MobX

Frameworks & Libraries

Transparent reactive state management through observable data structures.

Latest 7.0.0 · by MobXWebsitemobxjs/mobx

Release activity

Release activity — 7 releases across 7 days in the last year. Each cell is one day; darker means more releases that day. Older weeks are hidden at this screen width.
MayJunJulAug
SundayNo releases on Apr 26, 2026No releases on May 3, 2026No releases on May 10, 2026No releases on May 17, 20261 release on May 24, 2026No releases on May 31, 2026No releases on Jun 7, 2026No releases on Jun 14, 2026No releases on Jun 21, 2026No releases on Jun 28, 2026No releases on Jul 5, 2026No releases on Jul 12, 2026No releases on Jul 19, 2026No releases on Jul 26, 2026No releases on Aug 2, 2026No releases on Aug 9, 2026
MondayNo releases on Apr 27, 20261 release on May 4, 2026No releases on May 11, 2026No releases on May 18, 2026No releases on May 25, 2026No releases on Jun 1, 20261 release on Jun 8, 2026No releases on Jun 15, 2026No releases on Jun 22, 2026No releases on Jun 29, 2026No releases on Jul 6, 2026No releases on Jul 13, 2026No releases on Jul 20, 2026No releases on Jul 27, 2026No releases on Aug 3, 2026No releases on Aug 10, 2026
TuesdayNo releases on Apr 28, 2026No releases on May 5, 2026No releases on May 12, 2026No releases on May 19, 2026No releases on May 26, 2026No releases on Jun 2, 2026No releases on Jun 9, 2026No releases on Jun 16, 2026No releases on Jun 23, 2026No releases on Jun 30, 2026No releases on Jul 7, 2026No releases on Jul 14, 2026No releases on Jul 21, 2026No releases on Jul 28, 2026No releases on Aug 4, 2026No releases on Aug 11, 2026
WednesdayNo releases on Apr 29, 20261 release on May 6, 2026No releases on May 13, 2026No releases on May 20, 2026No releases on May 27, 20261 release on Jun 3, 2026No releases on Jun 10, 2026No releases on Jun 17, 2026No releases on Jun 24, 2026No releases on Jul 1, 2026No releases on Jul 8, 2026No releases on Jul 15, 2026No releases on Jul 22, 2026No releases on Jul 29, 2026No releases on Aug 5, 2026
ThursdayNo releases on Apr 30, 20261 release on May 7, 2026No releases on May 14, 2026No releases on May 21, 2026No releases on May 28, 2026No releases on Jun 4, 2026No releases on Jun 11, 2026No releases on Jun 18, 2026No releases on Jun 25, 2026No releases on Jul 2, 2026No releases on Jul 9, 2026No releases on Jul 16, 2026No releases on Jul 23, 20261 release on Jul 30, 2026No releases on Aug 6, 2026
FridayNo releases on May 1, 2026No releases on May 8, 2026No releases on May 15, 2026No releases on May 22, 2026No releases on May 29, 2026No releases on Jun 5, 2026No releases on Jun 12, 2026No releases on Jun 19, 2026No releases on Jun 26, 2026No releases on Jul 3, 2026No releases on Jul 10, 2026No releases on Jul 17, 2026No releases on Jul 24, 2026No releases on Jul 31, 2026No releases on Aug 7, 2026
SaturdayNo releases on May 2, 2026No releases on May 9, 2026No releases on May 16, 2026No releases on May 23, 2026No releases on May 30, 2026No releases on Jun 6, 2026No releases on Jun 13, 2026No releases on Jun 20, 2026No releases on Jun 27, 2026No releases on Jul 4, 2026No releases on Jul 11, 2026No releases on Jul 18, 2026No releases on Jul 25, 2026No releases on Aug 1, 2026No releases on Aug 8, 2026

7 releases in the last year

Changelog

7.0.0

Changed 3
  • mobx-react-lite now requires MobX 7 and React 18 or later
  • mobx-react now requires MobX 7 and React 18 or later
  • Minified error URLs shortened to reduce production bundle size
Removed 16
  • ES5/non-proxy fallback for observable objects and arrays; MobX now always uses Proxy-backed observables
  • configure({ useProxies: ... }) option
  • { proxy: false } option for observable, observable.object, and observable.array
  • Legacy decorators support
  • Namespaced annotation properties observable.ref, observable.shallow, observable.deep, and observable.struct in favor of named exports observableRef, observableShallow, observableDeep, and observableStruct
  • Namespaced comparer and computed properties comparer.identity, comparer.default, comparer.structural, comparer.shallow, computed.struct, action.bound, and flow.bound in favor of named exports compareIdentity, compareDefault, compareStructural, compareShallow, computedStruct, actionBound, and flowBound
Deprecated 1
  • observer(fn, { forwardRef: true }) syntax; pass an already-created React.forwardRef(...) component to observer instead
Major Changes

  • 1926c69f53168619d688f348aa587e8f3ae579ae #4671 Thanks @kubk! - Release MobX 7, mobx-react-lite 5, and mobx-react 10.

