A natural-language seed finder for Minecraft Java edition. Type what you want - a village in a plains biome with a ruined portal nearby, a pale garden next to a woodland mansion - and Claude translates that into a structured filter. A pool of WebAssembly workers then sweeps through seeds in your browser until they match.
Plain English. "village in plains with a ruined portal within 200 blocks and no oceans within 500 blocks". No DSL to learn.
A strict JSON schema enforces the shape: each condition is a structure-find, biome check, or distance constraint. The generated filter is shown to you - editable, transparent, debuggable.
Eight Web Workers in your browser, each running a WebAssembly build of Cubitect's cubiomes library, evaluate the filter against thousands of seeds per second. Matches stream back as they're found.
Click a result. The map jumps to the matching anchor, switches dimension if the structure lives in the Nether, and highlights the relevant biomes. Cross-verify a result on ChunkBase with one click.
Stack structure proximity, biome presence, biome exclusion, and distance constraints in a single search. Each condition can be anchored relative to another.
No backend. The Claude API call goes out from your browser; everything else - seed evaluation, worldgen, map rendering - runs on your machine.
You see the generated filter before searching. Edit it directly to tweak constraints or learn the DSL.
Every query, its translated DSL, the seeds it found, and what it cost - logged locally and (when running under npm start) written to seeder/logs/activity.json so you can audit it.
Minecraft Java edition 1.16 through 26.1 (the current Drop 26 release).cubiomes only lists versions where worldgen changed, so each dropdown entry covers all patches up to the next entry — "1.20" means "1.20 through 1.20.4".
1.21.4 vs 1.21.5+ is a real placement change. Mojang expanded the Pale Garden biome at snapshot 25w02a (the 1.21.5 cycle), dropping its weirdness lower-bound from 2666 to IMIN — it now consumes territory previously assigned to dark_forest. The Mojang Wiki confirms it ("Pale Garden biome now occupies more space that was previously taken by dark forests"). We pull in Cubitect/cubiomes PR #162's new biome tree (tables/btree215.h) so 1.21.5+ gets accurate Pale Garden placement, not 1.21.4's pre-expansion version.
1.21.5 → 26.1 are placement-identical. Cross-referenced Mojang's release notes, misode/technical-changes's per-snapshot logs, and the byte-identicalmulti_noise_biome_source_parameter_list JSONs across these versions. Per-biome JSONs and the overworld noise router changed in 1.21.9 / 1.21.11 / 26.1, but only for mob spawns, surface decorations, lava aquifers, and preliminary-surface terrain — none of which affect biome IDs or structure positions. So we serve them all from one slot.
Other caveats. On 1.18+, Desert Pyramids, Jungle Pyramids, and Woodland Mansions can have false-positive placements because cubiomes only approximates terrain height (same limitation ChunkBase has). For multi-piece structures like Nether Fortresses, the marker shows the region center; the real structure can extend ~150 blocks beyond — an "approximate extent" ring surrounds the anchor when you jump to a result.
The C implementation of Minecraft's overworld generation that ChunkBase and every other browser-based seed tool relies on. Compiled to WebAssembly here.
The React + WASM-cubiomes starting point - map rendering, web-worker scaffolding, single-condition search. We forked it and built the natural-language layer on top.
Translates English queries into the structured filter DSL. Uses strict JSON-schema tool-use so the output always matches the worker's expected shape.
The reference for what a Minecraft seed map looks like and what structures can be located. We add multi-condition AI search; we credit them as the bar.