# BUILDERS LAB: Getting Started with API Builder

**URL:** <https://connective.celigo.com/t/builders-lab-getting-started-with-api-builder/5404>\
**Category:** API Management\
**Tags:** apim\
**Created:** [September 3, 2025, 11:14am UTC](https://connective.celigo.com/t/builders-lab-getting-started-with-api-builder/5404 "2025-09-03T11:14:57Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![kaustavroy](https://sea1.discourse-cdn.com/flex001/user_avatar/connective.celigo.com/kaustavroy/32/6640_2.png) [@kaustavroy](https://connective.celigo.com/u/kaustavroy)\
**Post date:** [September 3, 2025, 11:14am UTC](https://connective.celigo.com/t/builders-lab-getting-started-with-api-builder/5404/1 "2025-09-03T11:14:57Z")

</div>

# Introduction

 ![ACME Chocolatiers logo](https://us1.discourse-cdn.com/flex001/uploads/celigo/original/2X/9/990490333fd27aca7e2f6b04f20e1667a9dc26e0.png)

This hands-on lab is designed to help intermediate-level builders - business technologists with little or no coding experience - get started with API development using Celigo’s API Builder. By following step-by-step instructions, you’ll learn how to quickly design, configure, and deploy APIs that solve real business problems.

You’ll play the role of an API builder at ACME Chocolatiers, a fast-growing confectionery company seeking to modernize its operations. From order tracking to internal data services, you’ll explore common API patterns that support digital business initiatives.

This lab focuses on practical application. Each exercise includes a scenario that frames a business need, followed by a guided build using Celigo's low-code interface. You'll build APIs that:

- Handle public requests from customers

- Enable secure data exchanges with partners

- Aggregate data from multiple sources

- Support internal developers with reusable services

No programming is required, but you'll gain exposure to key API concepts such as HTTP methods, relative URIs, query and path parameters, request and response body. Whether you're looking to improve customer experience, streamline operations, or empower developers, these labs provide the foundational skills to start building immediately.

# Getting Help

Builder Labs are designed to be self-guided, but you don’t have to learn alone. If you ever get stuck, there are few ways to get support and keep moving forward:

- **Ask in the Community**  
Use this **[community](https://connective.celigo.com/c/integrator-io)** to post your questions, share what you’re working on, and learn from fellow builders. Chances are, someone else has faced the same challenge and can help you out.

- **Join Office Hours**  
Celigo hosts regular Office Hours where you can bring your questions directly to our experts. Check the **[Upcoming Events](https://connective.celigo.com/upcoming-events)** for upcoming sessions and drop in whenever you need hands-on guidance.

All of these resources are linked right here in the Celigo Community - so if you need help, you’re already in the right place.

# Technology Overview

Modern digital businesses rely on APIs to connect systems, expose data securely, and enable innovation. To ensure APIs are scalable, secure, and manageable, organizations adopt a Full Lifecycle API Management approach. This lifecycle includes four key phases: **Build, Secure, Socialize and Monitor**.

 ![API management lifecycle](https://us1.discourse-cdn.com/flex001/uploads/celigo/original/2X/1/1df9fc472ae998cb668bdd3ccec33bab2f7e63b2.jpeg)

Celigo's **API Builder** focuses on simplifying the first phase - **Build** - for business technologists. With its low-code interface, API Builder enables users to:

- Visually define routes and methods

- Define business logic using the builder canvas

- Secure endpoints with authentication options

- Deploy APIs directly from the platform

While Celigo also provides features that support the other phases of **API management** , this lab centers on helping you get hands-on experience with designing, implementing and testing APIs using real business use cases.

# Hands-on Lab Overview

> ⏱ **ESTIMATED TIME** : 2.5 hours (all modules)

These hands-on exercises are designed for intermediate-level builders and focus on real-world use cases that demonstrate key capabilities of Celigo’s low-code API development platform.

- Prerequisite: Set up the Lab Environment
- Module 1: Create an API to fetch Product Pricing
- Module 2: Create a composite API to fetch Product and Supplier Info
- Module 3: Customize error responses in your APIs
- Module 4: Reuse existing custom API using Celigo APIs connector
- Module 5: Promote your APIs from Development to Production
- Module 6: Create new versions and deprecate your existing APIs
- Module 7: Manage your API lifecycle with snapshots, pull/merge

These modules are progressive - each module will teach you a new pattern in designing robust, scalable APIs using Celigo. Although you can finish the entire lab in 2 hours at a stretch, you may complete them at your own pace.

* * *

# Prerequisite: Set up the Lab Environment

> ⏱ **ESTIMATED TIME** : 20 minutes

## What You’ll Learn

Before building APIs, you'll need to create a free Celigo trial account and access API Builder. In this module, you'll set up the Lab environment and perform the prerequisites which will help you progress the next set of modules.

You’ll learn how to

- Create your free trial account in Celigo

- Create a new environment

- Connect to Airtable

- Connect to Slack

- Verify connections are online

Note: If you have already completed **Getting Started with Flow Builder** and have set up your lab environment, you can only follow Step 2 ( **Configure a new environment** ) and Step 4 ( **Configure an external tool to test API** ) in this Prerequisite section.

## Scenario

You’ve recently joined ACME Chocolatiers as an API developer. The company has been rapidly expanding its digital footprint and now needs to provide seamless access to product data and operational workflows. Before you can start building APIs, you need to set up a secure, isolated development environment where you can experiment without affecting production.

You’ll also prepare the apps and systems (like Airtable for product and supplier data, and Slack for team communication) that will be integrated into ACME’s ecosystem, ensuring your lab is ready for real-world scenarios.

## Step 1: Create Your Celigo Free Trial Account

If you do not already have an account for Celigo, follow these instructions to procure your free trial.

1. Visit [https://integrator.io/signup](https://integrator.io/signup).

2. Complete the registration form with your name, company, and email address.

> 📣 **REQUIREMENT**  
> Please use a valid business email address for this step.

