{"record":{"id":"e27c1bf1320e18fc","repo":"sveltejs/svelte","slug":"your-application-or-one-of-its-dependencies-impo","errorCode":null,"errorMessage":"Your application, or one of its dependencies, imported from 'svelte/internal', which was a private module used by Svelte 4 components that no longer exists in Svelte 5. It is not intended to be public API. If you're a library author and you used 'svelte/internal' deliberately, please raise an issue on https://github.com/sveltejs/svelte/issues detailing your use case.","messagePattern":"Your application, or one of its dependencies, imported from 'svelte/internal', which was a private module used by Svelte 4 components that no longer exists in Svelte 5\\. It is not intended to be public API\\. If you're a library author and you used 'svelte/internal' deliberately, please raise an issue on https://github\\.com/sveltejs/svelte/issues detailing your use case\\.","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"critical","filePath":"packages/svelte/src/internal/index.js","lineNumber":3,"sourceCode":"// TODO we may, on a best-effort basis, reimplement some of the legacy private APIs here so that certain libraries continue to work. Those APIs will be marked as deprecated (and should noisily warn the user) and will be removed in a future version of Svelte.\n\nthrow new Error(\n\t`Your application, or one of its dependencies, imported from 'svelte/internal', which was a private module used by Svelte 4 components that no longer exists in Svelte 5. It is not intended to be public API. If you're a library author and you used 'svelte/internal' deliberately, please raise an issue on https://github.com/sveltejs/svelte/issues detailing your use case.`\n);\n","sourceCodeStart":1,"sourceCodeEnd":6,"githubUrl":"https://github.com/sveltejs/svelte/blob/20b341f10048cf1016a2028ac7eee5595cfef6a5/packages/svelte/src/internal/index.js#L1-L6","documentation":"Svelte 5 removed the private `svelte/internal` module that Svelte 4 used for compiled-component runtime helpers. The module now exists only to throw this error on import, directing library authors to file an issue. There is no public replacement: Svelte 5 internals live under `svelte/internal/client` and `svelte/internal/server` but remain private API.","triggerScenarios":"Any code or dependency that does `import ... from 'svelte/internal'`. Common with Svelte 4-era libraries (UI kits, store utilities) that reached into internals for helpers like `onDestroy`, `getContext`, or DOM utilities.","commonSituations":"Upgrading a project from Svelte 4 to 5 while a dependency still ships Svelte-4-compiled code; a transitive dependency bundled against an old Svelte; duplicated `svelte` versions in node_modules resolving the wrong internal.","solutions":["Find offending packages: `grep -rl \"svelte/internal\" node_modules --include=\"*.js\"` and upgrade them to Svelte-5-compatible releases.","Deduplicate Svelte: `npm ls svelte`, ensure a single 5.x version, run `npm dedupe` / `pnpm dedupe`.","If you own the code, replace `svelte/internal` imports with the public `svelte` API (`onMount`, `getContext`, etc.) or `svelte/store`."],"exampleFix":"// before (Svelte 4 private import)\nimport { onDestroy } from 'svelte/internal';\n// after (Svelte 5 public API)\nimport { onDestroy } from 'svelte';","handlingStrategy":"validation","validationCode":"// CI / postinstall check: fail if any dependency imports svelte/internal\nconst { execSync } = require('child_process');\ntry {\n\tconst out = execSync(\"grep -rl \\\"svelte/internal\\\" node_modules --include=*.js\", { stdio: 'pipe' }).toString();\n\tif (out.trim()) { console.error('A dependency imports svelte/internal:\\n' + out); process.exit(1); }\n} catch {}","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Pin svelte to a single 5.x version across the monorepo.","Run `npm ls svelte` after upgrades to catch duplicates.","Keep UI libraries on Svelte-5-compatible releases.","Add a CI grep guard for `svelte/internal` imports."],"tags":["migration","svelte4","svelte5","import","breaking-change","dependencies"],"backgroundTag":null,"analyzedSha":"20b341f10048cf1016a2028ac7eee5595cfef6a5","analyzedAt":"2026-08-12T23:37:30.399Z","schemaVersion":2},"datasetVersion":"2026-08-13T04:17:16.726Z"}