    Bundle sizes are down: ESM prod 17.02 KiB gzip -> 13.96 KiB gzip; a minimal tree-shaken example is 10.32 KiB gzip now.

    It removes long-deprecated compatibility paths and keeps the React bindings split between mobx-react-lite for function components and mobx-react for class-component support.

    MobX 7

    MobX 7 is a cleanup release focused on the modern runtime and decorator model.

    • MobX now always uses Proxy-backed observable objects and arrays. The ES5/non-proxy fallback has been removed.
    • configure({ useProxies: ... }) is no longer supported.
    • { proxy: false } options for observable, observable.object, and observable.array are no longer supported.
    • Legacy decorators are no longer supported.
    • Namespaced annotation and comparer properties now use named exports to reduce bundle size:
    Removed APIReplacement
    observable.refobservableRef
    observable.shallowobservableShallow
    observable.deepobservableDeep
    observable.structobservableStruct
    computed.structcomputedStruct
    action.boundactionBound
    flow.boundflowBound
    comparer.identitycompareIdentity
    comparer.defaultcompareDefault
    comparer.structuralcompareStructural
    comparer.shallowcompareShallow
    • The public trace API and its related runtime support have been removed. Use toJS, getDependencyTree, getObserverTree, spy or mobx-log package for debugging.
    mobx-react-lite 5 and mobx-react 10

    mobx-react-lite 5 and mobx-react 10 require MobX 7 and React 18 or later.

    mobx-react-lite remains the function-component package. mobx-react remains a thin wrapper around mobx-react-lite that adds class component and Stage 3 @observer class decorator support.

    • Keep function-component imports on mobx-react-lite if you do not need class component support.
    • Use mobx-react when you need class components or @observer class decorators.
    • mobx-react-lite supports function components and forwardRef; mobx-react delegates function components to mobx-react-lite and handles classes itself.
    • Remove React batching imports, including the stale React Native batching deep import. React 18+ renderers handle batching.

    The recommended public React binding surface for both packages is:

    • observer
    • Observer
    • useLocalObservable
    • enableStaticRendering
    • isUsingStaticRendering

    The following APIs have been removed from the React binding packages:

    • Provider, inject, and MobXProviderContext; use React.createContext directly.
    • disposeOnUnmount; dispose reactions in componentWillUnmount or return cleanup functions from useEffect.
    • PropTypes; use TypeScript or the regular prop-types package.
    • useObserver; wrap components with observer or use <Observer>.
    • useLocalStore; use useLocalObservable.
    • useAsObservableSource; synchronize values from props into local observable state explicitly.
    • useStaticRendering; use enableStaticRendering.
    • observerBatching, isObserverBatched, batchingForReactDom, batchingOptOut, and batchingForReactNative; remove these imports because React 18+ renderers handle batching.
    • Deprecated observer(fn, { forwardRef: true }); pass an already-created React.forwardRef(...) component to observer instead.
    • Legacy function-component contextTypes handling.
Patch Changes
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How 7.0.0 went

6.16.1

Fixed 1
  • Fix Stage 3 @computed overrides that delegate to a same-named parent getter via super
Removed 1
  • Remove outdated Flow typechecker support artifacts from the package
Patch Changes
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How 6.16.1 went

6.16.0

Added 1
  • Add getOrInsert and getOrInsertComputed to ObservableMap for compatibility with ESNext Map typings
Changed 2
  • Make the 2022.3 @computed decorator lazy by creating ComputedValue on first read of the decorated getter rather than eagerly during instance construction
  • Make the 2022.3 @observable accessor decorator lazy by creating ObservableValue on first read/write/observe of the decorated accessor rather than eagerly during instance construction
Fixed 1
  • Fix regression where isComputedProp returned false for lazy @computed properties before first read
Minor Changes

  • 6b3fb0ee725c0521bbaf7ba901a30261472a0e71 #4639 Thanks @ashishkr96! - feat(mobx): make the 2022.3 @computed decorator lazy. ComputedValue is now created on first read of the decorated getter rather than eagerly during instance construction, avoiding wasted allocations for getters that are never used. On a 50k-instance × 10-getter class with one read per instance this cuts construction heap by ~50% and construction time by ~25%; the steady-state read path is unchanged. Closes #4616.