1. Check your inbox for an activation email and follow the instructions to set up your password.

2. Once activated, you will be logged into [https://integrator.io](https://integrator.io).

3. After logging in, click your profile icon in the top-right corner and select **Subscription.**

4. Ensure that **API builder** is listed among the features.

## Step 2: **Configure a new environment**

1. Click on the profile icon and select **Environments**.

2. Click on **+ Create environment** and enter a name - **Development** , and a description of the new environment.

3. Click on **Save** to create the environment.

4. Enable the environment by clicking on the toggle for **Status**.

5. On the top-right of the screen, select the word **Production**. A drop-down list appears. From the list, select **Development**. This takes you to the Development environment in [integrator.io](http://integrator.io).

 ![Navigate to Development environment](https://us1.discourse-cdn.com/flex001/uploads/celigo/original/2X/1/1328ef2f293c8a3df575fa15c5d87b6081dc2930.png)

## Step 3: Connect to endpoint apps

To help you build, test, and understand APIs effectively, we’ve selected two powerful but beginner friendly tools: **Airtable** and **Slack**. Both platforms offer free trials, making them perfect for experimentation without the need for paid accounts or setup overhead. By using Airtable and Slack, you’ll be working with real-world tools that make it easy to build, visualize, and test integration patterns all without writing code.

* * *

 ![image](https://us1.discourse-cdn.com/flex001/uploads/celigo/original/2X/c/c02097e6e499f478cb0ffbaa222db0f87cc758fd.png)

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Slack is a popular messaging tool used by teams to communicate in real-time. Here, you'll use it as an endpoint for your API - delivering notifications about products, inventory, and alerts directly into Slack channels using Celigo’s API builder.

### **Create a new Slack Workspace**

This lab uses Slack as a way to send interesting business events to other users within ACME Chocolatiers.

1. Sign up for a free account in **Slack** - [https://slack.com](https://slack.com/intl/en-in/). Click **Create a new workspace**. Sign in with your personal email ID. Enter the OTP sent to your email address.

2. Name and set up your Workspace: After logging in, click **Create a workspace**. Name your workspace (e.g., **ACME Chocolatiers** ). Enter your name. When prompted to invite colleagues, you may skip this step.

3. Choose **Start with the limited free version**. Close the initial tutorial by clicking the **X** icon.

4. Create a Slack App here - [https://api.slack.com/](https://api.slack.com/). Click **Your apps** at the top-right corner.

5. Select the **Create app** button. Select **From scratch**.

6. Name your app, e.g. **ACME**. Select your workspace from the dropdown, and create the app.

### Create Connection to Slack

1. In Celigo [integrator.io](http://integrator.io) go to Resources \> Connections.

2. Select **Create connection**. Choose **Slack**. Name your connection, set API type to **Web methods** , and Auth type to **OAuth 2.0**.

3. Click **Configure scopes**. Add relevant bot scopes in the scopes editor - calls:read, calls:write, channels:read, im:history, im:read, im:write, users:read, users:write. Click **Confirm**.

4. In the User scopes field below Configure scopes, select - channels.write, chat.write.

5. Click **Save & authorize**. This allows the app to post messages and manage channels, and more such operations.

6. After clicking **Save & Authorize** , a popup window will appear. Ensure the correct workspace is selected in the top-right corner, and then click **Allow**.

7. Your Slack connection is now ready.

 ![Slack connection in integrator.io](https://us1.discourse-cdn.com/flex001/uploads/celigo/original/2X/7/707a8abc6ed259f4357b96e86d6386a9b08b1cd5.png)

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 ![image](https://us1.discourse-cdn.com/flex001/uploads/celigo/original/2X/c/c574c6a7febea917eb90d5e44d63fd802b7919e8.png)

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Airtable acts as a simple, cloud-based database that combines the power of a spreadsheet with the flexibility of a relational database. In this lab, you'll use it to store and retrieve product and inventory data through its clean and easy-to-use API.

### **Create a new Airtable app**

1. Sign up for a free account in **Airtable** ([https://airtable.com/](https://airtable.com/)). You need not enter payment information in order to sign up for the free trial.

2. **Do not use the AI prompt** , we’ll use some ready to use csv files that you can download from here and upload in Airtable. Navigate to the home screen of Airtable by clicking on the **Airtable icon** on the top left.

3. You will see a button on the bottom left called **+ Create.** Click on it.

4. Choose the option **Build an app on your own.**

5. Please use the files provided here [Google Drive Link](https://drive.google.com/drive/folders/1nTq8H7LJGmVeO239lOAUVLq7KucHedkf)

6. Click on the **+ Add or import** icon. Choose CSV file from the drop down options.

7. In the dialog box that opens, click on **Browse files** to upload the CSV.

8. Click on **Upload file** button and then on **Next.** Then click on **Import** to confirm.

9. Repeat the same steps with **Suppliers-Grid view.csv,** ensure you choose the option **+ Add or import.**

10. Double-click on each of the table names, to rename the tables you have imported as **Products** and **Suppliers** respectively. You will need to pass the table names in the following modules to lookup information from these tables.

11. Select the Airtable **Profile** icon on the bottom-right, then select **Builder Hub** \> **Developers** \> **Personal access tokens**.

12. Select the **+ Create token** button. Name the token as per your choice.

13. Click **+ Add a scope** to add the scopes - data.records:read, data.recordComments:read, schema.bases:read.

14. A dialog box with a newly created token appears. Copy the token, select the **Done** button, close the panel and save the token securely. You will need it while configuring the Airtable connection in Celigo.

### Create Connection to Airtable

1. In Celigo [integrator.io](http://integrator.io) go to Resources \> Connections.

2. Select **Create connection**. Choose **Airtable**. Name your connection, select API type as **User info** , Auth type as **Token** , and enter the token that you saved earlier.

3. Click on **Test connection** and then **Save**  **& close**.

4. Your Airtable connection is now ready.

### **Verify Connections are online**

1. The Connections list should show both connections and their status. Confirm the Slack and Airtable connections are online in the **Development** environment.

## Step 4: Configure an external tool to test API

In this exercise, you’ll use **Postman** to test the API endpoint that you will build here.

1. In order to sign up, enter your work email, username and password here - [https://identity.getpostman.com/signup](https://identity.getpostman.com/signup).

2. Click **Create free account** to confirm registration.

3. Verify your account by entering the verification code sent to your email.

4. Fill in the introductory questions and select **Continue with Free Plan** if you don’t want to upgrade.

5. Click on **Get started** , and you’re ready to test the API

> 🏅 **SUCCESS**  
> You finished this section - great job! You have all the prerequisites to build and test a new API using the low code API builder tool.

