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

# Welcome

This documentation describes the **Flowxi backend platform** — the internal banking and financial infrastructure that powers all Flowxi products.

Flowxi is a **private, controlled backend system** designed to operate in production under **bank-level security, compliance, and reliability constraints**.\
It exposes a set of strictly versioned APIs consumed by Flowxi frontends and internal services.

This documentation exists to explain **how the platform works**, **how to integrate with it safely**, and **how to reason about its behavior in real-world scenarios**.

This is **not marketing documentation** and **not a public developer portal**.

***

## Audience

This documentation is written for three main audiences:

### Frontend engineers

* Integrating authentication and onboarding flows
* Handling sessions, devices, and 2FA
* Displaying errors and localized messages correctly
* Building wallet and financial user experiences

### Internal teams

* Operating and monitoring the platform
* Extending features without breaking guarantees
* Understanding system boundaries and invariants
* Debugging production behavior safely

### Investors, auditors, and technical reviewers

* Understanding platform architecture
* Reviewing security and compliance posture
* Verifying deterministic and auditable behavior
* Assessing scalability and risk controls

***

## What Flowxi provides

Flowxi exposes a **clear, opinionated backend surface** with the following responsibilities.

### Identity & access control

* User registration and activation
* Secure authentication (email/password)
* Two-factor authentication (TOTP)
* Session and device management
* Strict anti-enumeration guarantees
* Rate limiting on sensitive actions

### Wallet & balance infrastructure

* Custodial wallet ownership
* Balance tracking
* Transaction history
* Deterministic ledger behavior

### Financial operations

* Internal transfers and movements
* Idempotent financial actions
* Auditable money flows
* Explicit success and failure states

### Compliance primitives

* KYC / KYB workflows
* Document handling
* Regulatory state enforcement
* Account restriction and closure logic

### Localization-first APIs

* All API responses are localized
* Validation errors are localized
* Authentication errors are localized
* Transactional emails follow the same locale
* **FR is the default and guaranteed fallback**
* **EN is supported**

Localization is not optional and never partial.

***

## Design philosophy (important)

Flowxi follows a few **non-negotiable principles** that explain many implementation choices.

* **Security before convenience**\
  Every flow is designed to resist abuse, enumeration, and misuse.
* **API-first architecture**\
  All behavior is explicit, versioned, and documented.
* **State-driven logic**\
  No hidden or inferred states; everything is explicit and persisted.
* **Deterministic behavior**\
  Same input → same output, including error codes.
* **Frontend-safe contracts**\
  Frontends rely on stable `code` values, never on translated text.

If something feels strict, verbose, or conservative, it is intentional.

***

## Documentation structure

The documentation is organized by responsibility, not by user journey.

<Columns cols={2}>
  <Card title="Platform introduction" icon="layer-group" href="/introduction">
    High-level architecture, scope, and core platform principles.
  </Card>

  <Card title="Authentication & security" icon="lock" href="/auth/overview">
    Login, registration, tokens, sessions, devices, and 2FA flows.
  </Card>

  <Card title="Errors & localization" icon="language" href="/errors">
    Error formats, error codes, localization rules, and frontend handling.
  </Card>

  <Card title="API reference" icon="code" href="/api-reference">
    Endpoint-level documentation with request and response schemas.
  </Card>
</Columns>

***

## Core platform components

The Flowxi backend is built around a small number of clearly separated components.

<Columns cols={2}>
  <Card title="Users" icon="users">
    User accounts, lifecycle states, locale, and access rules.
  </Card>

  <Card title="Wallets" icon="wallet">
    Custodial wallets, balances, and transaction records.
  </Card>

  <Card title="Compliance" icon="shield-check">
    Verification workflows, regulatory states, and enforcement logic.
  </Card>

  <Card title="Security" icon="lock">
    Rate limiting, 2FA, audit logs, and abuse prevention.
  </Card>
</Columns>

Each component is documented independently but designed to work as a coherent system.

***

## How to use this documentation

Recommended reading order:

1. **Introduction**\
   Understand what the platform is responsible for.
2. **Authentication overview**\
   Learn how access, sessions, and security actually work.
3. **Errors & localization**\
   Learn how to handle failures correctly on the frontend.
4. **API reference**\
   Use as a precise contract for implementation.

This documentation assumes:

* Familiarity with REST APIs
* Experience with frontend ↔ backend integration
* Basic understanding of authentication and tokens

***

## Access & support

Flowxi is restricted to authorized teams and systems.

For access issues, production incidents, or technical questions:\
**[support@flowxi.app](mailto:support@flowxi.app)**

***

## Final note

Flowxi is designed for **financial-grade correctness**.

Clarity, predictability, and safety always take precedence over shortcuts.
Every rule documented here exists to reduce ambiguity, prevent misuse,
and ensure the platform behaves reliably at scale.