# Server version (IRPCQueryVersion)

Location: [gRPC API](https://developer.m-files.com/APIs/gRPC-API/index.md) > [Vault API](https://developer.m-files.com/APIs/gRPC-API/vault/index.md)

HTML version: https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCQueryVersion/

An interface for querying server version information.

This interface provides a method for querying server version information. This is used to
check the compatibility of the server and client.
Also methods for querying information about the versions
of other M-Files components can be placed here.

- **gRPC service:** `MFiles.IRPCQueryVersion`
- **Book and level:** [Vault API](https://developer.m-files.com/APIs/gRPC-API/vault/index.md), core
- **Methods:** 2
- **Proto file:** [`mfiles/IRPCQueryVersion.proto`](https://developer.m-files.com/APIs/gRPC-API/downloads/proto/mfiles/IRPCQueryVersion.proto)

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## Overview

The only service you can call before anything else: it needs no session and no login, so it is the
standard "is the server there, and which version is it?" probe.

- [QueryVersion](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCQueryVersion/QueryVersion/index.md) returns the server version. Call it
  first to check connectivity and to decide which methods and fields you can rely on.
- [GetUIVersionInfo](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCQueryVersion/GetUIVersionInfo/index.md) is used by M-Files clients
  to find the web UI assets to load; applications rarely need it.

Typical order: `QueryVersion`, then
[GetServerCapabilities](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCLogin/GetServerCapabilities/index.md) for optional features, then
[LogIn](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCLogin/LogIn/index.md). See
[Connecting to the server](https://developer.m-files.com/APIs/gRPC-API/runtime/connecting/index.md) and
[Versions and compatibility](https://developer.m-files.com/APIs/gRPC-API/runtime/versioning/index.md).

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## Highlighted methods

| Method | Summary | Facts |
|---|---|---|
| [QueryVersion](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCQueryVersion/QueryVersion/index.md) | Gets the server version and the oldest client version the server accepts. | `read` `no session` `idempotent` |

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## Other methods

| Method | Summary | Facts |
|---|---|---|
| [GetUIVersionInfo](https://developer.m-files.com/APIs/gRPC-API/Reference/MFiles.IRPCQueryVersion/GetUIVersionInfo/index.md) | Gets the version of the web UI assets that M-Files clients should load, and where to load them from. | `read` `no session` `idempotent` |