Vultisig MCP Server

An MCP server that exposes Vultisig vault operations, multi-chain balance queries, transaction building, and DeFi protocol interactions to LLM-powered agents. Supports both stdio and HTTP transports.

Quick Start

# Build
go build -o mcp-server ./cmd/mcp-server/

# Run over stdio (default)
./mcp-server

# Run over HTTP on port 8080
./mcp-server -http :8080

Environment Variables

Variable	Default	Description
`EVM_ETHEREUM_URL`	`https://ethereum-rpc.publicnode.com`	Ethereum JSON-RPC endpoint
`EVM_BSC_URL`	`https://bsc-rpc.publicnode.com`	BNB Smart Chain JSON-RPC endpoint
`EVM_POLYGON_URL`	`https://polygon-bor-rpc.publicnode.com`	Polygon JSON-RPC endpoint
`EVM_AVALANCHE_URL`	`https://avalanche-c-chain-rpc.publicnode.com`	Avalanche C-Chain JSON-RPC endpoint
`EVM_ARBITRUM_URL`	`https://arbitrum-one-rpc.publicnode.com`	Arbitrum One JSON-RPC endpoint
`EVM_OPTIMISM_URL`	`https://optimism-rpc.publicnode.com`	Optimism JSON-RPC endpoint
`EVM_BASE_URL`	`https://base-rpc.publicnode.com`	Base JSON-RPC endpoint
`EVM_BLAST_URL`	`https://blast-rpc.publicnode.com`	Blast JSON-RPC endpoint
`EVM_MANTLE_URL`	`https://mantle-rpc.publicnode.com`	Mantle JSON-RPC endpoint
`EVM_ZKSYNC_URL`	`https://mainnet.era.zksync.io`	zkSync Era JSON-RPC endpoint
`BLOCKCHAIR_API_URL`	`https://api.vultisig.com/blockchair`	Blockchair proxy base URL for UTXO chain queries
`THORCHAIN_URL`	`https://thornode.ninerealms.com`	THORChain node URL for fee rates (BTC, LTC, DOGE, BCH)
`MAYACHAIN_URL`	`https://mayanode.mayachain.info`	MayaChain node URL for fee rates (DASH, ZEC)
`SOLANA_RPC_URL`	`https://api.mainnet-beta.solana.com`	Solana JSON-RPC endpoint
`JUPITER_API_URL`	`https://api.jup.ag`	Jupiter DEX aggregator API base URL
`XRP_RPC_URL`	`https://s1.ripple.com:51234`	XRP Ledger JSON-RPC endpoint
`VERIFIER_URL`	`""`	Verifier service base URL — enables plugin management tools when set
`VERIFIER_API_KEY`	`""`	Service-to-service key sent as `X-Service-Key` for user-specific verifier queries

Tools

Vault

`set_vault_info`

Store vault key material for the current session. Must be called before any vault-derived address or balance queries.

Parameter	Required	Description
`ecdsa_public_key`	Yes	Hex-encoded compressed ECDSA public key (33 bytes / 66 hex chars)
`eddsa_public_key`	Yes	Hex-encoded EdDSA public key (32 bytes / 64 hex chars)
`chain_code`	Yes	Hex-encoded 32-byte chain code for BIP-32 derivation

`get_address`

Derive the address for a given blockchain network from vault key material. Requires set_vault_info first.

Parameter	Required	Description
`chain`	Yes	Blockchain network name (see supported chains below)

Supported chains: Arbitrum, Avalanche, Base, Bitcoin, Bitcoin-Cash, Blast, BSC, Cosmos, CronosChain, Dash, Dogecoin, Dydx, Ethereum, Kujira, Litecoin, Mantle, MayaChain, Noble, Optimism, Osmosis, Polygon, Ripple, Solana, Sui, Terra, TerraClassic, THORChain, Tron, Zcash, Zksync.