* * *

# **Module 1: Create an API to fetch Product Pricing**

> ⏱ **ESTIMATED TIME** : 25 minutes

## **What You’ll Learn**

In this lab, you'll gain foundational skills in building and deploying a simple API using Celigo’s API Builder. You’ll learn how to:

- Create a new API in Celigo API Builder

- Configure path (or query) parameter in the API request node

- Use transformation step to pass path (or query) parameter to the downstream steps

- Add a lookup using Airtable connection

- Map results into a structured API response

- Test and deploy a public API endpoint

This lab is designed for intermediate-level builders and shows how to build real-time APIs that bring together multiple data sources.

## Scenario

ACME Chocolatiers is partnering with multiple online distributors who need up-to-date pricing for products in order to display accurate information to their customers. As the API developer, you’re tasked with creating a public API that external partners can call to fetch real-time product pricing directly from ACME’s Airtable product catalog, by providing the SKU as input.

Instead of sharing static spreadsheets or manually updating partners, you’ll expose a secure API that ensures everyone always has access to the latest information - reducing errors, manual effort, and customer complaints.

## **Step 1: Create the API**

1. In Celigo [integrator.io](http://integrator.io), ensure you are in the **Development** environment by locating the environment name in the left sidebar menu, or in the environment selector on the top right corner of the screen. If your are Production environment, use the environment selector to go to the Development environment.

2. From the sidebar menu, navigate to **Resources \> APIs**.

3. Click **Create API.**

> 🖊 **NOTE**  
> If you already have a free Celigo [integrator.io](http://integrator.io) account and the trial has expired, you won’t see the API builder option. Reach out to a Celigo representative for support.

1. In the **Create API** form, enter:

2. Click **Next.** You’ll be taken to the API Builder canvas. You can see an **API request node** and two **API response nodes** - one for success and one for error. The API name, description and version that you entered is visible on the top left corner of the screen.

## **Step 2: Configure the API Request Node**

1. Click the **API request** node (first box in the API builder canvas which has **Configure** written over it)

2. Configure the API request:

3. Select **Mock API request** on the right panel. Update a valid SKU ( **ACME001** ) from your Airtable \> Products table.

4. Select **Preview** and then click on **Send** button to view the parsed output and the mock HTTP request for testing.

5. **Save & close** the API request node.

## **Step 3: Add Transformation Step**

1. On the API request node, select the ellipsis and choose **Transformation**.

2. With **Rules 2.0** selected at the top, map the query parameter:

## **Step 4: Lookup Pricing and Item Info from Airtable**

1. Click **+** after the Transformation step. Choose **Add destination / lookup**.

2. Select **Airtable** from the list of applications, choose **Look up additional records (per record)** in Flow step type. Enter the name and description (shown below\*\*)\*\*, and click **Next**.

3. Select the existing connection to your **Airtable** instance from the dropdown, or set up a new connection by following steps in **Prerequisite** section.

4. Under **What would you like to export** , select/enter:

5. On selecting the endpoint, you will see the path parameters ( **Base ID** , and **Table ID or name** ) for that Airtable endpoint. Enter the value for the path parameters from Airtable.

6. Add a query parameter **filterByFormula** from the dropdown. Provide the value as **`{SKU}='{{record.sku}}'`**.

7. With **Preview** tab selected, click on **Send** , to preview the data from Airtable.

8. **Save & close** the window.

9. Click on the ellipsis menu for the newly added lookup step and choose **Results mapping** , to add the lookup response fields to the source record.

10. Add the following mapping. Then **Preview** the output and click **Save & close**.

> 🛠 **PRO TIP**  
> When you expect a single record back from the lookup it's advised to use **data.0** or if you are expecting an array of records it’s advised to use **data** to merge complete data back into the source record.

## **Step 5: Configure API Response Node (Success & Error)**

1. Open **API response** node - **Success Response**

2. In the **Configure API response** section, set:

3. Click **Send** under **Preview** , and then **Save & close**.

## **Step 6: Map source fields to API response fields**

1. Click on the ellipsis for the **Success response** node and choose **Mapping.**

2. Map the source record fields to response record fields. Make sure the data types are as shown below. **Preview** the mapping and click **Save & close**.

> 🛠 **PRO TIP**  
> To quickly auto-map the fields, select **Auto-map destination fields** button, located to the right of Refresh fields. Then **Select all** fields and then confirm by clicking **Auto-map selected destination fields**.

## **Step 7: Test the API**

1. Select **Run test** button to verify the API using the mock API request that you configured earlier in the API request node.

2. Click on any of the nodes (e.g. lookup), and then on **View debug logs** link on the top right corner to see the **Test run debug logs**. Click **Close** to return to the API builder canvas.

3. Click on any of the node steps, e.g. Results mapping or Transformation, to view the **Test run results**. Click **Close** to return to the API builder canvas.

## **Step 8: Test the Endpoint using an external tool**

1. Open the API request node (named ACME Item Info API) and click **Send** under **Preview** tab.

2. Go to the **HTTP request** tab and click on the **Copy** icon on the bottom right corner of the panel, to copy the **cURL** command (shown here). **Close** the API request node.

3. In Postman,

4. You should see the API endpoint URL with the query parameter already configured. Next, you will need the Celigo **API token** to authenticate the API request externally in Postman.

5. In Celigo, go to **Resources \> API tokens** page from the sidebar menu, and select **+ Create API token**.

6. Add a name (e.g. ACME test), select any duration in **Auto purge token** , and set the Scope to **Custom**. Click the APIs drop-down option to select the API you’ve just created. **Save & close** the panel.

7. In the **Token** column, click on **Show token** to view the API token, and then copy the token.

8. In Postman, open the **Authorization** tab. Paste the API token with **Auth type** selected as **Bearer token**.

9. Hit **Send**. You should get a **200 OK** success response code, with a response body that incudes the item price and inventory information for the SKU that you’ve passed as a query parameter.

