claude-rust-tutor

Multi-provider LLM-based coding tutor in Rust. Port of kangwonlee/gemini-python-tutor, naming follows the convention "primary contributing LLM + impl language + tutor."

Status: v0.1.0 shipped 2026-05-23 — ghcr.io/kangwonlee/claude-rust-tutor:v0.1.0 (multi-arch, ~2.17 MB amd64). Full prompt builder + 5-provider HTTP client + 19 unit tests. Smoke test against a real LLM API key still pending.

Role

Drop-in feedback generator for autograded assignments. Reads:

• one or more pytest-json-report-shape JSON files (test results — from pytest, or from cargo nextest via an adapter),
• one or more student code files,
• a README.md with assignment instructions,

… and emits a markdown feedback block to stdout (which the calling CI workflow captures into $GITHUB_STEP_SUMMARY + uploads as an artifact).

Distribution model

Published as a multi-arch static binary inside a FROM scratch carrier image at ghcr.io/kangwonlee/claude-rust-tutor:vX.Y.Z. Downstream grader images consume it with a multi-stage COPY:

COPY --from=ghcr.io/kangwonlee/claude-rust-tutor:vX.Y.Z /claude-rust-tutor /usr/local/bin/

No python runtime needed in the grader image.

Provider support

Same five providers as gemini-python-tutor, default order picks whichever API key is set:

Provider	Env var (selector)	Default model
Gemini (default)	INPUT_GEMINI_API_KEY	gemini-2.5-flash
Claude	INPUT_CLAUDE_API_KEY	claude-sonnet-4-20250514
Grok	INPUT_GROK_API_KEY	grok-code-fast
NVIDIA NIM	INPUT_NVIDIA_API_KEY	google/gemma-2-9b-it
Perplexity	INPUT_PERPLEXITY_API_KEY	sonar

Env var contract

Env var	Meaning
INPUT_REPORT_FILES	Comma-separated paths to pytest-json-report-shape JSONs
INPUT_STUDENT_FILES	Comma-separated paths to student source files
INPUT_README_PATH	Path to assignment README
INPUT_EXPLANATION_IN	Locale name (e.g. Korean, English)
INPUT_MODEL	Optional model override
INPUT_FAIL_EXPECTED	true to assert failures expected (default false)
INPUT_<PROVIDER>_API_KEY	API key for the chosen provider

Names use underscores, not hyphens. The Python tutor (gemini-python-tutor) runs as a GitHub composite action, so GitHub injects its with: inputs as INPUT_REPORT-FILES etc., and Python's os.environ reads those hyphenated names fine. This Rust port is invoked directly via docker run -e, and std::env::var silently skips env names containing - — a hyphenated name reads as environment variable not found. The caller (classroom.yml) passes the underscore form; keep the two in sync.

License

BSD-3-Clause + Do Not Harm. See LICENSE.

Credits

• Architecture, prompt design, security posture (UID 1001 mount/permissions): inherited from gemini-python-tutor, which itself was substantially shaped by contributions from Gemini, Grok, and other LLMs.
• This Rust port: implementation mostly with Claude assistance (hence the name).