Stage Guide

A stage is one pipeline processing step implementing Slither.Stage.

Built-in Stage Types

• :beam -> Slither.Stage.Beam
• :python -> Slither.Stage.Python
• :router -> Slither.Stage.Router

Mapping is defined in lib/slither/pipe/definition.ex.

Beam Stage

Use for Elixir transformations.

• Per-item handler through :handler.
• Optional batch handler through :batch_handler.
• Supports :many cardinality expansion.

Python Stage

Always dispatches through Slither.Dispatch.

Key options:

• executor
• module / function (SnakeBridge)
• batching and timeout options

Router Stage

Routes by predicate list in order.

• First match wins.
• Unmatched items go to :default.
• Can return batch-routed maps.

Return Semantics

Per-item stage results include:

• {:ok, [items]}
• {:route, destination, [items]}
• {:skip, reason}
• {:error, reason}

Batch stage results include:

• {:ok, [items]}
• {:routed, %{dest => [items]}}
• {:error, reason}