8.23.1

8.23.1 / 2026-04-23

• fix(model): support sort option in Model.bulkWrite() updateOne and replaceOne operations #16091 #16079
• fix(setDefaultsOnInsert): check child filter paths before applying defaults (backport #16031 to 8.x) #16219 marklai1998
• fix(schema): always pass raw string value to error validators, only trim to 30 chars for maxlength validator #16238 #16236 #15550 #15571

9.5.0

9.5.0 / 2026-04-20

• feat(debug): add timestamp option to debug output #16216 rejunp
• feat(query): add cloneUpdate option to explicitly disable update cloning #16230 #16202
• feat(query): extend defaults query option to find() #16226 sderrow
• fix(query): avoid cloning update until absolutely necessary to better support updates with __proto__ #16230 #16202
• fix(query): avoid treating documents with a $set() method as objects with a $set property when casting updates #16230
• fix(queryHelpers): pass default options to discriminators #16227 #16226
• fix(document): handle including and excluding nested paths with optimistic concurrency #16177 #16054
• fix(model): throw ObjectParameterError in insertOne() if doc is not an object #16221 IshitaSingh0822
• fix(cast): preserve reason in CastError message after setModel() #16167 White-Devil2839
• perf(model): remove unnecessary clone in findOneAndUpdate() #16230
• perf: use kareem 3.3.0 mongoosejs/kareem#45 #16229
• chore: use TSTyche assertions #16222 mrazauskas

9.4.1

9.4.1 / 2026-04-03

• Revert "fix(setDefaultsOnInsert): run setters on default values during upsert" #16218 #16051

9.4.0

9.4.0 / 2026-04-03

• perf(document+model): avoid parallel save error instantiation, simplify resetting atomics, streamline validation and collection handling
• feat(document): add $getChanges() alias, deprecate getChanges() #15959 techcodie
• fix(schema): support toJSONSchema on unions #16179
• fix(schema): implement validation for Union schemas and subdocuments techcodie
• fix(connection): snapshot Date in heartbeat handler and flush queue on recovery #16183 andreialecu
• fix(model): use duck-typing with version check to validate the argument to useConnection() is actually a connection #16098
• fix(setDefaultsOnInsert): run setters on default values during upsert #16051 mahmoodhamdi
• fix(utils): properly compare Set objects in deepEqual KhanjarSingh
• fix(utils): wrap discriminator merge check in parentheses to fix precedence Necro-Rohan
• fix(schema): correct template literal in encryptionType error message Mridul012
• fix(schema): correct error when unsupported query operator with number #16062
• fix(types): make MergeType and UnpackedIntersection distributive over union types techcodie
• types: add id to HydratedDocument virtuals by default unless explicitly set #16178
• types(populate): use marker type to track populated vs depopulated type for perf
• types(populate): retain populated paths in toObject() and toJSON() unless depopulate: true set #16085
• types(query): make TypeScript error on $and with unrecognized query operator
• chore: use TSTyche assertions mrazauskas
• docs(connection): remove references to useUnifiedTopology and fix backtick
• docs: fix typo 'retreiving' -> 'retrieving' in SchemaType getter JSDoc yogesh968
• docs: fix typos around 'retrieve' in schemaType and tests ayushshukla1807
• docs: fix typos in code comments Goldyvaiiii

9.3.3

9.3.3 / 2026-03-25

• fix(schemaType): standardize to use MongooseError instead of plain Error #16172 VIPAX-JIT
• types: make MergeType distributive to better support populate on models where the hydrated doc type is a union #16101 #16161
• docs: upgrade http:// links to https:// in connections.md #16163 Puxhkar
• docs: fix typographical, grammatical errors & documentation clarity improvements #16175 yogesh968
• docs: clarify multi-mongos support documentation for sharded clusters

