Step by Step Guide to Building a Linear API Integration in C#

Introduction

Hey there, fellow developer! Ready to supercharge your project management workflow? Let's dive into building a Linear API integration using C#. Linear's API is a powerhouse for automating tasks, syncing data, and creating custom workflows. By the end of this guide, you'll have a robust integration that'll make your team wonder how they ever lived without it.

Prerequisites

Before we jump in, make sure you've got:

• Visual Studio or your favorite C# IDE
• .NET Core 3.1 or later
• A Linear account with an API key (grab one from your account settings)

Got all that? Great! Let's get our hands dirty.

Setting up the project

First things first, fire up Visual Studio and create a new C# console application. We'll keep it simple for now, but feel free to adapt this to your specific needs later.

Now, let's grab the packages we need. Open up the Package Manager Console and run:

Install-Package Newtonsoft.Json
Install-Package GraphQL.Client
Install-Package GraphQL.Client.Serializer.Newtonsoft

These will handle our JSON serialization and GraphQL queries like a champ.

Configuring the API client

Time to set up our HTTP client. Add this to your Program.cs:

using System.Net.Http;
using GraphQL.Client.Http;
using GraphQL.Client.Serializer.Newtonsoft;

class Program
{
    private static readonly HttpClient httpClient = new HttpClient();
    private static readonly GraphQLHttpClient graphQLClient;

    static Program()
    {
        httpClient.BaseAddress = new Uri("https://api.linear.app/graphql");
        httpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer YOUR_API_KEY_HERE");

        graphQLClient = new GraphQLHttpClient(new GraphQLHttpClientOptions
        {
            EndPoint = new Uri("https://api.linear.app/graphql")
        }, new NewtonsoftJsonSerializer(), httpClient);
    }

    // ... rest of your code will go here
}

Replace YOUR_API_KEY_HERE with your actual Linear API key. No sharing, okay?

Implementing core API functions

Now for the fun part - let's start talking to Linear! We'll use GraphQL for our queries and mutations. Here's a simple example to fetch issues:

public static async Task<List<Issue>> GetIssues()
{
    var query = new GraphQLRequest
    {
        Query = @"
        query {
          issues {
            nodes {
              id
              title
              description
            }
          }
        }"
    };

    var response = await graphQLClient.SendQueryAsync<IssuesResponse>(query);
    return response.Data.Issues.Nodes;
}

Don't forget to create your Issue and IssuesResponse classes to match the API response structure.

Building key integration features

Let's add some more meat to our integration. Here's how you might create a new issue:

public static async Task<Issue> CreateIssue(string title, string description)
{
    var mutation = new GraphQLRequest
    {
        Query = @"
        mutation($title: String!, $description: String) {
          issueCreate(input: { title: $title, description: $description }) {
            issue {
              id
              title
              description
            }
          }
        }",
        Variables = new { title, description }
    };

    var response = await graphQLClient.SendMutationAsync<IssueCreateResponse>(mutation);
    return response.Data.IssueCreate.Issue;
}

Optimizing the integration

To keep things snappy, let's implement some basic caching:

private static Dictionary<string, object> cache = new Dictionary<string, object>();

public static T GetOrSetCache<T>(string key, Func<T> getItemCallback)
{
    if (!cache.ContainsKey(key))
    {
        var item = getItemCallback();
        cache[key] = item;
        return item;
    }

    return (T)cache[key];
}

Use this for frequently accessed, relatively static data like team or project information.

Testing and debugging

Always test your code, folks! Here's a quick unit test example using xUnit:

public class LinearApiTests
{
    [Fact]
    public async Task GetIssues_ReturnsIssues()
    {
        var issues = await Program.GetIssues();
        Assert.NotEmpty(issues);
    }
}

Best practices and considerations

Remember to:

• Keep your API key secret and out of version control
• Implement proper error handling and logging
• Respect Linear's rate limits (they're pretty generous, but still)
• Use asynchronous methods to keep your application responsive

Conclusion

And there you have it! You've just built a solid foundation for a Linear API integration in C#. From here, you can expand on this to create custom dashboards, automate issue creation, or even build a full-fledged Linear client.

Remember, the best integrations evolve with your team's needs. Keep iterating, keep improving, and most importantly, keep coding! Happy integrating!