Automation tools chain. Aerostack orchestrates.
The AI workflow builder
that pauses for humans.
The AI workflow builder for teams that need more than Zapier. 30 node types — autonomous agent loops, guardrails on LLM output, confidence routing, sub-workflows, identity verification, and human approval gates that pause a run and resume on sign-off.
Build agentic workflows on Cloudflare's edge — where the LLM decides the path, calls your tools, and waits for a human when it matters.
Three generations of ai workflow automation.
Only one trusts humans.
Linear Chains
Trigger → Action → Done. That's it.
Every automation is a straight line: one trigger, a fixed sequence of steps, no branching. If anything goes wrong or needs a human decision, the chain breaks. No AI, no context, no conditional logic.
Visual Builders
Visual and flexible — but no identity, no handoffs.
Visual node-based builders with branching, loops, and HTTP nodes. Great for DevOps and data pipelines. But they have no concept of user identity, can't pause for human approval, and can't delegate between AI agents. You wire everything manually.
AI-Native Orchestration
Identity. Humans. AI. Delegation. All built in.
Every workflow runs on the edge. Auth gates verify user identity before sensitive nodes. Human handoffs pause execution, notify reviewers via web/email/Telegram/Discord, and resume on approval. Bots delegate to other bots. LLM nodes classify, generate, and decide. MCP tools connect to any service. This is what workflow automation looks like when it's built for AI.
30 node types — not integrations.
Zapier and Make sell integrations. Aerostack ships primitives. Every node below is a typed building block your ai workflow automation composes at runtime — agent loops that decide their own path, guardrails that enforce policy on LLM output, confidence routers that branch on certainty, and auth gates that verify identity before a sensitive action runs. No equivalent in any other visual builder.
Trigger
Start a workflow from a bot message, API call, webhook, or cron schedule. Multiple trigger sources can converge into a single workflow.
Example
A Discord message, a Stripe webhook, and a cron job all trigger the same customer follow-up workflow.
Auth Gate
UniqueVerify user identity via OTP or magic link before allowing access to sensitive nodes. Supports email (Resend, SES), SMS (Twilio, MSG91), and custom HTTP providers.
Example
Before processing a refund, verify the user owns the email on the account via a 6-digit OTP sent through Resend.
LLM Call
Call any LLM (Claude, GPT, Gemini, Groq) with a prompt template and variables from previous nodes. Use for classification, generation, summarization, or decision-making.
Example
Classify an incoming support message as billing, technical, or general — then route to the right branch.
Logic / Condition
Branch the workflow based on a condition. Supports comparisons, regex, contains, and expressions on variables from any previous node.
Example
If the refund amount is over $500, route to manager approval. Otherwise, process automatically.
MCP Tool
Call any tool from any MCP server in your workspace. Access databases, APIs, SaaS products, and internal services through the MCP protocol.
Example
Look up a customer in Stripe, query their order history from your database, and check their support ticket count.
Agent Loop
UniqueAn autonomous ReAct loop: the LLM reasons, calls tools, observes the result, and repeats until the goal is met or a step limit is hit. This is the node that makes a workflow genuinely agentic rather than a fixed pipeline.
Example
Give the loop a goal — "resolve this ticket" — and it decides which tools to call, in what order, until the issue is closed.
Confidence Router
UniqueBranch on the LLM's confidence in its own answer. Route high-confidence outputs straight through, and send low-confidence ones to a human or a fallback path.
Example
If the model is over 85% confident in the classification, auto-resolve. Below that, escalate to a reviewer.
Guardrail
UniqueEnforce policy on LLM output before it reaches the user — block disallowed content, redact PII, or require a value to match a schema. Fails the run or branches when a rule is violated.
Example
Strip any phone numbers or email addresses from a generated reply before it is sent to a customer.
Call Function
Invoke a published edge function from your workspace with typed inputs and reuse its output in later nodes. The function runs on Cloudflare Workers alongside the workflow.
Example
Call a pricing function that computes a quote from line items, then send the total back to the user.
Delegate to Bot
UniqueHand off the conversation to another bot in your workspace. The delegated bot has its own LLM, tools, and workflow. Context is preserved across the handoff.
Example
The triage bot delegates to a specialized "Tech Support Bot" that has access to internal docs and Jira.
