Canton .NET SDK 0.7.0 is out, for Canton 3.6

[monsieurleberre]

Canton .NET SDK 0.7.0 is out. It is the stable release for Canton 3.6: the protos and the JSON Ledger API spec are pinned at Canton 3.6.1, codegen runs on Daml SDK 3.6.0, and it is tested against LocalNet 0.9.1 (Splice 0.9.1) and PQS 3.6.0. If you are still on Canton 3.5, stay on 0.6.x.

If you are new here, the SDK lets a C# / .NET team build on a Canton/Daml ledger with types all the way through. dpm codegen-cs turns a DAR into C# records, typed choices and Try…Async submission methods. A single ICantonLedgerClient submits them over gRPC or the JSON Ledger API, and a PQS client, OpenTelemetry tracing and in-memory test doubles sit alongside. It targets .NET 10 and is Apache-2.0.

What changed in 0.7.0

• Prepared transactions are checked before you sign. PrepareSubmissionAsync recomputes the transaction hash on both transports (hashing schemes V2 and V3) and refuses a mismatch. External-party onboarding gets the same check: the generated topology and the allocated party must match what you asked for.
• Templates are matched by package name. A contract created under an earlier version of your package still matches its generated type after an upgrade. You can pin a version with WithPackageIdSelectionPreference when you need to.
• One failure contract on both transports. A token that can't be fetched is reported as NotCommitted. A retried write whose outcome is unknown is reported as Unknown, and it carries the CommandId to look up on the completion stream before you resubmit.
• Token fetches back off. After a failed fetch, the client-credentials provider cools down (500 ms, doubling up to 30 s), so an identity provider that is down isn't hit on every call.
• Tighter HTTP and release pipeline. JSON Ledger API responses are size-capped, neither client follows redirects, and the release pipeline checks the Daml SDK components and the Splice and Daml Finance bundles by SHA-256 before generating from them.

0.7.0 has breaking changes from 0.6.0. In short: move to Canton 3.6, bump every package together, clear the dpm component cache and regenerate. The upgrade section of the release notes lists each change.

Much of this came out of an outside review by the Rust SDK team (#82 to #91). Thank you for it.

What's published

• 16 core packages at 0.7.0 on nuget.org, such as Daml.Runtime, Canton.Ledger.Grpc.Client, Canton.Ledger.Rest.Client and Canton.Ledger.Pqs.Client
• 33 Splice.* packages built from Splice 0.9.1, for example Splice.Api.Token.Holding.V2 1.0.0.19
• 8 Daml Finance packages built from Daml Finance 2.10.0, for example Daml.Finance.Interface.Holding.V4 4.0.0.18
• the codegen, as the dpm component oci://ghcr.io/peacefulstudio/dpm-codegen-cs:0.7.0

Try it, and tell us how it went 🚀

The quickest way to see it working is the mini-demo, whose 0.7.0 release is on this SDK version. One dotnet run takes a Token Standard V2 transfer from Daml source to a local Canton ledger, over gRPC and the JSON Ledger API, and reads it back from PQS. On a fresh Ubuntu VM the whole quickstart took about 20 minutes from the dpm install to the demo's Done line, mostly downloads of the Daml SDK and the LocalNet images; the demo itself runs in about ten seconds. Its CI runs it against LocalNet on every push.

If you try it, tell us how it went in Quickstart feedback: your OS, roughly how long it took, and anything you'd improve. That thread also has the commands in one block. Bugs are easiest to track as issues.

Need a hand?

If you are building something on Canton with .NET, #79 is the place to tell us about it, and we are happy to help with an integration.

Links

• Release notes for 0.7.0 and the CHANGELOG
• Documentation: codegen, ledger clients, configuration, observability and supported Canton versions
• Mini-demo and its 0.7.0 release
• Canton LocalNet, the Docker Compose stack the demo and our integration tests run on
• Quickstart feedback

Peaceful Studio