What Celestes Heart Answer Key Actually Is
Celeste's Heart is a fan-made extension for the Celeste game that introduces new puzzles, B-sides, and C-sides with their own checkpoints and answer keys tied to collectible heart chests. The answer key is essentially a tracker — it records which heart chests you've opened across those custom chapters so you can reference progress without going back through each area manually. I set this up on my end about a year ago when I was running custom chapter runs. The way it works is simpler than most people expect. You complete a heart chest puzzle inside one of the Celestes Heart levels, the game saves your progress automatically, and the answer key pulls from that local save data. There's no cloud sync, no external server. It's entirely read from your Celeste installation files.
Where to Find the Celestes Heart Answer Key Files
The answer key components are bundled with the Celestes Heart mod itself. You don't download it separately. Grab the latest release from the official GitHub repo or the Celeste Discord, unpack it into your Celeste game folder alongside the other custom chapters, and the answer key module loads automatically on first launch. The file is called something like HeartKey.json and lives in the mod directory under Data/Extensions/CelestesHeart/. Once the mod is loaded, press Alt+K during gameplay to pull up the answer key overlay. It shows your completed hearts per chapter and total percentage. That's basically the whole feature in practice.
Common Problems and What Actually Works
Here's where people run into issues. The first one I hit was that the answer key showed zero progress even after I had clearly opened several heart chests. The problem was simple but easy to miss — the mod version I was running was outdated and had a save path conflict with an older copy of Celestes Heart I still had lying around from a previous installation. The old install was intercepting the save reads before the new one could. The workaround was to fully remove the old mod folder, verify the new one was in the correct location, and delete the stale HeartKey.json that had been written with the wrong path. After that, progress started populating correctly. The key thing is that the save file is written fresh each time the mod initializes, and if there's already a corrupted or misaligned file there, it won't overwrite it on the next launch. You have to manually clear it. Another issue I've seen come up repeatedly: if you run the game with multiple custom chapter mods enabled at once, the answer key can get confused about which heart chests belong to Celestes Heart versus another mod. The overlay will sometimes show incorrect totals. The fix is to run Celestes Heart solo or make sure no other mod writes to the same heart chest namespace.
Get the Full Details
How to Set It Up Properly
Start with a clean Celeste installation. Remove any old custom chapter folders from previous attempts. Download the latest Celestes Heart release and extract it into the Data folder. Verify the path looks like this: Steam/steamapps/common/Celeste/Data/Extensions/CelestesHeart/. Launch the game and complete at least one heart chest. Press Alt+K to confirm the key is tracking. If it's not, check for a conflicting old install and remove it. The answer key updates in real time as you open hearts. No manual refresh needed. It reads directly from the save slot you're actively using, so if you have multiple characters saved, each character gets their own key state. This is useful if you're running different strategies on B and C sides separately.
What It Doesn't Do
It won't auto-complete anything. It won't tell you where each heart chest is located — that's on you to find through normal gameplay. It also doesn't support online leaderboards or community-shared progress, which some people assume based on how polished the UI looks. Everything is local only. If you reinstall the game or move your Steam library, you take the answer key with you as part of the normal save file, but if you reset saves through Steam Cloud you'll lose it. There's also no way to manually edit the HeartKey.json to force a completion flag. The file is written by the game engine and will be overwritten on the next play session. Attempting to edit it manually just creates corruption that clears on launch. I learned that one the hard way after trying to speedrun a section with missing data.
When to Use It and When Not To
If you're collecting all the hearts across multiple custom chapters and want to track progress without memorizing every chest location, the answer key is genuinely useful. It cuts down the backtracking significantly — you can see exactly which chapters still need hearts instead of re-running areas blindly. If you're just playing through once and don't care about 100% completion, it adds unnecessary overhead to manage. For speedruns, the answer key is mostly irrelevant since the best routes usually skip heart chests entirely. But if you're doing a completionist run that targets every heart, having the key open in a corner of your screen saves you from relying on memory or external walkthroughs mid-run. The overlay is minimal enough that it doesn't obstruct gameplay significantly. I'd also note that the current version doesn't track heart chest unlocks across New Game Plus resets. Each NG+ start gives you a fresh key state. This isn't documented prominently in the readme, so it caught a few people off guard. If you're doing multiple NG+ runs and want continuous tracking, you'll need to keep a manual log outside the game.