## Step 9: Download the OpenAPI specification

1. In Resources \> APIs page, for the newly created API, click on the ellipsis in **Actions** column.

2. Select **Download OAS**.

3. Open the downloaded yaml file in a text editor. Alternatively, visit Swagger editor ([https://editor.swagger.io/](https://editor.swagger.io/)). Select **File** \> **Import file** and choose the file.

4. Review the contents of the file based on what you have provided in the previous steps. It should include:

 ![OpenAPI specification](https://us1.discourse-cdn.com/flex001/uploads/celigo/original/2X/b/b4f3a928335e4aeca2e4977ab2b8885540bc87dd.jpeg)

> 🏅 **SUCCESS**  
> You finished this section - great job! You have successfully built an API using the low code API builder tool. Continue to the next module.

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# Module 2: Create a composite API to fetch Product and Supplier info

> ⏱ **ESTIMATED TIME** : 10 minutes

## What You’ll Learn

You’ll create a composite API by updating the simple API you’ve created in the previous module, to also retrieve supplier information from a dedicated Airtable supplier table, and return the combined information as API response.

> 📗 **TERM - Composite API**  
> A **composite API** allows for the execution of multiple API requests within a single API call. Instead of making separate, sequential calls to different API endpoints, a client can send one request containing a series of sub-requests, and receive a single, consolidated response.

## Scenario

ACME’s external distributors not only want pricing data but also need visibility into supplier details to help with inventory planning and sourcing decisions. For example, a distributor may want to know which supplier provides a specific chocolate ingredient, along with their lead times and contact info. In this module, you’ll enhance the pricing API you built earlier to also fetch and return supplier data from a dedicated Airtable table.

This composite API will give ACME’s partners a single, unified response that includes all the product and supplier information they need - improving efficiency and reducing the number of API calls required.

## **Step 1: Add another Lookup Step to Fetch Supplier Info**

1. In Celigo [integrator.io](http://integrator.io), go to Resources \> APIs page.

2. Click on **ACME Item Info API** to open the API builder canvas.

3. Select **+** after the Lookup step - **Fetch pricing and item info**. Choose **Add destination / lookup**.

4. Select **Airtable** from the list of applications, choose **Look up additional records (per record)** in Flow step type. Enter the name and description, and click **Next**.

5. Select the existing connection to your **Airtable** instance from the dropdown.

6. Under **What would you like to export** , select:

7. Enter the value for the path parameters from Airtable.

8. Add a query parameter **filterByFormula** from the dropdown. Provide the value as:

9. **Preview** the changes, and click on **Save & close**.

10. Click on the ellipsis menu for the newly added lookup step and choose **Results mapping**.

11. Add the following mapping to add the lookup response fields to the source record.

12. **Preview** the output and then click on **Save & close**.

## **Step 2: Update API Response Body Schema with Supplier info**

1. Open **API response** node - **Success Response**.

2. In the **Configure API response** section, scroll down to **HTTP response body** section. Add new fields to schema manually. Click on + button to the right of price field to add a new field **supplier**. Change the datatype from string to **object**.

3. Expand the supplier (object) by selecting the caret-down icon, and add below fields. Optionally add the description fields.

4. Click **Save & close**.

5. Since you are updating the previously defined response schema, against which an OpenAPI specification has already been generated, on saving, you’ll see the message - **Response schema mismatch** - a reminder to open the response node mapper and sync the new fields. Click on **Ok**.

> 🖊 **NOTE: Alternative Option**  
> Instead of updating the HTTP response body schema in the API response node, add the new fields when mapping the API response fields. Mapping is covered in the next step.

## **Step 3: Map newly added fields to API response fields**

1. Click on the ellipsis icon for the Success response and choose **Mapping.**

2. Click on the **+** icon on the last row to add new fields for the **supplier** object as shown below. Map the newly added source record fields to response record fields.

3. **Preview** the mapping. **Save & close** the panel.

> 🛠 **PRO TIP**  
> Instead of adding the fields manually, you can click on the ellipsis and select **Auto-populate destination fields** , and then on **Auto-populate** in the modal that opens. Then select **Auto-map destination fields** as shown below to auto-map all the fields.

 ![Auto-populated destination fiels](https://us1.discourse-cdn.com/flex001/uploads/celigo/original/2X/d/d01e27fc1809c04858de052489ceed4338ab20f5.png)

 ![Auto-map fields in mapping](https://us1.discourse-cdn.com/flex001/uploads/celigo/original/2X/d/db3ac74666f1a00c2a1a1ea759fb39ed5e6389da.jpeg)

> 🖊 **NOTE: Updating the HTTP response body schema in mapping**  
> When new fields are created or existing fields are updated in mapping which are not in sync with the HTTP response body schema, you will have an option to automatically sync the schema. When saving your work, select the **Sync now** button, as shown below.

 ![Sync response schema](https://us1.discourse-cdn.com/flex001/uploads/celigo/original/2X/2/2118534cda61e5ab3fcfbf9e37ee6dc124b6cda7.jpeg)

## **Step 4: Test the API**

1. Click **Run test** button to verify the API using the mock API request that you configured earlier in the API request node.

2. Click on each of the steps to see the test run logs - same as you did in the previous module.

## **Step 5: Test the Endpoint using an external tool**

1. Open **Postman** to test the API which you have already imported in the previous module.

2. Ensure the API token is already entered with **Auth type** selected as **Bearer token**.

3. Hit **Send**. You should get a **200 OK** success response code, with a response body that includes the item price, inventory as well as supplier information. If the API response is not as shown below, reread the previous steps, or [reach out for help](https://connective.celigo.com/t/201-getting-started-with-api-builder/5404#p-12490-getting-help-2).

> 🏅 **SUCCESS**  
> You finished this section - great job! You have successfully built a composite API using the low code API builder tool. Continue to the next module.

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# Module 3: **Customize Error responses in your APIs**

> ⏱ **ESTIMATED TIME** : 25 minutes

## What You’ll Learn

You’ll explore all the different error handling options for the APIs and also how to customize the error response based on your business needs.

## Scenario

As ACME Chocolatiers expands its API offerings, partners increasingly depend on accurate error reporting to troubleshoot issues. Imagine a distributor’s system calls your API without any SKU or with an invalid SKU.

Without meaningful error messages, they won’t know whether the problem lies in their request, in ACME’s data, or in the API itself. To improve developer experience and reduce support tickets, you’ll customize error responses to return clear, actionable messages.

