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Realm on React Native 0.86+: iOS Undefined symbols for jsi::Value

After an upgrade to React Native 0.86 or later, the iOS build of an app on realm 20.2.0 stops at the link step. It was reported with pods built as dynamic frameworks.

Updated 9 November 2026.

The error

Undefined symbols for architecture x86_64:
  "facebook::jsi::Value::asBool() const", referenced from: ...
  "facebook::jsi::Value::asObject(facebook::jsi::IRuntime&) const &", referenced from: ...
  "facebook::react::TurboModule::TurboModule(...)", referenced from: ...

From the description of realm-js pull request #7157. The architecture in the first line depends on what you build.

When it happens

• realm 20.2.0 on iOS with React Native 0.86 or later, new architecture.
• Pods built as frameworks: use_frameworks! in the Podfile, often needed for Firebase. The pull request author used use_frameworks! :linkage => :dynamic with React Native 0.87.1, and verified the fix with that setup only.

Why

realm's RealmJS.podspec only declares s.dependency 'React'. According to the pull request, when pods are built as frameworks, React Native 0.86 and later no longer link hermes-engine, React-jsi and ReactCommon/turbomodule/core into the RealmJS target through that line, so the linker cannot find the JSI symbols.

A fix was proposed upstream in #7157 on 25 September 2026 by TPXP. It has no review and is not merged.

Fix with afterdb

afterdb includes the fix from #7157, credited to its author, plus one more change to the header search paths that the fix needed in our builds.

In package.json, point the two Realm packages to afterdb:

"realm": "npm:@pomwik/afterdb@20.3.0",
"@realm/react": "npm:@pomwik/afterdb-react@0.20.1"

Then reinstall, run pod install on iOS, and rebuild. For Expo dev builds, run npx expo prebuild --clean. Your code keeps import Realm from "realm". If you do not use @realm/react, the first line is enough.

afterdb is an independent open-source fork of the realm-js SDK v20 (Apache-2.0) that we maintain, for apps on realm 20.x without Device Sync. It is not an official Realm release. Code on GitHub, package on npm.

We build and run it in CI with React Native 0.88.1 on Xcode 26.6 with no frameworks, static frameworks and dynamic frameworks, and on Xcode 26.4.1 without frameworks: the app starts on the iPhone simulator and the build for iPhone devices succeeds. Not tested yet: iOS with React Native 0.86 or 0.87 (the setup of the pull request author), Expo on iOS, and real iPhones.

Without afterdb

• Apply the change from #7157 with patch-package: in RealmJS.podspec, replace s.dependency 'React' with install_modules_dependencies(s). The author reports it works in their app. In afterdb we also had to turn HEADER_SEARCH_PATHS from an array into a string, because install_modules_dependencies appends to it. Check that your build still finds every header.
• The pull request describes the error only with frameworks. If your app can build its pods without use_frameworks!, that should avoid it. We have not tested this.