Daml Stdlib

• Restrict the (>>) operator to instances of Action and make it lazy in its second argument. This gives expressions of the form do A; B the desirable semantics of only running B when A is a successful action.
• Remove the Action and ActionFail instances for Validation in DA.Validation. Please enable the ApplicativeDo language extension if you want to use Validation with do-notation and replace fail with DA.Validation.invalid.

Daml Ledger Integration Kit

• Enforce that all parties referenced as stakeholders, actors, or maintainers in a transaction have been allocated.
• Ledger API Test Tool default tests modified. Use --list for the updated list of default tests. Time service test dropped from the suite.

Sandbox

• Static time mode is being deprecated in the future. A warning has been added to notify users of this fact.
• Scenarios for ledger initialization are being deprecated in the future, in favor of Daml Script. A warning has been added to notify users of this fact. Scenarios can still be used for testing in Daml studio.
• Participant index contract lookups simplified. This should speed up command interpretation.
• If authentication is enabled, requests without a valid authentication are going to be rejected with an UNAUTHENTICATED return code instead of PERMISSION_DENIED.

JSON API - Experimental

• Add {"live": true} to WebSocket streams to mark the beginning of "live" data. See #4461. This marker is a placeholder feature; issue #4509 bookmarks in query streams will obsolete this marker, after which it will no longer be emitted. When building features on the marker, be aware of this forthcoming replacement.

Daml Standard Library

• Add a subtract function which is useful as a replacement for sections of (-), e.g., subtract 1 is equivalent to \x -> x - 1.