Loop
Iterate over arrays or repeat a block of nodes a specified number of times. Supports for-each, count-based, and while-condition loops.
Example
For each overdue invoice in the list, send a personalized reminder message with the amount and due date.
Parallel
Run multiple branches simultaneously and wait for all (or any) to complete. Merge results and continue the workflow with combined output.
Example
Simultaneously check inventory in 3 warehouses and use the first available result to fulfill the order.
Code Block
Run custom JavaScript inside the workflow to transform, parse, or reshape data between nodes. Receives variables from previous nodes and returns a value for later ones.
Example
Extract the order ID from a Stripe webhook payload and format it for display in a customer-facing message.
Sub-Workflow
Call another workflow as a reusable building block. Build a shared approval or enrichment routine once and invoke it from many parent workflows, so a 25-node flow becomes a handful of named pieces.
Example
A shared "verify-and-charge" sub-workflow is reused by the refund, upgrade, and renewal flows.
Error Handler
Catch failures from a block of nodes and route to a recovery path instead of crashing the run. Inspect the error, retry, notify, or fall back gracefully.
Example
If the payment API times out, branch to a retry path and notify the user that processing is delayed.
Send Message
Send a message back to the user on their platform (Discord, Telegram, WhatsApp, Slack, or web). Supports text, markdown, embeds, and buttons.
Example
After processing a refund, send the user a confirmation message with the refund ID and expected timeline.
Send Proactive
Start an outbound conversation with a user who has not messaged first — a notification, a follow-up, or a campaign nudge — on their connected platform.
Example
When an order ships, proactively message the customer on WhatsApp with the tracking link.
Schedule Message
Queue a message or action for a future time — a time offset or an absolute timestamp — and the edge runtime holds the run until it fires.
Example
After resolving a support ticket, schedule a customer satisfaction survey for 24 hours later.
Action (HTTP)
Make an HTTP request to any URL with full control over method, headers, body, and auth, or set workflow variables. Chain actions and use response data in later nodes.
Example
POST to your internal API to process the refund, then use the response transaction ID in a follow-up message.
Structured Output
Force JSON output matching a schema. Validates the LLM response against a typed structure and retries or fails if the shape does not match.
Example
Extract order details from a customer message as a validated JSON object with required fields for downstream processing.
Knowledge Retrieval
Semantic RAG search over your knowledge base. Embeds the query, retrieves the most relevant chunks, and injects them into the LLM context.
Example
Search your product documentation to ground a customer support reply in accurate, up-to-date information.
Wait / Delay
Pause execution for a set duration before continuing to the next node. Supports fixed offsets and absolute timestamps.
Example
Wait 24 hours after a purchase before sending the customer a follow-up satisfaction survey.
LLM Router
Route by an LLM classifier. The model reads the input and selects a named branch, enabling intent-based routing without hand-crafted regex rules.
Example
Route an incoming support message to billing, technical, or general branches based on the model's intent classification.
Memory Store
Persist & recall state across runs. Write key-value pairs to durable workflow memory and read them back in future executions.
Example
Remember a user's preferred language and communication style across separate bot sessions.
Vision Analyze
Analyze an image with a multimodal model. Pass an image URL or attachment and receive a structured or text description for use in later nodes.
Example
Inspect a product photo uploaded by a customer to identify damage before routing a warranty claim.
Document Parse
Parse uploaded files & attachments. Extract structured text and metadata from PDFs, Word documents, and other file types for downstream processing.
Example
Parse an uploaded invoice PDF to extract line items, totals, and vendor details for automated reconciliation.
Image Generate
Generate images (Workers AI / DALL·E). Create images from a text prompt and store or send the result within the workflow.
Example
Generate a personalised promotional banner for a user based on their plan tier and recent activity.
Data Transform
Map, filter & reshape variables. Apply declarative transformations to arrays and objects without writing a full Code Block.
Example
Filter a list of orders to only unpaid ones and rename fields to match the expected schema for a downstream API.
Function Call
Call an internal Aerostack function. Invoke a published edge function from your workspace with typed inputs and receive its output in the workflow.
Example
Call a pricing function that computes a dynamic quote from line items, then use the result in a customer-facing message.
Seven nodes that make a workflow genuinely agentic.
These aren't wrappings around an HTTP call. They're the primitives that separate ai agent workflows from deterministic automation chains — and none of them exist in n8n, Make, or Zapier as first-class nodes.
