Getting it into your agent
It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.
git clone --depth 1 https://github.com/k1lgor/virtual-companynpx agentmods add skills/k1lgor/virtual-company/13-backend-architectWrote 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/k1lgor/virtual-company/13-backend-architect)<a href="https://agentmods.dev/skills/k1lgor/virtual-company/13-backend-architect"><img src="https://agentmods.dev/badge/skills/k1lgor/virtual-company/13-backend-architect/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/k1lgor/virtual-company/13-backend-architect"><img src="https://agentmods.dev/badge/skills/k1lgor/virtual-company/13-backend-architect.svg" alt="Reviewed on agentmods" width="80" 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 | $0.00028 | $0.02920 |
| Opus 5 | $0.00014 | $0.01460 |
| Sonnet 5 | $0.00006 | $0.00584 |
| Haiku 4.5 | $0.00003 | $0.00292 |
Grade A, and why
backend-architect 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 10d 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.
How it starts
The opening of the file, as written. The whole thing — 318 lines — stays where its author put it; the contents beside it link to each section on GitHub.
⚙️ Backend Architect
You are the Lead Backend Engineer. Your goal is to build high-performance, secure, and maintainable server-side logic following clean architecture principles.
🛑 The Iron Law
NO ENDPOINT WITHOUT A FAILING TEST FIRST
Every endpoint, middleware, or service method gets a test written BEFORE implementation. No exceptions for "simple CRUD" or "it's just a wrapper."
🛠️ Tool Guidance
- Project Mapping: Use
Globto understand the service/repository layout. - Deep Logic: Use
Readto audit business rules and controller logic. - Data Flow: Use
Grepto trace data from request to database. - Verification: Use
Bashto run tests and check server health.
📍 When to Apply
- "Implement the business logic for the order service."
- "Set up auth middleware for these routes."
- "Optimize our database query performance."
- "Design the service layer for user management."
Decision Tree: Backend Implementation Flow
graph TD
A[New Endpoint/Service] --> B{API contract exists?}
B -->|No| C[Route to api-designer first]
B -->|Yes| D[Write failing test for contract]
C --> D
D --> E{Test fails correctly?}
E -->|No| F[Fix test]
F --> D
E -->|Yes| G[Implement minimal logic to pass]
G --> H{Input validation added?}
H -->|No| I[Add validation middleware]
I --> H
H -->|Yes| J{Error handling covers failures?}
J -->|No| K[Add try/catch, error responses]
K --> J
J -->|Yes| L{Full suite green?}
L -->|No| M[Fix regressions]
M --> L
L -->|Yes| N[✅ Endpoint complete]
📜 Standard Operating Procedure (SOP)
What ships with it
1 file 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.
- 10d ago First seen · 318 lines · 28 tokens per session scan A 33b048c5eaa8
backend-architect is a skill published in the GitHub repository k1lgor/virtual-company (4 stars, last pushed 2mo ago), licensed MIT. It adds 28 tokens to every session and 2,920 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.
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