MCP server

@integraledger/lcp-mcp-server is the LCP delivery surface for MCP. An agent host that already speaks the Model Context Protocol gains legal-context capability with no per-platform integration — and the same server works whichever commerce protocol the agent is transacting under, because where a reference belongs is the placement registry's decision, not this server's.

npm install @integraledger/lcp-mcp-server

Every tool is read-only and works against any counterparty's documents — whether or not they use Integra software. Nothing here calls home: no telemetry, no callback.

Run it over stdio

Which is what every desktop agent host speaks:

// .mcp.json
{
  "mcpServers": {
    "lcp": { "command": "npx", "args": ["-y", "@integraledger/lcp-mcp-server"] }
  }
}

Or mount it yourself

import {
  createLcpMcpServer,
  nodePorts,
  serveLcpStdio,
} from "@integraledger/lcp-mcp-server";

const ports = nodePorts(process.env);

serveLcpStdio(ports); // stdio, ports wired for Node
const server = createLcpMcpServer(ports); // or build one and connect any MCP transport

createLcpMcpServer is a factory, not a singleton, because that is what the transports want: they may build one instance per connection. Handing them a shared instance would make one client's state another's.

Ports

LcpMcpPorts has no defaults, and both entries are the reason.

fetcher

The buyer gate's own makeCachingFetcher: HTTPS-only, redirect: "error", every resolved address checked public unicast on every network fetch, body capped while streaming, LCP §2.6 cache discipline.

The URLs this server fetches are chosen by a counterparty. Bare fetch here would turn lcp_verify_before_pay into an SSRF primitive an agent can be talked into aiming anywhere. That is not hardening — it is the minimum.

deployment.reverseDomain

Optional, and absent by default. Only namespaced placements need it — Mastercard VI's custom Layer-2 constraint type.

LCP §8 canonizes no per-protocol integration profile, so a default would write our domain into someone else's signed document in every deployment that forgot to set it. Set LCP_MCP_REVERSE_DOMAIN and nodePorts passes it through; unset, that one placement throws and names what is missing, and every other tool is unaffected.

The LCP capability declaration

The server declares an LCP extension capability in its constructor, carrying the specification version the stack implements.

That is deliberately asserted rather than derived. tools is left to the registrations because the SDK derives it — restating it in the constructor would be a second statement of a fact something else owns. An extension has no such deriver: nothing about registering a tool implies this server speaks LCP, so the constructor is the only place the declaration can come from.

Both values are imported, never spelled locally: the identifier is a wire identity a counterparty must recognize, and the specification version is the kernel's own answer to which revision this stack implements.

One protocol line in the tree

This server declares the protocol line as a caret at the minor's zero patch, and agent-guard peers it the same way. That is what puts one line of the protocol packages in node_modules when you install both: the two ranges overlap, so a package manager resolves a single copy satisfying each.

An exact runtime pin would do the opposite — it cannot be satisfied by the sibling's range, so the resolver nests a second copy underneath, and the two halves of one install then read different protocol code.

If a mixed install ever does put two lines in one tree, the seam stays safe. What this package takes from agent-guard is the fetcher and nothing else: makeCachingFetcher, nodeDnsLookup, and the TermsFetcher type — whose entire vocabulary is fetch(url: string) in, { bytes, format, fetchedAt } out, plus a { address, family } DNS answer. Not one of those names a protocol type in either direction, so two lines never exchange a value.

Next

• The six tools — inputs, outputs, and what each one refuses.
• The boundary — the five tools that are not here, and will not be.