> For the complete documentation index, see [llms.txt](https://developer.barchart.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.barchart.com/apis.md).
# Openfeed APIs
Welcome to the **Openfeed Technical Documentation**.
Openfeed is Barchart’s market data protocol and delivery platform, designed to provide fast, reliable access to global exchange data through a single integration.
Instead of building and maintaining multiple exchange connections, Openfeed allows you to **consolidate full-pipe market data into one API connection**. The platform delivers **low-latency data in its native exchange format**, helping teams reduce infrastructure complexity while lowering development and maintenance costs.
### Available APIs
Openfeed provides two APIs for accessing market data, depending on your application needs.
**There are two application programming interfaces (APIs) available when accessing Barchart's Openfeed platform:**
**Streaming API** is designed for applications that monitor **large symbol universes** (for example, more than 2,000 instruments).
This API uses a real-time feed handler and is supported by SDKs in multiple languages:
* **Java**
* **.NET**
* **Go**
* **Python** (for data science and data operations)
* **TypeScript / JavaScript** (for front-end applications and visualizations)
The Streaming API is ideal for systems that require **continuous real-time market data across many instruments**.
#### REST API
The **REST API** provides access to Openfeed using a **query–response model**. It returns **JSON payloads**, allowing clients to request market data for specific instruments without implementing a streaming feed handler.
This API works best for applications that monitor a **smaller symbol universe** (typically fewer than 2,000 instruments).
Typical use cases include:
* Web applications
* Backend services
* Data pipelines
* Symbol-specific monitoring tools
### Jump right in
---
# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.
## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.
Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:
```
GET https://developer.barchart.com/apis.md?ask=&goal=
```
`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.
Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.