# elems — the periodic table of the AI-led startup
> There are 47,000 AI tools. You need about 20 elements. elems is the living,
> versioned, vendor-neutral map of the ~58 tool elements an AI-led startup runs
> on — 12 groups, 28 essential, refreshed quarterly. Edition v2026.Q3, verified 2026-08-06.

Canonical data: https://elems.ai/elements.json (CC BY 4.0, cite elems.ai)
Full taxonomy as markdown: https://elems.ai/llms-full.txt
Dated edition snapshots: https://elems.ai/editions/2026-q3.json

## Pages
- [The Table](https://elems.ai/): interactive periodic table of all 58 elements (full crawlable index at /#element-index)
- [Stack builder](https://elems.ai/quiz.html): 5 questions → a personalized element stack (no email required)
- [Field guides](https://elems.ai/guides.html): verdict-first buying guides — pattern https://elems.ai/best/<slug>.html
- [Manifesto](https://elems.ai/manifesto.html): why elements, not tools
- [Compounds](https://elems.ai/compounds.html): named proven stacks (Solo-Founder Compound, Agent Stack, Trust Stack, Bootstrap GTM)
- [Changelog](https://elems.ai/changelog.html): editions, successions, retirements
- [Data](https://elems.ai/data.html): the open dataset, license, and edition snapshots
- [Independence charter](https://elems.ai/charter.html): no pay-to-rank, ever
- Element pages: https://elems.ai/e/<symbol>.html · markdown twins at https://elems.ai/e/<symbol>.md (e.g. /e/ca.md = Coding Agent)
- Element dossiers: every element page carries a ranked top 5 with vendor-verified pricing,
  dated evidence, a comparison matrix, decision rules, and the complete field — including the
  tools we found dead, renamed, acquired, or sunsetting. 1,150 tools across 58 categories.
  Machine-readable at https://elems.ai/e/<symbol>.json — 58 files, CC BY 4.0, cite elems.ai.

## Layout
The 58 elements seat 1:1 onto the classical periodic table (hydrogen through
cerium): period 1 holds elements 1 and 2; periods 4-5 run the full 18 columns;
elements 57-58 (Taste, Founder Health — the human block) sit in the detached
rare-earth row, with seats 59-60 reserved for undiscovered elements. Seat
coordinates for every element are in elements.json under "seat".

## Editorial rules
Elements are jobs, not brands. No pay-to-rank, ever. Every claim is dated.
The table is bounded; new elements must earn a seat.