Token Discovery

`search_token`

Search for tokens by ticker symbol, name, or contract address via CoinGecko. Returns token metadata and all known contract deployments across chains, ranked by market cap.

Parameter	Required	Description
`query`	Yes	Ticker (e.g. `USDC`), name (e.g. `Uniswap`), or contract address

EVM (multi-chain)

All EVM tools accept a chain parameter (default: Ethereum). Supported chains: Ethereum, BSC, Polygon, Avalanche, Arbitrum, Optimism, Base, Blast, Mantle, Zksync.

`evm_get_balance`

Query the native coin balance of an address. Address falls back to vault-derived if omitted.

Parameter	Required	Description
`chain`	No	EVM chain name (default: `Ethereum`)
`address`	No	Wallet address. Falls back to vault-derived if omitted.

`evm_get_token_balance`

Query an ERC-20 token balance. Returns symbol, balance, and decimals.

Parameter	Required	Description
`chain`	No	EVM chain name (default: `Ethereum`)
`contract_address`	Yes	ERC-20 token contract address (0x-prefixed)
`address`	No	Holder address. Falls back to vault-derived if omitted.

`evm_check_allowance`

Check how much of an ERC-20 token a spender is allowed to transfer. Used to determine if an approve transaction is needed before a swap or protocol interaction.

Parameter	Required	Description
`chain`	No	EVM chain name (default: `Ethereum`)
`contract_address`	Yes	ERC-20 token contract address (0x-prefixed)
`owner`	No	Token holder address. Falls back to vault-derived if omitted.
`spender`	Yes	Address allowed to spend tokens (e.g. DEX router contract)

`evm_tx_info`

Get nonce, gas prices, and chain ID for building an EVM transaction. Optionally estimates gas if to/data/value are provided.

Parameter	Required	Description
`chain`	No	EVM chain name (default: `Ethereum`)
`address`	No	Sender address. Falls back to vault-derived if omitted.
`to`	No	Destination address for gas estimation
`data`	No	Hex calldata for gas estimation
`value`	No	Wei value for gas estimation (decimal string)

`evm_call`

Execute a read-only eth_call against a contract. Returns raw hex output and optionally decodes it.

Parameter	Required	Description
`chain`	No	EVM chain name (default: `Ethereum`)
`to`	Yes	Contract address (0x-prefixed)
`data`	Yes	Hex-encoded calldata (0x-prefixed)
`from`	No	Sender address for call context
`value`	No	Wei value to send with the call (decimal string)
`block`	No	Block number (decimal) or `"latest"` (default)
`output_types`	No	Comma-separated ABI types to decode output (e.g. `"uint256,address"`)

`build_evm_tx`

Build an unsigned EIP-1559 (type 2) transaction for any EVM chain. Obtain fee/nonce parameters from evm_tx_info first.

Parameter	Required	Description
`chain`	No	EVM chain name (default: `Ethereum`). Sets `chain_id` when not explicitly overridden.
`to`	Yes	Destination address (0x-prefixed)
`value`	Yes	Wei value to transfer (decimal string)
`nonce`	Yes	Sender nonce (decimal string)
`gas_limit`	Yes	Gas limit (decimal string)
`max_fee_per_gas`	Yes	Max fee per gas in wei (decimal string)
`max_priority_fee_per_gas`	Yes	Max priority fee (tip) per gas in wei (decimal string)
`data`	No	Hex-encoded calldata (default `"0x"`)
`chain_id`	No	Chain ID override (decimal string)

Swaps

`build_swap_tx`

Build unsigned transaction(s) for a token swap. Supports THORChain, MayaChain, 1inch, LiFi, Jupiter, and Uniswap. Returns the swap transaction and an optional ERC-20 approval transaction.

