Chain Signer
by Kevthetech143communityv0.5.31
chain-signer provides MCP tools and Python helpers to analyze unsigned EVM transactions, inspect EIP-712 typed data, and enforce action policies before an agent signs or executes them. It also includes a non-custodial wallet for creating, restoring, sending, swapping, and signing locally, with optional Bitcoin and Solana support.
From the registry: Security suite for AI agents: flag drains, permit-phishing & risky actions before signing.
Install & configure
Prerequisites
- requiredInstall chain-signer Python packageInstall the MCP server package from PyPI.
$ pip install chain-signer - optionalOptional API key for live balance reads and broadcastingSet an Etherscan API key if you want live balance reads and transaction broadcasting. The MCP server can run without it for read-only/offline guard functionality.
$ export ETHERSCAN_API_KEY=<your-api-key>
Install in your client
Paste into the AI you're chatting with — it will figure out the rest
Please install the `chain-signer` MCP server into my current AI client (that's you).
Required prerequisites (do these first if not already done):
- **Install chain-signer Python package** — Install the MCP server package from PyPI. Run: `pip install chain-signer`
Optional prerequisites:
- Optional API key for live balance reads and broadcasting — Set an Etherscan API key if you want live balance reads and transaction broadcasting. The MCP server can run without it for read-only/offline guard functionality. Run: `export ETHERSCAN_API_KEY=<your-api-key>`
Canonical MCP server config (stdio transport):
- command: `chain-signer-mcp`
- args: []
- optional environment variables:
- `ETHERSCAN_API_KEY`: Etherscan v2 API key for live balance reads and broadcasting; not required for offline/read-only guard tools. (example: `<your-api-key>`)
Note: The MCP server is started via the `chain-signer-mcp` CLI and communicates over stdio. README also notes `python -m chain_signer ...` for the general CLI, but the documented MCP entrypoint is `chain-signer-mcp`. Optional extras `pip install "chain-signer[all]"` add Bitcoin/Solana support, but the simplest portable install is `pip install chain-signer`.
Add this MCP server to my current client's config in the correct format for you. If you need secrets or credentials I haven't provided, ASK me — do not invent values or leave raw placeholders. After adding it, tell me how to verify the server is connected.Note: The MCP server is started via the `chain-signer-mcp` CLI and communicates over stdio. README also notes `python -m chain_signer ...` for the general CLI, but the documented MCP entrypoint is `chain-signer-mcp`. Optional extras `pip install "chain-signer[all]"` add Bitcoin/Solana support, but the simplest portable install is `pip install chain-signer`.
Tools (9)
preflight
Decode an unsigned transaction and flag known drain or risky approval patterns before signing.
inspect_signature
Inspect EIP-712 typed data for permit-phishing and giveaway-style marketplace orders before signing.
check_action
Enforce allow/forbid rules and value/recipient limits on a proposed action before it runs.
create_wallet
Create a new non-custodial wallet.
get_balance
Fetch a wallet’s live on-chain balance.
send
Send funds from a wallet with nonce, gas, and broadcast handled locally.
call_contract
Call a contract from the wallet tooling.
swap
Swap tokens through supported providers.
bridge
Bridge assets across chains.
Environment variables
ETHERSCAN_API_KEYrequiredUsed for live balance reads and transaction broadcast via Etherscan v2.Packages
chain-signer
pypiv0.5.31transport: stdio
Details
- Language
- Python
- License
- MIT
- Released
- Jun 12, 2026
- Last commit
- Jun 10, 2026
- Registry name
- io.github.Kevthetech143/chain-signer