RestSharp and Unirest user agents
RestSharp is a popular HTTP client for .NET, and Unirest is a lightweight request library available across several languages. Both send a default user agent that names the library unless the developer sets a custom one. Seeing those tokens marks a request as a programmatic REST call from an application, not a human browsing a page.
What this means
RestSharp is a long-standing HTTP client for the .NET ecosystem, often used to consume REST APIs from C# applications. By default it identifies itself with a RestSharp-named user agent and a version, unless the caller overrides it.
Unirest is a small, multi-language request library designed for simple calls. Its implementations likewise send a library-named default. Both tokens, when they appear, indicate programmatic clients rather than browsers.
How they appear
Look for a RestSharp or Unirest product token with a version and no browser compatibility chain. The lack of AppleWebKit, Gecko, or Chrome tokens reinforces that the caller is a library.
Because both make setting a custom user agent straightforward, production clients frequently replace the default with an application-specific string. Match the defaults to catch unconfigured clients, but do not assume their absence means no RestSharp or Unirest traffic.
- RestSharp is a .NET HTTP/REST client
- Unirest is a lightweight multi-language request library
- Both send library-named defaults; both are easily overridden
How it appears in analytics and logs
A user agent naming RestSharp or Unirest indicates an application making HTTP API calls through that client library. It is automation — an integration, job, or service — not a human page view.
Diagnostic use case
Identify scripted REST traffic from RestSharp or Unirest by their library-named defaults, and recognise that these defaults are commonly replaced.
What WebmasterID can help detect
WebmasterID classifies RestSharp and Unirest defaults as scripted, non-browser traffic, helping keep API-client calls separate from human analytics.
Common mistakes
- Assuming all .NET or REST traffic shows a RestSharp or Unirest token.
- Counting RestSharp or Unirest API calls as human page views.
- Reading a library token as proof of abuse rather than just the tool.
Privacy and accuracy notes
RestSharp and Unirest tokens identify HTTP libraries, not people. WebmasterID reads them as coarse automation signals only.
Related pages
- .NET HttpClient user agent
.NET's HttpClient is the standard HTTP client for .NET applications. By default it does not add a User-Agent header at all, so requests from .NET apps frequently arrive with no user agent unless the developer sets one. When set, it is a custom application string, not a fixed .NET browser token.
- API client user agents (Postman, etc.)
Developers exercise APIs with tools like Postman, Insomnia, and HTTPie, each of which sends a recognisable default user agent (for example a PostmanRuntime token). Seeing these means someone is testing or scripting against your API, not browsing your pages. This page covers the patterns and how to read them.
- Guzzle PHP HTTP client user agent
Guzzle is a widely used PHP HTTP client. Its default user agent contains a GuzzleHttp token together with a version and language details, so default-configured Guzzle traffic is easy to spot. Many PHP applications override it, so the token is a strong-but-optional signal. It is server-side automation, not a human visit.
- Bot intelligence
Surface RestSharp and Unirest API traffic separately from human visits.
Sources and verification notes
- RestSharp documentation.NET HTTP/REST client; sends a RestSharp-named default user agent unless overridden.
- Unirest documentationLightweight multi-language request library; sends a library default user agent.
Last reviewed 2026-06-24. Facts are checked against primary/official sources where available; uncertain specifics are marked “Data not yet verified” rather than guessed.