---
title: "DoclingServeConverter"
id: doclingserveconverter
slug: "/doclingserveconverter"
description: "`DoclingServeConverter` converts PDF, DOCX, HTML, and other document formats to Haystack Documents by calling a remote DoclingServe HTTP server, with no local ML dependencies."
---

# DoclingServeConverter

`DoclingServeConverter` converts PDF, DOCX, HTML, and other document formats to Haystack Documents by calling a [DoclingServe](https://github.com/docling-project/docling-serve) HTTP server. Unlike the local [`DoclingConverter`](doclingconverter.mdx), this component has no heavy ML dependencies — all document parsing happens on the remote server.

<div className="key-value-table">

|  |  |
| --- | --- |
| **Most common position in a pipeline** | Before [PreProcessors](../preprocessors.mdx), or right at the beginning of an indexing pipeline |
| **Mandatory run variables** | `sources`: A list of file paths, URLs, or [`ByteStream`](../../concepts/data-classes.mdx#bytestream) objects |
| **Output variables** | `documents`: A list of documents |
| **API reference** | [Docling Serve](/reference/integrations-docling_serve) |
| **GitHub link** | https://github.com/deepset-ai/haystack-core-integrations/tree/main/integrations/docling_serve |
| **Package name** | `docling-serve-haystack` |

</div>

## Overview

The `DoclingServeConverter` takes a list of file paths, URLs, or [`ByteStream`](../../concepts/data-classes.mdx#bytestream) objects and sends them to a running DoclingServe instance for parsing. Local files and `ByteStream` objects are uploaded to the `/v1/convert/file` endpoint; URL strings are sent to `/v1/convert/source`.

The component supports three export modes, controlled by the `export_type` parameter:

- **`ExportType.MARKDOWN`** (default): Returns the document content as a Markdown string. Use this mode when you want well-structured text output with formatting preserved.
- **`ExportType.TEXT`**: Returns plain text extracted from the document. Use this mode when you need clean, unformatted text.
- **`ExportType.JSON`**: Returns the full Docling document representation as a JSON string. Use this mode when you need access to the complete structured representation.

Each source produces one [`Document`](../../concepts/data-classes.mdx#document) in the output. Sources that fail to convert are skipped with a warning logged.

You can pass additional conversion options to the DoclingServe API via the `convert_options` parameter (for example, `{"do_ocr": True, "ocr_engine": "tesseract"}`). If the DoclingServe instance requires authentication, pass the API key via the `api_key` parameter or set the `DOCLING_SERVE_API_KEY` environment variable.

The component supports both synchronous (`run`) and asynchronous (`run_async`) execution.

## Usage

Install the Docling Serve integration:

```shell
pip install docling-serve-haystack
```

Start a DoclingServe instance locally (requires Docker):

```shell
docker run -p 5001:5001 ghcr.io/docling-project/docling-serve-cpu:latest
```

### On its own

```python
from haystack_integrations.components.converters.docling_serve import (
    DoclingServeConverter,
)

# Default: Markdown output
converter = DoclingServeConverter(base_url="http://localhost:5001")
result = converter.run(sources=["report.pdf", "notes.docx"])
documents = result["documents"]
print(documents[0].content[:200])

# Plain text output
from haystack_integrations.components.converters.docling_serve import ExportType

converter = DoclingServeConverter(
    base_url="http://localhost:5001",
    export_type=ExportType.TEXT,
)
result = converter.run(sources=["report.pdf"])
print(result["documents"][0].content)
```

### In a pipeline

```python
from haystack import Pipeline
from haystack.components.preprocessors import DocumentSplitter
from haystack.components.writers import DocumentWriter
from haystack.document_stores.in_memory import InMemoryDocumentStore
from haystack_integrations.components.converters.docling_serve import (
    DoclingServeConverter,
)

document_store = InMemoryDocumentStore()

pipeline = Pipeline()
pipeline.add_component(
    "converter",
    DoclingServeConverter(base_url="http://localhost:5001"),
)
pipeline.add_component("splitter", DocumentSplitter())
pipeline.add_component("writer", DocumentWriter(document_store=document_store))
pipeline.connect("converter", "splitter")
pipeline.connect("splitter", "writer")

pipeline.run({"converter": {"sources": ["report.pdf", "manual.docx"]}})
```

## Additional Features

### Converting URLs directly

Pass URL strings to convert remote documents without downloading them first:

```python
from haystack_integrations.components.converters.docling_serve import (
    DoclingServeConverter,
)

converter = DoclingServeConverter(base_url="http://localhost:5001")
result = converter.run(sources=["https://arxiv.org/pdf/2602.17316"])
print(result["documents"][0].content[:200])
```

### Attaching metadata

Pass a single dictionary to apply metadata to all output Documents, or a list to set metadata per source:

```python
from haystack_integrations.components.converters.docling_serve import (
    DoclingServeConverter,
)

converter = DoclingServeConverter(base_url="http://localhost:5001")

# Same metadata for all sources
result = converter.run(
    sources=["a.pdf", "b.pdf"],
    meta={"project": "research"},
)

# Per-source metadata
result = converter.run(
    sources=["a.pdf", "b.pdf"],
    meta=[{"title": "Report A"}, {"title": "Report B"}],
)
```

### Processing in-memory files

Pass [`ByteStream`](../../concepts/data-classes.mdx#bytestream) objects to convert files loaded into memory. Set `file_path` in the ByteStream metadata so DoclingServe can detect the file format:

```python
from haystack.dataclasses import ByteStream
from haystack_integrations.components.converters.docling_serve import (
    DoclingServeConverter,
)

with open("report.pdf", "rb") as f:
    data = f.read()

source = ByteStream(data=data, meta={"file_path": "report.pdf"})
converter = DoclingServeConverter(base_url="http://localhost:5001")
result = converter.run(sources=[source])
```
