The Azure SDK team is pleased to announce our October 2026 client library releases.

6 packages released this month.

Stable Packages (3)

  • Cosmos DB

  • Cosmos DB Client Driver

  • Cosmos DB SDK Macros

Beta Packages (3)

  • Cosmos DB

  • Cosmos DB Client Driver

  • Cosmos DB SDK Macros

Release highlights

Cosmos DB 1.0.0-beta.1 Changelog

Features Added

  • Added CosmosTracingHandlerBuilder::build_with_tracer for binding the handler to an explicit OpenTelemetry tracer. (#5332)
  • Added per-query QueryOptions::max_buffered_query_window and with_max_buffered_query_window to configure the maximum global OFFSET plus effective take for client-buffered queries (default 1000, no opt-out). (#5301)
  • Extended Cosmos binary JSON encoding to cross-partition DISTINCT query pages. (#5070)
  • Added QueryPlanMode::{LocalPreferred, GatewayOnly}, allowing applications to force Gateway query planning for an individual query as a livesite mitigation. (#5181)
  • Added finite cross-partition ORDER BY VectorDistance(...) queries with TOP or OFFSET/LIMIT. Results are fully buffered before the first page and cannot be resumed from continuation tokens. Hybrid/full-text vector ranking remains unsupported. (#5130)
  • Extended Cosmos binary JSON encoding to the thin client (Gateway 2.0) transport. (#5284)

Breaking Changes

  • Replaced EffectivePartitionKey string From conversions with strict TryFrom conversions; malformed hexadecimal bounds now return errors instead of being truncated, including when deserializing feed ranges. #5369
  • Re-exported the driver’s CosmosError, CosmosStatus, and SubStatusCode directly, removing the SDK-owned CosmosError wrapper and all associated CosmosStatus and SubStatusCode constants from the supported SDK surface. (#5355)
  • Replaced the metrics and distributed_tracing feature flags with the off-by-default preview_opentelemetry flag for both OpenTelemetry handlers; enable preview_opentelemetry to keep emitting metrics and traces. Diagnostics types remain available without it. (#5353)
  • CosmosTracingHandler is now constructed exclusively through CosmosTracingHandler::builder(). The new, with_thresholds, and with_thresholds_and_rate_limit constructors and the Default implementation were removed; configure the equivalent values with the builder and call build or build_with_tracer. (#5332)
  • Re-exported UserAgentSuffix replaces panicking new with TryFrom<String> and TryFrom<&str>, returning a typed CosmosError for invalid suffixes. (#5345)
  • Re-exported PartitionKey and PartitionKeyValue now use TryFrom for dynamically sized key vectors and floating-point values, returning typed errors instead of panicking on excess components or non-finite numbers. (#5345)
  • Removed throughput-control group registration and the group name/options re-exports; configure priority and throughput buckets directly through OperationOptions::throughput_control. (#5343)
  • Moved query_plan_mode from OperationOptions to per-query QueryOptions; removed client/runtime defaults and environment settings, including the query-plan-mode override. The default remains LocalPreferred. (#5301)
  • Unordered cross-partition DISTINCT and non-streaming ORDER BY require finite global TOP/LIMIT with OFFSET plus effective take within the configured maximum; missing bounds, excess windows, and overflow fail with 400/20125. (#5301)
  • Unified client-buffered continuation errors under 400/20124, retaining the shape-specific constants as aliases; finite-window admission moved from 20126 to 20125 and non-streaming window/storage errors from 20127 to 20126. (#5301)
  • Reviewed public API type consistency for time durations and integer sizes. ResponseHeaders::server_duration_ms() and retry_after_ms() are replaced by server_duration() and retry_after(), both returning Option<Duration>; TransactionalBatchOperationResult::retry_after_milliseconds() and DistributedTransactionResponse::retry_after_ms() are similarly replaced by retry_after() -> Option<Duration>. ThroughputProperties::manual, autoscale, throughput(), and autoscale_maximum() now use u64 instead of the platform-dependent usize, allowing RU/s values above 4 billion; autoscale_increment() now uses u32 because it returns a percentage. (#5204)
  • Replaced CosmosClientBuilder::with_partition_key_range_cache_enabled with PartitionFailoverOptionsBuilder::with_partition_topology_cache_mode; partition topology caching can no longer be disabled, and PartitionTopologyCacheMode::{Eager, Lazy} controls only when the cache is loaded. (#5319)
  • Container resolution now loads the complete partition topology by default and fails if it cannot load a valid routing map. PartitionTopologyCacheMode::Lazy preserves the previous first-use loading behavior as a compatibility escape hatch. (#5319)
  • Moved the PATCH-specific models, distributed transaction PATCH APIs, and PATCH-related operation options behind the preview_patch feature. These APIs remain available to preview-feature consumers but are no longer part of the default feature set. (#5346)
  • Removed the public ConsistencyLevel and CosmosClientOptions types and the OperationOptionsView, ThrottlingRetryOptionsView, and ThroughputControlOptionsView re-exports. Use ReadConsistencyStrategy and typed operation options instead; client configuration remains available through CosmosClientBuilder. The tuple fields of SessionToken and ExcludedRegions are now private; use their constructors, From, iter, len, and is_empty APIs. (#5352)

