Ark Documentation

Ark Documentation

Guidance for structuring Ark documentation using Diataxis adapted for Ark's needs.

When to use this skill

• Creating new documentation
• Deciding where content belongs
• Reviewing documentation PRs
• Restructuring existing documentation

Ark's Diataxis structure

docs/content/
├── Introduction
├── Quickstart
├── Tutorials          → Linear learning paths
├── How-to Guides      → Task-oriented, by persona
├── Core Concepts      → Understanding "why" and "how"
├── Reference          → Factual lookup material
├── Marketplace        → External link
└── Disclaimer

Terminology

The four quadrants

1. Tutorials (learning-oriented)

Purpose: Hands-on lessons for newcomers.

Characteristics:

• Linear, numbered paths (1, 2, 3...)
• Single prescribed path - no choices
• Frequent visible results
• Ends with "Next step" → How-to Guides

Writing style:

• Use "we" language
• Don't explain - link to Core Concepts

Content belongs here if:

• It teaches a skill through doing
• Reader is studying, not working
• Success requires following steps in order

Examples: Quickstart, Running the Dashboard, Starting a New Project, Complete Worked Example

2. How-to guides (task-oriented)

Purpose: Help competent users complete specific tasks.

Organized by persona:

Build with Ark (application developers)

• Configure models, create agents, coordinate teams, run queries, add tools.

Extend Ark (contributors)

• Build services locally, implement APIs, build A2A servers, add tests.

Operate Ark (operators / SRE / security)

• Platform operations: Provisioning, deploying
• CI/CD and supply chain: Build pipelines
• Security & assurance: Pen testing, code analysis

Writing style:

• Goal-oriented: "If you want X, do Y"
• Assumes competence
• Don't teach - link to Tutorials or Core Concepts

Content belongs here if:

• Reader has a specific task to complete
• Reader is working, not studying

3. Core concepts (understanding-oriented)

Purpose: Explain what Ark is, how it's designed, and why.

Topics:

• What Ark is and how it works.
• Design effective agentic systems.
• Platform architecture concepts.
• Extensibility concepts.
• Security and identity concepts.

Writing style:

• Discursive: "The reason for X is..."
• Make connections between concepts
• Provide design decision context

Content belongs here if:

• It answers "why" or "how does this work"
• Reader is deciding how to design/extend/operate
• Content provides context, not procedures

4. Reference (information-oriented)

Purpose: Factual lookup material.

Organized by type:

• Interfaces: Ark API, Broker Service.
• Kubernetes API: CRDs, resources.
• System behavior: Query execution, relationships.
• Operations: Upgrading, troubleshooting.
• Project: Contributors.

Writing style:

• Austere, factual, neutral
• Structure mirrors product
• No instruction, explanation, or opinion

Content belongs here if:

• It describes what something IS
• Reader needs to look up specific details
• Content is consulted, not read cover-to-cover

Decision guide

Is the reader LEARNING or WORKING?
│
├─ LEARNING (studying)
│   ├─ Hands-on, step-by-step? → TUTORIALS
│   └─ Understanding concepts? → CORE CONCEPTS
│
└─ WORKING (applying)
    ├─ Completing a task? → HOW-TO GUIDES
    └─ Looking up facts? → REFERENCE

Hub pages

Hub pages link to content without moving files:

• tutorials.mdx - Lists tutorials in order.
• how-to-guides.mdx - Groups by persona.
• core-concepts.mdx - Groups by topic.
• reference/index.mdx - Groups by type.

Hub pages should:

• Explain purpose in one sentence.
• Group links logically.
• Not duplicate content.

Personas

Writing guidelines

Lexicon

• The product is written Ark — capital A, lowercase rk. Never ARK. This matches the repo's CLAUDE.md and is enforced in review.

General style

• Be concise and direct.
• Use simple language.
• Keep descriptions to 1-2 sentences.
• Use active voice: "Creates agent" not "Agent is created".
• Write "Ark" not "ARK".
• Use US English.
• Use Oxford commas in lists.