## Step 1: Add a Script to validate whether SKU is available

1. In Celigo [integrator.io](http://integrator.io), go to Resources \> APIs page to view the APIs built in the account. Click on **ACME Item Info API** to open the API builder canvas.

2. Click on the ellipsis for the API request node, and choose **Transformation**. Navigate to **JavaScript** on the top center of the panel.

3. Under **Script** , click on the **+** icon to the right of **Function** field, to add a new script. Enter a script name - **Validate request parameter**.

4. Under **Script content** section, note that the function stub is set to **Transform** already, as this step is a transformation. Click **Save & close**.

5. Copy below JavaScript snippet and paste it in the left panel, to validate whether the SKU is available in the query parameter. If SKU is not available then you can return a customized error - “SKU is required”.

6. Click **Preview** on the top right corner of the panel to confirm whether the sku is mapped successfully, as shown below.

7. In the Function input column, remove the value of **sku** (as shown below) in the **Function Input** section, and click on **Preview**. Confirm whether the **Error** section shows the custom error you have configured in the script.

8. **Save & close** the Transformation step.

## Step 2: Test API without sending SKU in API Request

1. Open the API request node. Select **Edit mock API request**. Remove the value for the query parameter - **sku**.

2. **Save & close** the panel, and also the API request node.

3. Select **Run test** to test the API with a mock API request without SKU information.

4. Click on the **error** link beside the red dot to view the **Test run errors**. You should see the error message that you configured earlier, and the error source as Transformation. Close the panel by clicking the **x** icon on the top right corner.

5. In the API builder canvas, click on the Transformation icon to view the test run results as well as the error stack trace, as shown below.

6. Invoke the API from **Postman** , after removing the value for the query parameter - “sku”. You will get an error response with the message which you have configured earlier.

7. Revert the changes made earlier in **Mock API request** in API request node, ie. provide the value of sku as “ACME001”. **Save & close** the panel and the API request node.

## Step 3: Add Error Handling to return a custom Response Code when SKU is invalid

1. Test the API again from **Postman** by providing the value of “sku” as “ACME123” which doesn’t exist in the Airtable database.

2. Click on the ellipsis button and select **View request logs** to view the external API call and its response.

3. You will see a response code of 500 with the timestamp. Navigate to the **API response** tab and view the error details in the **Body** section. Make a note of the error code - “handlebars\_template\_parse\_error”, and the message.

4. Since the error message is showing the endpoint path as **/Suppliers** , configure error handling for the **Fetch supplier info** step to return a customized error response code and message. Click on the ellipsis for that lookup step, and choose **Error handling**.

5. In the **What should happen to a record if the lookup fails?** dialog, select **Proceed to the next application regardless**. Click **Save & close**.

6. Edit **results mapping** for the same lookup step, in order to map the error code to the source record, which you can later use in a downstream step (i.e. **Response picker** ) to route the record to its intended error response node. Save and close the results mapping UI.

7. Open the **Response picker** branching node, as shown below.

8. Click on **+ Branch** button at the bottom of the window, to add a new branch. Click on the pencil icon and name the new branch “ **Error response - 400** ”. Also rename the default success and error branches as shown below.

9. Drag and order the branches, as shown below, based on which branch condition needs to be evaluated first. This is because the record will flow through the **First matching branch** in the Response picker.

10. Click on **+ Condition** to add a new condition for the branch **Error response - 400**.

11. Select the field **record.error\_code\_lookup** , which you had mapped in a previous step, from the drop down list. Configure the condition such that the field **equals** the error code **handlebars\_template\_parse\_error** which you had noted in an earlier step.

12. Enter the error code value in the Input section, as shown below. Click **Preview** to confirm that the condition is working as expected. Save and close the Edit branching UI.

13. In the API builder canvas, you will see 3 response nodes, similar to how you have configured them in the **Response picker**. Click on the **Error response - 400** response node to open it.

14. Set the HTTP response code as **400 - Bad request**. **Save & close** the response node.

15. Click on the ellipsis icon for the **Error response - 400** and choose **Mapping.**

16. Add a response record field - **message**. Click on the gear icon to open **Settings**. Change the Field mapping type to **Hard-coded**. Enter a custom value - “SKU is invalid”.

## Step 4: Test API by sending invalid SKU in API Request

1. Invoke the API from an external tool like Postman with an invalid SKU, e.g. **ACME123**.
2. You will see a **400 - Bad request** being returned with the body showing the customized error message as expected. ![Screenshot 2025-09-15 at 8.36.48 PM](https://us1.discourse-cdn.com/flex001/uploads/celigo/original/2X/d/dea04607b60d65fe306825b6ff6824ec13b875ac.png)
3. Finally, test with a valid SKU, e.g. **ACME001** , to ensure the API is working fine even after making all these updates in error handling.

> 🏅 **SUCCESS**  
> You finished this section - great job! You have successfully added error handling in your API. Continue to the next module.

* * *

# Module 4: Reuse existing API using Celigo APIs connector

> ⏱ **ESTIMATED TIME** : 20 minutes

## What You’ll Learn

You’ll create a new composite API in API builder to send notifications to Slack when inventory level is below a threshold, by reusing the existing API. You’ll also reuse an existing Celigo standard API in your custom API built using API builder.

## Scenario

ACME wants to proactively monitor inventory levels to avoid stockouts, which can damage partner trust and customer satisfaction. You’ve been asked to create an API that triggers notifications in Slack whenever inventory for a product falls below a certain threshold.

Rather than building everything from scratch, you’ll reuse the **ACME Item Info API** you’ve already built via the **Celigo APIs** connector. This approach not only saves time but also demonstrates how ACME can accelerate their API-led integration strategies.

## Step 1: Create a Celigo APIs connector

1. In Celigo [integrator.io](http://integrator.io), go to Resources \> Connections. Click on **+ Create connection**.

2. Select the application - **Celigo APIs (New!)**.

3. Enter a descriptive name - **Celigo APIs connection**.

4. Select Scope as **Custom**.

5. Click on **APIs** to open the drop down option, and select the **ACME Item Info API** which you have built in the previous modules. Save & close the connection.