  • f0c68749428fd4d3bba48e9685e44fd1ddbbee76 #4658 Thanks @ashishkr96! - feat(mobx): make the 2022.3 @observable accessor decorator lazy. ObservableValue is now created on first read/write/observe of the decorated accessor rather than eagerly during instance construction, avoiding wasted allocations for fields that are never touched. On a 50k-instance × 10-field class with sparse access (1 of 10 fields read per instance), this cuts construction heap by ~82% and construction time by ~86% versus the eager path. Follow-up to #4639.

Patch Changes
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How 6.16.0 went

6.15.2

Fixed 1
  • Restore npm release build target forwarding so published tarballs include the standalone ESM development and production bundles
Patch Changes
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How 6.15.2 went

6.15.1

Added 1
  • Export CancellablePromise from the public mobx entrypoint
Fixed 1
  • Make FlowCancellationError a proper Error instance while preserving its previous string representation
Patch Changes
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How 6.15.1 went

6.12.5

Fixed 1
  • Fix ES6 Map/Set checks for cross-window scripts
Patch Changes
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How 6.12.5 went

6.12.1

Changed 1
  • Reduce memory overhead of tracking dependencies
Fixed 1
  • Prevent reaction from keeping a reference to the old value that would prevent garbage collection
Patch Changes
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How 6.12.1 went

6.12.0

Changed 1
  • Improve observablearray proxy performance for es2023.array and es2022.array methods
Fixed 1
  • Action transparently forwards toString of underlying function
Minor Changes
  • ec5db592 #3792 Thanks @tonyraoul! - Improve observablearray proxy pefromance for es2023.array and es2022.array methods
Patch Changes
  • 86616c11 #3654 Thanks @ahoisl! - fix: action transparently forwards toString of underlying function
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How 6.12.0 went

6.10.2

Fixed 1
  • Computed values no longer become stale if the underlying observable was created and updated outside a reactive context
Patch Changes
  • c8d9374d #3748 Thanks @mweststrate! - Fixed: #3747, computed values becoming stale if the underlying observable was created and updated outside a reactive context
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How 6.10.2 went

6.10.0

Added 1
  • Added support for signal (AbortSignal) in autorun, reaction and sync when options to dispose them
Removed 1
  • Removed proxy option for makeObservable and makeAutoObservable
Minor Changes
  • bebd5f05 #3727 Thanks @rluvaton! - Added support for signal (AbortSignal) in autorun, reaction and sync when options to dispose them
Patch Changes
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How 6.10.0 went

6.9.1

Changed 1
  • Make trace() a noop in production build
Patch Changes
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How 6.9.1 went

6.7.0

Added 1
  • Add new option signal to when() to support abortion using an AbortSignal or AbortController
Changed 1
  • Proxied observable arrays can now safely read/write out of bound indices
Fixed 1
  • Make return value of reportObserved match invoke of onBecomeObserved
Minor Changes
Patch Changes
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How 6.7.0 went

6.6.2

Changed 1
  • Update README with improved wording and clearer links
Fixed 2
  • Allow readonly tuples as part of IObservableMapInitialValues
  • Fix regression in LegacyObservableArray compatibility with Safari 9
Patch Changes
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How 6.6.2 went

6.6.0

Fixed 1
  • Remove observable.box type inconsistency
Minor Changes
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How 6.6.0 went

6.5.0

Changed 1
  • Replace any with a generic in Set methods
Minor Changes
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How 6.5.0 went

6.4.2

Fixed 1
  • requiresObservable always takes precedence over global reactionRequiresObservable
Patch Changes
  • 2caf7e1a #3316 Thanks @urugator! - requiresObservable always takes precedence over global reactionRequiresObservable
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How 6.4.2 went

6.4.1

Fixed 1
  • Fix missing type inference of observe and intercept for arrays
Patch Changes
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How 6.4.1 went

6.4.0

Changed 1
  • Remove any from 'merge' and 'replace' methods of ObservableMap
Fixed 1
  • Make the error message about Object.freeze more informative
Minor Changes
  • 6b926833 #3287 Thanks @kubk! - Remove any from 'merge' and 'replace' methods of ObservableMap
Patch Changes
  • dee35be4 #3300 Thanks @kubk! - Make the error message about Object.freeze more informative
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How 6.4.0 went

