Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/nschneir/project64/6502-debuggingnpx skills add nschneir/Project64 --skill 6502-debugginggit clone --depth 1 https://github.com/nschneir/Project64What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00055 | $0.02518 |
| Opus 5 | $0.00028 | $0.01259 |
| Sonnet 5 | $0.00011 | $0.00504 |
| Haiku 4.5 | $0.00006 | $0.00252 |
Grade A, and why
6502-debugging scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
The source is not reproduced here
No licence file
A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 190 lines · 55 tokens per session scan A 0e349c42d509
6502-debugging is a skill published in the GitHub repository nschneir/Project64 (2 stars, last pushed 9d ago), with no licence file. It adds 55 tokens to every session and 2,518 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other skills, from other repositories
6502-assembly
Use when writing or debugging 6502 assembly for the Commodore PET with ca65/ld65 via pet build or pet run. Covers the PET program skeleton, the BASIC SYS stub, calling ROM routines, and 6502 gotchas.
pet-development
Use when developing, running, or debugging Commodore PET software (Commodore BASIC or 6502 assembly) on the VICE emulator with the pet CLI or the pet-tools MCP server. Covers the build/run/observe/debug loop, the stopped-state discipline, PET text encodings, and per-model differences.
6502-debugging
Use when a PET program misbehaves at runtime — crashes, corruption, wrong values, dead input, visual glitches — and you need a procedure, not a guess. Symptom-indexed playbook of runtime debugging procedures using pet-tools.
hello-world
Run the fastest greeting or smoke-test path across VICE and C64U.
basic-program
Execute bespoke Commodore BASIC v2 programs through c64bridge.
assembly-program
Execute 6502/6510 assembly workflows through c64bridge.