{"record":{"id":"0fc4a3c2736d3a86","repo":"tauri-apps/tauri","slug":"tauri-couldn-t-find-callback-id-id-this-migh","errorCode":null,"errorMessage":"[TAURI] Couldn't find callback id ${id}. This might happen when the app is reloaded while Rust is running an asynchronous operation.","messagePattern":"\\[TAURI\\] Couldn't find callback id (.+?)\\. This might happen when the app is reloaded while Rust is running an asynchronous operation\\.","errorType":"console","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"crates/tauri/scripts/core.js","lineNumber":44,"sourceCode":"    callbacks.set(identifier, (data) => {\n      if (once) {\n        unregisterCallback(identifier)\n      }\n      return callback && callback(data)\n    })\n    return identifier\n  }\n\n  function unregisterCallback(id) {\n    callbacks.delete(id)\n  }\n\n  function runCallback(id, data) {\n    const callback = callbacks.get(id)\n    if (callback) {\n      callback(data)\n    } else {\n      console.warn(\n        `[TAURI] Couldn't find callback id ${id}. This might happen when the app is reloaded while Rust is running an asynchronous operation.`\n      )\n    }\n  }\n\n  // Maybe let's rename it to `registerCallback`?\n  Object.defineProperty(window.__TAURI_INTERNALS__, 'transformCallback', {\n    value: registerCallback\n  })\n\n  Object.defineProperty(window.__TAURI_INTERNALS__, 'unregisterCallback', {\n    value: unregisterCallback\n  })\n\n  Object.defineProperty(window.__TAURI_INTERNALS__, 'runCallback', {\n    value: runCallback\n  })\n","sourceCodeStart":26,"sourceCodeEnd":62,"githubUrl":"https://github.com/tauri-apps/tauri/blob/52e4b6e71d8632a7e648f866c442e287ecddee34/crates/tauri/scripts/core.js#L26-L62","documentation":"core.js keeps a Map of JS callbacks registered via window.__TAURI_INTERNALS__.transformCallback (the machinery behind invoke, events and Channels). When Rust finishes an asynchronous operation it calls runCallback(id, data); if the id is no longer in the Map — classically because the page reloaded or navigated, wiping all registered callbacks — Tauri logs this console.warn instead of delivering. It is a warning, not an exception: the pending response is dropped and nothing crashes.","triggerScenarios":"An in-flight invoke()/Channel/event delivery that resolves after location.reload(), a dev-server full reload (vite HMR fallback, manual Ctrl+R), or navigation to another URL; also delivering an event after unlisten()/unregisterCallback already removed the id.","commonSituations":"Development with hot reload while long-running Rust commands (export, download, shell) are pending; apps that navigate between pages and lose the callback registry; SPA listeners not torn down before route changes; firing events at a webview that just reloaded.","solutions":["Usually no action needed: if listeners are re-registered on page load (framework mount effect), the warning refers to the pre-reload generation and is harmless.","Await pending invoke() promises and call unlisten() for every listen()/Channel before triggering reload or navigation.","Reduce full page reloads in dev: rely on HMR and avoid location.reload() in application logic.","For long-running streams, create Channels per session and re-create them after reload instead of expecting ids to survive."],"exampleFix":"// before: reload while a Rust async op is in flight — its callback id\n// is gone when the response arrives, triggering the warning\ninvoke('export_file').catch(() => {})\nlocation.reload()\n\n// after: let the operation finish (or fail) before reloading\nawait invoke('export_file')\nlocation.reload()","handlingStrategy":"fallback","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":["Re-register listeners and Channels in the framework mount effect so each reload generation has fresh callbacks; the warning then refers only to the dead generation.","Await pending invoke() promises and unlisten() every listener before reload/navigation.","Prefer HMR over full page reloads in development; avoid location.reload() in production logic.","Scope Channels to a session and re-create them after reload instead of expecting callback ids to survive."],"tags":["javascript","ipc","callback","reload","async","frontend"],"backgroundTag":"callback-after-page-reload","analyzedSha":"52e4b6e71d8632a7e648f866c442e287ecddee34","analyzedAt":"2026-08-20T13:59:20.734Z","contentChangedAt":"2026-08-20T13:59:20.734Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}