Bullets

• Capitalize the first word and end with a period.
• Use numbered lists only for sequences of instructions or when referencing items later.

Capitalization

• Capitalize only proper nouns (product names, tools, services).
• Use sentence case for titles: "An introduction to data visualization" not "An Introduction to Data Visualization".
• Don't capitalize: cloud, internet, machine learning, advanced analytics.

Headings

• Avoid gerunds: "Get started" not "Getting started," "Customize a layout" not "Customizing a layout".
• Keep titles short and descriptive for search discoverability.

Instructions

• Use imperatives: "Complete the configuration steps".
• Don't use "please".
• Don't use passive tense: "Complete the steps" not "The steps should be completed".

Links

• Make hyperlinks descriptive: Learn how to [contribute to Ark](url).
• Don't write: To contribute, see [here](url).

Avoid

• Gerunds in headings.
• Colloquialisms (may not translate across regions/languages).
• Business speak: "leverage", "utilize", "facilitate".

What not to mix

Reference page structure

CRD and service reference pages follow a consistent template. Use reference/resources/query.mdx, team.mdx, and tools.mdx as the models:

1. Frontmatter — title and a description of the form "<Kind> CRD reference — ...".
2. Intro — one paragraph on what the resource is, linking the task-oriented user-guide walkthrough; state plainly that this page is the field-by-field reference.
3. ## Spec — a single annotated YAML example, comments grouped Required / optional.
4. ## Fields — a table with columns Field | Type | Required | Description, including enum values, defaults, and cross-field rules.
5. Topic sections as warranted (strategies, parameters, auth, …).
6. ## Status — a status YAML block, a ### Status fields table, a ### Phases table where a phase enum exists, and a ### Print columns line naming the columns kubectl get renders.
7. ## Related — links to adjacent pages.

For an overview/index page, use one table listing every resource with its Kind and API version. Don't keep a second overlapping overview page — one topic, one page. The same applies to service APIs: one service, one reference page (Ark API, Broker Service), with the built-in OpenAPI/Swagger framed as the always-current source of truth.

Accuracy: verify against the source

Reference docs must be true to the code, not to intent or memory. Pages can read plausibly and still be wrong — this is the most common defect. Before writing or reviewing a reference page, verify every claim:

• Fields, enums, defaults — read the Go types in ark/api/v1alpha1/*_types.go and the generated CRD in ark/config/crd/bases/. +kubebuilder:validation:Enum, +kubebuilder:default, and the json tags are authoritative — not the existing prose.
• Behavior and constraints — read the controller and webhooks (ark/internal/controller/, ark/internal/validation/). Migration targets, same- vs cross-namespace resolution, and validation rules live here. Example: a deprecated graph team strategy migrates to sequential (edges discarded), not selector — confirmed in validation/defaults.go. Verify even when a reviewer asserts otherwise.
• Live cluster — where one is available, confirm with kubectl explain, kubectl get <kind> (for the print columns), and real resource YAML. For a service API, hit the running service's /openapi.json and Swagger.
• Version and release claims — check the release tags, not the calendar. git grep <pattern> <tag> shows when something changed; git merge-base --is-ancestor <commit> <tag> confirms what actually shipped. Don't label a section "Unreleased" or cite a version (e.g. there is no v0.2.0) without checking.

This session's rewrites found extensive fictional fields (spec.model, systemPrompt, spec.agents), non-existent CLI commands (ark check, ark describe; it's devspace run routes, not make routes), and wrong migration targets — all in pages that looked fine.

Build and preview before pushing

• Build with cd docs && npm run build (Turbopack). The production build catches MDX and mermaid errors the dev server silently tolerates, and prints a page count on success. Never push a docs change without a clean build.
• Preview the rendered page (dev server + screenshot). Mermaid renders lazily — scroll to the diagram or render a tall enough viewport before capturing.
• Keep diagrams and prose complementary, not duplicated. When two pages cover related ground (e.g. Core Architecture and Query Execution Flow, or the Core Concepts and Core Architecture diagrams), cross-link and defer rather than repeat.

References

• Diataxis Framework
• Issue #338
• PR #620