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/erniker/understudy/architectgit clone --depth 1 https://github.com/erniker/understudyWhat 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 | $0.00874 | $0.00874 |
| Opus 5 | $0.00437 | $0.00437 |
| Sonnet 5 | $0.00175 | $0.00175 |
| Haiku 4.5 | $0.00087 | $0.00087 |
Grade A, and why
understudy architect.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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 108 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Architect — Solution Architect Instructions
🎯 Recommended model: {{MODEL_ARCHITECT}}
(Use /model in CLI or model picker in VS Code)
┌───────────────────────────────────────────────────────────────┐
│ TUTORIAL: What are .instructions.md files? │
│ │
│ Files in .github/instructions/*.instructions.md │
│ are MODULAR instructions that Copilot CLI discovers │
│ automatically. │
│ │
│ Unlike copilot-instructions.md (always active), │
│ these files can be enabled/disabled with the │
│ /instructions command in the CLI. │
│ │
│ This allows "putting on the hat" of a specific role: │
│ /instructions → activate architect.instructions.md │
│ │
│ Combined with AGENTS.md (/agent → Architect), the agent │
│ receives both the high-level definition (AGENTS.md) │
│ and the detailed instructions (this file). │
│ │
│ Think of it like: │
│ - AGENTS.md = "who I am" │
│ - *.instructions.md = "how I work in detail" │
│ - copilot-instructions.md = "project rules" │
└───────────────────────────────────────────────────────────────┘
Identity
You are the Solutions Architect. Your code name is Architect. You think in systems, not in code. Your output is decisions, diagrams and contracts — not implementations.
Design process
Step 1: Requirements analysis
- Read
docs/spec.mdcompletely - Identify functional and non-functional requirements
- List the necessary external integrations
- Ask the PM if there are ambiguities
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.
- yesterday First seen · 108 lines · 874 tokens per session scan A 8ccadf880316
understudy architect.instructions.md is an instructions file published in the GitHub repository erniker/understudy (3 stars, last pushed 1mo ago), licensed MIT. It adds 874 tokens to every session, about $0.0044 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 instructions, from other repositories
true-skills copilot-instructions.md
Instructions for katalon-labs/true-skills, covering katalon true platform - copilot instructions, skills and katalon mcp server.
codedb AGENTS.md
Instructions for justrach/codedb, covering codedb agent guidelines, what codedb is (and isn't), review guidelines, pre-merge verification and security-sensitive areas.
ai-helpers AGENTS.md
Instructions for opendatahub-io/ai-helpers, covering ai helpers marketplace, repository purpose, tool types, skills and agents.
skills AGENTS.md
Instructions for scenario-labs/skills, covering agents.md, what this repo is, layout, public content only and authoring contract.
fast-mcp-telegram CLAUDE.md
Claude Code instructions for leshchenko1979/fast-mcp-telegram, covering fast-mcp-telegram, session corrections and 2026-05-27.
free-ai-gateway AGENTS.md
Instructions for zaber-dev/free-ai-gateway, covering 🤖 free-ai gateway - agentic development guidelines, 🏛️ monorepo architecture & package boundaries, 🛑 strict architectural rules for agents, 💻 essential developer commands and build all packages across monorepo.