samples(workflow): routing samples#979
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Smallest end-to-end demonstration of workflow routing: a node generates a random integer 1..10, the next emits a routing event with that integer in Event.Routes, and the engine dispatches to one of three downstream branches keyed by MultiRoute[int]. * No LLM, no HITL, no persistence — pure routing primitives. * roll_die is a FunctionNode returning int; route_by_value is a custom BaseNode (FunctionNode cannot today emit Event.Routes, see the HITL design doc's open question on that gap). * handle_low / handle_mid / handle_high are FunctionNodes receiving the typed int input that route_by_value forwarded via StateDelta["output"]. * math/rand/v2 in roll_die so successive runs hit different branches; the README shows three sample transcripts. Run with: go run ./examples/workflow/route/ console
The smallest end-to-end demonstration of workflow.StringRoute and the Event.Routes contract. A trivial classifier picks the route based on the message's terminal punctuation: ? / . / ! map to "question" / "statement" / "exclamation" respectively, and the engine dispatches to one of three downstream FunctionNodes. * No LLM, no HITL, no random. * classifyNode is a custom BaseNode (FunctionNode cannot today emit Event.Routes; same gap noted in the route/ sample). * Three handler nodes are FunctionNodes receiving the original message as a typed string input via StateDelta["output"]. * Direct port of adk-python's workflow_samples/route/ pattern, with the LLM classifier replaced by a one-line Go switch. Run with: go run ./examples/workflow/route_string/ console
The smallest sample that uses an LLM as the routing brain inside a workflow graph. Builds on the freshly-added workflow.AgentNode to wrap an LLMAgent classifier; a trivial routing BaseNode reads the classifier's reply from the workflow's 'output' magic state key (LLMAgent.OutputKey="output") and emits the corresponding Event.Routes value. Same shape as adk-python's contributing/workflow_samples/route/ sample: LLM classifier + plain function emitting the routing event. Two nodes, not one — keep the LLM stateless about routing, keep routing logic in plain Go. Three handlers (answer_question / comment_statement / react_exclamation) read the original user message from ctx.UserContent rather than receiving it as graph input — the routing node only forwards the classification, not the original text. README explains the trade-off. Requires GOOGLE_API_KEY. Uses gemini-flash-latest (the most evergreen tag); a comment in the README points users to swap it for whatever model their key has access to. Run with: export GOOGLE_API_KEY=... go run ./examples/workflow/route_llm/ console
NewAgentNode on v2 (PR #840) returns (*AgentNode, error) instead of just *AgentNode. Handle the error in the example main.
wolo-lab
changed the title
The route and route_string samples set Event.Actions.StateDelta["output"] to pass the node value downstream, but the v2 engine reads node output only from Event.Output (since the StateDelta-output channel was removed). Routing worked, but successor handlers received the zero value. Switch both to ev.Output and refresh the stale OutputKey/StateDelta comments in route_llm, where AgentNode already synthesizes Event.Output.
…ents Move the three route samples into a shared examples/workflow/routing/ folder (int, string, llm), matching the dynamic/ layout, and drop the redundant route_ prefix. Trim sample comments that restated the code so they focus on the routing behavior being demonstrated; keep only the non-obvious "why" (BaseNode vs FunctionNode for Routes, defensive LLM parsing, SubAgents registration).
…go-specific The route README implied FunctionNode not emitting Event.Routes was an open design question. It is specific to adk-go's FunctionNode wrapper: adk-python has no such split — a plain function node there can yield Event(route=...) directly. Reword to state this accurately.
dpasiukevich
approved these changes
Jun 8, 2026
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Samples for routing