Bugs Fixed

  • Fixed serde_json::value::RawValue deserialization for binary-encoded responses: ResponseBody::into_single (and the into_model helpers built on it) now yield the document’s JSON text for a RawValue target instead of failing, restoring raw passthrough now that binary encoding is on by default. (#5338)
  • Container recreation now preserves collection RID mismatch errors during cold partition routing and rejects incompatible stale partition keys with a dedicated client substatus. (#5324)
  • Change feed reads now work over Gateway 2.0 by forwarding incremental-mode and wire-format-version request metadata. (#5332)
  • Cosmos root spans now use the last retained request endpoint for their fallback server.address, matching the operation-duration metric when no SDK operation context supplies an address. (#5332)
  • Added partition-merge support and preserved point-in-time change feed filtering across merged partitions by retaining If-Modified-Since alongside continuations on Gateway V1 and Gateway V2. (#4122)
  • Name-based container clients now automatically recover when a container is deleted and recreated. (#5219)

Cosmos DB 1.0.0 Changelog

Breaking Changes

  • Renamed the preview_dtx, preview_patch, and preview_opentelemetry feature flags to unstable_dtx, unstable_patch, and unstable_opentelemetry, respectively; update dependency feature selections to use the new names. (#5426)
  • Changed the User-Agent header format to azsdk-rust-cosmos/{sdk-version} (drv={driver-version}; {os}; {arch}; {rustc}[; ft={B64}]) [{suffix}], replacing the separate driver and platform tokens and the trailing |F<HEX> feature-flag token. To fit the 255-byte limit, platform segments are removed whole from right to left; once none remain, the parentheses are omitted and the suffix, then the SDK identifier, may be shortened. (#5406)
  • Terminal service 404/1002, 403/3, and 403/1008 errors now surface as synthetic 503/20310, 503/20311, and 503/20312 errors, retaining the original wire error in source(). (#5392)
  • Renamed CosmosCredential::MasterKey to CosmosCredential::AccountKey (#5421).

Cosmos DB Client Driver 1.0.0-beta.1 Changelog

Features Added

  • Added per-query PlanOptions::max_buffered_query_window, with_max_buffered_query_window, and DEFAULT_MAX_BUFFERED_QUERY_WINDOW (1000) to cap global OFFSET plus effective take for client-buffered queries, with no opt-out. (#5301)
  • Extended Cosmos binary JSON query-page handling to cross-partition DISTINCT, including composition with streaming ORDER BY and OFFSET/LIMIT/TOP. (#5070)
  • Added local Rust query planning for supported cross-partition queries, avoiding Gateway query-plan requests while retaining native and Gateway fallbacks for advanced query shapes, and QueryPlanMode::{LocalPreferred, GatewayOnly} to select providers per query. (#5181)
  • Added a fully buffered cross-partition merge for finite non-streaming ORDER BY plans, including VectorDistance(...). Resumed, DISTINCT, and hybrid non-streaming plans are rejected with typed statuses. (#5130)
  • Added Cosmos binary JSON encoding support over the thin client (Gateway 2.0) path by forwarding the x-ms-cosmos-supported-serialization-formats header as the RNTBD SupportedSerializationFormats token. (#5284)

