One-time registration of a multi-sig Bitcoin wallet policy with the Ledger BTC app (BIP-388 wallet policies). REQUIREMENTS: Ledger plugged in over USB, device unlocked, the 'Bitcoin' app open on-screen. Constructs a wsh(sortedmulti(M,@0/,@1/,...)) descriptor from the supplied cosigners, verifies ...
AI agents use register_btc_multisig_wallet to create or update resources in VaultPilot MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your VaultPilot MCP environment.
| Parameter | Type | Required | Description |
|---|---|---|---|
name | string | Yes | User-chosen label for the multi-sig setup, e.g. "Family vault". Must be printable ASCII, ≤ 16 bytes (Ledger BTC app caps wallet-policy names at 16 bytes). Surfa |
cosigners | array | Yes | Cosigner slots in the order they should appear in the descriptor's `@N` slots. Slot order is part of the descriptor identity — every cosigner must agree on the |
threshold | integer | Yes | M in M-of-N. Must be ≥ 1 and ≤ cosigner count. Phase 2 hard-caps at 15 (the Ledger BTC app's wallet-policy limit). |
scriptType | string | Yes | Script type for the multi-sig wrapper. Phase 2 supports "wsh" only (P2WSH native segwit, `bc1q...`-style addresses). Taproot multi-sig and P2SH-wrapped multi-si |
Parameters from the server's own tool schema.
An AI agent can call register_btc_multisig_wallet faster than any human can review — one bad instruction and it creates or modifies resources in VaultPilot MCP by the hundred, each call as confident as the last.
Risk signalsBulk/mass operation — affects multiple targets
Attacks that exploit this kind of access
One-time registration of a multi-sig Bitcoin wallet policy with the Ledger BTC app (BIP-388 wallet policies). REQUIREMENTS: Ledger plugged in over USB, device unlocked, the 'Bitcoin' app open on-screen. Constructs a wsh(sortedmulti(M,@0/,@1/,...)) descriptor from the supplied cosigners, verifies the connected Ledger's master fingerprint matches exactly one cosigner slot, calls Ledger's registerWallet (the device walks every cosigner xpub fingerprint on-screen for verification — the user MUST confirm each fingerprint matches what they expect, since this is the moment that anchors the policy), and persists the descriptor + 32-byte HMAC. The HMAC is reused on every subsequent sign_btc_multisig_psbt call so the user only walks the descriptor approval flow once per setup. Phase 2 scope: P2WSH (wsh) only. Hard-validates every cosigner xpub via @scure/bip32 round-trip — typos that would silently register a wallet we can never sign with are refused up-front. It is categorised as a Write tool in the VaultPilot MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
register_btc_multisig_wallet accepts 4 parameters: name, cosigners, threshold, scriptType. Required: name, cosigners, threshold, scriptType. The full parameter table on this page comes from the server's own tool schema.
Register the VaultPilot MCP server in PolicyLayer and add a rule for register_btc_multisig_wallet: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches VaultPilot MCP. Nothing to install.
register_btc_multisig_wallet is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the register_btc_multisig_wallet rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for register_btc_multisig_wallet. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
register_btc_multisig_wallet is provided by the VaultPilot MCP server (vaultpilot-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.