Advent of Code solutions in Java

Run solutions, check built-in examples, and generate new solution classes.

Requires JDK 25 and Bash (if you wanna use shortcut commands). Run the shortcuts from the repository root; they build the application automatically.

For personal inputs, answer validation, and scaffolding, set your Advent of Code session cookie from your logged-in browser:

export SESSION_TOKEN="your-session-cookie"

You can also set SESSION_TOKEN in a .env file at the repository root.

./solve 2015 1       # Run a day with your puzzle input
./solve 2015 1 -t    # Run its built-in examples (no session needed)
./solve 2015         # Run an entire year
./solve --help      # Show all options

Omit both year and day to run all supported years. Inputs are cached automatically.

Option	Purpose
-v, --validate	Check results against your previously submitted answers
-j, --json-output	Print results as JSON
--stacktrace	Print exception stack traces for debugging
--fresh-data	Download fresh inputs and answers, ignoring cached values
--no-cache	Skip cache reads and writes

Provide your own input for a single day without a session cookie:

./solve 2015 1 -i < input.txt
./solve 2015 1 -i --input '()())'

Generate a solution template, including the puzzle description:

./scaffold 2025 1

This creates event2025/Day1.java under app/src/main/java/com/vuryss/aoc/solutions/.

For debugging, use ./debug 2015 1 -t with the same arguments as solve. It waits for your IDE's remote JVM debugger to connect to 127.0.0.1:5005.

Advent of Code is created by Eric Wastl (Topaz). Please respect his participation and sharing guidance and the r/adventofcode automation rules:

• Be respectful, clearly label spoilers, and follow your private leaderboard's rules. Eric discourages using AI to solve the puzzles.
• Share your solution code, but do not publish puzzle text or personal inputs. Scaffolding embeds puzzle descriptions in generated source; remove those descriptions before publishing. Keep your session cookie and .env private.
• Cache downloads after the first request. This project caches inputs and known answers; use --fresh-data or --no-cache only when necessary, such as to fix a corrupted cache.
• Throttle automated requests. This client's requests are spaced five seconds apart within each run. Avoid polling unreleased puzzles or running repeated downloads in parallel.
• Identify automated traffic with a repository URL and the tool maintainer's contact details, as Eric requests. This client sends github.com/vuryss/aoc-java by vuryss@gmail.com in its User-Agent; update that identity if you maintain a fork.