Content Publishing

Schemas for creating, sharing, and responding to content on the Bitcoin blockchain.

Post

Post is meant to express a new piece of content to the network.

Key Features

• B Protocol Content: Posts can contain anything from plain text, images, markdown, or binary data
• Flexible Attachments: Additional content can be attached (see Messaging section for details)
• Context Support: Optional context and subcontext properties for categorization and threading

OP_RETURN Format

B <content> <mediaType> <encoding> | MAP SET app <appname> type post | AIP BITCOIN_ECDSA <address> <signature>

Optional Parameters

• Context
• ContextValue
• Subcontext
• Subcontext Value

Use Cases

The Context and Subcontext properties allow flexible content organization:

• Geolocation: Post within specific geographic contexts
• Platform Integration: Comment on YouTube videos using context "provider" = "youtube" and subcontext "videoID" = video ID
• Product Reviews: Comment on products using UPC codes as context

JavaScript Example

// Basic post
post := bschema.Post{
  MediaType:        MediaTypeTextMarkdown,
  Encoding:         EncodingUTF8,
  Content:          "# Hello small world!",
}
tx, err := bschema.CreatePost(post, utxos, changeAddress, privateKey)

// Post with context (e.g., YouTube video comment)
post := bschema.Post{
  MediaType:        MediaTypeTextMarkdown,
  Encoding:         EncodingUTF8,
  Content:          "# Great video!",
  Context:          ContextProvider,
  ContextValue:     "youtube",
  Subcontext:       ContextVideoID,
  SubcontextValue:  "IdNs8eVGbBs",
}
tx, err := bschema.CreatePost(post, utxos, changeAddress, privateKey)

Reply

Replies are Posts with a context of a transaction ID, creating threaded conversations.

OP_RETURN Format

B <content> <mediaType> <encoding> | MAP SET app <appname> type post context tx tx <txid> | AIP BITCOIN_ECDSA <address> <signature>

JavaScript Example

reply := bschema.Post{
  MediaType:        MediaTypeTextMarkdown,
  Encoding:         EncodingUTF8,
  Content:          "# This is a markdown reply!",
}
tx, err := CreateReply(reply, replyTxID, utxos, changeAddress, privateKey)

Repost

A repost amplifies existing content without duplicating it. Reposts can be made with new context and subcontext, allowing content to surface in multiple contexts.

Use Case Example

Imagine a post commenting on a physical product (UPC code context). Someone might repost that comment with a "url" context pointing to the company website, surfacing the comment in web-based apps like MetaLens.

Optional Parameters

• Context
• ContextValue
• Subcontext
• Subcontext Value

OP_RETURN Format

MAP SET app <appname> type repost tx <txid> | AIP BITCOIN_ECDSA <address> <signature>

JavaScript Example

tx, err := CreateRepost(repostTxID, utxos, changeAddress, privateKey)