Conditional Pipeline

A triage agent classifies the user’s intent, then conditional edges activate exactly one of two downstream handlers. The other node is silently skipped. Only the matching branch executes per run.

What it demonstrates

Conditional edges with when: expressions
Writing to a nested working.* path (working.triage.intent)
Safe expression evaluation — only working and output are in scope
Branching without duplicating agent definitions

Run it

# Triggers handle_refund
sirenspec run docs/cookbook/conditional-pipeline/workflow.yaml --input "I want a refund on my last order"

# Triggers handle_general
sirenspec run docs/cookbook/conditional-pipeline/workflow.yaml --input "What are your store hours?"

Workflow

docs/cookbook/conditional-pipeline/workflow.yaml

version: "0.1"

agents:
  triage_agent:
    model: "openai:gpt-4o-mini"
    system: |
      Classify the user's message as either a refund request or a general enquiry.
      Reply with ONLY one word — either "refund" or "general" — and nothing else.

  refund_handler:
    model: "openai:gpt-4o-mini"
    system: |
      You are a customer-support specialist handling refund requests.
      Acknowledge the request warmly, outline the refund process in two or three
      sentences, and let the customer know how long it typically takes.

  general_handler:
    model: "openai:gpt-4o-mini"
    system: |
      You are a helpful customer-support agent.
      Answer the user's question clearly and concisely in two or three sentences.

nodes:
  triage:
    agent: triage_agent
    writes: working.triage.intent

  handle_refund:
    agent: refund_handler
    writes: output.reply

  handle_general:
    agent: general_handler
    writes: output.reply

edges:
  - from: triage
    to: handle_refund
    when: working.triage.intent == "refund"

  - from: triage
    to: handle_general
    when: working.triage.intent == "general"

guardrails:
  - injection
  - length

How branching works

After triage writes its one-word label to working.triage.intent, the executor evaluates both outgoing when: expressions. Only the matching node runs. If neither expression matches (e.g. the LLM returns an unexpected label), both nodes are skipped and output.reply is never written.

when: expressions run in a sandboxed namespace. Only working and output are available — no built-ins, no imports. Evaluation errors are treated as False and the edge is silently skipped.

Basics

Multi-Agent Patterns

Swrm & Fan-Out

Factory & Iteration

Guardrails

Human in the Loop

Budget & Cost Control

Stress Tests

Tool Nodes

Conditional Pipeline

What it demonstrates

Run it

Workflow

How branching works

Graph

Next steps

Adversarial Pair

YAML Reference

​What it demonstrates

​Run it

​Workflow

​How branching works

​Graph

​Next steps

Adversarial Pair

YAML Reference

What it demonstrates

Run it

Workflow

How branching works

Graph

Next steps