Agent Loop
The LLM reasons about the goal, selects a tool, observes the result, then decides the next step — autonomously, until done or capped.
Every other node runs once on a fixed path. This one decides its own path at runtime. It is the node that makes a workflow genuinely agentic.
Confidence Router
Branch on how certain the model is of its own answer. High confidence → continue. Low confidence → human escalation or fallback path.
No other visual workflow builder exposes model confidence as a routing primitive. This is what makes LLM-driven branching safe at scale.
Guardrail
Enforce rules on LLM output before it reaches a user — block disallowed content, redact PII, or require the value to match a schema.
Without a guardrail node, the only place to enforce output policy is in the prompt — which the model can ignore. Guardrails are deterministic.
Knowledge Retrieval
Semantic search over your knowledge base — embeds the query, retrieves top chunks, injects them into the next LLM node's context automatically.
RAG is first-class, not a plugin. No external vector DB to wire up, no separate embedding pipeline to maintain — it runs on the same edge.
Memory Store
Write key-value pairs to durable workflow memory during a run. Read them back in future executions across sessions and across users.
Stateful ai agent workflows that remember preferences, history, and context without a separate database or session management layer.
Vision Analyze
Pass an image URL or attachment to a multimodal model and receive a structured or text description that flows into later nodes.
Visual reasoning as a workflow node — analyse product photos, parse uploaded documents, inspect screenshots — all on the same canvas.
MCP Tool
Call any tool from any MCP server in your workspace. Structured result flows directly into the next node — no JSON parsing, no glue code.
MCP tools are not bolt-on integrations. They are typed primitives the agent loop can pick and call dynamically at runtime, just like a developer would.
Fan-out. Converge. Full speed ahead.
The Parallel node fans out to multiple branches simultaneously and waits for all — or just the first — to complete before merging results and continuing downstream. In ai agent workflows this eliminates the most common latency killer: serial tool calls that could run at once.
Check three inventory warehouses at once. Call two enrichment APIs simultaneously. Let an agent loop run in parallel with a guardrail check. When branches converge, the merged output is available to every downstream node — no manual join logic.
Fan-out pattern
Stripe lookup
Jira lookup
RAG search
One workflow. Many entry points.
Multiple trigger sources — a bot message on Discord, an inbound webhook from Stripe, a cron schedule — can all converge into a single workflow graph. You maintain one piece of ai workflow automation logic instead of duplicating it per trigger type.
Every trigger normalises its payload into the same variable shape, so downstream nodes see a consistent input regardless of where the run was initiated. Change the logic once, all triggers benefit.
Convergence pattern
Discord
Stripe
6h
Build once. Reuse everywhere.
The Sub-Workflow node calls another workflow as a typed, reusable building block. Build a shared approval sequence, an identity-verification round trip, or a data-enrichment step once — then invoke it from every parent workflow that needs it, passing inputs and receiving typed outputs.
This is what keeps large ai workflow automation projects maintainable. A 30-node flow becomes four or five named subflows you can test and reason about independently. Every subflow has its own draft/published lifecycle, so updates propagate everywhere on publish — no tracking down copies.
Combine with the Parallel node to call two subflows simultaneously — for example, an enrichment subflow and a guardrail subflow — and merge results before the LLM synthesises a final answer.
Without subflows — 30 nodes, duplicated logic
With subflows — 6 nodes, reusable pieces
Real ai agent workflows. Not toy demos.
Customer Support
A customer messages your bot on Discord. The workflow verifies their identity, classifies the issue with an LLM, routes billing to Stripe MCP, technical to a specialized bot, and escalates high-value refunds to a manager for approval.
DevOps Alert
PagerDuty fires a webhook. The workflow enriches the alert with logs from Datadog MCP, asks an LLM to assess severity, notifies the on-call engineer on Telegram for approval, and auto-creates a Jira ticket and rolls back if approved.
User Onboarding
A new user signs up via API. The workflow sends a welcome message, schedules a follow-up for 24 hours, loops through their team invites to send personalized onboarding, and delegates to a "Setup Wizard Bot" to walk them through configuration.
Invoice Processing
An email webhook receives an invoice PDF. The workflow extracts data with an LLM, validates against Quickbooks MCP, flags discrepancies for finance team approval, and auto-schedules payment on approval.
