## DocumentQA

`DocumentQA` answers caller questions against documents using retrieval-augmented generation (RAG). It operates in one of two modes:

- **Server mode (default):** Documents are uploaded to the Guava server and questions are answered server-side. Intended for simple use cases with few documents.
- **Local mode:** Bring your own vector store and generation model for full control over the RAG pipeline. Guava provides ready-made backends for ChromaDB, LanceDB, pgvector, and Pinecone.

### Constructor

| Parameter | Type | Required | Default | Description |
|-----------|------|----------|---------|-------------|
| `store` | `VectorStore \| None` | No | `None` | Vector store for local mode. When omitted, server mode is used automatically. |
| `documents` | `list[str] \| str \| None` | No | `None` | Documents to index at construction time. Accepts a single string or a list. |
| `ids` | `list[str] \| None` | No | `None` | Caller-provided IDs for each document, enabling later `upsert_document` / `delete_document`. Length must match `documents` if provided. |
| `chunk_size` | `int` | No | `5000` | Maximum characters per chunk (local mode only). |
| `chunk_overlap` | `int` | No | `200` | Overlap between consecutive chunks in characters (local mode only). |
| `instructions` | `str \| None` | No | `None` | System instruction for the generation model. Overrides the built-in default. |
| `generation_model` | `GenerationModel \| None` | Local mode | `None` | Generation model for producing answers. Required when `store` is provided. |
| `namespace` | `str \| None` | Server mode | `None` | Stable string to scope this instance's documents on the server. |

### Methods

**`ask(question: str, k: int = 5) -> str`** — Retrieve relevant chunks and generate an answer. In server mode, `k` is ignored (the server uses full document context).

**`upsert_document(key: str, text: str) -> None`** — Add or replace a document by key. Stale chunks from a previously longer document are deleted automatically.

**`add_document(text: str) -> None`** — Add a document without specifying a key. In server mode, uses a content-derived key (SHA-256 hash).

**`delete_document(key: str) -> None`** — Delete a previously upserted document by key.

**`clear() -> None`** — Remove all documents from the store.

### Available VectorStore Backends (Local Mode)

| Class | Import | Install | Default Embedding |
|-------|--------|---------|-------------------|
| `ChromaVectorStore` | `guava.helpers.chromadb` | `pip install 'guava-sdk[chromadb]'` | Built-in `all-MiniLM-L6-v2` (no API needed) |
| `LanceDBStore` | `guava.helpers.lancedb` | `pip install 'guava-sdk[lancedb]'` | Required — pass an `EmbeddingModel` (`GenAIEmbedding`, `OpenAIEmbedding`, `PineconeInferenceEmbedding`, or a custom subclass) |
| `PgVectorStore` | `guava.helpers.pgvector` | `pip install 'guava-sdk[pgvector]'` | Required — pass an `EmbeddingModel` (`GenAIEmbedding`, `OpenAIEmbedding`, `PineconeInferenceEmbedding`, or a custom subclass) |
| `PineconeVectorStore` | `guava.helpers.pinecone` | `pip install 'guava-sdk[pinecone]'` | `multilingual-e5-large` via Pinecone Inference |

Embedding and generation provider extras: `pip install 'guava-sdk[genai]'` (Google Gemini) or `pip install 'guava-sdk[openai]'` (OpenAI). See the [Vector Stores]( /docs/vector-stores) reference for full constructor details and backend-specific options.

### Examples

### Incremental Document Management

Use `ids` to assign stable keys to documents at construction time, then use `upsert_document`, `delete_document`, and `clear` to manage documents without re-creating the `DocumentQA` instance.