Report · marked 8 Oct 2026

vercel-labs/agent-browser

Solid foundations, held back in a few specific places.

Rust · 43,672 stars · 482 files · branch main

73 /100 B+

Instructions 24/27Whether the repo tells an agent how to behave before it starts guessing. Losing marks on readme as an entry point.Setup 14/18Whether an agent can install the project and get it running without a human. Losing marks on environment config.Verification loop 10/22Whether an agent can check its own work. This is the category that most decides whether agent output is trustworthy. Losing marks on tests exist and test command is discoverable.Context economy 14/20Whether the repo fits in a context window, or fights it. Losing marks on file sizes fit in context.Navigability 9/10How quickly anything new can orient itself. Losing marks on repository description.

Higher is better. Accent marks what is costing you most.

Fix these first

Test command is discoverable

Add a `test` script or a `test` target that runs the whole suite with no arguments. The convention is the interface — an agent tries `npm test` and `make test` before it tries reading your CI config.

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.

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.

The full marking

Every deduction below names the file or setting it came from.

Instructions 24/27 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.

✓Instruction quality 12/12

Specific enough that an agent can act on it.

9,701 characters, a workable length

names the actual commands to run

uses headings, so an agent can skim it

includes copyable code blocks

✗README as an entry point 0/3

No README. This is the first file anything reads, human or machine.

Give the README an Install and a Usage heading with real commands under each. Agents pattern-match on those headings.

Setup 14/18 A-

Whether an agent can install the project and get it running without a human.

✓Deterministic install 6/6

pnpm-lock.yaml pins the dependency tree.

Found pnpm-lock.yaml

✓Discoverable commands 6/6

Commands are declared where an agent will look for them.

package.json scripts (version:sync, version, build:native, build:linux, build:macos, build:windows…)

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 .node-version

–Reproducible environment n/a

Not applicable — a library doesn't need a container to be worked on.

Verification loop 10/22 C

Whether an agent can check its own work. This is the category that most decides whether agent output is trustworthy.

✗Tests exist 6/8

26 test files against 302 source files.

e.g. cli/tests/dashboard_cli.rs, cli/tests/doctor_cli.rs, cli/tests/fixtures/tls/ca-a.pem

✗Test command is discoverable 0/7

There's no obvious way to run the tests. Even if tests exist, an agent won't reliably find the entry point.

✓Continuous integration 4/4

2 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 n/a

Not applicable — the Rust compiler type checks every build.

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 39 patterns.

✗File sizes fit in context 0/6

10 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.

cli/src/native/actions.rs — 675KB

cli/src/native/e2e_tests.rs — 425KB

cli/src/commands.rs — 253KB

✓Repository weight 5/5

About 24.5MB 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 — drafted for vercel-labs/agent-browser

# AGENTS.md

Browser automation CLI for AI agents

## Setup

```
pnpm install
```

## Commands

```
pnpm version:sync
pnpm version
pnpm build:native
pnpm build:linux
pnpm build:macos
pnpm build:windows
pnpm build:all-platforms
pnpm build:docker
```

## Layout

- `cli/`      89 source files
- `packages/` 74 source files
- `examples/` 59 source files
- `docs/`     55 source files
- `evals/`    13 source files
- `scripts/`  5 source files

## Conventions

- Tests live alongside the code they cover, following `cli/tests/dashboard_cli.rs`.
- CI defines what passing means. See `.github/workflows/ci.yml`, and keep it green.
- TODO: add the two or three conventions a newcomer always gets wrong here.

## Gotchas

- `cli/src/native/actions.rs` is 675KB. 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/vercel-labs/agent-browser.md

A draft gets the commands right and stops at the things only a maintainer knows. What a good Rust AGENTS.md looks like covers what to add by hand, and what AGENTS.md is explains the format itself.

Show the mark

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[![agent ready](https://agentreadme.com/badge/vercel-labs/agent-browser.svg)](https://agentreadme.com/vercel-labs/agent-browser)

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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.

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