Table of Contents

Creating a post

The following code will login to Bluesky and create a simple post.

using idunno.Bluesky;

using BlueskyAgent agent = new();
await agent.Login(handle, password);
var postResult = await agent.Post("Hello World");

The result of a successful call to Post() creates a record in your Bluesky repository.

The call will return, amongst other information, the at:// uri of the post record and its content identifier (CID).

if (postResult.Succeeded)
{
    var postUri = postResult.Result.Uri;
    var postCid = postResult.Result.Cid;
}

The post record in the repository will look something like this

{
  "text": "Hello World",
  "$type": "app.bsky.feed.post",
  "createdAt": "2025-04-25T17:25:46.3164586+00:00"
}

Setting a language

Setting the post's language helps custom feeds or other services filter and parse posts.

await agent.Post(
  text: "Hello World",
  langs: "en-US")


await agent.Post(
  text: "สวัสดีชาวโลก\nHello World",
  langs: ["th", "en-US"])

You can include multiple values in langs if there are multiple languages present in the post.

Tip

If you're writing a UX app you can pass the user's current OS language with langs: [Thread.CurrentThread.CurrentUICulture.Name].

You can include mentions of other users, hashtags and links like you would when using the app, mentions by @handle, hashtags with #, and links by their URL.

await agent.Post(
  text: "Hello @sinclairinat0r.com, the Heinz #beans factory is one of the largest food factories in Europe! https://en.wikipedia.org/wiki/H._J._Heinz,_Wigan");
Tip

The URL extractor is simplistic and will strip things like query string, much like the Bluesky app does. For more complicated links you can use a PostBuilder to create a post and add links, hashtags and mentions into it.

Replies and quote posts

Reply and quote posts contain strong references to other posts.

Replies

Replies and quote posts contain strong references to other records.

  • at:// uri: indicating the repository DID, collection and record key
  • CID: the hash to the record itself

You can get a post's strong reference from the timeline view, author view or other views that contain posts like search views or feed views.

await agent.ReplyTo(strongReference, "This is a reply");

Quote posts

A quote post embeds a reference to another post record.

await agent.Quote(strongReference, "This is a post quoting a post");

Images

To add an image, or images to a post, you first upload the image(s) as a byte array, providing its MIME type, alt text and size and then refer to the upload when creating the post.

// Read the image from the file specified by pathToImage

var pathToImage = "D:\beans1000x1000.jpg";
byte[] imageAsBytes;
using (FileStream fs = File.OpenRead(pathToImage))
using (MemoryStream ms = new())
{
    fs.CopyTo(ms);
    imageAsBytes = ms.ToArray();
}

var imageUploadResult = await agent.UploadImage(
    imageAsBytes,
    mimeType: "image/jpg",
    altText: "The Bluesky Logo",
    aspectRatio: new AspectRatio(1000, 1000));

if (imageUploadResult.Succeeded)
{
    var createPostResult = await agent.Post(
        "Hello world with an image.",
        image: imageUploadResult.Result!);
}

You can pass an array of up to four images to Post() using the images parameter.

More detailed information on how to use the Post() api, as well as how to use a PostBuild() can be found on the Posting page.

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