Checked other resources

• This is a bug, not a usage question. For questions, please use the LangChain Forum (https://forum.langchain.com/).
• I added a very descriptive title to this issue.
• I searched the LangChain.js documentation with the integrated search.
• I used the GitHub search to find a similar question and didn't find it.
• I am sure that this is a bug in LangChain.js rather than my code.
• The bug is not resolved by updating to the latest stable version of LangChain (or the specific integration package).

Example Code

import { VertexAIEmbeddings } from "@langchain/google-vertexai";

const embeddings = new VertexAIEmbeddings({
  location: "us-central1",
  authOptions: {
    projectId: "my-project"
  },
  model: "text-embedding-005",
  outputDimensionality: 768,
});

const vector = await embeddings.embedQuery("What color is my favorite shirt?");

Error Message and Stack Trace (if applicable)

n/a

Description

• I'm trying to use @langchain/google-vertexai to embed both corpus documents and subsequent user queries
• I expect to be able to pass an embedding taskType to the VertexAIEmbeddings constructor
• As far as I can tell, I'm not able to specify a taskType value anywhere

I've never opened an issue before, so I apologize in advance if this doesn't belong here. If that's the case, I'm happy to submit it elsewhere.

Per the Vertex AI documentation, I'm expecting to be able to provide a task type when generating embeddings. It looks like this field is supported by the GoogleGenerativeAIEmbeddings class present in @langchain/google-genai (python docs, TypeScript source), but is missing from VertexAIEmbeddings.

System Info

• Platform: Windows
• Node version: 22.12.0
• Yarn version: 4.3.1
• yarn info langchain:

  └─ langchain@npm:1.0.3
   ├─ Instances: 1
   ├─ Version: 1.0.3
   │
   └─ Dependencies
      ├─ @langchain/langgraph-checkpoint@npm:^1.0.0 → npm:1.0.0
      ├─ @langchain/langgraph@npm:^1.0.0 → npm:1.0.1
      ├─ langsmith@npm:~0.3.74 → npm:0.3.78
      ├─ uuid@npm:^10.0.0 → npm:10.0.0
      └─ zod@npm:^3.25.76 || ^4 → npm:4.1.12
  

• yarn info @langchain/google-vertexai:

  └─ @langchain/google-vertexai@npm:1.0.0
   ├─ Version: 1.0.0
   │ 
   └─ Dependencies
      └─ @langchain/google-gauth@npm:^1.0.0 → npm:1.0.0