BoundaryML/baml · error · Error

Update to @boundaryml/baml required. Version from generators

Error message

Update to @boundaryml/baml required.
Version from generators.baml: ${generatedVersion}
Current @boundaryml/baml version: ${runtimeVersion}

Please upgrade @boundaryml/baml to version ${generatedVersion}.

$ npm install @boundaryml/baml@${generatedVersion}
$ yarn add @boundaryml/baml@${generatedVersion}
$ pnpm add @boundaryml/baml@${generatedVersion}

If nothing else works, please ask for help:

https://github.com/boundaryml/baml/issues
https://boundaryml.com/discord

What it means

BAML generated client code was produced by a newer baml CLI than the installed @boundaryml/baml runtime supports. ThrowIfVersionMismatch compares the version recorded from generators.baml against the runtime version and throws when they differ, since the generated code may use FFI surfaces the runtime lacks. The error includes the exact install commands to fix it.

Source

Thrown at engine/language_client_typescript/typescript_src/safe_imports.ts:32

export function ThrowIfVersionMismatch(generatedVersion: string) {
  const runtimeVersion = get_version();
  if (!ensureVersionCompatibility(generatedVersion, runtimeVersion)) {
    const errorMessage = `Update to @boundaryml/baml required.
Version from generators.baml: ${generatedVersion}
Current @boundaryml/baml version: ${runtimeVersion}

Please upgrade @boundaryml/baml to version ${generatedVersion}.

$ npm install @boundaryml/baml@${generatedVersion}
$ yarn add @boundaryml/baml@${generatedVersion}
$ pnpm add @boundaryml/baml@${generatedVersion}

If nothing else works, please ask for help:

https://github.com/boundaryml/baml/issues
https://boundaryml.com/discord`;
    
    throw new Error(errorMessage.trim());
  }
}

View on GitHub (pinned to bd85ce9dee)

Solutions

  1. Run your package manager's install command with the required version, e.g. `npm install @boundaryml/baml@<generatedVersion>` (or yarn/pnpm add).
  2. Commit the updated lockfile so CI and teammates get the matching version.
  3. If you cannot upgrade, downgrade the baml CLI and regenerate so generators.baml matches the installed runtime.
  4. If versions appear to match but the error persists, clear node_modules and reinstall, then report at the linked GitHub issues page.

Example fix

// package.json before
"dependencies": { "@boundaryml/baml": "^0.60.0" }
// after
"dependencies": { "@boundaryml/baml": "^0.75.0" }
// then: npm install && baml generate
Defensive patterns

Strategy: validation

Validate before calling

import { version as runtimeVersion } from '@boundaryml/baml/package.json'
// read generatedVersion from generators.baml and compare before initializing the client
if (runtimeVersion !== generatedVersion) {
  throw new Error(`Install @boundaryml/baml@${generatedVersion} (currently ${runtimeVersion})`)
}

Prevention

When it happens

Trigger: Importing or initializing the generated BAML client when the version embedded in generators.baml differs from the installed @boundaryml/baml package version; regenerating with an updated CLI (`baml generate`) without upgrading the runtime package, or vice versa.

Common situations: A teammate updated baml CLI and committed regenerated code; CI cache installs an older package; pnpm/yarn lockfile not updated after a generator upgrade; monorepo where one workspace pins an old @boundaryml/baml.

Understand the failure class

Background: "not installed", "pip install", "required for": how missing-dependency errors surface across open-source libraries — this error's family across 34 libraries.

Related errors

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/6132bd391505c0be. Report an issue: GitHub.