> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kvant.sbs/jeston/llms.txt
> Use this file to discover all available pages before exploring further.

# SaaS starter

# SaaS starter

***

## Start · SaaS starter

> **Purpose** — Model a multi-user product as cooperating boundaries instead of one oversized route handler.

# SaaS starter

***

## Start · SaaS starter

> **Purpose** — Model a multi-user product as cooperating boundaries instead of one oversized route handler.

A SaaS foundation with tenant context, identity, billing seams, jobs, and operational ownershipA SaaS foundation with tenant context, identity, billing seams, jobs, and operational ownership.

### Key concepts

<Columns cols={3}>
  <Card title="Identity" icon="sparkles">
    Who is the actor?
  </Card>

  <Card title="Scope" icon="shield-check">
    Which tenant?
  </Card>

  <Card title="Usage" icon="gauge-high">
    What was consumed?
  </Card>
</Columns>

### What to verify

| Area     | Expected state     | Evidence                              |
| -------- | ------------------ | ------------------------------------- |
| Identity | Who is the actor?  | Session and provider boundary.        |
| Scope    | Which tenant?      | Request context and query predicates. |
| Usage    | What was consumed? | Event or metering record.             |

### Working example

```text theme={null}
request -> Jeston runtime -> typed boundary -> observable response
```

### Before you move on

SaaS complexity is mostly coordination: who owns data, who may act, what can be retried, and how usage is measured.

### Implementation notes

| Engineering move                         | Guidance                                                                      |
| ---------------------------------------- | ----------------------------------------------------------------------------- |
| **Define tenancy**                       | Choose how tenant identity enters the request and how it is enforced.         |
| **Separate identity from authorization** | A valid session does not automatically grant access to every tenant resource. |
| **Move slow work to jobs**               | Email, exports, indexing, and model tasks need durable status.                |
| **Instrument usage**                     | Record the signals required for limits, billing, and support.                 |

### Decision lens

| Mode              | Practical emphasis                                              |
| ----------------- | --------------------------------------------------------------- |
| **Single tenant** | Optimize for clarity and simple local development.              |
| **Multi tenant**  | Make tenant scope explicit in every query and cache key.        |
| **Enterprise**    | Add auditability, stronger isolation, and operational runbooks. |

## Related topics

<Columns cols={3}>
  <Card title="Secure identity" icon="user-lock" horizontal href="/jeston/jeston/platform/auth">
    Read the focused guide for this boundary.
  </Card>

  <Card title="Scope data access" icon="database" horizontal href="/jeston/jeston/platform/sql">
    Read the focused guide for this boundary.
  </Card>

  <Card title="Operate the SaaS" color="#ffffff" icon="alien-8bit" horizontal href="/jeston/jeston/operations/production">
    Read the focused guide for this boundary.
  </Card>
</Columns>

## References

[1]: https://github.com/jeffersoncampos12p-dev/jeston "Jeston source repository"

[2]: https://www.npmjs.com/package/@kvantjs/jeston "Jeston package on npm"

[3]: https://nodejs.org/api/http.html "Node.js HTTP API"

[4]: https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal "AbortSignal Web API"

[5]: https://react.dev/reference/react-dom/server "React server rendering APIs"

[6]: https://www.typescriptlang.org/docs/handbook/intro.html "TypeScript handbook"

### Key concepts

<Columns cols={3}>
  <Card title="Identity" icon="sparkles">
    Who is the actor?
  </Card>

  <Card title="Scope" icon="shield-check">
    Which tenant?
  </Card>

  <Card title="Usage" icon="gauge-high">
    What was consumed?
  </Card>
</Columns>

### What to verify

| Area     | Expected state     | Evidence                              |
| -------- | ------------------ | ------------------------------------- |
| Identity | Who is the actor?  | Session and provider boundary.        |
| Scope    | Which tenant?      | Request context and query predicates. |
| Usage    | What was consumed? | Event or metering record.             |

### Working example

```text theme={null}
request -> Jeston runtime -> typed boundary -> observable response
```

### Before you move on

SaaS complexity is mostly coordination: who owns data, who may act, what can be retried, and how usage is measured.

### Implementation notes

| Engineering move                         | Guidance                                                                      |
| ---------------------------------------- | ----------------------------------------------------------------------------- |
| **Define tenancy**                       | Choose how tenant identity enters the request and how it is enforced.         |
| **Separate identity from authorization** | A valid session does not automatically grant access to every tenant resource. |
| **Move slow work to jobs**               | Email, exports, indexing, and model tasks need durable status.                |
| **Instrument usage**                     | Record the signals required for limits, billing, and support.                 |

### Decision lens

| Mode              | Practical emphasis                                              |
| ----------------- | --------------------------------------------------------------- |
| **Single tenant** | Optimize for clarity and simple local development.              |
| **Multi tenant**  | Make tenant scope explicit in every query and cache key.        |
| **Enterprise**    | Add auditability, stronger isolation, and operational runbooks. |

## Related topics

<Columns cols={3}>
  * [user-lock · **Secure identity**](/jeston/jeston/platform/auth) — Read the focused guide for this boundary.
  * [database · **Scope data access**](/jeston/jeston/platform/sql) — Read the focused guide for this boundary.
  * [server-stack · **Operate the SaaS**](/jeston/jeston/operations/production) — Read the focused guide for this boundary.
</Columns>

## References

[1]: https://github.com/jeffersoncampos12p-dev/jeston "Jeston source repository"

[2]: https://www.npmjs.com/package/@kvantjs/jeston "Jeston package on npm"

[3]: https://nodejs.org/api/http.html "Node.js HTTP API"

[4]: https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal "AbortSignal Web API"

[5]: https://react.dev/reference/react-dom/server "React server rendering APIs"

[6]: https://www.typescriptlang.org/docs/handbook/intro.html "TypeScript handbook"