Report · marked 26 Aug 2026
storybookjs/storybook
Solid foundations, held back in a few specific places.
TypeScript · 90,935 stars · 7,877 files · branch next
75
/100
B+
Instructions
25/27Whether the repo tells an agent how to behave before it starts guessing. Losing marks on instruction quality.Setup
14/20Whether an agent can install the project and get it running without a human. Losing marks on environment config and reproducible environment.Verification loop
19/25Whether an agent can check its own work. This is the category that most decides whether agent output is trustworthy. Losing marks on lint and format rules and static type checking.Context economy
9/20Whether the repo fits in a context window, or fights it. Losing marks on file sizes fit in context and repository weight.Navigability
10/10How quickly anything new can orient itself. Full marks.
Higher is better. Accent marks what is costing you most.
Fix these first
01
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.
02
Environment config
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.
03
Repository weight
Large binaries and vendored trees slow every operation an agent performs. Git LFS or a separate assets repo keeps the working tree navigable.
The full marking
Every deduction below names the file or setting it came from.
Instructions 25/27 A+
Whether the repo tells an agent how to behave before it starts guessing.
✓Agent instruction file
12/12
AGENTS.md is present, which is the format the most tools read.
Also found: CLAUDE.md, .cursorrules
✗Instruction quality
10/12
Specific enough that an agent can act on it.
Worth fixing: it's 22k characters, which burns context on every single turn.
names the actual commands to run
uses headings, so an agent can skim it
includes copyable code blocks
✓README as an entry point
3/3
README has a clear getting-started section.
Setup 14/20 B+
Whether an agent can install the project and get it running without a human.
✓Deterministic install
6/6
yarn.lock pins the dependency tree.
Found yarn.lock
✓Discoverable commands
6/6
Commands are declared where an agent will look for them.
package.json scripts (ci-tests, docs:check, fmt:check, fmt:write, get-report-message, get-sandbox-dir…)
scripts/ directory
✗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
2/2
The language runtime version is pinned.
Found .nvmrc
✗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 19/25 B+
Whether an agent can check its own work. This is the category that most decides whether agent output is trustworthy.
✓Tests exist
8/8
857 test files against 5007 source files.
e.g. agent-eval/lib/mcp/codex-browser-mock.test.ts, agent-eval/lib/mcp/preview-browser-mock.test.ts, agent-eval/lib/templates.test.ts
✓Test command is discoverable
7/7
An agent can find and run `npm run test`.
✓Continuous integration
4/4
17 GitHub Actions workflows define what "passing" means.
✗Lint and format rules
0/3
No linter or formatter config. Style is tribal knowledge, so agent output will drift from yours.
A formatter config is the cheapest way to stop reviewing whitespace in agent diffs. It moves style from opinion to a command.
✗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 9/20 C
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 82 patterns.
✗File sizes fit in context
0/6
4 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.
.yarn/releases/yarn-4.18.0.cjs — 3696KB
test-storybooks/ember-cli/ember-output/assets/vendor.js — 2140KB
code/core/src/manager/components/sidebar/mockdata.large.ts — 830KB
✗Repository weight
0/5
About 1095MB checked out. Large enough that cloning and searching are both slow.
Large binaries and vendored trees slow every operation an agent performs. Git LFS or a separate assets repo keeps the working tree navigable.
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 Storybook is the industry standard workshop for building, documenting, and testing UI components in isolation ## Setup ``` yarn install ``` ## Commands ``` yarn start # run the app yarn test # run the test suite, must pass before any commit yarn lint # lint yarn ci-tests yarn docs:check yarn fmt:check yarn fmt:write yarn get-report-message ``` ## Layout - `code/` 4450 source files - `scripts/` 185 source files - `test-storybooks/` 184 source files - `agent-eval/` 179 source files - `docs/` 1 source file ## Conventions - Tests live alongside the code they cover, following `agent-eval/lib/mcp/codex-browser-mock.test.ts`. - CI defines what passing means. See `.github/workflows/agent-eval.yml`, and keep it green. - TODO: add the two or three conventions a newcomer always gets wrong here. ## Gotchas - `.yarn/releases/yarn-4.18.0.cjs` is 3696KB. 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/storybookjs/storybook.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.