Issues

• React 19.2 dev mode breaks MST: "creation of the observable instance must be done on the initializing phase"

  bugneeds reproduction/info
  mobxjs/mobx-state-tree#2279 · Filter by author scottlet opened on Dec 5, 2025
  5

• Error when React 19 component has MST node as prop with observer defined later

  bug
  mobxjs/mobx-state-tree#2277 · Filter by author filipkis opened on Oct 24, 2025
  13

• MSTMap does not have observe method, but IMSTMap does

  bugTypescript
  mobxjs/mobx-state-tree#2275 · Filter by author n9 opened on Jul 23, 2025
  12

• Duplicates in Identifier Cache

  needs reproduction/info
  mobxjs/mobx-state-tree#2255 · Filter by author CraigHarley opened on Mar 27, 2025
  3

• SnapshotIn Type unexpectedly changed behavior in MST version 7 (when upgrading from 6)

  Typescript
  mobxjs/mobx-state-tree#2254 · Filter by author jrmyio opened on Mar 25, 2025
  4

• types.compose does not override base properties for snapshot requirements.

  docs or exampleshelp/PR welcomelevel: easy
  mobxjs/mobx-state-tree#2253 · Filter by author kylemeenehan opened on Mar 17, 2025
  4

• Remove ts-essentials dependency

  dependencieshelp/PR welcomelevel: intermediate
  mobxjs/mobx-state-tree#2246 · Filter by author coolsoftwaretyler opened on Feb 17, 2025
  1

  

• Replacing large array very slow (possibly due to reconciliation)

  bughelp/PR welcomelevel: intermediate
  mobxjs/mobx-state-tree#2237 · Filter by author yossivainshtein opened on Dec 30, 2024
  4

  

• Use Changesets

  enhancementhacktoberfesthelp/PR welcomelevel: easy
  mobxjs/mobx-state-tree#2232 · Filter by author coolsoftwaretyler opened on Dec 13, 2024

• Move off TSLint

  help/PR welcomelevel: easy
  mobxjs/mobx-state-tree#2227 · Filter by author coolsoftwaretyler opened on Nov 27, 2024
  1

  

• got 「unknown」 type when using Instance<typeof SomeModel>

  docs or examplesTypescript
  mobxjs/mobx-state-tree#2217 · Filter by author JLUiceman opened on Oct 22, 2024
  7

• TypeScript does not recognize overriding mandatory property with optional one in sub-model

  Typescript
  mobxjs/mobx-state-tree#2216 · Filter by author andreykurilin opened on Oct 11, 2024
  6

  

• Unexpected patches for Dates with applySnapshot

  enhancementhelp/PR welcomelevel: intermediate
  mobxjs/mobx-state-tree#2215 · Filter by author thegedge opened on Sep 16, 2024
  3

• onBecomeUnobserved is never called

  can't fix
  mobxjs/mobx-state-tree#2211 · Filter by author vitaliyslion opened on Aug 23, 2024
  10

• Invalidate Parent (Not just Immediate object) on Types.SafeReference

  enhancementhacktoberfesthelp/PR welcomelevel: easy
  mobxjs/mobx-state-tree#2205 · Filter by author ChristopherGabba opened on Aug 12, 2024
  5

• Mobx/Mobx-state-tree doesnt work in module federation of Webpack.

  needs reproduction/info
  mobxjs/mobx-state-tree#2185 · Filter by author AshwinAsp opened on Jun 15, 2024
  8

• Missing docs for types.lazy

  docs or examples
  mobxjs/mobx-state-tree#2156 · Filter by author coolsoftwaretyler opened on Feb 26, 2024
  4

• Better documentation on action/view definitions and their impact on IDE introspection, navigation and refactoring

  docs or examples
  mobxjs/mobx-state-tree#2155 · Filter by author beepsoft opened on Feb 26, 2024
  3

• Unexpected error "Сannot finalize the creation of a node that is already dead" while applying snapshot

  bugdocs or examples
  mobxjs/mobx-state-tree#2136 · Filter by author dfilatov opened on Jan 30, 2024
  18

• Add safeMap utility (or something like it)

  brainstorming/wild ideadocs or examplesenhancementhacktoberfestlevel: easy
  mobxjs/mobx-state-tree#2109 · Filter by author coolsoftwaretyler opened on Oct 24, 2023

• When observe() a MST node's primitive property, TypeScript get the wrong type of oldValue & newValue

  bughelp/PR welcome
  mobxjs/mobx-state-tree#2105 · Filter by author songzhenqi opened on Oct 16, 2023
  1

• Use getTime() to check for Date equality

  breaking changelevel: intermediate
  mobxjs/mobx-state-tree#2080 · Filter by author davetapley opened on Sep 11, 2023
  8

• Document how MST lazily creates objects

  docs or examples
  mobxjs/mobx-state-tree#2058 · Filter by author scytacki opened on Aug 7, 2023
  1

  

• RootStore type becomes "any" the moment we call a RootStore model action using yield on a child model action

  help/PR welcomeTypescript
  mobxjs/mobx-state-tree#2040 · Filter by author cpintos-sc opened on Jul 5, 2023
  3

• Aborting action with AbortController does not work immediately, causes trouble with React.StrictMode

  bughelp/PR welcomelevel: intermediate
  mobxjs/mobx-state-tree#1987 · Filter by author DamianPereira opened on Dec 4, 2022
  3