Announcing 2.3.1 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

libbson

Fixes

• Fix length check in bson_new_from_buffer.
• Fix documentation generation on Sphinx 9.0+.

libmongoc

Improvements

• Improve forward compatibility with OpenSSL 4.0.0 when handling EAGAIN errors in old-style read callbacks where BIO_FLAGS_AUTO_EOF is enabled.
• Improve decompressed message length constraints.

Fixes

• Fix documentation generation on Sphinx 9.0+.
• Propagate username to custom OIDC callback.

Links:

• All the issues resolved in 2.3.1
• Documentation

Thanks to everyone who contributed to this release.

• Ezra Chung
• Colby Pike
• Kevin Albertson

Announcing 2.3.0 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

libbson

Improvements

• bson_t is now trivially relocatable.

Deprecated

• bson_append_array_begin. Use bson_append_array_builder_begin or bson_append_array_unsafe_begin instead.

libmongoc

New Features

• Added support for MongoDB's Intelligent Workload Management (IWM) and ingress connection rate limiting features. The driver now gracefully handles write-blocking scenarios and optimizes connection establishment during high-load conditions to maintain application availability.
  • Supported on all commands.
  • Custom application retry logic may need to be adjusted to avoid retrying too long.
  • Upgrade is recommended to avoid impacts of server changes related to overload errors.
    • If not upgrading, custom application retry logic may need to be adjusted to handle higher rates of overload errors. See Overload Errors.
  • Add URI option maxAdaptiveRetries to configure the maximum number of retries for operations that fail with a SystemOverloadedError (default: 2).
  • Add URI option enableOverloadRetargeting to control whether retries of SystemOverloadedError will attempt to use a different server (default: false).
• Support appending client handshake metadata after initialization and per-client/pool.
  • Adds mongoc_client_append_metadata and mongoc_client_pool_append_metadata.
  • Useful for projects wrapping the C driver to self-identify.
• Support Kubernetes as a credential provider for MONGODB-OIDC authentication.

Improvements

• Improve cursor handling on client-side timeouts:
  • Send killCursors after cursor receives client-side timeout.
  • Break early if change stream resumes on repeated client-side timeouts.

Removed

• Support for macOS versions 13 and older. These versions are EOL and not tested. Use macOS version 14 or newer.

Links:

• All the issues resolved in 2.3.0
• Documentation

Thanks to everyone who contributed to this release.

• Kevin Albertson
• Connor MacDonald
• Ezra Chung
• GitHub user: user-45-20
• Colby Pike
• GitHub user: swigger

Announcing 2.2.4 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

libbson

No changes since 2.2.3. Version incremented to match the libmongoc version.

libmongoc

Fixes:

• Fix handling of corrupt GridFS files.

Links:

• All the issues resolved in 2.2.4
• Documentation

Thanks to everyone who contributed to this release.

• Kevin Albertson

Announcing 1.30.8 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

No further 1.x releases are planned. See "v1 support notice" in 2.0.0 release notes.

libbson

No changes since 1.30.7. Version incremented to match the libmongoc version.

libmongoc

Fixes:

• Fix handling of corrupt GridFS files.
• Fix handling in HTTP response parser.

Links:

• All the issues resolved in 1.30.8
• Documentation

Thanks to everyone who contributed to this release.

• Kevin Albertson
• Remi Collet

Announcing 2.2.3 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

libbson

No changes since 2.2.2. Version incremented to match the libmongoc version.

libmongoc

Fixed

• Fix handling in HTTP response parser.

Links:

• All the issues resolved in 2.2.3
• Documentation

Thanks to everyone who contributed to this release.

• Kevin Albertson

Announcing 2.2.2 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

libbson

No changes since 2.2.1. Version incremented to match the libmongoc version.

libmongoc

Fixed

• Restore $clusterTime on first command of single-threaded client.
• Wait between polling if serverMonitoringMode=poll is used on server supporting streaming.

Links:

• All the issues resolved in 2.2.2
• Documentation

Thanks to everyone who contributed to this release.

• Connor MacDonald
• Kevin Albertson

Announcing 1.30.7 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

libbson

No changes since 1.30.6. Version incremented to match the libmongoc version.

libmongoc

Fixes:

• Fix documentation build with python-docutils 0.22.2
• Omit saslSupportedMechs in single-threaded monitoring commands.

Links:

• All the issues resolved in 1.30.7
• Documentation

Thanks to everyone who contributed to this release.

• Ezra Chung
• Julia Garland

Announcing 2.2.1 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

libbson

No changes since 2.2.0. Version incremented to match the libmongoc version.

libmongoc

Fixed

• Fix applied timeout on Azure and GCP KMS requests.
• Do not error if server reply to bulkWrite omits nModified.

Links:

• All the issues resolved in 2.2.1
• Documentation

Thanks to everyone who contributed to this release.

• Kevin Albertson

Announcing 2.2.0 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

libbson

Improvements

• Increase resolution of bson_get_monotonic_time on Windows.

Deprecated

• Support for macOS 11 (EOL since September 2023) and macOS 12 (EOL since September 2024).

Removed

• Support for Visual Studio 2015 (EOL since October 2025). Use Visual Studio 2017 or newer.

libmongoc

New Features

• MONGODB-OIDC authentication mechanism.
  • Support a custom callback with mongoc_client_set_oidc_callback and mongoc_client_pool_set_oidc_callback.
  • Support Azure environment with property environment:azure.
  • Support GCP environment with property environment:gcp.
  • Kubernetes environment is not-yet supported.
• Add features to mongoc_bulkwrite_t:
  • Add mongoc_bulkwrite_is_acknowledged.
  • Add mongoc_bulkwriteresult_serverid.
  • Support Queryable Encryption.
• Support text indexes for Queryable Encryption:
  • Add mongoc_client_encryption_encrypt_text_opts_t.
  • Substring, prefix and suffix search are in preview and should be used for experimental workloads only. These features are unstable and their security is not guaranteed until released as Generally Available (GA). The GA version of these features may not be backwards compatible with the preview version
• Support TLS v1.3 with Windows Secure Channel.

Fixed

• Do not try to resume when iterating a closed change stream.

Notes

• Raise required version of libmongocrypt from 1.13.0 to 1.15.0 to support In-Use Encryption (corresponds to the CMake option: ENABLE_CLIENT_SIDE_ENCRYPTION).

Deprecated

• Support for macOS 11 (EOL since September 2023) and macOS 12 (EOL since September 2024).

Removed

• Support for Visual Studio 2015 (EOL since October 2025). Use Visual Studio 2017 or newer.

Links:

• All the issues resolved in 2.2.0
• Documentation

Thanks to everyone who contributed to this release.

• Kevin Albertson
• Connor MacDonald
• Julia Garland
• Ezra Chung
• Adrian Dole
• Colby Pike
• Roberto C. Sánchez
• shubhamhii

Announcing 2.1.2 of libbson and libmongoc, the libraries constituting the MongoDB C Driver.

libbson

No changes since 2.1.1. Version incremented to match the libmongoc version.

libmongoc

Fixes

• Fix write command options handling.

Links:

• All the issues resolved in 2.1.2
• Documentation

Thanks to everyone who contributed to this release.

• Ezra Chung
• Kevin Albertson