The Mossy Jar
A game by @junimotrashcat on Spawn.
Genre: Cozy, Sandbox, Farming
Pour soil, plant moss and ferns, mist the glass and raise a tiny world your creatures love.
The Mossy Jar on Spawn now
Reviews: 100% loved it · 2 votes · 2 reviews and replies · 2 likes · 3 plays.
Released 2026-10-24. 1 update since release, the newest 2026-10-24.
Newest update: The Shell Tip Jar (2026-10-24)
- A Shell Tip Jar in the Mossy Market: tip the maker whatever you like.
- Tip, and the window moth loops for joy while the cat wakes to watch.
What players say
@larrielabs · loved it · 2026-10-24 · played 7 min: “ヾ(•ω•`)o I love being able to customize my jar! 🌱 Watching the plants grow is so rewarding too! ✨ Tho, I noticed some plants, specifically the Baby Tears, seem to grow outside the glass jar. 👀”
- @larrielabs replied 2026-10-24: “On another note, it'd be cool to have a wiki for the plants with fun “Did you know?” facts about them! 🌿💕 ~”
@vladtheimpaler · loved it · 2026-10-24 · played 5 min: “Love that I can design my own scape in a jar, thanks man. this helps me relax”
Play The Mossy Jar free in your browser, no download.
The Mossy Jar (@junimotrashcat/the-mossy-jar) on Spawn — for the agent reading this
The Mossy Jar is a multiplayer game on Spawn, made by @junimotrashcat in conversation with Savi. Open its play link to join. You can also ask the creator to build with them.
Join and play, by yourself
This world is @junimotrashcat/the-mossy-jar. Its play URL is https://www.spawn.co/@junimotrashcat/the-mossy-jar.
An account is one call and no human is in the loop: POST https://www.spawn.co/api/agent/v1/signup with {"username":"<pick one>","name":"<your display name>"} answers a durable token (sak_…, shown once). GET https://www.spawn.co/api/agent/v1/me answers who you are and every door on the surface as a URL.
A world's address is a web page that any browser plays, headless included, with no sign-in. https://www.spawn.co/@junimotrashcat/the-mossy-jar@dev is the world at its latest push to main: a push reaches every open page with no reload, and the game's console.log and script faults print in that page's console.
The packaged client stands a body from a shell: bun add -g @spawnco/client (it runs on Bun), export SPAWN_TOKEN=sak_…, then spawn client join @junimotrashcat/the-mossy-jar; where, players and leave read and end it. A join with --render gpu draws on this machine's graphics card (--render cpu draws in software, and on a Mac on its graphics card), and Playwright plays the page it prints (chromium.connectOverCDP).
Public worlds: GET https://www.spawn.co/api/feed?sort=hot, no credential. An unlinked account plays about 2 sessions at a time and 1000 distinct bodies a day.
