fix(langgraph): recognize JSON-erased Overwrite values across runtimes#2553
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Christian Bromann (christian-bromann) merged 1 commit intoJun 17, 2026
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_getOverwriteValue now also accepts the { type: "__overwrite__", value }
discriminator form produced when a typed Overwrite from another runtime
(e.g. a Python dataclass routed through the LangGraph API server) is
serialized and its type is erased, keeping Overwrite/DeltaChannel
semantics intact across cross-runtime JSON boundaries.
🦋 Changeset detectedLatest commit: cdc582d The changes in this PR will be included in the next version bump. This PR includes changesets to release 7 packages
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@langchain/langgraph-checkpoint
@langchain/langgraph-checkpoint-mongodb
@langchain/langgraph-checkpoint-postgres
@langchain/langgraph-checkpoint-redis
@langchain/langgraph-checkpoint-sqlite
@langchain/langgraph-checkpoint-validation
create-langgraph
@langchain/langgraph-api
@langchain/langgraph-cli
@langchain/langgraph
@langchain/langgraph-cua
@langchain/langgraph-supervisor
@langchain/langgraph-swarm
@langchain/langgraph-ui
@langchain/langgraph-sdk
@langchain/angular
@langchain/react
@langchain/svelte
@langchain/vue
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This PR was opened by the [Changesets release](https://github.com/changesets/action) GitHub action. When you're ready to do a release, you can merge this and the packages will be published to npm automatically. If you're not ready to do a release yet, that's fine, whenever you add more changesets to main, this PR will be updated. # Releases ## @langchain/langgraph@1.4.4 ### Patch Changes - [#2552](#2552) [`d662cbb`](d662cbb) Thanks [@christian-bromann](https://github.com/christian-bromann)! - fix(langgraph): isolate concurrent singleton-agent invocations by thread `ensureLangGraphConfig` ignores the ambient `AsyncLocalStorage` `configurable` on root-level invokes that supply an invoke-time `thread_id` and have no nesting keys (ignoring graph-bound `.withConfig()` defaults). On a fresh top-level run the ambient `configurable` can belong to another concurrent invocation, so its keys — internal scratchpad/task-input as well as user keys like `tenant_id`/`user_id` — must not leak in; values the caller wants arrive through the explicit (bound + invoke-time) configs. Ambient nesting (`__pregel_read__`) and bound child graphs invoked from parent tasks are unaffected. This prevents cross-invocation leakage between concurrent `invoke()` calls on a shared compiled graph (e.g. BullMQ workers with `concurrency > 1`). Complements the config-merge fix that stopped shared graph-bound `metadata`/`configurable` objects from being mutated across invocations ([#2040](#2040)). - [#2553](#2553) [`1c2aa5b`](1c2aa5b) Thanks [@christian-bromann](https://github.com/christian-bromann)! - fix(langgraph): recognize JSON-erased `Overwrite` values across runtimes `Overwrite` already survives JSON serialization in JS because `Overwrite.toJSON()` emits the canonical `{ "__overwrite__": value }` sentinel. `_getOverwriteValue` now additionally recognizes the discriminator form `{ "type": "__overwrite__", value }` produced when a typed `Overwrite` from another runtime (e.g. a Python dataclass routed through the LangGraph API server) is serialized and its type is erased. This keeps `Overwrite` (and `DeltaChannel`) semantics intact across cross-runtime JSON boundaries. These delta-channel APIs remain Beta. ## @example/ai-elements@0.1.40 ### Patch Changes - Updated dependencies \[[`d662cbb`](d662cbb), [`1c2aa5b`](1c2aa5b)]: - @langchain/langgraph@1.4.4 ## @examples/assistant-ui-claude@0.1.40 ### Patch Changes - Updated dependencies \[[`d662cbb`](d662cbb), [`1c2aa5b`](1c2aa5b)]: - @langchain/langgraph@1.4.4 ## @examples/ui-angular@0.0.50 ### Patch Changes - Updated dependencies \[[`d662cbb`](d662cbb), [`1c2aa5b`](1c2aa5b)]: - @langchain/langgraph@1.4.4 ## @examples/ui-multimodal@0.0.26 ### Patch Changes - Updated dependencies \[[`d662cbb`](d662cbb), [`1c2aa5b`](1c2aa5b)]: - @langchain/langgraph@1.4.4 ## @examples/ui-react@0.0.26 ### Patch Changes - Updated dependencies \[[`d662cbb`](d662cbb), [`1c2aa5b`](1c2aa5b)]: - @langchain/langgraph@1.4.4 ## langgraph@1.0.44 ### Patch Changes - Updated dependencies \[[`d662cbb`](d662cbb), [`1c2aa5b`](1c2aa5b)]: - @langchain/langgraph@1.4.4 Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
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Summary
Overwritealready survives JSON serialization becauseOverwrite.toJSON()emits the canonical{ "__overwrite__": value }sentinel, which_getOverwriteValuerecognizes.{ "type": "__overwrite__", value }that results when a typedOverwritefrom another runtime (notably a Python dataclass, post fix(langgraph): MakeOverwritesurvive JSON roundtrips langgraph#8127) is serialized through a JSON boundary and its type is erased._get_overwrite(instance, sentinel dict, discriminator dict), soOverwriteround-trips both directions across the JS↔Python API boundary. Delta-channel APIs remain Beta.