What is ark-sdk-development?

A development guide for keeping Ark's Python, API, and TypeScript types synchronized when its Kubernetes resource definitions change.

It is for regenerating SDK types, updating API models, refreshing dashboard types, and adding custom SDK code.

It removes repetitive manual updates and helps resolve errors caused by code using outdated data shapes.

How mckinsey/agents-at-scale-ark configures Claude Code

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/skills/ark-sdk-development/SKILL.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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/mckinsey/agents-at-scale-ark/ark-sdk-development/github.svg)](https://agentmods.dev/skills/mckinsey/agents-at-scale-ark/ark-sdk-development)

Your own site

<a href="https://agentmods.dev/skills/mckinsey/agents-at-scale-ark/ark-sdk-development"><img src="https://agentmods.dev/badge/skills/mckinsey/agents-at-scale-ark/ark-sdk-development/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/mckinsey/agents-at-scale-ark/ark-sdk-development"><img src="https://agentmods.dev/badge/skills/mckinsey/agents-at-scale-ark/ark-sdk-development.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 81 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,112 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits

NVIDIA SkillSpector pass 7 Sept 2026

How audits are shown

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.

Model	Per session	Once invoked
Fable 5.1	$0.00081	$0.01112
Opus 5.5	$0.00032	$0.00445
Sonnet 5.5	$0.00016	$0.00222
Haiku 4.5	$0.00008	$0.00111

Measured 2mo ago against content hash f24586e762bb, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

ark-sdk-development 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 2mo 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.

.claude/skills/ark-sdk-development/SKILL.md · 115 lines

How it starts

The opening of the file, as written. The whole thing — 115 lines — stays where its author put it; the contents beside it link to each section on GitHub.

ARK SDK and Type Development

Type Generation Pipeline

Types flow through the ARK stack:

CRD YAML (ark/config/crd/)
    ↓ make ark-sdk-build (automatic)
ark-sdk Python types + overlay utilities
    ↓
ark-api Pydantic models (manual updates if exposing new fields)
    ↓ make ark-api-build → generates openapi.json
ark-dashboard TypeScript types
    ↓ npm run generate:api → generates types.ts

ark-sdk: Automatic Type Generation

CRD types are automatically generated from Kubernetes CRD YAML files.

make ark-sdk-build

This runs:

crd_to_openapi.py - converts CRDs to OpenAPI schema
openapi-generator-cli - generates Python types from schema
Copies overlay files on top of generated code
Builds wheel package

Adding Custom SDK Functionality (Overlays)

The lib/ark-sdk/gen_sdk/overlay/python/ark_sdk/ directory contains custom Python modules that are copied on top of generated code. This is how utilities like client.py, k8s.py, and executor.py are added.

To add custom SDK functionality:

Add Python files to lib/ark-sdk/gen_sdk/overlay/python/ark_sdk/
Run make ark-sdk-build

ark-api: Manual Model Updates

The ark-api has manually written Pydantic models in services/ark-api/ark-api/src/ark_api/models/.

When to update ark-api models:

When exposing new CRD fields via the HTTP API
When adding new API response types

make ark-api-build

This generates services/ark-api/openapi.json from FastAPI routes and Pydantic models.

Pydantic Model Naming (CRITICAL)

Pydantic model class names MUST be globally unique across all model files. When multiple files define classes with the same name (e.g., ConfigMapKeyRef, Header, ValueFrom), FastAPI generates non-deterministic OpenAPI schema names like ark_api__models__agents__Header-Input. These names depend on import order and cause CI failures when types.ts differs between environments.

Solution: Prefix class names with their domain context:

Read the full file on GitHub · 115 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.

2mo ago First seen · 115 lines · 81 tokens per session scan A f24586e762bb

Subscribe to this mod's changes

ark-sdk-development is a skill published in the GitHub repository mckinsey/agents-at-scale-ark (434 stars, last pushed yesterday), licensed Apache-2.0. It adds 81 tokens to every session and 1,112 once invoked, about $0.0003 per session on Opus 5.5. 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 2026-09-03.

Backend and APIs Cloud DevOps and cloud Languages Python TypeScript agentic-ai ai kubernetes productid-20863

ark-sdk-development next to 6 skills from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
ark-sdk-developmentmckinsey/agents-at-scale-ark	Skill	434	yesterday	Apache-2.0	A	81	Claude Code
fastapi-templateswshobson/agents	Skill	42k	yesterday	MIT	A	37	Claude Code
langgraph-docslangchain-ai/deepagents	Skill	31k	yesterday	MIT	A	62	Claude Code, Codex
stripe-projectse2b-dev/E2B	Skill	15k	yesterday	Apache-2.0	A	51	Claude Code, Codex
fastapiericrisco/rsc-harness	Skill	503	2d ago	MIT	A	94	Claude Code, Codex
djangoericrisco/rsc-harness	Skill	503	2d ago	MIT	A	84	Claude Code, Codex
modalericrisco/rsc-harness	Skill	503	2d ago	MIT	A	78	Claude Code, Codex

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