## Step 2: Create new API in API Builder

1. Go to **Tools** and select **API builder**.

2. In the API builder canvas,

3. Click on the **API Request** node to configure the request parameters.

4. Configure the API request:

5. Click **Mock API request** and update a SKU ( **ACME001** ) from your Airtable \> Products table.

6. **Save & close** the API request node.

## **Step 3: Add Transformation Step**

1. Click on the **ellipsis** icon on the API request node. Choose **Transformation**.

2. Map the query parameter:

## **Step 4: Reuse ACME Item Info API using Celigo APIs connector**

1. Click **+** after the Transformation step. Choose **Add destination / lookup**.

2. In Create destination/lookup UI,

3. Select the connection which you have created in a previous step.

4. Select the Option - **Invoke an API created in my account**.

5. Select the API endpoint - **ACME Item Info API**.

6. Select the Query parameter **sku** from the drop down. Enter **{{record.sku}}** as value.

7. **Preview** , and **save & close** the panel.

8. Click on the ellipsis icon for the new step added to open the drop down options. Select **Results mapping**.

9. Map the lookup results to the source record, as shown below. **Save & close** the panel.

## **Step 5: Add a Slack Import to send Notification**

1. Click **+** after the **Fetch item info from Airtable** lookup step. Choose **Add destination / lookup**.

2. Select **Slack** from the list of applications, choose **Import records into destination application** in Flow step type. Enter the name and description.

3. Click **Next**.

4. Select the **Slack**  **connection** which you have configured in the **Prerequisite** section.

5. Select

6. **Save & close** the import.

7. Click on the ellipsis for the **Send Slack notification** import. Choose **Mapping**.

8. Open your **Slack** application by visiting [https://slack.com/](https://slack.com/) and clicking on **Launch Slack**. Go to the channel where you want to send the notification and copy the **Channel ID** as shown below.

9. In the Mapping UI, map the **channel** and the **text** destination fields as shown below.

10. Click on **Preview** to verify whether the mapping is done correctly. **Save & close** the panel.

## Step 6: Add an Input Filter to only Send Notification when Stock is less

1. Click on the ellipsis for **Send Slack notification** import.

2. Choose **Input filter** , to filter records based on inventory count.

3. Click **+ Condition** to add a new filter condition.

4. Select **record.acme.inventory** from the drop down list of fields. Then select “ **is less then** ” from the drop down list of filter condition, and enter the value as **10** , to configure the following filter condition.

5. To test whether the filter condition is working as expected, update the inventory count to **9** in the **Input** section and click **Preview**. The Output section should show **TRUE: record will be processed**.

## Step 7: Test the API by updating inventory count in Airtable

1. Go to Celigo \> Resources \> **API tokens**. Click on the token you had created previously.

2. Click on APIs and select **ACME Fetch Items and Send Notifications API,** to add the token permission for the newly created API. **Save & close** the panel.

3. Go to Resources \> APIs, click on the ellipsis icon for **ACME Fetch Items and Send Notifications API** , and choose **Copy cURL**.

4. Go to **Postman** and select your workspace. Click on Import, paste the cURL command, and then click on **Import Into Collection**.

5. In Celigo \> Resources \> API tokens, click on **Show token** to view the token. Copy the token.

6. In Postman, provide the API token with Auth type as **Bearer token** , as shown below.

7. Click Send to invoke the API. You should get a 200 OK response with the item information retrieved from the existing **ACME Item Info API** that have been reused in the new **ACME Fetch Items and Send Notifications API**.

8. In Airtable \> **Products** table, double click on the below cell and update inventory level for ACME001 to **9** (or any number less than 10).

9. Invoke the API again with the updated inventory count (which is below the threshold of 10).

10. Validate whether a Slack notification for “Low inventory alert” along with item information is being sent to the channel you have configured earlier.

> 🏅 **SUCCESS**  
> You finished this section - great job! You have successfully reused an existing custom API using Celigo APIs connector, and sent a Slack notification based on an input filter condition. Continue to the next module.

* * *

# Module 5: Promote APIs from Development to Production

> ⏱ **ESTIMATED TIME** : 10 minutes

## What You’ll Learn

You’ll learn how to move your APIs from one environment to another while preserving its full configuration. You don’t have to manually replicate the setup, reducing the chance of errors and ensuring consistency.

## Scenario

Your APIs are now critical for ACME’s external distributors, who rely on them for real-time data. But before rolling them out broadly, you must ensure that APIs move safely from the development environment (where you’ve been experimenting) to production (where real partners will consume them). Manual migration is risky and error-prone, as small misconfigurations could lead to downtime or incorrect data being exposed.

In this module, you’ll use Celigo’s deployment capabilities to seamlessly promote APIs between environments, ensuring consistency, reliability, and faster release cycles for ACME’s partners.

## Step 1: Create Connections in Production environment

1. In Celigo [integrator.io](http://integrator.io), on the top-right of the screen, click on the environment **Development**. A drop-down list appears. From the list, select **Production**.

2. Go to Resources \> Connections.

3. Create and configure connections to Slack and Airtable, in the same manner as you have done earlier in the Development environment, as mentioned in the [Pre-requisites section](https://connective.celigo.com/t/201-getting-started-with-api-builder/5404#p-12490-step-3-connect-to-endpoint-apps-10).

4. Verify the Slack and Airtable connections are Online. You can ignore any other connection that can show up in the Connections page since you will not use them in this exercise.

## Step 2: Clone API from Development to Production

1. From the environment selector drop-down, select **Development** to navigate back to the Development environment where you have created and tested your API.

2. Go to Resources \> APIs.

3. For the **ACME Item Info API** , click on the ellipsis to open the **Actions** menu drop down.

4. Select **Clone API**.

5. Update the name of the API that will be created when cloning is complete.

6. Enter a description for your choice - “API to fetch item pricing, inventory and supplier information to be used in Production environment”.

7. Select **Production** from the **Environment** drop down.

8. Enter the version - **v1**.

9. Expand the sections below the Versions field to see which resources will be cloned.

10. Click on the **Clone API** button to start the cloning process.

11. In the Install page, select **Configure** to configure the Airtable connection that is being used in the API.

12. Use the existing Airtable connection that you’ve already created in the Production environment. 

13. Save the changes. You will be navigated to the cloned API in the new (Production) environment automatically

14. Click on Run test button to verify whether all the dependent resources are also successfully cloned, and the API is executed as expected.

