> ## 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.

# Upgrading from Previous Versions

> Pointers to migration guides and component release notes for upgrading Canton Network applications

Per-version migration steps live with the component release notes. Use the links below for the change you are migrating across.

## Within Canton 3.x

* **Splice and the Global Synchronizer** — [Release notes](/release-notes), [release history](/global-synchronizer/release-notes/release-history), [weekly patch releases](/global-synchronizer/release-notes/weekly-patch-releases)
* **Wallet SDK** — [Wallet SDK release notes](/integrations/wallet/release-notes)
* **Canton and Daml SDK** — [GitHub releases (digital-asset/daml)](https://github.com/digital-asset/daml/releases)

## From Canton 2.x to 3.x

Canton 3.x is a major release with backward-incompatible changes across the SDK, APIs, and runtime. The high-level shape of the migration:

* **SDK tooling** — `daml` CLI is replaced by [`dpm`](/sdks-tools/cli-tools/dpm).
* **Ledger API** — services have been restructured. Regenerate gRPC stubs from the 3.x protobuf definitions, or update to a 3.x client library.
* **Package management** — the new [Smart Contract Upgrade (SCU)](/appdev/modules/m6-overview) mechanism replaces the previous upgrade model.
* **Synchronizer terminology** — what was previously called a "domain" is now called a **synchronizer** throughout the APIs and documentation.
* **Daml exceptions** — deprecated and being removed. Replace with preconditions, encoded return types, or workflow patterns.

For a worked migration path, build against the [cn-quickstart](https://github.com/digital-asset/cn-quickstart) reference application and consult the version-specific release notes above.

## Related

* [Development Stack](/appdev/modules/m1-development-stack) — the 3.x technology stack
* [Smart Contract Upgrades Overview](/appdev/modules/m6-overview) — SCU model
* [Backend Development](/appdev/modules/m4-backend-dev) — 3.x Ledger API usage patterns