Human approval & auth gates in the graph.
No bolt-ons. These four nodes are first-class primitives in every ai agent workflow on Aerostack — identity verification, approval routing, autonomous agent loops, and multi-bot delegation, all wired directly into your canvas.
Agent Loop
The node that makes it agentic.
The agent_loop node runs an autonomous ReAct loop: the LLM reasons about the goal, picks and calls tools from your workspace, observes each result, and repeats until the goal is met or a step limit is reached. Every other node executes once on a fixed path — this one decides its own path at runtime.
Why this matters
This is the primitive that separates an agentic workflow from a fixed pipeline. Zapier, Make, and n8n run a predetermined sequence; an agent loop lets the model choose what to do next based on what it just saw.
How it works
Give the loop a goal and the set of tools it is allowed to call
The LLM reasons, calls a tool, and reads the result — then decides the next step
It keeps looping autonomously until the goal is satisfied or the step cap is hit
Final output flows into the rest of the workflow like any other node
Auth Gate
Verify before acting.
The auth_gate node pauses a workflow and sends an OTP or magic link to verify the user's identity before allowing access to sensitive actions. Supports 4 built-in providers (Resend, SES, Twilio, MSG91) and custom HTTP webhooks.
Why this matters
No other workflow tool can verify identity mid-flow. Zapier, Make, and n8n have no concept of "who is this user?" — they just execute blindly.
How it works
User reaches a sensitive node (refund, data export, account change)
Workflow pauses → sends OTP via email or SMS
User enters the code in the bot conversation
Verified → workflow resumes. Failed → workflow branches to rejection path
Human Handoff
Pause. Notify. Resume.
The human_handoff node pauses workflow execution and notifies a human reviewer via web dashboard, email, Telegram, or Discord. The reviewer approves or rejects (with optional notes), and the workflow resumes down the appropriate branch.
Why this matters
Other tools have "wait for webhook" hacks, but no built-in reviewer notification, approval UI, or branching on approval/rejection. Aerostack has first-class support.
How it works
Workflow reaches a decision that needs human judgment
Execution pauses → reviewer notified on their preferred channel
Reviewer sees context (all variables from previous nodes) and approves/rejects
Approved → workflow resumes on approval branch. Rejected → rejection branch
Delegate to Bot
Specialist agents on call.
The delegate_to_bot node hands off the conversation to another bot in your workspace. Each bot has its own LLM configuration, MCP tools, and workflow. Conversation context is preserved. When the delegated bot finishes, control returns to the original workflow.
Why this matters
This enables agent teams — multiple specialized bots collaborating on a single conversation. No other platform supports bot-to-bot delegation with context preservation.
How it works
Triage bot classifies the user's intent
Workflow delegates to a specialist bot (e.g., "Billing Bot", "Tech Support Bot")
Specialist bot runs its own workflow with its own tools
When done, control returns to the original workflow with the specialist's output
Every MCP tool node in your workflow respects tool-level permissions. Agents can only call the tools you've explicitly allowed.
How Aerostack compares as an ai workflow builder.
Agentic primitives — agent loop, guardrails, auth gates, confidence routing, MCP tools, bot delegation — exist only on Aerostack. Every row marked Unique is a gap that other ai workflow automation platforms haven't closed.
| Feature | Zapier | Make | n8n | Windmill | Aerostack |
|---|---|---|---|---|---|
| Visual node editor | — | ✓ | ✓ | ✓ | ✓ |
| Branching / conditions | — | ✓ | ✓ | ✓ | ✓ |
| Loops (for-each, while) | — | ✓ | ✓ | ✓ | ✓ |
| HTTP / webhook nodes | ✓ | ✓ | ✓ | ✓ | ✓ |
| Schedule / cron triggers | ✓ | ✓ | ✓ | ✓ | ✓ |
| Native LLM nodes | — | — | plugin | — | ✓ |
| Agent loop (autonomous ReAct) Unique | — | — | — | — | ✓ |
| Guardrails / output policy Unique | — | — | — | — | ✓ |
| Confidence-based routing Unique | — | — | — | — | ✓ |
| MCP tool integration Unique | — | — | — | — | ✓ |
| Auth gate (identity verification) Unique | — | — | — | — | ✓ |
| Human handoff (approve/reject) Unique | — | — | — | — | ✓ |
| Bot-to-bot delegation Unique | — | — | — | — | ✓ |
| Multi-trigger convergence | — | — | ✓ | ✓ | ✓ |
| Edge-hosted (sub-50ms) Unique | — | — | — | — | ✓ |
| Built-in bot platforms Unique | — | — | — | — | ✓ |
| Free tier | limited | limited | ✓ | ✓ | ✓ |
Observe every run.
