azure_data_cosmos@0.37.0

0.37.0 (2026-07-20)

Features Added

• Added runtime diagnostics output configuration via CosmosRuntimeBuilder::with_diagnostics_options, including the env-backed AZURE_COSMOS_DIAGNOSTICS_DEFAULT_VERBOSITY option. The built-in default is now summary diagnostics JSON. (#4733)
• Gateway 2.0 transport (a regional proxy forwarding RNTBD-over-HTTP/2) is selected automatically when the account advertises thin-client endpoints, the connectivity probe confirms them, and the runtime has not opted out. (#4319, #4803)
• Added the re-exported ConnectionPoolOptions::gateway_v2_disabled and ConnectionPoolOptionsBuilder::with_gateway_v2_disabled, with AZURE_COSMOS_CONNECTION_POOL_GATEWAY_V2_DISABLED configuration and an environment-only _OVERRIDE incident switch. (#4763)
• HTTP 449 (RetryWith) responses are now retried transparently in-region with exponential backoff, so callers no longer see spurious 449 errors from concurrent writes. (#4319)
• ReadConsistencyStrategy is now honored across Gateway V1 and V2 reads. Adds the LatestCommitted variant (a quorum read independent of the account default); GlobalStrong is rejected with BadRequest unless the account default is Strong. Per-request strategy overrides the client default. (#4319)
• Added preview distributed transaction SDK builders, patch operations, diagnostics, and response accessors behind the disabled-by-default preview_dtx feature. (#4702)
• Added change feed pull support via ContainerClient::query_change_feed(), which takes a required ChangeFeedStartFrom start position (Beginning, Now, PointInTime) and returns a ChangeFeedPageIterator<T> that streams FeedPage<T> results. New feed types ChangeFeedPageIterator, FeedScope, and ContinuationToken, plus options types ChangeFeedOptions and ChangeFeedMode (currently LatestVersion); supports single-partition, per-partition-key, and full-container (cross-partition fan-out) reads with continuation-token resumption that persists the original start position so never-polled partitions don't replay history on resume. (#4621)
• Change feed items are now surfaced as an envelope. ContainerClient::query_change_feed::<YourDoc>() yields ChangeFeedItem<YourDoc>, binding the envelope into the return type so the post-change document is read via ChangeFeedItem::current() and cannot be silently deserialized away. The envelope also exposes the pre-change document (previous()) and per-change metadata() (populated by full-fidelity reads; absent for LatestVersion). A full-fidelity delete returns an empty current object, which maps to None so callers with strict document types still deserialize the delete; the deleted item's identity is available via ChangeFeedMetadata::id() and ChangeFeedMetadata::partition_key(). ChangeFeedOperationType includes an Unknown catch-all so a future operation type cannot fail a page and stall the feed. A backend that does not envelope change feed items (such as the Cosmos emulator) returns the bare document, which is mapped onto current() so no data is lost. Added the models types ChangeFeedItem<T>, ChangeFeedMetadata, ChangeFeedOperationType, and LogicalSequenceNumber. (#4723)
• Added TlsBackend (re-exported) and a tls_backend option on ConnectionPoolOptions (ConnectionPoolOptionsBuilder::with_tls_backend), defaulting to TlsBackend::Rustls, available under the rustls feature, to pin the TLS backend used by the transport. This is additive and changes no behavior for the default (rustls) build; it only has an effect in builds that compile in multiple reqwest TLS backends, where reqwest would otherwise default to native-tls and the driver now pins rustls instead. (#4649)

Bugs Fixed

• http:// (non-HTTPS) account endpoints are now rejected unless the host is a known Cosmos DB emulator host, failing fast during client construction with an "invalid account endpoint" error instead of attempting an insecure connection to a production account. This validation also covers configured backup endpoints. (#4757)
• Fixed hierarchical-partition-key (HPK) queries. A FeedScope::partition scope with only a prefix of the key hierarchy (e.g. ("USA", "CA") on a /country/state/city container) now filters to that prefix instead of returning every item in the physical partition (issue #4680), and cross-partition queries over an HPK container no longer fail with 400 Bad Request (issue #4681). (#4729)
• Fixed the AZURE_COSMOS_PPCB_* environment variables (including AZURE_COSMOS_PPCB_ENABLED and the AZURE_COSMOS_PPCB_ENABLED_OVERRIDE kill switch) being ignored when a CosmosClient was built without calling CosmosClientBuilder::with_partition_failover_options. The per-partition circuit breaker (PPCB) stayed enabled even with AZURE_COSMOS_PPCB_ENABLED=false. The client's driver now resolves these options from the environment when they are not supplied explicitly. (#4655)