lc

lc is a small Rust CLI for LeetCode workflows. It keeps read-only discovery on a public convenience endpoint, shows profile activity, and uses authenticated LeetCode endpoints for judge runs and real submissions.

Motivation

I made this because I wanted to learn Neovim, and LeetCode felt like a good source of small finger exercises. I tried a few other CLIs, but authentication was rough enough that building a small one around browser-cookie auth felt simpler.

Install

cargo install --path . --force

This installs lc to Cargo's binary directory, usually ~/.cargo/bin.

Authentication

Authenticated commands need LEETCODE_SESSION and LEETCODE_CSRF_TOKEN. The CLI can read them from the environment or probe your browser cookies with the helper script:

lc login

The command prints shell exports. Source or paste those exports if browser probing is not available automatically in your shell.

Treat the printed values like credentials: avoid pasting them into shared terminals, shell history, or logs.

Configuration

Read-only discovery commands use https://leetcode-api-pied.vercel.app by default. Override it with LC_PUBLIC_API_BASE_URL if you run a compatible mirror:

export LC_PUBLIC_API_BASE_URL='https://example.com'

Commands

lc daily
lc list
lc list --limit 100
lc list --topic string
lc problem two-sum
lc profile
lc profile ynbh
lc edit two-sum
lc edit two-sum --lang rust
lc edit two-sum --editor nvim
lc test two-sum solutions/two-sum.py
lc test solutions/two-sum.py
lc test two-sum solutions/two-sum.cpp
lc check two-sum solutions/two-sum.py
lc check solutions/two-sum.py
lc check two-sum solutions/two-sum.rs
lc run two-sum solutions/two-sum.py
lc run solutions/two-sum.py
lc run two-sum solutions/two-sum.py --input-file input.txt
lc submit two-sum solutions/two-sum.py
lc submit solutions/two-sum.py
lc submit two-sum solutions/two-sum.rs
lc status <submission-or-run-id>

Files created by lc edit include a small metadata header, so test, run, check, and submit can infer the problem when called with only the solution path. Explicit <problem> <file> calls still work and are required for files without metadata.

lc test uses LeetCode's provided example testcases through the authenticated custom-run endpoint. It does not submit.

lc check runs LeetCode's provided example testcases first. If they pass, it submits; if they fail, it prints the judge result and skips the real submission.

lc run also uses the custom-run endpoint. Without --input-file, it uses the problem's example testcases; with --input-file, it sends your custom input.

lc submit sends a real LeetCode submission.

lc edit creates solutions/<problem-slug>.<extension> from LeetCode's starter template when it does not already exist, then opens it in --editor, $VISUAL, $EDITOR, or nvim.

lc profile includes profile stats and a compact contribution-style activity chart when LeetCode returns calendar data.

Language Detection

The CLI auto-detects the LeetCode language from the solution file extension. Currently supported:

Extension	LeetCode language
.py	python3
.cpp	cpp
.java	java
.js	javascript
.ts	typescript
.rs	rust
.go	golang
.c	c
.cs	csharp
.kt	kotlin
.swift	swift
.php	php
.rb	ruby
.scala	scala
.dart	dart
.rkt	racket
.erl	erlang
.ex	elixir

You can override detection with --lang when the extension is ambiguous or you want to force the LeetCode slug:

lc test two-sum ./scratch.txt --lang python3
lc run two-sum ./solution.cc --lang cpp
lc submit two-sum ./main.go --lang golang

Development

The project is test-first. See docs/development.md for the architecture contract and docs/endpoints.md for the LeetCode endpoint notes.

cargo fmt -- --check
cargo test