Lightning Wallet MCP

keysend

Send spontaneous payments directly to any Lightning node without an invoice. Specify destination public key and amount in satoshis, optionally include a TLV message.

Instructions

Send a payment directly to a node without an invoice (keysend/spontaneous payment). REQUIRES AGENT KEY.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "destination": "<destination>",
      "amount_sats": "<amount_sats>"
    },
    "name": "keysend"
  }
}

Input Schema

Name	Required	Description
`message`	No	Optional TLV message
`amount_sats`	Yes	Amount in satoshis
`destination`	Yes	Destination node public key

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.2.9Mar 23, 2026

TDQS

B3.3/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations provided; description carries full burden. Mentions 'keysend/spontaneous payment' and agent key requirement but fails to disclose that sending funds is irreversible, rate limits, or failure scenarios. Lacks critical behavioral context for a payment tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Single sentence plus mandatory note; no wasted words. Front-loaded with clear action and method.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema; description does not explain return value or confirmation. Complexity is moderate (payment), but missing post-action info makes it adequate rather than complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema covers 100% of parameter descriptions, so baseline is 3. The tool description adds no parameter-specific meaning beyond what schema provides; the note about agent key is a prerequisite, not a parameter detail.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

Clearly states verb 'send', resource 'payment to a node', and method 'keysend/spontaneous payment'. Distinguishes from siblings like pay_invoice and pay_lightning_address by specifying no invoice required.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines2/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

No guidance on when to use this tool vs alternatives like pay_invoice or pay_lightning_address. Only mentions prerequisite 'REQUIRES AGENT KEY' but no contextual cues for selection.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server