Plugins Overview

Flowneer ships with a focused set of plugin methods plus a smaller set of helper modules. Plugin methods follow the same pattern: create a subclass with FlowBuilder.extend([...plugins]), then call the added methods on any instance of that subclass. Helper utilities such as createAgent, crew patterns, and output parsers are imported directly and do not participate in plugin registration.

import { FlowBuilder } from "flowneer";
import { withTiming } from "flowneer/plugins/observability";

const AppFlow = FlowBuilder.extend([withTiming]);

const flow = new AppFlow<MyState>().withTiming().startWith(myStep);

Plugin Categories

Category	Surface
LLM	withCostTracker, withRateLimit, withStructuredOutput, withTokenBudget
Memory	withMemory, BufferWindowMemory, KVMemory, SummaryMemory
Observability	withCallbacks, withHistory, withInterrupts, withTiming, withVerbose
Persistence	withCheckpoint, withAuditLog, withReplay, withVersionedCheckpoint, withManualStepping
Resilience	withCircuitBreaker, withTimeout, withFallback, withCycles
Dev / Testing	withDryRun, withMocks, withStepLimit, withAtomicUpdates, withFlowAnalyzer, withPerfAnalyzer
Agent plugins	withReActLoop, withHumanNode, resumeFlow
Agent helpers	tool, createAgent, supervisorCrew, sequentialCrew, hierarchicalCrew, roundRobinDebate
Tools	withTools, ToolRegistry, executeTool, executeTools
Messaging	withChannels, withStream, emit, sendTo, receiveFrom
Output helpers	parseJsonOutput, parseListOutput, parseRegexOutput, parseMarkdownTable
Telemetry	withTelemetry, TelemetryDaemon, consoleExporter, otlpExporter
Graph	withGraph, withExportGraph, withExportFlow
Eval	runEvalSuite, exactMatch, containsMatch, f1Score, retrievalPrecision, retrievalRecall
Compliance	withAuditFlow, withRuntimeCompliance, scanShared
Config	JsonFlowBuilder, validate

Import Paths

Plugins are bundled under flowneer/plugins/*:

// LLM
import { withCostTracker } from "flowneer/plugins/llm";
import { withRateLimit } from "flowneer/plugins/llm";

// Memory
import {
  withMemory,
  BufferWindowMemory,
  KVMemory,
  SummaryMemory,
} from "flowneer/plugins/memory";

// Observability
import {
  withCallbacks,
  withHistory,
  withTiming,
  withVerbose,
} from "flowneer/plugins/observability";
import { withInterrupts } from "flowneer/plugins/observability";

// Persistence
import {
  withCheckpoint,
  withAuditLog,
  withReplay,
  withVersionedCheckpoint,
  withManualStepping,
} from "flowneer/plugins/persistence";

// Resilience
import {
  withCircuitBreaker,
  withTimeout,
  withFallback,
  withCycles,
} from "flowneer/plugins/resilience";

// Dev
import { withDryRun, withMocks, withStepLimit } from "flowneer/plugins/dev";
import { withAtomicUpdates } from "flowneer/plugins/dev";

// Agent plugins
import { withReActLoop } from "flowneer/plugins/agent";
import { withHumanNode, resumeFlow } from "flowneer/plugins/agent";

// Agent helpers
import { tool, createAgent } from "flowneer/plugins/agent";
import {
  supervisorCrew,
  sequentialCrew,
  hierarchicalCrew,
  roundRobinDebate,
} from "flowneer/plugins/agent";

// Tools
import {
  withTools,
  ToolRegistry,
  executeTool,
  executeTools,
} from "flowneer/plugins/tools";

// Messaging
import { withChannels, sendTo, receiveFrom } from "flowneer/plugins/messaging";
import { withStream, emit } from "flowneer/plugins/messaging";

// Output helpers
import { parseJsonOutput } from "flowneer/plugins/output";
import { parseListOutput } from "flowneer/plugins/output";
import { parseRegexOutput } from "flowneer/plugins/output";
import { parseMarkdownTable } from "flowneer/plugins/output";

// Telemetry
import { TelemetryDaemon, consoleExporter } from "flowneer/plugins/telemetry";

// Graph
import { withGraph } from "flowneer/plugins/graph";
import { withExportGraph, withExportFlow } from "flowneer/plugins/graph";

// Eval
import { runEvalSuite, exactMatch, f1Score } from "flowneer/plugins/eval";

// Compliance
import {
  withAuditFlow,
  withRuntimeCompliance,
  scanShared,
} from "flowneer/plugins/compliance";

// Dev — analysis
import { withFlowAnalyzer } from "flowneer/plugins/dev";
import { withPerfAnalyzer } from "flowneer/plugins/dev";
import type {
  StepPerfStats,
  PerfReport,
  PerfAnalyzerOptions,
} from "flowneer/plugins/dev";

// Config
import { JsonFlowBuilder } from "flowneer/plugins/config";

Shared State Conventions

Many plugins use reserved keys on the shared state object. By convention, built-in plugin keys are prefixed with __ to avoid collisions with application data.

AugmentedState — automatic typing

All plugin-provided __* keys are declared on the exported AugmentedState interface via TypeScript declaration merging. Extend your state with it to get every key typed and documented automatically:

import type { AugmentedState } from "flowneer";

interface MyState extends AugmentedState {
  topic: string; // your domain fields
  results: string[];
  // __cost, __history, __tools … all typed automatically
}

No additional imports or setup are needed. Augmentations are applied per-plugin when the plugin module is imported.

Key reference

Key	Set by
__cost	withCostTracker
__stepCost	Your step (consumed by withCostTracker)
__llmOutput	Your step (consumed by withStructuredOutput)
__structuredOutput	withStructuredOutput
__validationError	withStructuredOutput (on failure)
__memory	withMemory
__history	withHistory
__timings	withTiming
__fallbackError	withFallback
__tryError	withTryCatch
__tools	withTools
__channels	withChannels
__stream	withStream / .stream()
__humanPrompt	withHumanNode
__humanFeedback	Written by caller before resumeFlow()
__toolResults	withReActLoop
__reactExhausted	withReActLoop
__batchItem	.batch() (configurable via key)
__perfStats	withPerfAnalyzer (per-step stats array)
__perfReport	withPerfAnalyzer (flow-level summary)