Parameter	Required	Description
`from_chain`	Yes	Source chain (e.g. `"Ethereum"`, `"Bitcoin"`)
`from_symbol`	Yes	Source token symbol (e.g. `"ETH"`, `"USDC"`)
`from_address`	No	Source token contract address (empty for native coins)
`from_decimals`	Yes	Source token decimals (e.g. `18` for ETH, `6` for USDC)
`to_chain`	Yes	Destination chain
`to_symbol`	Yes	Destination token symbol
`to_address`	No	Destination token contract address (empty for native coins)
`to_decimals`	Yes	Destination token decimals
`amount`	Yes	Amount in base units (e.g. `"1000000"` for 1 USDC)
`sender`	Yes	Sender wallet address
`destination`	Yes	Destination wallet address

Bitcoin

`btc_fee_rate`

Get the recommended Bitcoin fee rate in sat/vB from THORChain. No parameters.

`build_btc_send`

Build an unsigned Bitcoin PSBT for a send or swap. Automatically selects UTXOs, calculates fees, and handles change. Requires set_vault_info first.

Parameter	Required	Description
`to_address`	Yes	Recipient Bitcoin address (or THORChain vault address for swaps)
`amount`	Yes	Amount to send in satoshis (decimal string)
`fee_rate`	Yes	Fee rate in sat/vB (use `btc_fee_rate` tool to get recommended rate)
`memo`	No	OP_RETURN memo (e.g. THORChain swap instruction, max 80 bytes)
`address`	No	Sender Bitcoin address. Falls back to vault-derived if omitted.

Litecoin

`ltc_fee_rate`

Get the recommended Litecoin fee rate in sat/vB from THORChain. No parameters.

`build_ltc_send`

Build an unsigned Litecoin PSBT for a send or swap. Requires set_vault_info first.

Parameter	Required	Description
`to_address`	Yes	Recipient Litecoin address
`amount`	Yes	Amount to send in litoshis (decimal string)
`fee_rate`	Yes	Fee rate in sat/vB (use `ltc_fee_rate` to get recommended rate)
`memo`	No	OP_RETURN memo (e.g. THORChain swap instruction, max 80 bytes)
`address`	No	Sender Litecoin address. Falls back to vault-derived if omitted.

Dogecoin

`doge_fee_rate`

Get the recommended Dogecoin fee rate in sat/vB from THORChain. No parameters.

`build_doge_send`

Build an unsigned Dogecoin PSBT for a send or swap. Requires set_vault_info first.

Parameter	Required	Description
`to_address`	Yes	Recipient Dogecoin address
`amount`	Yes	Amount to send in koinus (1 DOGE = 100,000,000 koinus, decimal string)
`fee_rate`	Yes	Fee rate in sat/vB (use `doge_fee_rate` to get recommended rate)
`memo`	No	OP_RETURN memo (e.g. THORChain swap instruction, max 80 bytes)
`address`	No	Sender Dogecoin address. Falls back to vault-derived if omitted.

Bitcoin Cash

`bch_fee_rate`

Get the recommended Bitcoin Cash fee rate in sat/vB from THORChain. No parameters.

`build_bch_send`

Build an unsigned Bitcoin Cash PSBT for a send or swap. Requires set_vault_info first.

Parameter	Required	Description
`to_address`	Yes	Recipient Bitcoin Cash address (CashAddr or legacy format)
`amount`	Yes	Amount to send in satoshis (decimal string)
`fee_rate`	Yes	Fee rate in sat/vB (use `bch_fee_rate` to get recommended rate)
`memo`	No	OP_RETURN memo (e.g. THORChain swap instruction, max 80 bytes)
`address`	No	Sender Bitcoin Cash address. Falls back to vault-derived if omitted.

Dash

`dash_fee_rate`

Get the recommended Dash fee rate in sat/vB from MayaChain. No parameters.

`build_dash_send`

Build an unsigned Dash PSBT for a send or swap. Requires set_vault_info first.

