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 instructions/popoloni/non_deterministic_sw_eng/copilot-instructionsgit clone --depth 1 https://github.com/popoloni/non_deterministic_sw_engWrote 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/instructions/popoloni/non_deterministic_sw_eng/copilot-instructions)<a href="https://agentmods.dev/instructions/popoloni/non_deterministic_sw_eng/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/popoloni/non_deterministic_sw_eng/copilot-instructions.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 | $0.00422 | $0.00422 |
| Opus 5 | $0.00211 | $0.00211 |
| Sonnet 5 | $0.00084 | $0.00084 |
| Haiku 4.5 | $0.00042 | $0.00042 |
Grade A, and why
non_deterministic_sw_eng copilot-instructions.md 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
GitHub Copilot Instructions
This file provides project-wide instructions for GitHub Copilot.
Project Overview
E-commerce platform built with:
- Frontend: React 18, TypeScript, TailwindCSS
- Backend: Node.js 20, Express 4, TypeScript
- Database: PostgreSQL 16 with Prisma ORM
- Auth: OAuth2 with JWT tokens
Code Standards
TypeScript
- Use strict mode, avoid
anytypes - All functions require explicit return types
- Use interfaces for object shapes
- Prefer
constoverlet
React
- Functional components only (no class components)
- Use custom hooks for shared logic
- Props interfaces named
{ComponentName}Props - Use React Query for server state management
API Design
- RESTful endpoints following naming conventions
- Use zod schemas for request validation
- Standardized error responses
- All endpoints require authentication unless explicitly public
Testing Requirements
- Minimum 80% coverage for new code
- Table-driven tests for utilities
- Integration tests for API endpoints
- Use React Testing Library for components
Security Requirements
- Validate all user input at API boundary
- Use parameterized queries only
- Never hardcode secrets
- Sanitize output for XSS prevention
Key Patterns
API Calls
// Use the API service, never raw fetch
import { api } from '@/services/api';
const users = await api.users.list();
Error Handling
import { ApplicationError, ErrorCode } from '@/errors';
throw new ApplicationError(ErrorCode.NOT_FOUND, 'User not found');
Reference Files
- Component example:
src/components/UserProfile/ - Service pattern:
src/services/authService.ts - Test example:
src/utils/__tests__/
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 · 70 lines · 422 tokens per session scan A 86d3d1d9dd3f
non_deterministic_sw_eng copilot-instructions.md is an instructions file published in the GitHub repository popoloni/non_deterministic_sw_eng (6 stars, last pushed 8mo ago), licensed MIT. It adds 422 tokens to every session, about $0.0021 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.
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