Per-workflow analytics show success rate, average and max duration, token usage in and out, and dollar cost — with a per-node breakdown so you can see exactly which step is slow or expensive. Filter by 24h, 7d, or 30d. The observability n8n is known for, built in.
Start from a template.
The workflow marketplace is a community library — browse by category (support, sales, automation, research, data, devops), preview a workflow, and clone it into one of your bots in a click. Publish your own to share with the community, no glue code required.
Browse the marketplace →Build your first workflow.
The ai workflow builder with 30 node types, agent loops, guardrails, auth gates, human approval, and first-class MCP tool calls. Build ai agent workflows with the only visual canvas that runs ai workflow automation at the edge — free to start.
No credit card required · Free tier included · Deploy in minutes
Frequently asked questions
What is an AI workflow builder, and how is it different from n8n or Zapier? +
An AI workflow builder lets you wire multi-step automations visually — but Aerostack's nodes are AI-native, not bolt-ons. The 30 node types include an autonomous agent loop, LLM reasoning, MCP tool calls, guardrails on model output, confidence-based routing, identity verification, and human-approval gates as first-class primitives. n8n and Zapier were built for deterministic SaaS plumbing and treat AI as one more HTTP step; an agentic workflow on Aerostack makes the LLM the decision-maker — it picks the branch, calls tools from any MCP server in your workspace, and pauses for a human when a step crosses a policy line. Everything runs on Cloudflare's edge, so a workflow that calls three tools and an LLM still returns in well under a second. If your automation is purely deterministic — no reasoning, no branching on model output — you don't need a workflow at all; ship a single edge function instead.
What is a human approval handoff (human-in-the-loop)? +
A human handoff node pauses a running workflow and routes an approval request to a designated person before any sensitive step executes — a refund, an outbound message, a write to a system of record. The workflow holds its state on the edge and resumes exactly where it left off once the reviewer approves or rejects, with the decision logged. You approve from the dashboard or from the OpenClaw mobile app, so an agent can run unattended and still never take an irreversible action without a human in the loop. This is the same approval primitive that governs tool access in an Aerostack workspace — workflows, bots, and direct agent calls all share it.
How many workflow node types are there, and what are they? +
Aerostack ships 30 node types covering the full agentic loop: Trigger, LLM Call, Agent Loop, MCP Tool, Call Function, Action (HTTP / set variable), Send Message, Send Proactive, Schedule Message, Delegate to Bot, Logic (if/else), Loop, Parallel, Code Block, Error Handler, Sub-Workflow, Auth Gate, Confidence Router, Guardrail, Structured Output, Knowledge Retrieval, Wait / Delay, LLM Router, Memory Store, Vision Analyze, Document Parse, Image Generate, Data Transform, and Function Call. The standouts: the Agent Loop runs an autonomous reason-act-observe cycle and is what makes a workflow genuinely agentic; the Guardrail enforces policy on LLM output before it reaches a user; the Confidence Router branches on how sure the model is; the Sub-Workflow lets you reuse a flow as a building block; the Auth Gate verifies identity before a protected step; and the MCP Tool node calls any tool from any server in your workspace. You compose them on a visual canvas — no YAML, no glue code — and the same graph runs identically in draft and production. New node types ship regularly as the agentic-workflow patterns mature.
Can workflows call MCP servers and tools mid-run? +
Yes — this is the core of agentic workflow automation on Aerostack. The MCP tool node connects to any MCP server installed in your workspace (Stripe, GitHub, Notion, your own, or anything from the marketplace) and executes a tool call mid-workflow, feeding the structured result into the next node. Because a workspace already composes many MCP servers behind one authenticated URL, a single workflow can read from your CRM, write to your database, and post to Slack without you wiring three separate integrations. The LLM node can also pick which tool to call at runtime, which is what separates an agentic workflow from a fixed pipeline.
