Unit 3: Build Challenge

Hands-On Challenge (25 minutes)

The Goal

Design and build a new orchestrator recipe, deploy it, and invoke it from chat. You’ve seen how the existing tools work end-to-end — now build one yourself.

Choose Your Challenge

Challenge	Difficulty	Systems	Choose If…
Option A: Extended Stay	Standard	Salesforce only	You don’t have Stripe connected
Option B: Room Upgrade	Advanced	Salesforce + Stripe	You have Stripe connected and want a cross-system challenge

Choose How to Build

You have two paths to build your recipe:

Path 1: Build with a Coding Agent

If you have access to a coding agent (Claude Code, Cursor, GitHub Copilot, etc.), you can install additional tools that give your agent the knowledge to write Workato recipes:

Install Recipe Skills — an agent-consumable knowledge base covering connector configuration, datapill syntax, control flow, and error handling:
```
git clone https://github.com/workato-devs/recipe-skills.git
```

Install the Recipe Linter — catches datapill syntax errors, schema mismatches, and structural issues:

macOS/Linux:

brew install workato-devs/tap/recipe-lint
wk plugins install recipe-lint

Windows:

scoop install recipe-lint
wk plugins install recipe-lint

(Optional) Install the Recipe Visualizer — VS Code/Cursor/Windsurf extension that renders recipe JSON as interactive workflow graphs. Download the .vsix from the Workato Labs page and install via your IDE.

Your workflow: Agent writes recipe JSON → Linter validates → make push deploys → Test from chat

For full setup details and documentation, see workato-devs.github.io/labs

Path 2: Build in the Workato UI

Navigate to Projects → orchestrator-recipes in Workato
Click Create Recipe
Use the visual recipe editor to build your orchestrator step by step
Start the recipe when you’re ready to test

Both paths end the same way: invoke your new tool from the hotel app chat and trace the execution in Workato.

Challenge Rules

Rule	Details
Time	20 minutes to build + test
Teams	Individual or pairs
Goal	Working orchestrator, invocable from chat
Stretch	Trace your tool call end-to-end in Workato logs

Option A: Extended Stay

The Scenario

A guest currently checked in wants to extend their stay by a few more nights. The front desk needs to verify availability and update the reservation.

Build an extend_stay orchestrator.

Available Atomic Skills

Atomic Skill	Purpose	Returns
`search_contact_by_email`	Find guest contact	id, found
`search_booking_by_contact_and_date`	Find current booking	booking_id, room_id, check_out_date
`search_bookings_by_room_and_dates`	Check availability for new dates	bookings[] or empty
`upsert_booking`	Update reservation	booking_id
`update_opportunity_stage`	Update revenue tracking	opportunity_id

Requirements

Input Parameters

Parameter	Required	Description
`guest_email`	Yes	Guest’s email address
`new_checkout_date`	Yes	New departure date (ISO format)
`idempotency_token`	Yes	UUID for retry safety

Success Criteria

Your solution must:

Find the guest’s current active booking
Check room availability for the extended dates
Update the booking with the new checkout date
Handle “room unavailable for extension” gracefully
Be idempotent (safe to retry)

Response Codes

HTTP Status	Condition	error_code
200	Success	(none)
404	Guest not found	`GUEST_NOT_FOUND`
404	No active booking	`NO_ACTIVE_BOOKING`
409	Room not available for extended dates	`EXTENSION_NOT_AVAILABLE`

Option B: Room Upgrade

The Scenario

A guest wants to upgrade to a better room and is willing to pay the price difference. This requires checking availability, processing an additional payment, and updating the reservation.

Build an upgrade_room orchestrator that coordinates Salesforce and Stripe.

Available Atomic Skills

Salesforce:

Atomic Skill	Purpose	Returns
`search_contact_by_email`	Find guest contact	id, found
`search_booking_by_contact_and_date`	Find current booking	booking_id, room_id, room_number, opportunity_id
`search_room_by_number`	Find target room	id, status, nightly_rate
`update_room_status`	Update room availability	room_id, updated
`upsert_booking`	Update reservation	booking_id

Stripe:

Atomic Skill	Purpose	Returns
`create_stripe_payment_intent`	Charge price difference	payment_intent_id
`confirm_stripe_payment`	Confirm the charge	status, confirmed

Requirements

Input Parameters

Parameter	Required	Description
`guest_email`	Yes	Guest’s email address
`new_room_number`	Yes	Target room for upgrade
`payment_method_id`	Yes	Stripe payment method token
`idempotency_token`	Yes	UUID for retry safety

Success Criteria

Your solution must:

Find the guest’s current active booking
Validate the target room is available
Calculate the price difference (remaining nights x rate difference)
Process the additional payment via Stripe
Update room statuses (old room → Dirty, new room → Occupied)
Update the booking with the new room
Handle payment failures gracefully
Be idempotent (safe to retry)

Response Codes

HTTP Status	Condition	error_code
200	Success	(none)
404	Guest not found	`GUEST_NOT_FOUND`
404	No active booking	`NO_ACTIVE_BOOKING`
404	Target room not found	`ROOM_NOT_FOUND`
409	Target room not available	`ROOM_NOT_AVAILABLE`
402	Payment failed	`PAYMENT_FAILED`

