Module graph 

Available on crate feature graph only.

Graph-based workflow engine (LangGraph-inspired).

Build complex agent workflows with:

• StateGraph - Graph builder with nodes and edges
• GraphAgent - ADK Agent integration
• Checkpointer - Persistent state for human-in-the-loop
• Router - Conditional edge routing helpers
• Cycle support with recursion limits
• Streaming execution modes

Available with feature: graph

Modules

agent

GraphAgent - ADK Agent integration for graph workflows

cachenode-cache

Node-level caching for graph execution.

checkpoint

Checkpointing for persistent graph state

child

Invoking a node from inside another node’s body.

deferred

Deferred node (fan-in barrier) support for graph workflows.

deltadelta-checkpoint

Delta checkpoint compression for graph state.

edge

Edge types for graph control flow

error

Error types for adk-graph

executor

Pregel-based execution engine for graphs

functionalfunctional

Functional API for Graph Workflows

graph

StateGraph builder for constructing graphs

interrupt

Human-in-the-loop interrupt types

node

Node types for graph execution

prelude

Prelude module for convenient imports

retry

Per-node retry with exponential backoff.

state

State management for graph execution

stream

Streaming types for graph execution

subgraph

Running one graph as a node of another.

time_traveltime-travel

Time-travel debugging for graph execution history.

timeout

Timeout enforcement for graph node execution.

tool

Exposing a node or a whole graph as a tool an LLM can call.

Structs

AgentNode

Wrapper to use an existing ADK Agent as a graph node

AppendReducer

Built-in reducer: append to a Vec (list concatenation).

Channel

Channel definition for a state field

Checkpoint

Checkpoint data structure for persistence

CompiledGraph

A compiled graph ready for execution

DeferredNodeConfig

Configuration for a deferred (fan-in) node.

DeltaCheckpointer

Wraps any Checkpointer with delta compression.

DeltaConfig

Configuration for delta-based checkpoint compression.

ExecutionConfig

Configuration passed to nodes during execution

ExecutionLog

Tracks task completion status within a workflow run. Stored as part of the checkpoint metadata.

FanInTracker

Tracks which upstream paths have completed for a deferred node.

FunctionNode

Function node - wraps an async function as a node

GraphAgent

GraphAgent wraps a CompiledGraph as an ADK Agent

GraphAgentBuilder

Builder for GraphAgent

InterruptedExecution

Information about an interrupted execution

MapDelta

Delta representation for HashMap<String, Value>.

MemoryCheckpointer

In-memory checkpointer for development and testing

MergeReducer

Built-in reducer: deep merge for JSON-like structures.

MessagesValue

Chat message container with ID-based deduplication.

NodeCache

Node cache that stores and retrieves execution results.

NodeCachePolicy

Cache policy for a graph node.

NodeContext

Context passed to nodes during execution

NodeOutput

Output from a node execution

PregelExecutor

Pregel-based executor for graphs

ProgressHandle

A shared progress handle that nodes can use to report progress, resetting the idle timeout counter.

ReducedValue

Append-only state container. Accumulates values across tasks. Persisted to checkpoints on each task completion.

ReplaceReducer

Built-in reducer: replace with incoming value (last-write-wins).

Router

Router helper functions for common patterns

StateGraph

Builder for constructing graphs

StateSchema

State schema defines channels and their reducers

StateSchemaBuilder

Builder for StateSchema

StateSchemaValidator

Validates workflow state against a declared schema.

StepInfo

Information about a single execution step in the graph history.

StringDelta

Delta representation for String.

TaskContext

Runtime context passed to #[entrypoint] and #[task] functions.

TimeTravelHandle

Handle for time-travel operations on a graph thread.

TimeoutPolicy

Timeout configuration for a graph node.

UntrackedValue

Transient runtime value excluded from checkpoints.

VecDelta

Delta representation for Vec<Value>.

Enums

CacheBackend

Cache backend selection.

CheckpointType

Discriminates between full state snapshots and incremental delta records.

Edge

Edge type

EdgeTarget

Target of an edge

ExpectedType

Expected JSON value type for a state field.

FunctionalError

Errors specific to the functional API.

GraphError

Errors that can occur during graph operations

Interrupt

Interrupt request from a node or configuration

MergeStrategy

How to combine outputs from multiple upstream parallel paths.

OnTimeout

Recovery action when a node times out.

Reducer

Reducer determines how state updates are merged

StreamEvent

Events emitted during streaming

StreamMode

Stream mode options

StringOp

An individual edit operation for string diffs.

Constants

END

START

Special node identifiers

Traits

Checkpointer

Checkpointer trait for persistence

Diff

Trait for types that can compute and apply incremental diffs.

Node

A node in the graph

TypedReducer

Trait for defining custom merge strategies for state values.

Functions

compute_cache_key

Computes a deterministic cache key from a node name and its input state.

execute_with_timeout

Execute a node with timeout enforcement.

interrupt

Helper to create a dynamic interrupt from within a node

interrupt_with_data

Helper to create a dynamic interrupt with data

Type Aliases

Result

Result type for graph operations

State

Graph state - a map of channel names to values