Pair the host's directly-connected Ledger device for Bitcoin signing. REQUIREMENTS: Ledger plugged in over USB, device unlocked, the 'Bitcoin' app open on-screen. Ledger Live's WalletConnect relay does NOT expose bip122 accounts to dApps, so Bitcoin signing goes over USB HID via @ledgerhq/hw-app-...
AI agents call pair_ledger_btc to retrieve information from VaultPilot MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
| Parameter | Type | Required | Description |
|---|---|---|---|
gapLimit | integer | — | BIP44 gap limit — stop walking each (type, chain) after this many consecutive addresses with zero on-chain history. Default 20 (matches Electrum / Sparrow / Tre |
accountIndex | integer | — | Ledger Bitcoin account slot. One call enumerates ALL FOUR address types for the given index (legacy at `44'/0'/<n>'/...`, p2sh-segwit at `49'/0'/<n>'/...`, nati |
Parameters from the server's own tool schema.
Even though pair_ledger_btc only reads data, uncontrolled read access leaks sensitive information and racks up API costs — an agent caught in a retry loop can make thousands of calls a minute without anyone noticing.
Attacks that exploit this kind of access
Pair the host's directly-connected Ledger device for Bitcoin signing. REQUIREMENTS: Ledger plugged in over USB, device unlocked, the 'Bitcoin' app open on-screen. Ledger Live's WalletConnect relay does NOT expose bip122 accounts to dApps, so Bitcoin signing goes over USB HID via @ledgerhq/hw-app-btc (same USB path as Solana / TRON). ONE CALL ENUMERATES ALL FOUR ADDRESS TYPES for the requested accountIndex (default 0): legacy P2PKH (44'/0'/<n>'/0/0 → 1...), P2SH-wrapped segwit (49'/0'/<n>'/0/0 → 3...), native segwit P2WPKH (84'/0'/<n>'/0/0 → bc1q...), and taproot P2TR (86'/0'/<n>'/0/0 → bc1p...). All four are cached so get_ledger_status can report them under the bitcoin: [...] section. Call again with a different accountIndex to expose additional accounts. Read-only on the device — the Ledger BTC app does not prompt during getWalletPublicKey by default. Phase 1 is mainnet-only. It is categorised as a Read tool in the VaultPilot MCP MCP Server, which means it retrieves data without modifying state.
pair_ledger_btc accepts 2 parameters: gapLimit, accountIndex. 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 pair_ledger_btc: 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.
pair_ledger_btc is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the pair_ledger_btc 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 pair_ledger_btc. 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.
pair_ledger_btc 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.