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 skills add Nolane-x/forge-os --skill designing-interaction-contractsgit clone --depth 1 https://github.com/Nolane-x/forge-osWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/nolane-x/forge-os/designing-interaction-contracts)<a href="https://agentmods.dev/skills/nolane-x/forge-os/designing-interaction-contracts"><img src="https://agentmods.dev/badge/skills/nolane-x/forge-os/designing-interaction-contracts.svg" alt="Measured on agentmods" height="20"></a>What 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 5.1 | $0.00039 | $0.00176 |
| Opus 5 | $0.00019 | $0.00088 |
| Sonnet 5 | $0.00008 | $0.00035 |
| Haiku 4.5 | $0.00004 | $0.00018 |
Grade A, and why
designing-interaction-contracts 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 4d 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.
What it actually says
Designing Interaction Contracts
Core principle
Specify complete user-system behavior across states, errors, latency, permissions, recovery, and accessibility. Activate only when the typed entry conditions are present; stop rather than inventing a missing tool, decision, or proof.
When not to use
- visual styling without user interaction states
- backend-only behavior with no user-facing contract
Load only the sections selected by the RoutePlan.
What ships with it
6 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 4d ago First seen · 24 lines · 39 tokens per session scan A b1114754b4b6
designing-interaction-contracts is a skill published in the GitHub repository Nolane-x/forge-os (10 stars, last pushed 1mo ago), licensed MIT. It adds 39 tokens to every session and 176 once invoked, about $0.0002 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 2026-09-03.
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