Advanced Functions

Advanced schemas for registering and executing on-chain functions, enabling complex application interactions.

Function

The function type registers the intent to service function calls. Applications can register functions that will be executed when properly formatted calls are detected on-chain.

Key Components

• Function Name: Unique identifier for the function
• Arguments Schema: AJV schema defining accepted arguments and types
• Price: Cost in satoshis to execute the function
• BAP Signing: Functions must be signed with BAP identity for uniqueness

OP_RETURN Format

MAP SET app <appname> type function name <functionName> argsType <objectTypeLiteral> price <satoshiPrice> | AIP BITCOIN_ECDSA address <signature>

Function Updates

When looking up functions, indexers should deliver the most recent function record that matches the function name and bapID. This allows developers to update their functions over time.

Example: Mention Bot Function

A bot that responds to mentions might define a function accepting a message parameter:

Arguments Schema:

{
  message: "string",
  mentions: ["string"],
  context: "string"
}

Function Registration:

MAP SET app mybot type function name respondToMention argsType {"message":"string","mentions":["string"],"context":"string"} price 1000 | AIP BITCOIN_ECDSA <address> <signature>

Function Call

Calls are used to execute functions registered on the blockchain. Since function names are not unique, calls target functions using the registering application's bapID.

Key Components

• Function Name: The function to execute
• Arguments: JSON object with function parameters
• Target bapID: Identity of the function provider
• Payment: Transaction must include payment matching the function's price

OP_RETURN Format

MAP SET app <appname> type function name <functionName> args <args> context bapID bapID <bapID> | AIP BITCOIN_ECDSA address <signature>

Example: Calling the Mention Bot

To call the mention bot function from above:

MAP SET app mychat type function name respondToMention args {"message":"Hello @bot, help me!","mentions":["bot"],"context":"general"} context bapID bapID <bot-bap-id> | AIP BITCOIN_ECDSA <address> <signature>

Execution Flow

1. Function Discovery: Applications monitor for function registrations
2. Call Detection: Monitor for function calls targeting their bapID
3. Validation: Verify arguments match the function schema
4. Payment: Ensure proper payment is included
5. Execution: Execute the function and optionally respond on-chain

Use Cases

• AI Services: Register AI models that respond to prompts
• Data Processing: Offer data transformation services
• API Integration: Bridge blockchain data with external APIs
• Automated Trading: Execute trading strategies based on market data
• Content Moderation: Provide automated content filtering
• Oracle Services: Deliver external data on-chain