Report · marked 25 Aug 2026
ghostty-org/ghostty
An agent can work here, but it will waste turns finding its footing.
Zig · 60,223 stars · 5,865 files · branch main
66
/100
B
Instructions
20/27Whether the repo tells an agent how to behave before it starts guessing. Losing marks on instruction quality and readme as an entry point.Setup
6/14Whether an agent can install the project and get it running without a human. Losing marks on deterministic install and pinned runtime version.Verification loop
15/22Whether an agent can check its own work. This is the category that most decides whether agent output is trustworthy. Losing marks on test command is discoverable.Context economy
13/20Whether the repo fits in a context window, or fights it. Losing marks on file sizes fit in context and repository weight.Navigability
7/10How quickly anything new can orient itself. Losing marks on written documentation and repository description.
Higher is better. Accent marks what is costing you most.
Fix these first
01
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.
02
Deterministic install
Commit the lockfile your package manager generates. Without it, an agent's install and your install are different builds, and 'works on my machine' becomes unfalsifiable.
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 20/27 B+
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
✗Instruction quality
6/12
Real instructions, with gaps.
Worth fixing: it never states a build, test, or run command; has no code blocks.
1,387 characters, a workable length
uses headings, so an agent can skim it
✗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 6/14 C
Whether an agent can install the project and get it running without a human.
✗Deterministic install
0/6
No lockfile. An agent installing dependencies may not get what CI got.
Commit the lockfile your package manager generates. Without it, an agent's install and your install are different builds, and 'works on my machine' becomes unfalsifiable.
✓Discoverable commands
6/6
Commands are declared where an agent will look for them.
Makefile
–Environment config
n/a
Not applicable — this reads as a library, with no environment to configure.
✗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
n/a
Not applicable — a library doesn't need a container to be worked on.
Verification loop 15/22 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
4048 test files against 1062 source files.
e.g. macos/Tests/BenchmarkTests.swift, macos/Tests/ColorizedGhosttyIconTests.swift, macos/Tests/CommandLineOpenFileFilterTests.swift
✗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.
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.
✓Continuous integration
4/4
15 GitHub Actions workflows define what "passing" means.
✓Lint and format rules
3/3
.swiftlint.yml encodes the house style.
–Static type checking
n/a
Not applicable — the Zig compiler type checks every build.
Context economy 13/20 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 31 patterns.
✗File sizes fit in context
0/6
22 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.
src/terminal/PageList.zig — 698KB
src/terminal/Terminal.zig — 563KB
src/terminal/Screen.zig — 418KB
✗Repository weight
4/5
About 78.7MB 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 👻 Ghostty is a fast, feature-rich, and cross-platform terminal emulator that uses platform-native UI and GPU acceleration. ## Setup ``` # TODO: the install command. No lockfile was found, so this could not be inferred. ``` ## Commands ``` make init make glad make clean ``` ## Layout - `src/` 557 source files - `macos/` 197 source files - `pkg/` 193 source files - `example/` 57 source files - `include/` 35 source files - `test/` 9 source files ## Conventions - Tests live alongside the code they cover, following `macos/Tests/BenchmarkTests.swift`. - CI defines what passing means. See `.github/workflows/clean-artifacts.yml`, and keep it green. - TODO: add the two or three conventions a newcomer always gets wrong here. ## Gotchas - Generated output is committed (`dist/`). Search will return the compiled copy, so edit the source, not that. - `src/terminal/PageList.zig` is 698KB. It will not fit comfortably in context, so read it in parts. - No lockfile is committed, so an install here may not match what CI produced. --- 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/ghostty-org/ghostty.md
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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.