§ 00 · INTRODUCTION arc42 C4 Mermaid PlantUML

Architeeli — generate architecture docs with editable diagrams.

Architeeli helps software architects turn briefs, notes and repository context into a complete first draft of arc42 documentation — including editable C4, Mermaid and PlantUML diagrams.

Generate your first architecture draft

Built for architects who want structured documentation they can review, edit, version and maintain.

Outline · arc42

1 Introduction & Goals

2 Constraints

3 Context & Scope

4 Solution Strategy

5 Building Block View

5.1 Level 1 — System Context

5.2 Level 2 — Containers

5.3 Level 3 — Components

6 Runtime View

7 Deployment View

8 Crosscutting

9 Architecture Decisions

10 Quality Requirements

11 Risks

12 Glossary

§ 5 › Building Block View › 5.2 Level 2 — Containers

§ 5.2 Level 2 — Containers

The Payment Service decomposes into three first-class containers and one external dependency. The Payment API is the only entry point; the Ledger owns persistence and the Web Client never reaches the database directly.

Document Payment Service Architecture

Section § 5.2

Revision REV-03

Owner Maja Kowalska

Status APPROVED

§ 01 Why Architeeli

A first draft that follows the arc42 structure — not a wall of prose.

arc42 has twelve chapters, each with its own purpose and its own kind of diagram. A generic chatbot treats that as one big prompt and produces a glossy first page with placeholders underneath. Architeeli is built around the arc42 workflow: each chapter is generated as its own task, with the diagrams that belong to it, in a form you can keep maintaining.

FEATURE · 01BLOCK

arc42 structure from the start

Documentation is generated chapter by chapter, following the well-known arc42 template — from Introduction and Goals through Quality Requirements to Architecture Decisions. Each chapter has the context of the ones before it and the role it plays in the document.

FEATURE · 02BLOCK

Diagrams as code, not images

C4, Mermaid and PlantUML diagrams are emitted as code and embedded in the chapter where they belong. They stay editable, reviewable and versionable — and render live in the browser as you work.

FEATURE · 03BLOCK

Regenerate only what changed

When the system evolves, improve a single chapter or diagram without rebuilding the entire document. The rest of the doc stays put, with its glossary, decisions and cross-references intact.

§ 02 How it works

From a short brief to a reviewable arc42 draft.

Three stages, in order. Each is its own step in the workflow — paste in context, generate the draft, then refine and export. You can stop, edit, or regenerate anywhere along the way.

1/ 03

Start from existing context

Paste a short brief, point at a repository, or bring in your notes and markdown files. Architeeli builds a single source of truth about the system — goals, stakeholders, building blocks, runtime, constraints — before writing anything.

$ architeeli init payment-svc

→ ingest github.com/acme/payment-svc

→ read NOTES.md, ADRs/*.md

→ extract stakeholders ················ 9

→ extract building blocks ·············· 14

→ extract constraints ·················· 6

context.architeeli.json ready ✓

2/ 03

Generate a first draft

Architeeli fills each arc42 chapter in turn and produces the diagrams that belong with it, streamed in the browser. You watch sections appear, diagrams render live, and decisions get cross-referenced into the chapters that need them.

§ 1 Introduction & Goals ········ done

§ 2 Constraints ···················· done

§ 3 Context & Scope ················ done

§ 4 Solution Strategy ·············· done

§ 5 Building Block View ··········· ● drafting

§ 6 Runtime View ··················· queued

§ 7 Deployment View ··············· queued

3/ 03

Review, refine, export

Edit any chapter or diagram in place; regenerate one without disturbing the rest. Export as Markdown or PDF, or publish a read-only web doc on your own subdomain — in a form your team can version and maintain.

▸ Edit § 5.2 Containers ················ inline

▸ Regenerate § 7 only ················· 32s

▸ Export → architecture.md ········· 14.3 KB

▸ Export → architecture.pdf ········ 1.8 MB

▸ Publish → docs.acme.io

version 0.4 · 2026-05-08

§ 03 Diagrams

Editable diagrams, in the chapter where they belong.

Architecture documentation without diagrams isn't really architecture documentation. Architeeli emits every diagram as text so you can re-run, version, diff and edit it like code — always rendered inline, in the arc42 chapter it supports.

// arc42 § 5.2 — Containers (C4-PlantUML) @startuml !include C4_Container.puml Person(customer, "Customer", "iOS · Web") System_Boundary(pay, "Payment Service") { Container(web, "Web Client", "Next.js") Container(api, "Payment API", "Kotlin · Spring") ContainerDb(ledger, "Ledger", "Postgres 16") } System_Ext(stripe, "Stripe", "API v2024") Rel(customer, web, "opens") Rel(web, api, "HTTPS · JSON") Rel(api, ledger, "gRPC") Rel(api, stripe, "charge") @enduml

§ 5.2 · CONTAINERS·scale 1 : 1

Architect in control

Architeeli doesn't replace the architect.

Unlike a generic chatbot, Architeeli is designed around real architecture documentation workflows. It follows the arc42 structure, produces diagram code, and keeps the output maintainable. It creates a strong first draft — you review it, refine it, and make the final decisions.

§ 04 Pricing

Subscription. 14-day free trial. No credit card to start.

Architeeli is a hosted app — the model, the editor, the renderer and your documents all live on app.architeeli.com. Sign up, generate a first draft of a real arc42 document on day one, decide on day fourteen.

Free trial 14 days

$0 / 14 days

Full access. No card.

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All arc42 chapters
All diagram types
Markdown & PDF export

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Skip the blank page. Start with a solid arc42 draft.

14-day free trial. Full access. No credit card. Generate a first draft of your arc42 documentation — with editable diagrams — on day one.

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