---
title: VoyageAI Rerank
 | Developer Documentation
---

If you’re opening this Notebook on colab, you will probably need to install LlamaIndex 🦙.

```
%pip install llama-index > /dev/null
%pip install llama-index-postprocessor-voyageai-rerank > /dev/null
%pip install llama-index-embeddings-voyageai > /dev/null
```

```
[notice] A new release of pip is available: 23.3.2 -> 24.0
[notice] To update, run: pip install --upgrade pip
Note: you may need to restart the kernel to use updated packages.
```

```
from llama_index.core import VectorStoreIndex, SimpleDirectoryReader
from llama_index.core.response.pprint_utils import pprint_response
```

Download Data

```
!mkdir -p 'data/paul_graham/'
!wget 'https://raw.githubusercontent.com/run-llama/llama_index/main/docs/examples/data/paul_graham/paul_graham_essay.txt' -O 'data/paul_graham/paul_graham_essay.txt'
```

```
--2024-05-09 17:56:26--  https://raw.githubusercontent.com/run-llama/llama_index/main/docs/examples/data/paul_graham/paul_graham_essay.txt
Resolving raw.githubusercontent.com (raw.githubusercontent.com)... 2606:50c0:8003::154, 2606:50c0:8000::154, 2606:50c0:8002::154, ...
Connecting to raw.githubusercontent.com (raw.githubusercontent.com)|2606:50c0:8003::154|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 75042 (73K) [text/plain]
Saving to: ‘data/paul_graham/paul_graham_essay.txt’


data/paul_graham/pa 100%[===================>]  73.28K  --.-KB/s    in 0.009s


2024-05-09 17:56:26 (7.81 MB/s) - ‘data/paul_graham/paul_graham_essay.txt’ saved [75042/75042]
```

```
import os
from llama_index.embeddings.voyageai import VoyageEmbedding


api_key = os.environ["VOYAGE_API_KEY"]
voyageai_embeddings = VoyageEmbedding(
    voyage_api_key=api_key, model_name="voyage-3"
)


# load documents
documents = SimpleDirectoryReader("./data/paul_graham/").load_data()


# build index
index = VectorStoreIndex.from_documents(
    documents=documents, embed_model=voyageai_embeddings
)
```

#### Retrieve top 10 most relevant nodes, then filter with VoyageAI Rerank

```
from llama_index.postprocessor.voyageai_rerank import VoyageAIRerank


voyageai_rerank = VoyageAIRerank(
    api_key=api_key, top_k=2, model="rerank-2", truncation=True
)
```

```
query_engine = index.as_query_engine(
    similarity_top_k=10,
    node_postprocessors=[voyageai_rerank],
)
response = query_engine.query(
    "What did Sam Altman do in this essay?",
)
```

```
pprint_response(response, show_source=True)
```

### Directly retrieve top 2 most similar nodes

```
query_engine = index.as_query_engine(
    similarity_top_k=2,
)
response = query_engine.query(
    "What did Sam Altman do in this essay?",
)
```

Retrieved context is irrelevant and response is hallucinated.

```
pprint_response(response, show_source=True)
```