15. Similarly, promote the **ACME Fetch Items and Send Notifications API** from Development to Production environment.

> 🏅 **SUCCESS**  
> You finished this section - great job! You have successfully cloned an API from the Development to Production environment. Continue to the next module.

* * *

# Module 6: Create new versions and deprecate your existing APIs

> ⏱ **ESTIMATED TIME** : 10 minutes

## What You’ll Learn

You’ll learn how to create new versions of your API in the same environment when you’re making breaking changes to your API, since otherwise it would impact your API consumers and also create long-term technical debt. You’ll also learn how to deprecate the older versions of your APIs once your API consumers have fully migrated over to the new version.

## Scenario

Over time, ACME Chocolatiers wants to enhance its APIs with new features that involves a breaking change - for instance, adding a path parameter in the relative URI, or updating the business logic in the lookups used in the API. However, you can’t simply overwrite the existing API, because distributors are already depending on its current structure. To avoid disruption, you’ll create a new version of the API while keeping the old version live. This enables partners to migrate at their own pace.

Later, once all partners have transitioned, you’ll deprecate the older version. This approach ensures backward compatibility while still allowing ACME to innovate and evolve its digital capabilities.

## Step 1: Clone API to create a new version

1. In Celigo [integrator.io](http://integrator.io), click on the environment selector on the top right corner, and select **Development**.

2. Go to Resources \> APIs. Click on the **ACME Fetch Items and Send Notifications API** to open the builder canvas.

3. Open the API request node, and update the Relative URI from **/item** to **/items**. Now, this is a breaking change which you don’t want to make in this current version (i.e. v1) of the API.

4. Click **Close** instead of saving the changes, and then select **Discard changes** in the dialog that opens.

5. Click on the ellipsis on the top right corner of the screen, and select **Clone API**.

6. Add the version as v2, keeping the environment unchanged.

7. Click on **Clone API** button to start the cloning process.

8. Click on Configure button for the Slack connection. Choose the existing connection and click **Done** to confirm.

9. Similarly configure the Celigo APIs connection, by choosing your existing connection.

10. You will be navigated to the API builder canvas for the cloned API. Review the version of this API at the top of the screen, to the right of the API name.

## Step 2: Update your new API to make a breaking change

1. Make the changes to the API which you wanted to do earlier in a previous step, i.e. open the API request node and update the Relative URI from **/item** to **/items**.

2. **Save & close** the request node.

3. On the top-right the API builder canvas, click on the gear icon to open the **API settings**.

4. Update the API name and description as per your need.

## Step 3: Deprecate your existing API

1. In the API settings page for the newly created v2 API, click on **Download OpenAPI spec** button to download, so that the OpenAPI specification can be shared with your API consumers. **Save & close** the panel.

2. Let’s say your customers and partners have started adopting the new API and have stopped using the existing API.

3. To verify the same, go to the APIs page, and select **View request logs** from the ellipsis for the v1 API, as shown below.

4. In the View request logs page, click on the filter icon for Time, and choose a duration, e.g. Last 15 minutes. Click **Apply**.

5. You should see the message - _“You don’t have any request log entries”_, if there are no calls made during that time duration. **Close** the panel.

6. In the APIs page, click on the **Off/On** toggle to disable the v1 API of ACME Fetch Items and Send Notifications API, as shown below.

7. After disabling the API, if you don’t see a need to keep the old version, you may want to delete the API. Click on the ellipsis icon again for that API, to open the **Actions** menu drop down.

8. Choose **Delete API** from the drop down. Click **Delete** in the dialog box that opens to confirm the API delete.

> 🏅 **SUCCESS**  
> You finished this section - great job! You have successfully created a new version of an API and deprecated the existing API.

* * *

# Module 7: Manage your API lifecycle with snapshots, pull/merge

> ⏱ **ESTIMATED TIME** : 30 minutes

## What You'll Learn

APIs now get the same **Integration Lifecycle Management (ILM)** controls that flows have always had — snapshot, clone, pull, merge, revert, and download/upload. In this module you'll learn how to:

- Group your APIs into an integration so they participate in ILM

- Create a **snapshot** that captures your APIs alongside your flows, and revert to it when a change goes wrong

- Promote API changes across environments using **clone** and **pull/merge** , so multiple builders can work in parallel and reconcile safely

- Review API changes on the **Review changes** page before merging

- **Ignore** environment-specific API fields (name, version, relative URI) so they aren't overwritten during a pull/merge

- **Download** and **upload** integrations — and standalone APIs — as portable zip files

> 📗 **TERM - Integration Lifecycle Management (ILM)**  
> **ILM** gives your integrations ability to version control — snapshot, clone, pull, merge, revert, and download/upload. APIs get the same lifecycle management as flows, so you can snapshot, promote, and transport them right alongside your flows.

## Scenario

ACME's APIs are now business-critical — external distributors depend on them every day, and several builders on your team iterate on them at the same time.

In this module you'll bring your APIs under ILM: back them up with snapshots, let teammates build in parallel and reconcile changes with pull/merge, promote safely across environments, and package everything for transport to another account.

> 🖊 **NOTE**  
> ILM operations — snapshots, revisions, pull/merge, and download/upload — work at the **integration** level. To manage an API's lifecycle, the API must belong to an integration. Snapshots and pulls are supported for integrations that contain flows, APIs, or both.

## Step 1: Move your APIs to group them into an integration

1. In Celigo [integrator.io](http://integrator.io), ensure you are in the **Development** environment.

2. Go to the Resources \> APIs page and open the Actions menu drop down for the **ACME Item Info API**.

3. Select **Move to integration**.

4. Select **Create new integration** , and name it **ACME API Services**. Click **Save & next**.

5. From Resources \> APIs page, select **Move to integration** again for **ACME Fetch Items and Send Notifications API**.

6. Select Move to existing integration, and select **ACME API Services**. Click **Save & next**.

7. Go back to the Home page and open **ACME API Services** integration. Your APIs now appear inside the integration — this is what enables the ILM operations in the following steps.

