nlohmann/json

At a glance

Rank

#186 of 401

Top 46% · #6 of 21 C++ repos

Checks passed

7 of 17

Full list below

Best set up for

Claude Code

Score 72.8

Needs most work for

Cursor

Biggest fix: Cursor rules (.cursor/rules) (+11.5 pts)

What to fix first

Showing fixes for Claude Code

1. 1
   AGENTS.md / CLAUDE.md

   Add an AGENTS.md covering project goals, layout, setup commands, and conventions. Aim for 800+ chars of real guidance (not boilerplate).
   +13.2 pts
2. 2
   Pre-commit / git hooks

   Set up pre-commit (.pre-commit-config.yaml), husky, or lefthook to run format+lint on every commit.
   +5.3 pts
3. 3
   License file

   Add a LICENSE (or COPYING) file — MIT, Apache-2.0, BSD, GPL, etc. — at the repo root.
   +3.9 pts

Score for each AI agent

Each agent weighs the checks by its own docs. Under each score are its top three. How each agent is scored →

Does nlohmann/json have agent instructions?

An AGENTS.md (or CLAUDE.md) at the root tells AI coding agents how to build, test and work in the repo. A few agents also read a file of their own.

AGENTS.md / CLAUDE.md

✗None at the root (no AGENTS.md, CLAUDE.md, AGENT.md, .claude/CLAUDE.md or .claude/AGENTS.md)

Agent-specific files

None: no GEMINI.md, .cursor/rules, .openhands/setup.sh, .aider.conf.yml or .agents/skills

Repos that have one

10 of 21 C++ repos · 221 of 401 repos on the leaderboard · See examples →

# AGENTS.md

Guidance for AI coding agents working in nlohmann/json. JSON for Modern C++. Written mainly in C++.

## Where things are

- Dependencies are declared in `Package.swift`.
- Tests live in `tests`.
- Lint and format rules are configured in `.clang-tidy`.
- CI is defined in `.github/workflows`; read it for the exact install, lint and test steps.
- Common tasks are targets in `Makefile`.
- Follow the conventions in `.github/CONTRIBUTING.md`.

## Commands

<!-- Fill in the exact commands CI runs. -->
- Install: TODO
- Test: TODO
- Lint: TODO

How nlohmann/json compares

vs leaderboard average

2.2 pts above

Average 66.8

vs C++ average

9.7 pts above

Average 59.3

Stars among C++ repos

#7 of 21

One fix for the most agents: AGENTS.md / CLAUDE.md would raise the score for all 9 agents, by up to 13.3 points.

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