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/chrisgleissner/c64bridge/assembly-programnpx skills add chrisgleissner/c64bridge --skill assembly-programgit clone --depth 1 https://github.com/chrisgleissner/c64bridgeWhat 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 | $0.00017 | $0.00323 |
| Opus 5 | $0.00009 | $0.00161 |
| Sonnet 5 | $0.00003 | $0.00065 |
| Haiku 4.5 | $0.00002 | $0.00032 |
Grade A, and why
assembly-program 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
Licensed GPL-2.0
The repository is licensed GPL-2.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.
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 · 38 lines · 17 tokens per session scan A 56c50e1a08f8
assembly-program is a skill published in the GitHub repository chrisgleissner/c64bridge (33 stars, last pushed 16d ago), licensed GPL-2.0. It adds 17 tokens to every session and 323 once invoked, about $0.0001 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 2026-08-30.
Other skills, from other repositories
6502-assembly
Use when writing or debugging 6502 assembly for the Commodore 64 with ca65/ld65 via c64 build or c64 run. Covers the C64 program skeleton, the BASIC SYS stub, calling ROM routines, and 6502 gotchas.
c64-development
Use when developing, running, or debugging Commodore 64 software (Commodore BASIC or 6510/6502 assembly) on the VICE emulator with the c64 CLI or the c64-tools MCP server. Covers the build/run/observe/debug loop, the stopped-state discipline, C64 text encodings, graphics and sprites, and the memory map.
cartridge-programming
Use when writing, building, or debugging a Commodore 64 cartridge — plain 8K/16K/Ultimax or bank-switched EasyFlash — with the c64 CLI or the c64-tools MCP server. Covers the two boot mechanisms (CBM80 vs the $FFFC reset vector), the memory modes, cart-native code in ROM, the EasyFlash banking discipline from…
disk-io-programming
Use when a Commodore 64 program has to touch a disk while it runs — loading levels, music or graphics on demand, saving a high-score file, or streaming a data file byte by byte. Covers the KERNAL LOAD/SAVE and channel calls, device and secondary-address conventions, reading the DOS error channel, and the…
6502-debugging
Use when a C64 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 c64-tools.
jupyter-notebook
Iterative Python via live Jupyter kernel (hamelnb).