> ## Documentation Index
> Fetch the complete documentation index at: https://resq-dependabot-github-actions-github-actions-478e18be3d.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# .NET SDK

> Use the ResQ .NET 9 client libraries — typed clients, Protobuf protocol contracts, and simulation harnesses.

The ResQ .NET workspace lives at
[`resq-software/dotnet-sdk`](https://github.com/resq-software/dotnet-sdk).
It targets .NET 9 and ships:

* Typed HTTP clients for both APIs
* Protobuf protocol contracts for telemetry and mission state
* Blockchain-anchoring helpers
* Simulation harnesses for integration tests

<Note>
  Package names and exact symbol surfaces are documented in the
  [README](https://github.com/resq-software/dotnet-sdk#readme). The example
  below uses the framework `HttpClient` so it works regardless of which
  package you pin.
</Note>

## Requirements

* .NET 9 SDK
* A ResQ operator credential (see [Authentication](/authentication))

## Install

Once you've identified the package(s) you need from the
[README](https://github.com/resq-software/dotnet-sdk#readme):

```bash theme={null}
dotnet add package <package-name>
```

(Substitute the actual package name from the README — workspace publishing
is in flux.)

## Calling the API directly

```csharp theme={null}
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text.Json;
using System.Text.Json.Serialization;

record LoginRequest(string Username, string Password);
record LoginResponse(
    [property: JsonPropertyName("token")] string Token,
    [property: JsonPropertyName("expires_at")] long ExpiresAt
);

var http = new HttpClient { BaseAddress = new Uri("https://api.resq.software") };

var login = await http.PostAsJsonAsync("/login", new LoginRequest(
    Environment.GetEnvironmentVariable("RESQ_USERNAME")!,
    Environment.GetEnvironmentVariable("RESQ_PASSWORD")!
));
login.EnsureSuccessStatusCode();

var session = await login.Content.ReadFromJsonAsync<LoginResponse>()
    ?? throw new InvalidOperationException("empty login response");

http.DefaultRequestHeaders.Authorization =
    new AuthenticationHeaderValue("Bearer", session.Token);

var evidence = await http.GetFromJsonAsync<JsonElement>("/evidence?limit=50");
Console.WriteLine(evidence);
```

`ExpiresAt` is a Unix timestamp in seconds. Refresh proactively when fewer
than 60 seconds remain. See [Authentication](/authentication).

## Errors

`EnsureSuccessStatusCode()` throws `HttpRequestException` on non-2xx.
Status codes follow the table at [Errors](/errors). Wrap calls in a retry
policy (Polly is a common choice) honoring `Retry-After` on `429` and
exponential backoff on `5xx`.

## Protocol contracts

The `dotnet-sdk` workspace ships Protobuf-generated record types for
telemetry, mission state, and HITL approval messages. Consume them when
producing telemetry frames or interpreting fleet events — they're the
authoritative wire format.

## Next

<CardGroup cols={2}>
  <Card title="API reference" icon="code" href="/api-reference/introduction">
    Full endpoint catalog.
  </Card>

  <Card title="Other SDKs" icon="rocket" href="/sdks">
    TypeScript, Python, Rust, and more.
  </Card>
</CardGroup>