LCP (Lightning Compute Protocol)

Docs site (Mintlify): Lightning Compute Protocol

LCP (Lightning Compute Protocol) is an application-layer protocol for paying for small compute jobs over Lightning. It uses BOLT #1 custom messages on a direct Lightning peer connection.

LCP v0.2 defines a quote → pay → stream flow:

• Both sides exchange lcp_manifest (mandatory) to advertise limits.
• The Requester sends lcp_quote_request, then streams the input (lcp_stream_begin/chunk/end with stream_kind=input).
• The Provider replies with lcp_quote_response containing price_msat, terms_hash, and a BOLT11 invoice.
• After settlement, the Provider streams the result (stream_kind=result) and then sends lcp_result (terminal completion + metadata).

LCP binds payment to job terms by setting the invoice description_hash to terms_hash.

Limitations:

• Payloads are limited by the BOLT #1 custom message size (about 65 KB), but v0.2 supports large inputs/results via chunked streams bounded by peer-declared limits (max_payload_bytes, max_stream_bytes, max_job_bytes).
• The Requester and Provider must be directly peered. This leaks metadata compared to onion messages or blinded paths.
• Payment happens before execution. This is not an atomic swap (and v0.2 also requires sending the full input stream before quoting).

Reference: BOLT #1 messaging (https://github.com/lightning/bolts/blob/master/01-messaging.md).

Potential future work

These are design ideas. They are not implemented in this repo:

• Privacy improvements: BOLT 12 offers and blinded paths to reduce direct peering requirements.

Safety / use at your own risk

This project is unaudited. Running it against real funds and real peers can lead to loss of funds.

• Sending funds / opening channels / paying invoices on mainnet can lead to loss of funds.
• Never leak secrets such as seed phrases, wallet passwords, macaroons, or API keys.
• Start with docs/go-lcpd/docs/regtest.md first (free and safer), then try mainnet with small amounts.
• go-lcpd integrates with lnd (gRPC) for peer messaging and payments. Other Lightning implementations are not supported by this repo. This repository does not ship an lnd/ folder or binaries — bring your own lnd.
• LCP runs over direct Lightning peer connections (BOLT #1 custom messages). You must be peered with the Provider, and you may need a channel/route to pay.

Start here

• Overview: this README
• Contributing: CONTRIBUTING.md
• Quickstart (mainnet): docs/go-lcpd/docs/quickstart-mainnet.md
• Configuration: docs/go-lcpd/docs/configuration.md
• Background run + logging: docs/go-lcpd/docs/background.md
• regtest walkthrough: docs/go-lcpd/docs/regtest.md
• Protocol spec (LCP v0.2): docs/protocol/protocol.md
• One-shot client (demo): go-lcpd/tools/lcpd-oneshot

Docs site (Mintlify)

This repository’s docs site is managed with Mintlify (docs/docs.json). All Mintlify pages and assets live under docs/ (Japanese pages are colocated with English and use a -ja suffix).

Local preview:

cd docs
npx --yes mintlify@4.2.255 dev --no-open

Validate navigation + check docs quality:

cd docs
node scripts/check-docs-json.mjs
npx --yes mintlify@4.2.255 a11y
npx --yes mintlify@4.2.255 broken-links

Repository layout (high level)

• docs/protocol/: the LCP wire protocol spec (BOLT-style TLV + state machine)
• proto-go/: shared Go protobuf/gRPC types for the LCPD API
• go-lcpd/: reference implementation (Lightning Compute Protocol Daemon)
• apps/openai-serve/: OpenAI-compatible HTTP gateway (forwards to lcpd-grpcd over gRPC)

Go workspace (go.work.sum)

This repo is a multi-module Go repository (each subproject has its own go.mod).

If you use Go workspaces locally (go work), Go will generate:

• go.work (the workspace definition)
• go.work.sum (workspace checksums, similar to go.sum)

In this repo, these workspace files are treated as local dev artifacts and are ignored by git. If you see a go.work.sum appear locally, it is safe to delete; it will be regenerated as needed.

Note: a single workspace that includes both go-lcpd/ and apps/openai-serve/ can hit an ambiguous import: google.golang.org/genproto... error because protoc-gen-cobra pulls the legacy google.golang.org/genproto module while gRPC uses the split google.golang.org/genproto/googleapis/... modules. If you run into this, prefer running Go commands from each module directory without a workspace.

Development (go-lcpd)

cd go-lcpd
go test ./...

Details: go-lcpd/README.md