AshBaml.Resource

The AshBaml resource extension.

Adds the baml do ... end DSL block to Ash resources.

The call_baml/1 helper macro is automatically available when using this extension:

defmodule MyApp.ChatResource do
  use Ash.Resource,
    domain: MyApp.Domain,
    extensions: [AshBaml.Resource]

  baml do
    client_module MyApp.BamlClient
  end

  actions do
    action :chat, MyApp.BamlClient.Types.Reply do
      argument :message, :string
      run call_baml(:ChatAgent)
    end
  end
end

baml

Configure BAML client integration for this resource.

Client Configuration

client - Client identifier that references a client configured in application config. This is the recommended approach for defining BAML clients. Configure your clients in config and reference them by identifier:

config/config.exs

config :ash_baml, clients: [ support: {MyApp.BamlClients.Support, baml_src: "baml_src/support"}, content: {MyApp.BamlClients.Content, baml_src: "baml_src/content"} ]

In your resource

baml do client :support import_functions [:AnalyzeTicket] end

The client module will be automatically generated at compile time using the configured module name and baml_src path. Multiple resources can share the same client by using the same identifier.

client_module - The module that uses BamlElixir.Client to define BAML functions. This is an alternative approach where you manually create a client module file. For most use cases, consider using client with config-based clients instead, which auto-generates the module and centralizes configuration.

Either client or client_module must be provided, but not both.

Importing Functions

import_functions - List of BAML function names to import as Ash actions. For each function listed, two actions are automatically generated:

1. Regular action: :function_name - Returns the complete result
2. Streaming action: :function_name_stream - Returns a Stream

The function names must match BAML function definitions, and their return types must have corresponding generated types in ClientModule.Types.

Example:

baml do client :support import_functions [:ExtractTasks, :SummarizeTasks] end

This generates 4 actions:

• :extract_tasks - Regular action
• :extract_tasks_stream - Streaming action
• :summarize_tasks - Regular action
• :summarize_tasks_stream - Streaming action

Before importing functions, you must:

1. Define BAML functions in your baml_src/ directory
2. Run mix ash_baml.gen.types YourClient to generate types
3. Ensure types exist in YourClient.Types namespace

The transformer will validate at compile-time that functions exist in the BAML client, return types have been generated, and argument types are valid.

Example

baml do client :support

telemetry do enabled true end end

Nested DSLs

• telemetry

Examples

# Config-driven client (recommended)
baml do
  client :default
  import_functions [:AnalyzeTicket]
end

# With telemetry
baml do
  client :support

  telemetry do
    enabled true
    metadata [:function_name, :llm_client]
  end
end

# Manual client module (alternative)
baml do
  client_module MyApp.BamlClient
end

Options

baml.telemetry

Configure telemetry for BAML function calls.

Telemetry is opt-in and disabled by default. When enabled, emits :telemetry events for observability into LLM interactions.

Telemetry Options

enabled - When false, no collectors are created and no telemetry events are emitted, resulting in zero overhead. Default: false

prefix - Event name prefix for telemetry events. Events will be named prefix ++ [:call, event_type]. Default: [:ash_baml] which produces events like [:ash_baml, :call, :start], [:ash_baml, :call, :stop], [:ash_baml, :call, :exception]

events - Which telemetry events to emit. Allowed values: :start, :stop, :exception. Default: [:start, :stop, :exception]

metadata - Additional metadata fields to include in telemetry events. Safe fields (always included): :resource, :action, :function_name, :collector_name. Opt-in fields (must be explicitly listed): :llm_client, :stream. Default: [] (only safe fields included)

sample_rate - Sampling rate for telemetry (0.0 - 1.0). Use lower rates for high-volume operations to reduce overhead. 1.0 = 100% of calls tracked, 0.1 = 10% of calls tracked, 0.0 = effectively disables telemetry. Default: 1.0

collector_name - Custom name for collectors. Can be a string like "my-collector" or a function that receives the input and returns a string like fn input -> "#{input.resource}-#{input.action.name}" end. If not provided, a unique name is generated: "ResourceModule-FunctionName-unique_integer". Default: nil (auto-generated)

Events Emitted

• [:ash_baml, :call, :start] - Before BAML function call
• [:ash_baml, :call, :stop] - After successful call
• [:ash_baml, :call, :exception] - On error

Example

telemetry do enabled true metadata [:function_name, :resource] sample_rate 1.0 end

Examples

telemetry do
  enabled true
  prefix [:my_app, :ai]
  metadata [:function_name, :resource, :action]
  sample_rate 0.1  # Track 10% of calls
end

Options