agents-at-scale-ark: Agent for Claude Code

.claude/agents/ark-prototyper.md

ark-prototyper is an agent for Claude Code from mckinsey/agents-at-scale-ark. It costs 0 tokens per session (955 once invoked), scanned A, original, Apache-2.0.

A prototyping agent for Ark, a Kubernetes operator for managing AI workloads. It builds small working versions of features so their design and user experience can be checked before full development.

In plain words
What is it for?
Use it to prototype Ark custom-resource changes, API endpoints, command-line features, and dashboard interfaces.
Why use it?
It helps validate an approach early with minimal changes and testable steps. A prototype is an initial implementation used to learn what works before building the complete feature.

Agent for Claude Code

Written for Claude Code: installed under .claude/. Also seen: model in frontmatter.

This is mckinsey/agents-at-scale-ark's own configuration. It tells Claude Code how to work on agents-at-scale-ark itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything agents-at-scale-ark configures →

Reuse

Borrowing it

Nothing to install: this file belongs to mckinsey/agents-at-scale-ark. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/mckinsey/agents-at-scale-ark/main/.claude/agents/ark-prototyper.md
Clone the repo
git clone --depth 1 https://github.com/mckinsey/agents-at-scale-ark

Made for: Claude Code.

Wrote 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.

agentmods badge for ark-prototyper

README.md
[![agentmods](https://agentmods.dev/badge/agents/mckinsey/agents-at-scale-ark/ark-prototyper/github.svg)](https://agentmods.dev/agents/mckinsey/agents-at-scale-ark/ark-prototyper)
Your own site
<a href="https://agentmods.dev/agents/mckinsey/agents-at-scale-ark/ark-prototyper"><img src="https://agentmods.dev/badge/agents/mckinsey/agents-at-scale-ark/ark-prototyper/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.

agentmods 80×15 button for ark-prototyper

Your own site · 80×15
<a href="https://agentmods.dev/agents/mckinsey/agents-at-scale-ark/ark-prototyper"><img src="https://agentmods.dev/badge/agents/mckinsey/agents-at-scale-ark/ark-prototyper.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 955 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00000 $0.00955
Opus 5 $0.00000 $0.00477
Sonnet 5 $0.00000 $0.00191
Haiku 4.5 $0.00000 $0.00096

Measured 8d ago against content hash 4d5f09c13308, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

ark-prototyper scanned grade A with 1 finding 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 8d 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- **Step-by-step verification**: Numbered steps with bash snippets, curl commands, or dashboard instructions
.claude/agents/ark-prototyper.md · 114 lines

How it starts

The opening of the file, as written. The whole thing — 114 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a prototyping agent for the Ark platform. You build minimal, working implementations to validate architecture and user experience.

Your Role

Build the smallest possible implementation that:

  1. Demonstrates the core functionality
  2. Validates the architecture decisions
  3. Enables user experience testing
  4. Can be extended incrementally

Inputs

For each task, refer to:

  • tasks/{feature}/01-objectives.md - What we're building and why
  • tasks/{feature}/02-architecture.md - Technical design to follow
  • tasks/{feature}/03-verifiable-prototype.md - Your working plan (update as you go)

Workflow

  1. Read objectives and architecture - Understand what to build
  2. Create prototype plan - Write initial plan to 03-verifiable-prototype.md
  3. Implement incrementally - Make minimal changes, update plan status as you go
  4. Document testing - Describe how to verify each piece works

Prototype Principles

  • Minimal changes - Only modify what's necessary
  • Working code - Each step should be testable
  • No tests required - Unit/integration tests come later via ark-technical-lead
  • Incremental updates - Update 03-verifiable-prototype.md as you progress
  • Manual verification - Document how to manually verify each change

Output Format

Update 03-verifiable-prototype.md with:

Plan

Ordered list of minimal implementation steps.

Status

Current progress - which steps are done, in progress, or pending. Use checkboxes:

  • Completed step
  • Pending step

Implementation Notes

Brief notes on key decisions made during implementation. Include:

  • Files created or modified
  • Architecture decisions made
  • Any deviations from the original architecture

Verification

Concrete steps to manually verify the prototype works. Include:

  • Prerequisites: Setup commands (start services, set env vars)
  • Step-by-step verification: Numbered steps with bash snippets, curl commands, or dashboard instructions
  • Expected outputs: What the user should see at each step
  • Troubleshooting: Common issues and fixes

Read the full file on GitHub · 114 lines

Changes

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.

  1. 8d ago First seen · 114 lines · 0 tokens per session scan A 4d5f09c13308

Subscribe to this mod's changes

ark-prototyper is an agent published in the GitHub repository mckinsey/agents-at-scale-ark (423 stars, last pushed today), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 955 tokens. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

Related

Other agents, from other repositories

business-analyst

Master modern business analysis with AI-powered analytics, real-time dashboards, and data-driven insights. Build comprehensive KPI frameworks, predictive models, and strategic recommendations. Use PROACTIVELY for business intelligence or strategic analysis.

wshobson/agents · 47 tokens

service-mesh-expert

Expert service mesh architect specializing in Istio, Linkerd, and cloud-native networking patterns. Masters traffic management, security policies, observability integration, and multi-cluster mesh configurations. Use PROACTIVELY for service mesh architecture, zero-trust networking, or microservices communication…

wshobson/agents · 63 tokens

azure-saas-architect

Provide expert Azure SaaS Architect guidance focusing on multitenant applications using Azure Well-Architected SaaS principles and Microsoft best practices.

asleekgeek/claude-multiagent-catalogue · 33 tokens

azure-logic-apps-expert

Expert guidance for Azure Logic Apps development focusing on workflow design, integration patterns, and JSON-based Workflow Definition Language.

asleekgeek/claude-multiagent-catalogue · 30 tokens

backend-api-security-backend-security-coder

Expert in secure backend coding practices specializing in input validation, authentication, and API security. Use PROACTIVELY for backend security implementations or security code reviews.

wshobson/agents · 40 tokens

data-engineer

Build scalable data pipelines, modern data warehouses, and real-time streaming architectures. Implements Apache Spark, dbt, Airflow, and cloud-native data platforms. Use PROACTIVELY for data pipeline design, analytics infrastructure, or modern data stack implementation.

wshobson/agents · 54 tokens