURI

{
  "method": "tools/call",
  "params": {"name": "get_nft_info", "arguments": {"tokenAddress": "0x...", "tokenId": "1"}}
}

ERC1155 balance

{
  "method": "tools/call",
  "params": {"name": "get_erc1155_balance", "arguments": {"tokenAddress": "0x...", "tokenId": "1", "ownerAddress": "0x..."}}
}

Read Contract (ABI)

{
  "method": "tools/call",
  "params": {"name": "read_contract", "arguments": {"contractAddress": "0x...", "abi": "[ ... ABI JSON ... ]", "functionName": "balanceOf", "args": ["0x..."]}}
}

Write Contract (ABI)

{
  "method": "tools/call",
  "params": {"name": "write_contract", "arguments": {"private_key": "<hex>", "contractAddress": "0x...", "abi": "[ ... ABI JSON ... ]", "functionName": "approve", "args": ["0x...", "1000"]}}
}

Decoding

For many calls we return both raw (hex) and decoded (string/decimal) when possible. Consumers can rely on decoded for human-readable values.

Security

Never commit or log private keys/mnemonics.
Use the secure wallet storage tools for encryption at rest.
Testnet faucet is for development only.

Development

cargo build
cargo test

Key modules:

mcp-server/src/mcp/handler.rs: MCP dispatcher and tool registry
mcp-server/src/blockchain/client.rs: RPC orchestration
mcp-server/src/blockchain/services/: blockchain and utility services

Faucet Service

The server delegates testnet token requests to an external Faucet API. A reference implementation lives in faucet-api/.

Configure the server with FAUCET_API_URL (see mcp-server/mcp.json example below).
See faucet-api/README.md for its own environment and deploy instructions.

MCP client configuration example

If you use an MCP-capable client, add an entry. After installing with the script, prefer referencing the binary name directly and pass env inline:

{
  "mcpServers": {
    "sei-mcp": {
      "command": "seiyn_mcp",
      "args": ["--mcp"],
      "cwd": "/path/to/mcp-server", 
      "env": {
        "CHAIN_RPC_URLS": "{\"sei-evm-testnet\":\"https://evm-rpc-testnet.sei-apis.com\",\"atlantic-2\":\"https://rpc-testnet.sei-apis.com\",\"sei-evm-mainnet\":\"https://evm-rpc.sei-apis.com\",\"pacific-1\":\"https://sei-rpc.polkachu.com\"}",
        "FAUCET_API_URL": "https://sei-mcp.onrender.com",
        "PORT": "8080"
      }
    }
  }
}

Setup (env files)

Copy mcp-server/env.example to mcp-server/.env and adjust values.
If you deploy the faucet, copy faucet-api/env.example to faucet-api/.env and adjust values.

Name		Name	Last commit message	Last commit date
Latest commit History 50 Commits
.github/workflows		.github/workflows
discord-api		discord-api
faucet-api		faucet-api
mcp-server		mcp-server
scripts		scripts
README.md		README.md

0xnvoid/seiyn-mcp

Folders and files

Latest commit

History

Repository files navigation