Report · marked 25 Aug 2026
react/create-react-app
An agent can work here, but it will waste turns finding its footing.
JavaScript · 103,280 stars · 522 files · branch main
57
/100
B-
Instructions
2/27Whether the repo tells an agent how to behave before it starts guessing. Losing marks on agent instruction file and instruction quality.Setup
12/20Whether an agent can install the project and get it running without a human. Losing marks on environment config and pinned runtime version.Verification loop
22/25Whether an agent can check its own work. This is the category that most decides whether agent output is trustworthy. Losing marks on static type checking.Context economy
14/20Whether the repo fits in a context window, or fights it. Losing marks on file sizes fit in context.Navigability
8/10How quickly anything new can orient itself. Losing marks on written documentation.
Higher is better. Accent marks what is costing you most.
Fix these first
01
Agent instruction file
Add an AGENTS.md at the root: what the project is, how to install, how to run, how to test, and the two or three conventions a newcomer always gets wrong.
02
Instruction quality
Instructions earn their keep by naming exact commands. 'Run the tests with `pnpm test`' beats three paragraphs of philosophy.
03
File sizes fit in context
A single file that fills the context window forces an agent to work from fragments, and it will confidently edit code it never saw. Splitting the worst offenders pays for itself immediately.
The full marking
Every deduction below names the file or setting it came from.
Instructions 2/27 F
Whether the repo tells an agent how to behave before it starts guessing.
✗Agent instruction file
0/12
None found. Every agent that opens this repo starts from zero.
Add an AGENTS.md at the root: what the project is, how to install, how to run, how to test, and the two or three conventions a newcomer always gets wrong.
Looked for AGENTS.md, CLAUDE.md, .github/copilot-instructions.md, .cursorrules
✗Instruction quality
0/12
Nothing to judge, since there are no instructions.
Instructions earn their keep by naming exact commands. 'Run the tests with `pnpm test`' beats three paragraphs of philosophy.
✗README as an entry point
2/3
README exists but never explains how to get the thing running.
Give the README an Install and a Usage heading with real commands under each. Agents pattern-match on those headings.
Setup 12/20 B-
Whether an agent can install the project and get it running without a human.
✓Deterministic install
6/6
package-lock.json pins the dependency tree.
Found package-lock.json
✓Discoverable commands
6/6
Commands are declared where an agent will look for them.
package.json scripts (build, changelog, create-react-app, e2e, e2e:docker, postinstall…)
✗Environment config
0/4
Nothing documents the environment this needs. An agent will get a runtime error it can't diagnose.
Add a .env.example listing every variable with a safe placeholder value. It's the cheapest possible fix and it unblocks the whole first run.
✗Pinned runtime version
0/2
No pinned runtime version.
Add a .nvmrc, .python-version, or equivalent so the agent's toolchain matches yours.
✗Reproducible environment
0/2
No container or devcontainer definition.
A Dockerfile or devcontainer removes an entire class of 'it won't install' failures.
Verification loop 22/25 A
Whether an agent can check its own work. This is the category that most decides whether agent output is trustworthy.
✓Tests exist
8/8
151 test files against 297 source files.
e.g. .github/workflows/build-and-test.yml, packages/babel-plugin-named-asset-import/index.test.js, packages/cra-template-typescript/template/src/App.test.tsx
✓Test command is discoverable
7/7
An agent can find and run `npm run test`.
✓Continuous integration
4/4
3 GitHub Actions workflows define what "passing" means.
✓Lint and format rules
3/3
.eslintrc.json encodes the house style.
✗Static type checking
0/3
No static type checking.
A type checker gives an agent an error message instead of a runtime surprise. It's the second-fastest feedback loop after the compiler.
Context economy 14/20 B+
Whether the repo fits in a context window, or fights it.
✓No committed build output
6/6
No generated directories committed.
✓.gitignore hygiene
3/3
.gitignore covers 14 patterns.
✗File sizes fit in context
0/6
2 source files are over 100KB.
A single file that fills the context window forces an agent to work from fragments, and it will confidently edit code it never saw. Splitting the worst offenders pays for itself immediately.
packages/react-error-overlay/fixtures/bundle_u.mjs — 1407KB
packages/react-error-overlay/fixtures/bundle.mjs — 1397KB
✓Repository weight
5/5
About 25.2MB checked out, which is comfortable.
Here is your AGENTS.md
Drafted from what is actually in this repository: the install
command from your lockfile, the commands you already declare, your real directory layout. Anything
marked TODO needs a person. Save it at the root as AGENTS.md.
# AGENTS.md Set up a modern web app by running one command. ## Setup ``` npm ci ``` ## Commands ``` npm run start # run the app npm run build # produce a build npm run test # run the test suite, must pass before any commit npm run format # format npm run changelog npm run create-react-app npm run e2e npm run e2e:docker ``` ## Layout - `packages/` 229 source files - `test/` 53 source files - `tasks/` 13 source files - `docusaurus/` 2 source files ## Conventions - Tests live alongside the code they cover, following `.github/workflows/build-and-test.yml`. - CI defines what passing means. See `.github/workflows/build-and-test.yml`, and keep it green. - TODO: add the two or three conventions a newcomer always gets wrong here. ## Gotchas - `packages/react-error-overlay/fixtures/bundle_u.mjs` is 1407KB. It will not fit comfortably in context, so read it in parts. --- Drafted by agentreadme.com from what is in this repository. Everything marked TODO needs a human. Check it in as AGENTS.md at the root.
Open the raw markdown
or
curl -o AGENTS.md agentreadme.com/draft/react/create-react-app.md
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Think this mark is wrong?
Every deduction above names the file it came from, so this can be settled by looking. If a check missed something, that is a rule worth fixing.