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

# Validator Architecture

> Internal components of a Canton Network validator node

A validator is the fundamental infrastructure unit on Canton Network. It hosts parties, stores their contract data, and processes transactions on their behalf. Understanding what's inside a validator helps with deployment planning, troubleshooting, and capacity sizing.

## Components of a validator

A validator consists of two main processes and their supporting infrastructure:

```mermaid theme={"theme":{"light":"github-light","dark":"github-dark"}}
flowchart TB
    subgraph Validator["Validator Node"]
        VP[Validator Process]
        subgraph PN["Participant Node"]
            LE[Ledger API]
            CE[Canton Engine]
            CS[(Contract Store)]
        end
        WA[Wallet App]
        DB[(PostgreSQL)]
    end

    APP[Application or backend] --> LE
    PN <--> SYNC[Synchronizer]
    VP --> PN
    WA --> PN
    PN --> DB
    VP --> DB
```

### Participant node

The participant node is the core component. It:

* Hosts parties and manages their identities
* Stores contract data for hosted parties in its local database
* Exposes the Ledger API for applications to submit commands, read transactions, and manage parties
* Runs the Canton protocol engine that handles transaction processing, validation, and privacy
* Communicates with synchronizers to submit and receive data transactions
* Communicates with synchronizers to submit and receive topology transactions

### Validator process

The validator process handles Canton Network-specific functionality on top of the participant node:

* Manages onboarding to the Global Synchronizer
* Handles traffic purchases using Canton Coin
* Runs the Splice wallet application for hosted parties
* Manages automatic operations like traffic top-ups and Canton Coin sweep configurations

### Database

Both the participant node and validator process use PostgreSQL for persistent storage. In production, this should be a managed database service (like Cloud SQL or RDS) with appropriate backup and high-availability configuration.

## How validators connect to synchronizers

Validators connect to synchronizers through the sequencer endpoint over TLS (port 443). The connection is outbound only — validators do not need to accept incoming connections from the network.

A validator can connect to multiple synchronizers simultaneously. It receives only the transactions relevant to its hosted parties, maintaining privacy even though the synchronizer coordinates across all participants.

## Ledger API

The Ledger API is the primary interface for applications to interact with the ledger. You can use the gRPC or JSON API transport to perform:

* **Command submission** — Create contracts and exercise choices
* **Transaction stream** — Read confirmed transactions as they are committed
* **Active contract set** — Query the current set of active contracts
* **Party management** — Allocate and manage parties

Applications connect to the Ledger API either directly via gRPC or through the JSON API, which provides an HTTP/JSON layer on top.