# Concord v2.1.1 - Table of Contents

## Pages

- Getting Started
  - [Concord](readme.md)
  - [Getting Started](getting-started.md)

- Guides
  - [Elixir API Guide](elixir-guide.md)
  - [Observability](observability.md)
  - [Backup and Restore](backup-restore.md)
  - [Configuration](configuration.md)

- Architecture
  - [Project Concord: Design Blueprint](design.md)

- Release Notes
  - [Changelog](changelog.md)
  - [LICENSE](license.md)

## Modules

- [Concord](Concord.md): Public API for the Concord distributed key-value store.
- [Concord.Application](Concord.Application.md): Application supervisor for Concord embedded key-value store.
Starts and manages the Raft consensus cluster, telemetry, TTL cleanup, and node discovery.

- [Concord.Backup](Concord.Backup.md): Backup and restore functionality for Concord distributed KV store.
- [Concord.Compression](Concord.Compression.md): Value compression for Concord KV store.
- [Concord.Index](Concord.Index.md): Secondary index support for efficient value-based queries.
- [Concord.Index.Extractor](Concord.Index.Extractor.md): Declarative index extractor specifications.
- [Concord.KV](Concord.KV.md): Public API for Concord's revisioned key-value store.
- [Concord.KV.Record](Concord.KV.Record.md): Per-key revisioned record in Concord's MVCC store.
- [Concord.KV.Selector](Concord.KV.Selector.md): Unified selector type for addressing keys in Concord.
- [Concord.Lease](Concord.Lease.md): Public API for Concord's grouped TTL / lease system.
- [Concord.Query](Concord.Query.md): Query language for Concord key-value store.
- [Concord.StateMachine](Concord.StateMachine.md): The Raft state machine for Concord (Version 3).
- [Concord.Sync](Concord.Sync.md): Public API for Concord's sync and watch protocol.
- [Concord.Sync.ChangeLog](Concord.Sync.ChangeLog.md): ETS-backed bounded change log for Concord.
- [Concord.Sync.Dispatcher](Concord.Sync.Dispatcher.md): Receives change events from the Raft state machine via Ra `:send_msg` effects
and forwards them to the Watch Hub and Change Log.
- [Concord.Sync.Event](Concord.Sync.Event.md): A single mutation event in the Concord change stream.
- [Concord.Sync.WatchHub](Concord.Sync.WatchHub.md): Registry-based subscriber management for Concord's watch protocol.
- [Concord.TTL](Concord.TTL.md): TTL (Time-To-Live) management for Concord.
- [Concord.Telemetry](Concord.Telemetry.md): Telemetry integration for Concord.
Emits metrics for monitoring cluster health and performance.

- [Concord.Telemetry.Poller](Concord.Telemetry.Poller.md)
- [Concord.Txn](Concord.Txn.md): Atomic multi-key transactions for Concord.
- [Concord.Txn.Result](Concord.Txn.Result.md): Result of a committed transaction.
- [Concord.Validation](Concord.Validation.md): Recursive validation for Raft command safety.

## Mix Tasks

- [mix concord.backup](Mix.Tasks.Concord.Backup.md): Concord backup management tasks.
- [mix concord.cluster](Mix.Tasks.Concord.Cluster.md): Mix tasks for managing Concord clusters.