Parameter	Required	Description
`to_address`	Yes	Recipient Dash address
`amount`	Yes	Amount to send in duffs (1 DASH = 100,000,000 duffs, decimal string)
`fee_rate`	Yes	Fee rate in sat/vB (use `dash_fee_rate` to get recommended rate)
`memo`	No	OP_RETURN memo (e.g. MayaChain swap instruction, max 80 bytes)
`address`	No	Sender Dash address. Falls back to vault-derived if omitted.

Zcash

`build_zec_send`

Build an unsigned Zcash v4 (Sapling) transaction for a send or swap. Fee is calculated automatically using ZIP-317 — no fee_rate parameter needed. Requires set_vault_info first.

Parameter	Required	Description
`to_address`	Yes	Recipient Zcash transparent address (t1... or t3...)
`amount`	Yes	Amount to send in zatoshis (1 ZEC = 100,000,000 zatoshis, decimal string)
`memo`	No	OP_RETURN memo (e.g. MayaChain swap instruction, max 80 bytes)
`address`	No	Sender Zcash address. Falls back to vault-derived if omitted.

MayaChain

`maya_fee_rate`

Get the recommended fee rate for any MayaChain-supported chain in sat/vB.

Parameter	Required	Description
`chain`	Yes	MayaChain chain identifier: `BTC`, `ETH`, `ARB`, `ZEC`, `DASH`, or `THOR`

Solana

`get_sol_balance`

Query the native SOL balance of a Solana address.

Parameter	Required	Description
`address`	No	Solana address (base58). Falls back to vault-derived if omitted.

`get_spl_token_balance`

Query the SPL token balance of a Solana address for a given mint.

Parameter	Required	Description
`mint`	Yes	Token mint address (base58)
`address`	No	Solana address (base58). Falls back to vault-derived if omitted.

`build_solana_tx`

Build an unsigned native SOL transfer transaction. Requires set_vault_info first.

Parameter	Required	Description
`to`	Yes	Recipient Solana address (base58)
`amount`	Yes	Amount in lamports (decimal string)
`from`	No	Sender Solana address. Falls back to vault-derived if omitted.

`build_spl_transfer_tx`

Build an unsigned SPL token transfer transaction. Auto-detects token program (SPL vs Token-2022) and creates the destination ATA if it doesn't exist. Requires set_vault_info first.

Parameter	Required	Description
`to`	Yes	Recipient Solana address (base58, the owner — not the ATA)
`mint`	Yes	Token mint address (base58)
`amount`	Yes	Amount in base units (decimal string)
`from`	No	Sender Solana address. Falls back to vault-derived if omitted.

`build_solana_swap`

Build an unsigned Solana swap transaction via Jupiter aggregator. Requires set_vault_info first.

Parameter	Required	Description
`output_mint`	Yes	Destination token mint address (base58). Leave empty for native SOL.
`amount`	Yes	Amount to swap in base units (lamports for SOL, smallest unit for tokens)
`input_mint`	No	Source token mint address (base58). Empty for native SOL.
`slippage_bps`	No	Slippage tolerance in basis points (default: 100 = 1%)
`from`	No	Sender Solana address. Falls back to vault-derived if omitted.

XRP (Ripple)

`get_xrp_balance`

Query the native XRP balance of an XRP Ledger address.

Parameter	Required	Description
`address`	No	XRP Ledger address. Falls back to vault-derived if omitted.

`build_xrp_send`

Build an unsigned XRP Ledger Payment transaction. Automatically fetches sequence number, current ledger, and base fee. Requires set_vault_info first.

Parameter	Required	Description
`to`	Yes	Recipient XRP address (or THORChain vault address for swaps)
`amount`	Yes	Amount in drops (1 XRP = 1,000,000 drops, decimal string)
`memo`	No	THORChain swap memo (ASCII). Gets hex-encoded into the XRPL Memos field.
`from`	No	Sender XRP address. Falls back to vault-derived if omitted.

Encoding / Utilities

`abi_encode`

ABI-encode a Solidity function call or pack raw arguments. Handles 4-byte selector prepending for function calls.