Deploy and Test

Once your recipe is built:

Deploy:
- Coding agent path: wk lint to validate, then make push to deploy
- Workato UI path: Save and start the recipe
Add to an API Collection:
- In Workato, go to Platform → API Platform → API Collections
- Open the dewy-resort-manager collection
- Add your new recipe as an endpoint (Method: POST)
- Write a description that tells the LLM when and how to use your tool
- Enable the endpoint
Test from chat:
- Open the hotel app as Manager
- Ask the agent to perform the action your tool handles
- Watch the debug panel for your tool invocation
- Check Workato logs to trace the execution

Hints

Hint 1: Order of Operations

Think about dependencies: - What must you validate before making any changes? - For Option B: What happens if payment fails after you've already updated the room? - Validate first, mutate last

Hint 2: Checking Extended Dates (Option A)

You need to check availability between: - Current checkout date (from existing booking) - New checkout date (from input) The current booking already covers up to the original checkout date.

Hint 3: Calculating Price Difference (Option B)

Price difference = (new_room_rate - old_room_rate) x remaining_nights You'll need: - Current room's nightly rate (from booking or room lookup) - New room's nightly rate (from room lookup) - Remaining nights (checkout_date - today)

Hint 4: Idempotency Pattern

Use the `idempotency_token` in multiple places: - As `external_id` in upsert_booking - As `Idempotency-Key` header in Stripe calls (Option B)

Facilitator Notes

Pacing: 20 minutes for building, 5 minutes for demo/discussion. If teams finish early, encourage them to trace their tool call in Workato logs or test edge cases (invalid email, unavailable room).

Coding agent path: Attendees using coding agents may finish significantly faster. Encourage them to tackle Option B or refine their error handling and tool description.

If attendees get stuck on recipe-skills setup: The repo README has step-by-step instructions for each agent platform. Prioritize getting the skills loaded — the linter and visualizer are nice-to-haves.

If time is running short: Have attendees focus on designing the steps (which atomics, in what order, what error handling) even if they don’t finish building. The design exercise is still valuable.

Judging Criteria

Criterion	Weight	What We’re Looking For
Working End-to-End	40%	Can it be invoked from chat and produce the right result?
Composition	25%	Proper use of atomic skills? Logical ordering?
Error Handling	20%	What happens when things go wrong? Structured error codes?
Tool Description	15%	Would the LLM know when and how to use this tool?

Solution Walkthrough

Option A: Extended Stay

extend_stay
|
+-- search_contact_by_email
|   +-- Error if not found: 404 GUEST_NOT_FOUND
|
+-- search_booking_by_contact_and_date
|   +-- Error if not found: 404 NO_ACTIVE_BOOKING
|   +-- Save: current checkout_date, room_id
|
+-- search_bookings_by_room_and_dates
|   +-- Check: current_checkout_date to new_checkout_date
|   +-- IF conflicts exist: 409 EXTENSION_NOT_AVAILABLE
|
+-- upsert_booking
|   +-- Update: check_out_date = new_checkout_date
|   +-- Uses: idempotency_token as external_id
|
+-- Return: booking_id, new_checkout_date, total_nights

Option B: Room Upgrade

upgrade_room
|
+-- search_contact_by_email
|   +-- Error if not found: 404 GUEST_NOT_FOUND
|
+-- search_booking_by_contact_and_date
|   +-- Error if not found: 404 NO_ACTIVE_BOOKING
|   +-- Save: room_id (old), opportunity_id, checkout_date
|
+-- search_room_by_number (target room)
|   +-- Error if not found: 404 ROOM_NOT_FOUND
|   +-- Error if not Vacant: 409 ROOM_NOT_AVAILABLE
|   +-- Save: new room_id, nightly_rate
|
+-- Calculate price difference
|   +-- (new_rate - old_rate) x remaining_nights
|
+-- create_stripe_payment_intent + confirm_stripe_payment
|   +-- Error if fails: 402 PAYMENT_FAILED
|   +-- Use idempotency_token as Idempotency-Key
|
+-- update_room_status (old room -> Dirty)
|
+-- update_room_status (new room -> Occupied)
|
+-- upsert_booking (update room reference)
|
+-- Return: booking_id, previous_room, new_room, amount_charged

Key Teaching Points

Point	Why It Matters
Validate everything before mutating	Prevents partial updates on failure
Check availability for the RIGHT date range	Common mistake: checking wrong dates
Payment before room updates (Option B)	Don’t change rooms if payment fails
Idempotency at every external call	Safe retries across systems

Common Mistakes

Mistake	Better Approach
Checking wrong date range for availability	Extension: check from current checkout TO new checkout
Updating rooms before payment confirmed	Process payment first, then update state
Forgetting to calculate price difference	Need both room rates and remaining nights
No rollback plan for partial failures	Design for all-or-nothing where possible
Vague tool description	Be specific about required params and error codes — the LLM needs this