RTL/CLAUDE.md

RTL — notes for AI coding agents

RTL (Ride The Lightning) is a device-agnostic web UI for Lightning node operations: an Angular single-page frontend plus a Node/Express backend, both TypeScript.

CONTRIBUTING.md is the process document — how to install, run the dev servers, package a build, open a PR, add a library, and handle Dependabot. Read it first. This file covers only the things that are easy to get wrong and aren't obvious from the tree.

Source vs. generated — read this before editing anything

Directory	What it is	Edit it?
src/	Angular frontend source	yes
server/	Express backend source	yes
frontend/	Built AOT bundle, committed	never by hand
backend/	Compiled server/ output, committed	never by hand

frontend/ and backend/ look like ignorable build artifacts, but they are tracked in git and are expected to stay in sync with the sources. So a code change is a two-step edit: change src//server/, then rebuild and commit the regenerated output in the same PR.

npm run buildbackend     # tsc: server/ -> backend/
npm run buildfrontend    # ng build --configuration production: src/ -> frontend/

backend/ is a plain tsc transpile of server/, so it changes only when server/ does — a dependency bump alone won't move it. frontend/ is a bundle, so it also carries the app version and any bundled dependency.

The three-implementation pattern

RTL supports three Lightning implementations, and the layout mirrors that everywhere:

src/app/{lnd,cln,eclair,shared}/
server/controllers/{lnd,cln,eclair,shared}/
server/routes/{lnd,cln,eclair,shared}/

A feature or fix usually touches the matching folder in each layer for the implementations it affects; genuinely cross-cutting logic belongs in shared/. When fixing a bug in one implementation, check whether the same shape exists in the other two — they frequently do, since the controllers were written in parallel.

Commands, and where they bite

• Install with npm ci --legacy-peer-deps, not npm install. Plain npm ci fails on an ERESOLVE conflict from @fortawesome/angular-fontawesome.
• npm run server only works on Windows — it sets NODE_ENV with set X=Y&& syntax. On macOS/Linux use npm run serverUbuntu.
• npm run lint and npm run test must both be green before a PR.
• If lint reports hundreds of template "Parsing error" failures, look for a stale coverage/ directory (git-ignored Karma output). The template linter walks its HTML report. Delete it and re-run.
• The repo README is at .github/README.md — there is none at the root.

Branches and releases

• PRs target the current Release-x.y.z branch, not master. Because release branches merge into master by rebase, a Fixes #N reference never auto-closes its issue (GitHub only does that for the default branch) — close it manually after the merge.
• Every PR adds its own release-note entry, in the same PR as the change: release-notes/Release-notes-<x.y.z>.md, under ## Bug Fixes, ## Enhancements, ## Code Health or ## Developer Tooling. Create the file if it doesn't exist yet. Link the PR and any issue, and state the root cause briefly. Because the PR number isn't known until the PR exists, commit the entry with #TBD and follow up with a Fill in PR number in release note (#N) commit.

If a release ships while your PR is open

The rebase-merge rewrites every commit of the release branch to a new hash, and the next release branch is cut from master — so a branch based on the old release branch shares no recent ancestor with the new one. Retargeting it makes the merge base collapse to before the release cycle, and GitHub replays the entire cycle into your PR: hundreds of files, and a CONFLICTING state. Replay just your own commits instead:

git rebase --onto Release-<new> Release-<old> <your-branch>

Then confirm git diff Release-<old>..<old-head> is identical to git diff Release-<new>..<new-head> before force-pushing. Retargeting before the release branch is merged avoids the problem entirely.

Testing against real nodes

docker/ is a self-contained regtest fixture — bitcoind, three LND nodes, Core Lightning and Eclair, wired to RTL — for end-to-end testing across all three implementations. See docker/README.md, or the rtl-docker-fixture skill in .claude/skills/. It is dev-only; every credential in it is throwaway.

Backend regression tests live in test/backend/ (plain node:test, run against the compiled backend/). npm run test compiles the backend, then runs them (npm run testbackend) before the frontend Karma/Jasmine specs, so they never test stale code. For backend changes, also verify against the fixture and say so in the PR.

Conventions

• Be conservative about dependencies. This is security-sensitive software. Prefer what's already there, and raise an issue before adding anything. Never run npm audit fix — it reaches for breaking major bumps. Dependabot PRs are batched, not merged individually; see CONTRIBUTING.md.
• Match the surrounding code's style, naming and structure. Only fix style in code you're already changing.
• RTL-Config.json is local runtime config and git-ignored; Sample-RTL-Config.json is the template, and RTL.conf is an alternate config format.