Parameter	Required	Description
`signature`	Yes	Function signature (e.g. `"transfer(address,uint256)"`) or bare types (e.g. `"uint256,address"`)
`args`	Yes	Array of argument values as strings (addresses as `0x`-hex, integers as decimal)

`abi_decode`

ABI-decode hex-encoded calldata or return data.

Parameter	Required	Description
`signature`	Yes	Function signature or bare types string
`data`	Yes	Hex-encoded data to decode (0x-prefixed)

`convert_amount`

Convert between human-readable and base unit amounts.

Parameter	Required	Description
`amount`	Yes	Amount to convert
`decimals`	Yes	Number of decimal places (e.g. `18` for ETH, `6` for USDC)
`direction`	Yes	`"to_base"` (human→base) or `"to_human"` (base→human)

Aave V3 (Ethereum)

Aave V3 tools operate on Ethereum mainnet only.

`aave_v3_deposit`

Build unsigned transactions to deposit (supply) tokens into Aave V3. Returns an approve tx and a supply tx.

Parameter	Required	Description
`asset`	Yes	ERC-20 token contract address (0x-prefixed)
`amount`	Yes	Amount in human-readable units (e.g. `"100.5"`) or `"max"` for full balance
`address`	No	Depositor's Ethereum address. Falls back to vault-derived if omitted.

`aave_v3_withdraw`

Build an unsigned transaction to withdraw tokens from Aave V3.

Parameter	Required	Description
`asset`	Yes	ERC-20 token contract address (0x-prefixed)
`amount`	Yes	Amount in human-readable units or `"max"` for full withdrawal
`address`	No	Withdrawer's Ethereum address. Falls back to vault-derived if omitted.

`aave_v3_borrow`

Build an unsigned transaction to borrow tokens from Aave V3 at variable rate.

Parameter	Required	Description
`asset`	Yes	ERC-20 token contract address (0x-prefixed)
`amount`	Yes	Amount in human-readable units
`address`	No	Borrower's Ethereum address. Falls back to vault-derived if omitted.

`aave_v3_repay`

Build unsigned transactions to repay a borrow on Aave V3. Returns an approve tx and a repay tx.

Parameter	Required	Description
`asset`	Yes	ERC-20 token contract address (0x-prefixed)
`amount`	Yes	Amount in human-readable units or `"max"` to repay entire debt
`address`	No	Repayer's Ethereum address. Falls back to vault-derived if omitted.

`aave_v3_get_balances`

Query Aave V3 account summary: total collateral, debt, available borrows (USD), LTV, and health factor.

Parameter	Required	Description
`address`	No	Ethereum address. Falls back to vault-derived if omitted.

`aave_v3_get_rates`

Query Aave V3 supply APY, variable borrow APY, and reserve configuration for a token.

Parameter	Required	Description
`asset`	Yes	ERC-20 token contract address (0x-prefixed)

Plugin Management

These tools are only registered when VERIFIER_URL is set. They allow the agent to query plugin installation and billing status and to build plugin configurations.

`get_recipe_schema`

Fetch the configuration schema and examples for a plugin. Returns supported resources, parameter constraints, and configuration examples.

Parameter	Required	Description
`plugin_id`	Yes	Plugin identifier (e.g. `vultisig-dca`)

`suggest_policy`

Validate a plugin configuration and get the resulting policy rules. Call after get_recipe_schema.

Parameter	Required	Description
`plugin_id`	Yes	Plugin identifier
`configuration`	Yes	Plugin configuration as a JSON object string matching the recipe schema

`check_plugin_installed`

Check whether a plugin is installed for the current session's vault. Requires set_vault_info first. Requires VERIFIER_API_KEY to be configured.

Parameter	Required	Description
`plugin_id`	Yes	Plugin identifier to check

`check_billing_status`

Check whether the current session's vault has active billing (free trial or billing plugin installed). Requires set_vault_info first. Requires VERIFIER_API_KEY to be configured.

