QuestDB - Client Library for Rust, C and C++
This library makes it easy to insert data into QuestDB.
This client library implements the QuestDB's variant of the InfluxDB Line Protocol (ILP) over HTTP and TCP, and the QuestDB Wire Protocol (QWP) over UDP for high-throughput ingestion on trusted networks.
When connecting to QuestDB over HTTP, the library will auto-detect the server's latest supported version and use it. Version 1 is compatible with the InfluxDB Database.
- Implementation is in Rust, with no additional run-time or link-time dependencies on the C++ standard library or other libraries.
- We ship both a static and a dynamic library.
- The library exposes Rust, C11 and C++17 APIs.
- The C++ API is a header-only wrapper over the C API.
- This library also has separate Python bindings.
Inserting data into QuestDB can be done in several ways.
This library supports three ingestion transports:
- ILP/HTTP (default-recommended): request-response, server errors returned to the client, supports authentication and TLS.
- ILP/TCP: streaming, legacy; errors cause disconnect and surface only in server logs.
- QWP/UDP: best-effort datagram transport for high-throughput ingestion on trusted networks; no acknowledgements, no authentication, no TLS.
| Protocol | Record Insertion Reporting | Data Insertion Performance |
|---|---|---|
| ILP/HTTP | Transaction-level (on flush) | Excellent |
| ILP/TCP | Errors in logs; Disconnect on error | Best (tolerates higher-latency networks) |
| QWP/UDP | None (best-effort, unacknowledged) | Best (lowest overhead; datagrams may be dropped) |
| CSV Upload via HTTP | Configurable | Very Good |
| PostgreSQL | Transaction-level | Good |
Server errors are reported back to the client only for ILP/HTTP. ILP/TCP surfaces errors via server-side disconnect; QWP/UDP has no error-reporting path at all. See the flush troubleshooting docs for more details on how to debug ILP/TCP and QWP/UDP.
For an overview and code examples, see the Ingestion overview page of the developer docs.
To understand the protocol in more depth, consult the protocol reference docs.
The library supports the following ILP protocol versions. These apply to ILP/HTTP and ILP/TCP only — QWP/UDP uses its own wire format and is not versioned through this mechanism.
- If you use HTTP and
protocol_version=autoor unset, the library will automatically detect the server's latest supported protocol version and use it (recommended). - If you use TCP, you can specify the
protocol_version=Nparameter when constructing theSenderobject (TCP defaults toprotocol_version=1).
| Version | Description | Server Compatibility |
|---|---|---|
| 1 | Over HTTP it's compatible with InfluxDB Line Protocol (ILP) | All QuestDB versions |
| 2 | 64-bit floats sent as binary, adds n-dimensional arrays | 9.0.0+ (2025-07-11) |
To get started, read the language-specific guides.
C
C++
Rust
- Getting started with Rust
questdb-rscrate on crates.io- API docs on docs.rs
questdb-rssource codequestdb-rs-ffisource code - C bindings code
Python
If you need help, have additional questions or want to provide feedback, you may find us on our Community Forum.
You can also sign up to our mailing list to get notified of new releases.
The code is released under the Apache License.