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 rules/gustavobarbosab/sage/sage-harness-initgit clone --depth 1 https://github.com/gustavobarbosab/sageWrote 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/rules/gustavobarbosab/sage/sage-harness-init)<a href="https://agentmods.dev/rules/gustavobarbosab/sage/sage-harness-init"><img src="https://agentmods.dev/badge/rules/gustavobarbosab/sage/sage-harness-init.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 | $0.00016 | $0.00552 |
| Opus 5 | $0.00008 | $0.00276 |
| Sonnet 5 | $0.00003 | $0.00110 |
| Haiku 4.5 | $0.00002 | $0.00055 |
Grade A, and why
sage-harness-init 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 5d 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
/sage harness init
Creates .sage/harness.md via an interactive wizard.
Instructions
Ask the user the following questions one at a time. Wait for each answer before asking the next.
- "What's your primary language and version? (e.g. Kotlin 2.0, TypeScript 5.4)"
- "What UI framework or runtime are you using? (e.g. Jetpack Compose BOM 2024.06, React 18, none)"
- "How do you handle dependency injection? (e.g. Hilt, Inversify, manual, none)"
- "What architecture pattern do you follow? (e.g. MVI, MVVM, Clean Architecture)"
- "How do you manage state? (e.g. StateFlow, Redux, Zustand, signals)"
- "How does navigation work? (e.g. lambda callbacks, NavController, React Router)"
- "What's your async/concurrency approach? (e.g. Kotlin Coroutines + Flow, async/await)"
- "What test framework do you use? (e.g. JUnit5 + MockK + Turbine, Jest + RTL)"
- "What naming conventions do you follow for key files? (e.g. ViewModels, Screens, Tests)"
- "What should I avoid? (e.g. LiveData, XML views, Material2, hardcoded strings)"
- "Anything else I should always know about this project?"
After collecting all answers, generate .sage/harness.md:
## Project Harness — <project name>
### Stack
- <bullet list of stack items>
### Conventions
- <naming patterns>
- <architecture rules>
- <required practices>
### Avoid
- <anti-patterns>
- <deprecated APIs>
- <things explicitly out of scope>
Rules
- Every rule must be checkable in code review — no vague guidance
- The "Avoid" section is often more valuable than "Conventions"
- Start lean — the harness can always be extended later
- Save to
.sage/harness.mdat the project root
After generation
Tell the user:
"Harness saved to .sage/harness.md. Commit it to version control so your whole team shares the same conventions. Run /sage harness review periodically to catch drift. Now run /sage spec <feature description> to start your first feature."
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.
- 5d ago First seen · 60 lines · 16 tokens per session scan A 167a98c5d898
sage-harness-init is a cursor rule published in the GitHub repository gustavobarbosab/sage (2 stars, last pushed 2mo ago), licensed MIT. It adds 16 tokens to every session and 552 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 2026-08-31.
Other cursor rules, from other repositories
ponytail
Ponytail, lazy senior dev mode. Always pick the simplest solution that works.
angular-20
This rule provides comprehensive best practices and coding standards for Angular development, focusing on modern TypeScript, standalone components, signals, and performance optimizations.
dev-standard
Apache Superset development standards and guidelines for Cursor IDE.
cli-error-handling
CLI command error handling patterns.
control-plane-descriptors
Control plane descriptor and instance implementation patterns.
family-instance-domain-actions
Family instance domain action implementation patterns.