SaaSAllTheThings

Multi-tenant B2B SaaS on Azure

Build a B2B SaaS from scratch, or turn a working proof of concept or an existing app into a mature, multi-tenant SaaS, with an AI assistant doing the building. You own the product: what it does, for whom and in what order. The framework owns the architecture and enforces it. The AI builds within that architecture, tests and keeps the records.

The architecture: an event-driven Azure Functions backend, separate Windows and mobile clients, OIDC sign-in with Entra ID and federated identity, pooled multi-tenancy that can move a customer to its own deployment later, and enterprise integrations starting with Navision (Dynamics NAV and Business Central). The product is anchored in the customer's own security framework: architecture sessions read the security and compliance requirements kept in the app's compliance/ folder, and weigh every option against them.

Repository README Procedures Reference architecture

What the check enforces

bash tools/check.sh runs four steps:

1. The architecture rules (tools/archcheck.awk).
2. The backend stack's build and tests (dotnet, typescript, python or none).
3. The Bicep files in infra/, when the Bicep CLI is installed.
4. tools/check.local.sh, if the app has one (client builds, emulator tests).

bash tools/check.sh --architecture runs step 1 alone in seconds, with no toolchain. The check never calls Azure, the network or an external system.

Rule	Fails when
layers	A layer depends on a layer it may not, or the domain or contracts take an external package
domain-purity	Domain code reads the clock, makes ids or random numbers, reads the environment, or does I/O
tenant-source	A host reads the tenant from a header, query, route or form, or an API contract carries a tenant id
tenant-branching	Code compares a tenant with a literal
secrets	A file holds something that looks like a key, password, connection secret or private key
file-size	A source file is longer than max_lines (300 by default)
host-size	A host or platform file is longer than host_max_lines (80 by default)
message-version	An event or command type isn't named …V<n>
cost-sku	Bicep asks for a premium, isolated or dedicated SKU, or provisioned Cosmos DB throughput

Deviation is an ADR

The only way past a rule is an architecture decision record that you accept. An exception is one line in an accepted ADR, naming a rule and a path pattern:

- Exception: domain-purity src/OrderDesk.Domain/Legacy/**

/architect runs the session that produces the ADR, with "comply" always as the first option. A hook asks you before an ADR is marked accepted or a framework file changes.

Install

You need git with no uncommitted changes, bash (on Windows it comes with Git for Windows), and the toolchain of your backend stack: the .NET SDK 8 or newer for the default. Every option installs the latest release, tagged v followed by its version, not main.

Claude Code pluginManualSkill

/plugin marketplace add Freakling/SaaSAllTheThings
/plugin install saasallthethings@saasallthethings

Then open a new session in the app's folder and run /saasallthethings:saas-all-the-things.

Clone the latest release into the app's root folder as SaaSAllTheThings, using the release's tag from the Releases page:

git clone --branch <tag> --depth 1 https://github.com/Freakling/SaaSAllTheThings.git SaaSAllTheThings

Then ask your assistant:

Read SaaSAllTheThings/ONBOARDING.md and follow it to install SaaSAllTheThings into this project.

npx skills add Freakling/SaaSAllTheThings

Then ask your assistant to "SaaS all the things" in the app's folder.

Onboarding works out whether this is a new app, an existing app or an upgrade, settles the backend stack with you, interviews you or reads the app (including its single-tenant habits and secrets; it offers a product brief template, product/director-brief.md, to fill in first, in your own words, with sections for the customer's enterprise architecture, requirements, security requirements and control frameworks, which anchors the sessions, the assessment and the builds that follow in the customer's security framework), writes the first stages of the roadmap into TASKS.md, and ends with one commit for you to approve. Restart Claude Code afterwards so the commands load. Each new clone later needs bash tools/setup-clone.sh. Step by step, with what onboarding asks: where do I start with a SaaS?, or I already have a project for an existing app or proof of concept, which starts with an assessment.

Skills you can use without installing

Skill	What it does
saas-all-the-things	Installs or upgrades SaaSAllTheThings in the app open in the session
saas-assessment	Analyses an existing app without changing it: readiness with evidence, the roadmap by stage with rough effort, and the workshops to hold
saas-design-session	Runs architecture and product sessions, integration contracts and workshops in Claude Code, Cowork or the Claude apps, with or without the repository

Commands

Command	What it does
/next-task	Builds the next ready item in a fresh context within the reference architecture, proves it with the check, updates the records and commits it once you approve. A run you ask for, such as "grab tasks until you're blocked", commits each item without pausing. Step by step: how do I get things built?
/assess	A read-only assessment report; "process the workshop notes" turns a workshop's decisions into records
/roadmap	Plans the next stage of the move to SaaS as small items
/design	A product design session on a topic, or /design questions to rank the open questions. Step by step: how do I decide what gets built?
/research	A read-only researcher answers one question in a fresh context and writes a dated note with its sources to product/research/. It informs; you decide. Procedure: research.md. Step by step: I need facts before I decide
/architect	An architecture session that ends in an ADR you accept
/integrate	Works out an integration contract with you (direction, system of record, conflicts), then plans it in stages
/tenant	Checks readiness for a new customer and hands you the consent and setup steps
/acceptance	Prepares or processes a checklist of built behaviour for you to tick Works or Broken. Step by step: how do I check that what was built works?
/feedback	Turns a customer or pilot session into bugs, score trends and product proposals
/release	Check, what-if, deploy and smoke test, each Azure step with your approval. Production is yours to run. Shared behaviour and this repo's section: /release. Step by step: how do I ship it?
/align	Consistency pass across the PRD, decisions, ADRs, integration contracts, tasks, AGENTS.md, settings and code. Step by step: the records and the code don't agree
/drift-reset	Product design drift reset, started only by you; /drift-reset postmortem after the rebuild. Step by step: the system was not built as I intended
/prune	Moves done items to TASKS-archive.md. Step by step: the task list is getting long
/refresh-model-sizing	Sets or updates the model for each task size. Step by step: it's costing more than I'd like

Read more

• In use: the Azure SaaS worked example
• Build a B2B SaaS on Azure with Director-Driven Development, the step-by-step guide
• The concept and agent development flow

You own the product. The framework owns the architecture.Freakling/SaaSAllTheThings