Breaking Changes

  • Replaced EffectivePartitionKey string From conversions with strict TryFrom conversions and made deserialization reject malformed hexadecimal bounds; PartitionKeyRange::new now requires parsed EffectivePartitionKey bounds. #5369
  • Moved all CosmosStatus constants and the independently used SubStatusCode constants to error::status_codes; raw substatus constants are under error::status_codes::substatus, and constants used only to construct combined statuses were removed. (#5355)
  • UserAgentSuffix replaces panicking new with TryFrom<String> and TryFrom<&str>, returning a typed CosmosError for invalid suffixes. (#5345)
  • Replaced panicking partition-key vector and floating-point From conversions with typed TryFrom errors; infallible key conversions remain unchanged. (#5345)
  • Removed throughput-control group registration, group types, and ThroughputControlOptions::group_name; direct priority and throughput-bucket options remain available. (#5343)
  • Moved query_plan_mode from OperationOptions to PlanOptions; removed account/runtime defaults and environment settings, including the query-plan-mode override. The default remains LocalPreferred. (#5301)
  • Unordered cross-partition DISTINCT and non-streaming ORDER BY require finite global TOP/LIMIT with OFFSET plus effective take within the configured maximum; missing bounds, excess windows, and overflow share 400/20125 (CLIENT_BUFFERED_QUERY_REQUIRES_FINITE_WINDOW). (#5301)
  • Unified client-buffered continuation errors under 400/20124 (CLIENT_BUFFERED_QUERY_CONTINUATION_UNSUPPORTED), retaining the shape-specific constants as aliases; finite-window admission moved from 20126 to 20125 and non-streaming window/storage errors from 20127 to 20126. (#5301)
  • Replaced DriverOptionsBuilder::with_partition_key_range_cache_enabled with PartitionFailoverOptionsBuilder::with_partition_topology_cache_mode; partition topology caching can no longer be disabled, and PartitionTopologyCacheMode::{Eager, Lazy} controls only when the cache is loaded. (#5319)

  • CosmosDriver::resolve_container_by_name and resolve_container_by_rid now load the complete partition topology by default and fail with CLIENT_TOPOLOGY_RESOLUTION_FAILED when no valid routing map can be loaded. PartitionTopologyCacheMode::Lazy preserves first-use loading. (#5319)

  • error::cosmos_status is no longer a public module; CosmosStatus and SubStatusCode remain available as re-exports from error. The internal-only query module (gated behind the __internal_testing feature) is now #[doc(hidden)] so it no longer appears as an empty public module in generated API surfaces. (#5205)
  • CosmosRequestHeaders::offer_throughput, OfferAutoscaleSettings::max_throughput, OfferAutoscaleSettings::new, OfferAutoscaleSettings::with_increment_percent, and AutoscaleThroughputPolicy::increment_percent now use u32 instead of the platform-dependent usize, matching the RU/s values Cosmos DB actually returns. (#5204)
  • Renamed several types for naming consistency: diagnostics::PipelineType is now diagnostics::PipelineKind (following the Kind-over-Type convention), diagnostics::ProxyConfiguration is now diagnostics::ProxyConfig (matching the Config naming used elsewhere), and in_memory_emulator::RuChargingModel is now in_memory_emulator::RequestUnitChargingModel (expanding the RU acronym). The unstable testing module (__internal_mocking feature) was renamed to test. (#5203)
  • Moved OperationOptions::patch_strategy and its generated builder, view, and environment APIs behind the preview_patch feature. Core PATCH execution remains available without the feature. (#5346)
  • Made the tuple fields of SessionToken and ExcludedRegions private. Use SessionToken::new and its From, as_str, AsRef<str>, and Display implementations, or ExcludedRegions::new, with_region, FromIterator, iter, len, and is_empty instead. (#5352)

