Report · marked 10 Oct 2026

PostHog/posthog

Solid foundations, held back in a few specific places.

Python · 40,211 stars · 50,970 files · branch master

80 /100 A-

Instructions 25/27Whether the repo tells an agent how to behave before it starts guessing. Losing marks on instruction quality.Setup 20/20Whether an agent can install the project and get it running without a human. Full marks.Verification loop 21/25Whether 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 7/10How quickly anything new can orient itself. Losing marks on license.

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

Fix these first

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.

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.

Lint and format rules

A formatter config is the cheapest way to stop reviewing whitespace in agent diffs. It moves style from opinion to a command.

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 44k 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 20/20 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 (prepare, schema:build, openapi:build, schema:build:python, grammar:build, grammar:build:cpp…)

✓Environment config 4/4

.env.example documents what the app needs to run.

✓Pinned runtime version 2/2

The language runtime version is pinned.

Found .nvmrc

✓Reproducible environment 2/2

dockerfile gives a known-good environment.

Verification loop 21/25 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

12038 test files against 38983 source files.

e.g. .agents/skills/triaging-merge-queue-failures/scripts/mq-queue-state.test.sh, .depot/actions/paths-filter/__tests__/csv-escape.test.ts, .depot/actions/paths-filter/__tests__/filter.test.ts

✓Test command is discoverable 7/7

An agent can find and run `npm run test:unit`.

✓Continuous integration 4/4

140 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 2/3

Type checking is configured, but not in strict mode.

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 160 patterns.

✗File sizes fit in context 0/6

273 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.

posthog/schema.py — 1417KB

products/product_analytics/frontend/insights/trends/WorldMap/countryVectors.tsx — 1106KB

frontend/src/queries/validators.js — 887KB

✗Repository weight 0/5

About 7757MB 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.

File tree exceeded GitHub's limit, so 58,176 entries were sampled

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 PostHog/posthog

# AGENTS.md

:hedgehog: PostHog is the leading platform for building self-driving products. Our developer tools – AI observability, analytics, session replay, flags, experiments, error tracking, logs, and more – capture all the context agents need to diagnose problems, uncover opportunities, and ship fixes. Steer it all from Slack, web, desktop, or the MCP.

## Setup

```
pnpm install
```

## Commands

```
pnpm start                 # run the app
pnpm lint                  # lint
pnpm format                # format
pnpm prepare
pnpm schema:build
pnpm openapi:build
pnpm schema:build:python
pnpm grammar:build
```

## Layout

- `products/` 24622 source files
- `frontend/` 5952 source files
- `posthog/`  3631 source files
- `nodejs/`   1806 source files
- `packages/` 1142 source files
- `ee/`       788 source files

## Conventions

- Tests live alongside the code they cover, following `.agents/skills/triaging-merge-queue-failures/scripts/mq-queue-state.test.sh`.
- CI defines what passing means. See `.github/workflows/_rust-build-images.yml`, and keep it green.
- TODO: add the two or three conventions a newcomer always gets wrong here.

## Gotchas

- `posthog/schema.py` is 1417KB. It will not fit comfortably in context, so read it in parts.
- Copy `.env.example` before running anything that needs configuration.

---

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/PostHog/posthog.md

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

Show the mark

The badge re-checks daily, so it keeps up as the repository changes. Use mark again to force it now.

[![agent ready](https://agentreadme.com/badge/PostHog/posthog.svg)](https://agentreadme.com/PostHog/posthog)

Other Python repositories, marked

vinta/awesome-python 81 A- NousResearch/hermes-agent 84 A- TheAlgorithms/Python 89 A yt-dlp/yt-dlp 54 C+ microsoft/markitdown 48 C+ Significant-Gravitas/AutoGPT 65 B

All Python repositories

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.

Open an issue, already filled in

This repository is large enough that GitHub truncated the file listing, so the file-level checks ran on a sample.