AI SDK @ai-sdk/anthropic 3.0.142: by-value tool additions now need allowInlineToolDefinitions (November 10, 2026)

What changed

@ai-sdk/anthropic 3.0.142 (the AI SDK 6 line, npm tag ai-v6) came out on November 10, 2026. Tools added by value in a mid-conversation system message, through toolChanges with a tool object, now need a request-level opt-in: providerOptions.anthropic.allowInlineToolDefinitions: true.

The reason is safety. Message history from a client UI could carry a by-value tool and slip in a tool your server never declared, or undo your tool restrictions. The opt-in can only be set on the request, not inside a message. Tools declared in tools and additions by reference (toolName) work as before.

If you already use by-value additions on v6, they stop being sent after this update until you add the option.

Prerequisites

• A project on ai 6 with @ai-sdk/anthropic 3.x that uses toolChanges with a tool object
• An Anthropic API key in ANTHROPIC_API_KEY

Steps

1. Update the package: npm install @ai-sdk/anthropic@3.0.142.
2. Find the calls whose messages include toolChanges with type: 'tool_addition' and a tool object.
3. Only when those system messages are written by your server, add the opt-in to the request:

const result = await generateText({
  model: anthropic('claude-opus-4-8'),
  messages,
  providerOptions: {
    anthropic: { allowInlineToolDefinitions: true },
  },
});