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

# Architecture

> Walkthrough of the DFNS architecture and how the platform helps businesses securely manage digital assets across authentication, policies, and MPC signing.

## Overview

DFNS is a **Core Banking Platform** for onchain finance. It handles the security infrastructure so clients can focus on building their products and services.

At the core is a wallet infrastructure built on Multi-Party Computation. Rather than a single private key that can be stolen or lost, MPC splits the signing key across multiple nodes in separate secure enclaves — so there is no single point of failure, and no single party that could unilaterally move funds. The platform exposes this through APIs and SDKs covering 30+ blockchains and 1,000+ tokens, with support for both org-controlled wallets (where your team manages signing) and user-controlled wallets (where your end users hold signing authority from within your app).

Layered on top of the signing infrastructure is a policy and permissions engine. It lets you define exactly who can do what: multi-level approval workflows, role-based access, destination allowlists and denylists, and a real-time audit log of every action taken on every wallet.

The signing key shards themselves can be deployed to match your regulatory requirements — fully managed by DFNS in geographically distributed data centers, split between your infrastructure and DFNS in a hybrid model, or hosted entirely on your own infrastructure.

```mermaid theme={null}
flowchart LR
    Client([Your app]) --> Auth[Authentication]
    Auth --> Permissions[Permissions]
    Permissions --> Policies[Policy engine]
    Policies --> Signers[MPC signers]
    Signers --> Chain([Blockchain])
```

***

## Transaction walkthrough

The following describes the full lifecycle of a transfer request in a DFNS-powered application.

### 1. Authentication

Alice, a finance operator at Acme Corp, opens the treasury app and logs in with her passkey. Her device's secure hardware signs a challenge from the DFNS authentication service. DFNS validates the signature and issues a session token.

### 2. Authorization check

Alice submits a payment order: "Send 50,000 USDC to Vendor XYZ." DFNS checks her session token against the wallet's permission rules. Her `Finance Operator` role has permission to initiate transfers on this wallet. The request proceeds.

### 3. Policy evaluation

The Policy Engine evaluates the request against Acme's configured policies:

* Destination address is on the approved vendor list. ✓
* Amount is within the daily transfer limit. ✓
* Amount exceeds \$10,000 → requires manager approval.

The transaction moves to `Pending Approval` and an approval request is sent to the configured approvers.

### 4. Approval

Bob, a treasury manager, receives a notification. He logs in with his own passkey, reviews the transaction, and approves it. The approval quorum is met and the transaction is cleared for signing.

### 5. MPC signing

The approved transaction is sent to the MPC signing cluster. Each node holds one shard of the signing key in a Secure Enclave — no node ever holds the full key. The nodes run a multi-party computation protocol: each contributes its shard to produce a valid signature without any shard leaving its enclave.

### 6. Broadcast

The signed transaction is submitted to the blockchain. Once included in a block, a confirmation flows back through the system. Alice and Bob see the status update: "Payment Complete."