.cursorrules is in 36 repositories. The median one runs 360 words.
Cursor's original single-file format, superseded by .cursor/rules/*.mdc. Tracked here precisely because it is dead: how much of the ecosystem is still shipping a deprecated file is a measurable answer, and a large share of the "best cursor rules" pages on the web still teach this format.
Measured
What the nightly counted in real repositories
Counted 13 September 2026Repositories carrying it36 3.5% of the corpus
Files that write down a command13.9%
Files carrying a code block25.6%
Hard prohibitions58.6% of 29 root files
Agent behaviour51.7% of 29 root files
Code style48.3% of 29 root files
Tests34.5% of 29 root files
Architecture27.6% of 29 root files
Lint & format24.1% of 29 root files
Git, commits & PRs24.1% of 29 root files
Types20.7% of 29 root files
Documentation17.2% of 29 root files
Performance17.2% of 29 root files
Security17.2% of 29 root files
Database & migrations13.8% of 29 root files
Setup & install13.8% of 29 root files
Build13.8% of 29 root files
Deploy & release10.3% of 29 root files
Dependencies10.3% of 29 root files
Testing strategy10.3% of 29 root files
APIs & contracts10.3% of 29 root files
UI & components10.3% of 29 root files
Every night counted
Repositories carrying .cursorrules, one column a night
24 nights stored2026-08-0119 to 36 repositories2026-09-13
Asserted
What the documentation says this file can express
Read 2 August 2026File.cursorrules
OwnerCursor
Tools that read itCursor (legacy) only
Glob targetingNo
ImportsNo
FrontmatterNo
Nested filesNo
User scopeNo
Read from the format’s own documentation and checked by hand. Capabilities are asserted; adoption is measured.
Always in scope, single file at the repo root.
Cursor (legacy)What it does well
One file, nothing to configure
What it cannot do
Deprecated, do not start here
No targeting, no composition, no metadata
Counted pairwise
Repositories that carry .cursorrules and something else
Counted 13 September 2026The percentage is of repositories carrying .cursorrules, which is the number a “.cursorrules versus something” search is really asking for.
Cursor rules58.3%21 carry both, 6.8% the other wayAGENTS.md44.4%16 carry both, 2.6% the other wayCLAUDE.md41.7%15 carry both, 4.2% the other wayWindsurf rules19.4%7 carry both, 18.4% the other wayCline rules16.7%6 carry both, 3.2% the other wayGEMINI.md13.9%5 carry both, 10.4% the other wayCopilot instructions13.9%5 carry both, 2.6% the other way
NoRepository and pathCoversScoreChanged
001survivorforge/cursor-rulesrules/rust-axum/.cursorrules99 /1001 month ago002survivorforge/cursor-rulesrules/python-django/.cursorrules99 /1001 month ago003survivorforge/cursor-rulesrules/python-fastapi/.cursorrules99 /1001 month ago004
SkeneTechnologies/skene-cookbook.cursorrules96 /1001 month ago005survivorforge/cursor-rulesrules/fullstack-nextjs-prisma/.cursorrules96 /1001 month ago006HerringtonDarkholme/megarepo.cursorrules96 /1001 month ago007enuno/unifi-mcp-server.cursorrules93 /10029 days ago008survivorforge/cursor-rulesrules/devops-docker/.cursorrules93 /1001 month ago009survivorforge/cursor-rulesrules/devops-infrastructure/.cursorrules93 /1001 month ago010survivorforge/cursor-rulesrules/sveltekit/.cursorrules92 /1001 month ago011survivorforge/cursor-rulesrules/rust-actix/.cursorrules92 /1001 month ago012survivorforge/cursor-rulesrules/nodejs-express/.cursorrules92 /1001 month ago
SkeneTechnologies/skene-cookbook.cursorrules96 /1001 month ago005survivorforge/cursor-rulesrules/fullstack-nextjs-prisma/.cursorrules96 /1001 month ago006HerringtonDarkholme/megarepo.cursorrules96 /1001 month ago007enuno/unifi-mcp-server.cursorrules93 /10029 days ago008survivorforge/cursor-rulesrules/devops-docker/.cursorrules93 /1001 month ago009survivorforge/cursor-rulesrules/devops-infrastructure/.cursorrules93 /1001 month ago010survivorforge/cursor-rulesrules/sveltekit/.cursorrules92 /1001 month ago011survivorforge/cursor-rulesrules/rust-actix/.cursorrules92 /1001 month ago012survivorforge/cursor-rulesrules/nodejs-express/.cursorrules92 /1001 month ago