Bugs Fixed

  • Account metadata now honors the service-provided disableCrossRegionalHedging signal for data-plane and eligible metadata operations, including refresh transitions and omitted-property retention. (#5350)
  • Fixed serde_json::value::RawValue deserialization on the Cosmos binary JSON path: binary_json::from_slice and ResponseBody::into_single/into_items now render the value’s JSON text for a RawValue target instead of failing with a misclassified serialization error, so RawValue callers keep working now that binary encoding is on by default. (#5338)
  • Reconciled dataflow partition-range identity resolution across logical, EPK, sequential, and hedged requests, preserving split-parent session tokens on Gateway 2.0 while keeping logical partition-key wire routing unchanged, and enforcing the end-to-end timeout across planning and first-page execution. (#5315)
  • Container recreation now preserves collection RID mismatch errors during cold partition routing and rejects incompatible stale partition keys with a dedicated client substatus. (#5324)
  • Gateway 2.0 change feed requests now forward incremental-mode and wire-format-version metadata, so change feeds work over the thin-client transport. (#5332)
  • In-memory emulator query, change-feed, and point reads now apply composite session-token range validation only to the physical partitions selected by the request, so an obsolete unrelated segment no longer rejects an otherwise valid scoped read. Explicit stale physical-range targets still return 410/1002 and trigger partition-topology refresh and retry. (#5332)
  • Fixed V1 partition key routing for non-ASCII strings by truncating at 100 UTF-16 code units and applying the service’s separate binary byte limit without panicking on split characters. (#5280)
  • Added partition-merge routing support, advertised the merge capability bits, and retained point-in-time change feed filtering across merged partitions on Gateway V1 and Gateway V2. (#4122)
  • Cosmos driver user agents now include the build-time Rust compiler version instead of rustc/unknown. (#5201)
  • Name-addressed container operations now refresh metadata and retry once after container recreation, clearing generation-specific session and partition-routing state before targeting the replacement. (#5219)

Cosmos DB Client Driver 1.0.0 Changelog

Features Added

  • Added UserAgentProperty and CosmosDriverRuntimeBuilder::with_user_agent_property so wrapping SDKs can add validated key=value entries (for example a language runtime version such as rt=.NET 8.0.1; values may contain spaces but never ;, (, or )) to the User-Agent metadata segment. (#5406)

Bugs Fixed

  • Preserve admitted throttle retry settings during operation-triggered account metadata refresh, including regional and HTTP-version recovery paths. (#5366)
  • Honor per-operation endpoint unavailability TTL and runtime TTL updates during routing without changing sibling operations’ cooldown intervals. (#5366)

Breaking Changes

  • Renamed the preview_dtx and preview_patch feature flags to unstable_dtx and unstable_patch, respectively; update dependency feature selections to use the new names. (#5426)
  • Changed the User-Agent header to a compact, parsable format used by every Cosmos SDK: {sdk}/{version} (drv={driver}; {os}; {arch}; {rustc}[; ft={B64}][; {key}={value}]...) [{suffix}]. Feature flags are big-endian bytes without leading zeros, base64url-encoded without padding (e.g. ft=Eg for 0x12). To fit the 255-byte limit, platform segments are removed whole from right to left, with drv removed last; empty parentheses are omitted, then the suffix is shortened if needed, and finally the SDK identifier. The suffix is never normalized. (#5406)
  • Terminal service 404/1002, 403/3, and 403/1008 errors now surface as synthetic 503/20310, 503/20311, and 503/20312 errors, retaining the original wire error in source(). (#5392)
  • Renamed Credential::MasterKey to Credential::AccountKey and AccountReference::with_master_key() to AccountReference::with_account_key(). (#5421)

Cosmos DB SDK Macros 1.0.0-beta.1 Changelog

Breaking Changes

  • CosmosOptions now propagates field-level #[cfg] attributes to generated builders, views, defaults, and environment-variable APIs. (#5346)

Cosmos DB SDK Macros 1.0.0 Changelog

Features Added

  • Added #[option(skip)] for internal optional state excluded from configuration views and builder setters. (#5366)

Latest Releases

View all the latest versions of Rust crates here.

Installation Instructions

To install any of our crates, copy and paste the following commands into a terminal:

$> cargo add azure_data_cosmos@1.0.0-beta.1
$> cargo add azure_data_cosmos@1.0.0
$> cargo add azure_data_cosmos_driver@1.0.0-beta.1
$> cargo add azure_data_cosmos_driver@1.0.0
$> cargo add azure_data_cosmos_macros@1.0.0-beta.1
$> cargo add azure_data_cosmos_macros@1.0.0

Feedback

If you have a bug or feature request for one of the libraries, please post an issue to GitHub.