Shorthand¶

Tip

What you’ll learn How to use dict-based routing.

Source: 18_dict_routing.py

adk-fluent

from adk_fluent import Agent, Pipeline

# Step 1: Language detector outputs the detected language to state
detector = (
    Agent("language_detector")
    .model("gemini-2.5-flash")
    .instruct("Detect the language of the customer message. Output exactly one of: 'english', 'spanish', 'french'.")
    .writes("language")
)

# Step 2: Dict >> creates deterministic routing (zero LLM calls for routing)
english_support = (
    Agent("english_support")
    .model("gemini-2.5-flash")
    .instruct("Respond to the customer in English. Be helpful and professional.")
)
spanish_support = (
    Agent("spanish_support")
    .model("gemini-2.5-flash")
    .instruct("Responde al cliente en espanol. Se profesional y amable.")
)
french_support = (
    Agent("french_support")
    .model("gemini-2.5-flash")
    .instruct("Repondez au client en francais. Soyez professionnel et aimable.")
)

pipeline = detector >> {
    "english": english_support,
    "spanish": spanish_support,
    "french": french_support,
}

Native ADK

# Native ADK has no concise syntax for intent-based routing.
# You'd wire up a coordinator LlmAgent with sub_agents,
# which uses LLM calls to decide routing -- slow and expensive
# for deterministic decisions like language detection.

Architecture

        graph TD
    n1[["language_detector_routed (sequence)"]]
    n2["language_detector"]
    n3{"route_language (route)"}
    n4["english_support"]
    n5["spanish_support"]
    n6["french_support"]
    n3 --> n4
    n3 --> n5
    n3 --> n6
    n2 --> n3
    n2 -. "language" .-> n3

Equivalence¶

from google.adk.agents.base_agent import BaseAgent
from google.adk.agents.llm_agent import LlmAgent

# Result is a Pipeline (detector -> router)
assert isinstance(pipeline, Pipeline)

# Pipeline has 2 steps: detector + route
assert len(pipeline._lists["sub_agents"]) == 2

# Build the pipeline to verify the route agent is deterministic
built_pipeline = pipeline.build()
assert len(built_pipeline.sub_agents) == 2

# The second sub_agent (the router) is deterministic (BaseAgent, NOT LlmAgent)
route_agent = built_pipeline.sub_agents[1]
assert isinstance(route_agent, BaseAgent)
assert not isinstance(route_agent, LlmAgent)

# Route agent has the 3 language-specific agents as sub_agents
assert len(route_agent.sub_agents) == 3