Most agent-friendly C++ repos

21 C++ repos, ranked by overall score (the average across agents). They average 59.3, and ggml-org/llama.cpp leads with 87.7.

10 of them have an AGENTS.md or CLAUDE.md: C++ AGENTS.md examples.

What C++ repos most often miss

Cursor rules (.cursor/rules): 0% pass rate
Skills (.agents/skills): 5% pass rate
Type configuration: 24% pass rate

Leaves out checks only one agent reads, which almost no repo passes. The methodology explains each check.

Leaderboard — page 1 of 1 for C++ repos, overall
Rank	Repo	Stars	Score	External link
1	ggml-org/llama.cppGitHub LLM inference in C/C++	132.9k ★	87.7	open
2	microsoft/onnxruntimeGitHub ONNX Runtime: cross-platform, high performance ML inferencing and training accelerator	22.2k ★	74.9	open
3	ml-explore/mlxGitHub MLX: An array framework for Apple silicon	29k ★	72.6	open
4	duckdb/duckdbGitHub DuckDB is a high-performance analytical database system	42.7k ★	70.2	open
5	scylladb/scylladbGitHub NoSQL data store using the Seastar framework, compatible with Apache Cassandra and Amazon DynamoDB	15.8k ★	69.4	open
6	nlohmann/jsonGitHub JSON for Modern C++	50.8k ★	69.0	open
7	ClickHouse/ClickHouseGitHub ClickHouse® is a real-time analytics database management system	50.7k ★	67.6	open
8	godotengine/godotGitHub Godot Engine – Multi-platform 2D and 3D game engine	119.3k ★	67.5	open
9	ggml-org/whisper.cppGitHub Port of OpenAI's Whisper model in C/C++	54.8k ★	65.3	open
10	libeigen/eigenGitLab Eigen is a C++ template library for linear algebra: matrices, vectors, numerical solvers, and related algorithms.	1.2k ★	62.3	open
11	google-deepmind/mujocoGitHub Multi-Joint dynamics with Contact. A general purpose physics simulator.	16k ★	61.4	open
12	protocolbuffers/protobufGitHub Protocol Buffers - Google's data interchange format	72.1k ★	61.1	open
13	kicad/code/kicadGitLab	1.1k ★	60.6	open
14	fmtlib/fmtGitHub A modern formatting library	25.9k ★	59.4	open
15	facebookresearch/faissGitHub A library for efficient similarity search and clustering of dense vectors.	41.2k ★	58.2	open
16	redpanda-data/redpandaGitHub Redpanda is a streaming data platform for developers. Kafka API compatible. 10x faster. No ZooKeeper. No JVM!	12.6k ★	55.9	open
17	apache/arrowGitHub Apache Arrow is the universal columnar format and multi-language toolbox for fast data interchange and in-memory analytics	17.3k ★	53.0	open
18	inkscape/inkscapeGitLab Inkscape vector image editor	4k ★	42.9	open
19	opencv/opencvGitHub Open Source Computer Vision Library	91.4k ★	42.7	open
20	multicoreware/x265_gitBitbucket Open Source H.265 / HEVC video encoder This repository has been migrated to GitHub. Please use the GitHub repository for all development and issue tracking: https://github.com/Multicorewareinc/x265 This repository will remain in sync until June 30, 2026 for transition purposes.	—	22.7	open
21	ocornut/imguiGitHub Dear ImGui: Bloat-free Graphical User interface for C++ with minimal dependencies	76.9k ★	21.2	open