6.3.12

Fixed 1
  • Observable map initialization no longer violates enforceActions: "always"
Patch Changes
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How 6.3.12 went

6.3.9

Fixed 2
  • requiresReaction always takes precedence over global computedRequiresReaction
  • fix isPlainObject implementation
Patch Changes
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How 6.3.9 went

6.3.8

Changed 1
  • Make IAtom['reportObserved'] return boolean
Fixed 1
  • Fix RangeError in ObservableArray.replace for large arrays
Patch Changes
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How 6.3.8 went

6.3.7

Fixed 1
  • Fix type inference of observe function
Patch Changes
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How 6.3.7 went

6.3.6

Fixed 2
  • Have cancelled when reject with an error rather than a string
  • makeObservable throws when mixing @decorator syntax with annotations
Patch Changes
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How 6.3.6 went

6.3.5

Fixed 1
  • Spy computed values no longer report updates unless the value actually changed
Patch Changes
  • 4ac6b454 #3146 Thanks @urugator! - fix #3109: spy: computed shouldn't report update unless the value changed
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How 6.3.5 went

6.3.3

Added 1
  • Polyfill Object.is for old/unsupported browsers
Changed 3
  • trace() now logs when computed becomes suspended
  • requiresReaction warns instead of throwing
  • Give proper typing to opts.equals of reaction
Fixed 2
  • Create WHEN_TIMEOUT error earlier to capture useful stack
  • Remove duplicate global property check
Patch Changes
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How 6.3.3 went

6.3.2

Fixed 1
  • flow now respects the autoBind option
Patch Changes
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How 6.3.2 went

6.3.1

Fixed 1
  • flow.bound no longer replaces the method on the prototype with a bound function
Patch Changes
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How 6.3.1 went

6.3.0

Added 1
  • Provide flow.bound annotation/decorator
Fixed 1
  • Make toJS work with computed value props
Minor Changes
Patch Changes
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How 6.3.0 went

6.1.7

Fixed 5
  • User provided debug names are not preserved on production
  • Property atom's debug name is dynamic on production
  • observable(primitive, options) ignores options
  • getDebugName(action) throws [MobX] Cannot obtain atom from undefined
  • Terser using unsafe: true
Patch Changes
  • 5640aa77 #2799 Thanks @urugator! - - fix: user provided debug names are not preserved on production
    • fix: property atom's debug name is dynamic on production
    • fix: observable(primitive, options) ignores options
    • fix: getDebugName(action) throws [MobX] Cannot obtain atom from undefined
    • fix: terser using unsafe: true
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How 6.1.7 went

6.1.6

Fixed 1
  • Reduced overall memory usage of MobX in production builds by skipping the generation of debug identifiers
Removed 1
  • Removed the internal mapid_ field of Reaction
Patch Changes
  • 9b195b17 #2780 Thanks @iChenLei! - The overall memory usage of MobX has been reduced in production builds by skipping the generation of debug identifiers. The internal mapid_ field of Reaction has been removed as part of the change.
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How 6.1.6 went

6.1.5

Added 1
  • Add warning for extending builtins
Changed 2
  • Optimize decorators
  • Use globalThis in global detection
Fixed 2
  • makeAutoObservable now works properly with symbolic keys
  • isComputedProp and getAtom second argument type is now compatible with Symbols
Patch Changes
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How 6.1.5 went

6.1.4

Fixed 1
  • Inherited annotated fields are now assignable
Patch Changes
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How 6.1.4 went

6.1.3

Added 1
  • Add safeDescriptors to configure options type
Patch Changes
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How 6.1.3 went

6.1.2

Changed 1
  • configure({ safeDescriptors: false }) now forces all props of observable objects to be writable and configurable
Patch Changes
  • ca09f2f5 #2761 Thanks @urugator! - configure({ safeDescriptors: false }) now forces all props of observable objects to be writable and configurable
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How 6.1.2 went

6.1.1

Fixed 3
  • Fix error stringification on minified build
  • Fix isObservableProp not supporting Symbols
  • Fix makeAutoObservable not ignoring inferredAnnotationsSymbol
Patch Changes
  • 39eca50d #2757 Thanks @urugator! - Fix error stringification on minified build Fix isObservableProp not supporting Symbols Fix makeAutoObservable not ignoring inferredAnnotationsSymbol
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How 6.1.1 went

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