No parameters.

MCP Client Configuration

Stdio (default)

{
  "mcpServers": {
    "vultisig": {
      "command": "/path/to/mcp-server",
      "env": {
        "EVM_ETHEREUM_URL": "https://ethereum-rpc.publicnode.com"
      }
    }
  }
}

HTTP

# Start the server
./mcp-server -http :8080

# MCP endpoint: POST/GET/DELETE http://localhost:8080/mcp

{
  "mcpServers": {
    "vultisig": {
      "url": "http://localhost:8080/mcp"
    }
  }
}

Name		Name	Last commit message	Last commit date
Latest commit History 177 Commits
.claude		.claude
.github		.github
cmd/mcp-server		cmd/mcp-server
deploy		deploy
internal		internal
.coderabbit.yaml		.coderabbit.yaml
.env.example		.env.example
.gitignore		.gitignore
.mcp.json		.mcp.json
AGENTS.md		AGENTS.md
CLAUDE.md		CLAUDE.md
CONTRIBUTING-SKILLS.md		CONTRIBUTING-SKILLS.md
Dockerfile		Dockerfile
README.md		README.md
flake.lock		flake.lock
flake.nix		flake.nix
go.mod		go.mod
go.sum		go.sum
main.go		main.go

Folders and files

Latest commit

History

Repository files navigation

Vultisig MCP Server

Quick Start

Environment Variables

Tools

Vault

set_vault_info

get_address

Token Discovery

search_token

EVM (multi-chain)

evm_get_balance

evm_get_token_balance

evm_check_allowance

evm_tx_info

evm_call

build_evm_tx

Swaps

build_swap_tx

Bitcoin

btc_fee_rate

build_btc_send

Litecoin

ltc_fee_rate

build_ltc_send

Dogecoin

doge_fee_rate

build_doge_send

Bitcoin Cash

bch_fee_rate

build_bch_send

Dash

dash_fee_rate

build_dash_send

Zcash

build_zec_send

MayaChain

maya_fee_rate

Solana

get_sol_balance

get_spl_token_balance

build_solana_tx

build_spl_transfer_tx

build_solana_swap

XRP (Ripple)

get_xrp_balance

build_xrp_send

Encoding / Utilities

abi_encode

abi_decode

convert_amount

Aave V3 (Ethereum)

aave_v3_deposit

aave_v3_withdraw

aave_v3_borrow

aave_v3_repay

aave_v3_get_balances

aave_v3_get_rates

Plugin Management

get_recipe_schema

suggest_policy

check_plugin_installed

check_billing_status

MCP Client Configuration

Stdio (default)

HTTP

About

Resources

Uh oh!

Stars

Watchers

Forks

Releases 2

Packages 0

Uh oh!

Contributors

Uh oh!

`set_vault_info`

`get_address`

`search_token`

`evm_get_balance`

`evm_get_token_balance`

`evm_check_allowance`

`evm_tx_info`

`evm_call`

`build_evm_tx`

`build_swap_tx`

`btc_fee_rate`

`build_btc_send`

`ltc_fee_rate`

`build_ltc_send`

`doge_fee_rate`

`build_doge_send`

`bch_fee_rate`

`build_bch_send`

`dash_fee_rate`

`build_dash_send`

`build_zec_send`

`maya_fee_rate`

`get_sol_balance`

`get_spl_token_balance`

`build_solana_tx`

`build_spl_transfer_tx`

`build_solana_swap`

`get_xrp_balance`

`build_xrp_send`

`abi_encode`

`abi_decode`

`convert_amount`

`aave_v3_deposit`

`aave_v3_withdraw`

`aave_v3_borrow`

`aave_v3_repay`

`aave_v3_get_balances`

`aave_v3_get_rates`

`get_recipe_schema`

`suggest_policy`

`check_plugin_installed`

`check_billing_status`

Packages