9.3.2

9.3.2 / 2026-03-23

• fix(mongoose): throw error when trying to set null or undefined as options #16130 #16140
• fix(cast): include array value in query filter error message #16127 White-Devil2839
• fix(cast): replace assert.ok with descriptive Error in castNumber #16110 mrsandy1965
• fix(connection): standardize throw new Error to MongooseError #16142 techcodie
• fix(query): use MongooseError instead of Error #16132 ace-tk
• docs: add production environment example for autoIndex #16151 mrsandy1965
• docs: upgrade self-referencing http:// links to https:// #16150 mrsandy1965
• docs: fix incorrect Double cast comment and upgrade insecure plugin link #16148 mrsandy1965
• docs: fix redundant text and http link in installation section #16146 Puxhkar
• docs: fix typo 'mutiple' → 'multiple' in queries.md #16147 mrsandy1965
• docs: use HTTPS for external links in docs navigation #16133 ace-tk
• docs: use HTTPS for external links in CONTRIBUTING and homepage #16134 ace-tk
• docs(populate): replace removed mapReduce() API link #16135 ace-tk
• docs(models): replace removed count() and mapReduce() references #16123 White-Devil2839
• docs: fix broken count() and update() links in queries docs White-Devil2839
• docs: fix broken update() link in validation docs #16121 White-Devil2839
• docs: update GitHub link to use https #16120 White-Devil2839
• docs(documents): fix incorrect variable name in nullish coalescing example #16119 White-Devil2839
• docs: fix missing quotes in populate path examples #16118 White-Devil2839
• docs: fix missing comma in populate dynamic ref example #16117 White-Devil2839
• docs: clarify that transaction rollback marks fields as modified to allow re-saving #16112 ramanverse

9.3.1

9.3.1 / 2026-03-17

• fix(model): handle passing string projection to hydrate() #16082
• fix(model): fix bulkWrite() sorting #16079 #16080 pnkov
• fix(QueryCursor): fix wrong this context in QueryCursor close callback #16104 techcodie
• types(schema): infer schema options correctly for model context in statics #16046 #16102
• types(schema): fix type definition for HydratedDocType in autoTypedVirtuals #16083
• types(plugin): allow passing model with custom TStatics into Schema.prototype.plugin() #16090 #16086
• chore: use MongooseError instead of Error in schema, model, and aggregate #15995 mahmoodhamdi
• docs(projection): clean up jsdoc for parseProjection()

9.3.0

9.3.0 / 2026-03-10

• feat(schema): support discriminators option inline for better TypeScript support #16053
• feat(aggregate): add pipelineForUnionWith() helper to allow reusing pipelines with $unionWith in TypeScript #16033
• feat(setDefaultsOnInsert): pass query as context to default functions #16041 #16025
• fix: resolve deeply nested discriminator paths in arrayFilters #16072 Yatin81
• fix(changeStream): emit ready on next tick to allow stream to initialize
• fix(connection): handle calling watch() on disconnected connection
• fix: remove references to mongodb option "promiseLibrary" hasezoey
• fix(model+query): backwards compatible validateBeforeSave handling and avoid TypeError in removeUnusedArrayFilters on nullish update
• perf(model): remove unnecessary overhead when saving new doc
• types(InferRawDocType): fall back to using InferRawDocType instead of pulling non-raw inferred doc type if EnforcedDocType not set #16053
• types: add type constraints for Document#$model() and Document#model() mrazauskas
• docs: fix broken links and update MongoDB documentation links #16037 hasezoey
• docs(contributing): update issue tracker links to Automattic org AkaHarshit

9.2.4

9.2.4 / 2026-03-03

• types(models): allow unknown keys in subdocs while retaining autocomplete suggestions #16048
• types(schema): fix issues related to defining timestamps and virtuals with methods and/or statics in schema options #16052 #16046
• docs: use lowercase primitive types in JSDoc and fix incorrect @returns declarations #16036 #16018
• docs(field-level-encryption): improve CSFLE docs with model registration guidance and schema definition example #16065 #16015

9.2.3

9.2.3 / 2026-02-26

• types(model): make bulkSave() correctly take array of THydratedDocumentType #16032