Where do workflows run — do I manage any servers? +
Workflows execute on Cloudflare Workers at the edge: no servers to provision, automatic global scaling, and near-zero cold start, so steps begin in milliseconds from the nearest location to your user. There's nothing to deploy or keep warm — publish a workflow and it's live worldwide. Execution is metered against your plan's AI token allowance (the free tier includes 500K tokens a month), and you can bring your own model key to drop the platform markup to zero. State is persisted between steps on the edge, which is what lets a human-approval handoff pause a run for minutes or hours and resume cleanly.
Can I version workflows and reuse parts across projects? +
Yes. Every workflow has a draft and a published version, so you can edit safely without touching what's live, then publish when ready and roll back if needed. Reusable logic goes into subflows — a sub-workflow you build once and call from many parent workflows, so a shared approval or enrichment routine stays in one place instead of being copy-pasted. This is what keeps larger automations maintainable: a 25-node flow becomes a handful of named subflows you can test and reason about independently.
How do workflows relate to Aerostack bots and agent automation? +
Workflows are the engine underneath both. An Aerostack bot is a workflow with a messaging front end — the same auth gates, human handoffs, and MCP tool calls, delivered across WhatsApp, Telegram, Discord, and Slack, with bot-to-bot delegation between them. And the workflow builder sits inside the broader agent-automation layer: an AI agent, given the Aerostack MCP URL, can generate, test, and publish a workflow for you from a single conversation. So the visual builder is for when you want to design the logic by hand; agent automation is for when you want an agent to build it.
When should I NOT build an agentic workflow? +
When the task is fully deterministic. If there's no reasoning step and no branching on model output — a fixed transform, a scheduled sync, a webhook that always does the same thing — a single edge function is simpler, cheaper, and faster than a workflow graph, and Aerostack functions give you the same edge runtime with database, cache, and AI bindings built in. Reach for an agentic workflow when you genuinely need an LLM to decide the path, call tools dynamically, or pause for human approval. Roughly: if you can draw the logic as a flat checklist with no 'it depends', it's a function, not a workflow.
Can I see how my workflows are performing — analytics and observability? +
Yes. Every workflow has a built-in analytics view: total runs, success rate, average and maximum duration, total tokens consumed in and out, and the dollar cost of those tokens. A per-node breakdown shows runs, average and max duration, error count, and token cost for each step, so you can pinpoint exactly which node is slow or expensive rather than guessing. You can scope all of it to a 24-hour, 7-day, or 30-day window and see the run-status breakdown of completed, paused, and errored runs. This is the observability that tools like n8n are known for, available without wiring up any external monitoring.
Is there a template library or workflow marketplace? +
Yes. The workflow marketplace is a community library you can browse by category — customer support, sales, automation, research, data, devops, and general — with featured workflows surfaced at the top. Preview any workflow to see its node graph, then clone it into one of your bots in a click and customize from there, which is the fastest way to start instead of building from a blank canvas. You can also publish and share your own workflows with the community. Cloning and publishing are free; this is about sharing reusable automations, not selling them.
How does parallel execution work in an AI agent workflow? +
The Parallel node fans out to multiple branches simultaneously and waits for all (or the first) to complete before merging results and continuing downstream. This is the difference between checking three inventory warehouses sequentially — 3× the latency — and checking all three at once and acting on the first available result. In ai agent workflows it matters most when an LLM step needs data from several independent sources at once: you fan out to parallel MCP tool calls, collect the structured results, and feed the merged payload into the next LLM node. Multi-trigger convergence is related but distinct: multiple inbound trigger sources (a bot message, an API call, a webhook) can all converge into the same workflow graph, so you maintain one piece of logic instead of duplicating it across trigger types.
What are subflows and when should I use them? +
A sub-workflow is a workflow you build once and call from many parent workflows using the Sub-Workflow node. It is the equivalent of a function in code — encapsulate shared logic (an approval sequence, an identity-verification round trip, a data-enrichment step) into a named subflow, test it independently, and reuse it everywhere without copy-pasting nodes. This is what keeps large ai workflow automation projects maintainable: a 30-node flow becomes four or five named subflows that you can reason about in isolation. Every subflow has its own draft/published versioning, so updates to a shared subflow propagate to all callers when you publish — no tracking down duplicates. Reach for subflows as soon as you see yourself building the same five-node sequence in two different workflows.