## Step 2: Create a snapshot and revert

1. Open **ACME API Services** integration and select the **Revisions** tab. You may need to click on **More** to access it.

2. Select **Create snapshot**. In the **Create snapshot** pane, enter a description — e.g. _"Baseline before API changes"_ — and select **Create**.

3. The snapshot appears in the **Revisions** list with a **Completed** status. Because your APIs are part of this integration, the snapshot captures their full configuration — request node, transformation, lookups, response nodes, and mappings — right alongside your flows.

> 📗 **TERM - Snapshot**  
> A **snapshot** is a point-in-time backup of an integration's configuration — that you can revert to at any time. [integrator.io](http://integrator.io) also creates snapshots automatically before and after every completed pull, giving you two restore points per pull.

1. Now make a change you might want to undo: open **ACME Item Info API** under **APIs** tab, change the relative URI or a response mapping, and **Save & close**.

2. Return to the **Revisions** tab. On the snapshot row, select **Actions (…)** \> **Revert to this revision** and confirm. Enter a description - **Revert to baseline**.

3. Reopen **ACME Item Info API** and confirm your change is gone — the API state is restored along with the rest of the integration.

> 🛠 **PRO TIP**  
> This is the "revert without fear" safety net: the whole integration — flows and APIs — rolls back together to a consistent state. No more rolling back a flow only to discover the API it depends on is now out of sync.

## Step 3: Promote API changes with clone and pull/merge

> 📗 **TERM - Clone, Pull, and Merge**  
> A **clone** creates a _directly related_ copy of an integration (including its APIs). Related integrations can exchange changes through **pull** (bring changes from a related integration into your current one) and **merge** (apply the reviewed changes) — the basis for parallel development and environment promotion.

1. On the Home page, open **ACME API Services**. From the integration **Actions (…)** menu, select **Clone integration**. Choose a target — a clone in **Development** for parallel work, or the **Production** environment to promote. The clone includes the integration's APIs and flows.

2. In the clone, make a change to an API — for example, add a new query parameter to **ACME Item Info API** or update a response field. **Save** and test.

> 🖊 **NOTE**  
> Only change **one** integration at a time. If you edit both the original and the clone before merging, the merge will fail. Any change made _after_ you start a pull isn't included — you'd need a second pull to bring it in.

1. In the integration you want to bring the changes into (the original, or your Production integration), select **Revisions** \> **Create pull**. [integrator.io](http://integrator.io) compares the two related integrations and opens the **Review changes** page.

2. On the **Review changes** page, changes are grouped by resource type. With this release, a dedicated **APIs** section appears alongside Flows, Exports, Imports, and Scripts. Each changed API shows an **Action** label — **New** , **Update** , or **Removed**.

3. Select **View resource changed** for the changed API to see the diff — exactly what's different (e.g. the new query parameter or updated relative URI) — before you commit anything.

4. Select **Next** to approve and **Merge** the changes. [integrator.io](http://integrator.io) automatically creates snapshots before and after the merge, so you can revert either way. The pull is recorded in the **Revisions** tab.

> 🛠 **PRO TIP**  
> Use pull/merge to promote APIs to a higher environment (Development → Production) instead of manual rebuilds. Multiple builders can iterate on their own clones in parallel and reconcile through pull/merge — the same way flows have always worked.

## Step 4: Ignore environment-specific API fields during pull/merge

Some API fields are meant to differ between environments and shouldn't be overwritten when you pull — for example an API's **name** , **version** , or **relative URI**.

1. In the integration, before you create a pull, select **Ignore fields during pull**.

2. Locate your API in the resource list and select the fields to ignore — e.g. **name** , **version** , **relative URI**. These fields are then skipped during both pull and merge, and their values in the target integration are preserved.

3. Create the pull again and confirm on the **Review changes** page that the ignored API fields are no longer part of the changes.

> 🖊 **NOTE**  
> Ignoring a field only skips **updates** to that field — it does not prevent a resource from being newly created or deleted. Revert also supports these API changes.

## Step 5: Download and upload integrations for transport

1. To back up or move your work, open **ACME API Services** and, from the **Actions (…)** menu, select **Download integration**. [integrator.io](http://integrator.io) generates a zip that now includes your APIs along with your flows.

2. To move a single API, you can also **download an API standalone** from its **Actions** menu on the **Resources \> APIs** page.

> 📗 **TERM - Download / Upload**  
> **Download** packages an integration (or a standalone API) into a portable zip. **Upload** installs that zip into another account or environment — so you can transport complete solutions, APIs included.

1. To bring a packaged integration into another account or environment, use **Upload integration** from the Home page and select the zip. The uploaded integration includes its APIs and flows.

> 🛠 **PRO TIP**  
> Revisions (snapshots) are best for in-place rollback within an account; download/upload is best for portability _across_ accounts — sharing a reference build, seeding a new account, or archiving a known-good version outside [integrator.io](http://integrator.io).

> 🏅 **SUCCESS**  
> You finished this section — great job! Your APIs now enjoy the same full lifecycle management as flows: snapshot and revert, clone and pull/merge across environments, and download/upload for transport. You can **promote in one step, revert without fear, and build in parallel**.

# **Completion**

Congratulations! You've finished your second Builder Lab and are now ready to start solving real world automation challenges using APIs. You've earned another chocolate bar!

Please let us know you completed this lab by replying to this topic below with " **COMPLETED**". We'll validate and then mark the badge on our profile here in Connective. We'd also love to hear any other feedback you might have, so please do tell.

If you are ready to take the next step, we suggest as the next follow-up to tackle lab [202 - Getting started with API management](https://connective.celigo.com/t/202-getting-started-with-api-management/5596). You will learn the API management product and also extends on many of the concepts you've just learned.

---

<div class="post-metadata">

**Author:** ![nuriensing](https://sea1.discourse-cdn.com/flex001/user_avatar/connective.celigo.com/nuriensing/32/6918_2.png) [@nuriensing](https://connective.celigo.com/u/nuriensing)\
**Post date:** [October 28, 2025, 8:37am UTC](https://connective.celigo.com/t/builders-lab-getting-started-with-api-builder/5404/8 "2025-10-28T08:37:49Z")

</div>

Thanks for the detailed tutorial. Exactly what we needed!