REST API

Overview

A REST API is an application programming interface that conforms to the constraints of REST (representational state transfer) architectural style and allows for interaction with RESTful web services.

REST APIs work by fielding requests for a resource and returning all relevant information about the resource, translated into a format that clients can easily interpret (this format is determined by the API receiving requests). Clients can also modify items on the server and even add new items to the server through a REST API.

The REST API source support batch syncs.

Info tab

You can find the parameters in the Info tab below (Image 1).

Values

Parameter	Description	Example
Title	Mandatory. Input a name for your data sync	REST API Sync
Variables	Optional. Review our documentation on Variables here for more information about this field.
Permissions	Data syncs are role based access systems where you can give specific groups read, write, execute, and/or all of the above with admin access. Inputting at least an Admin Group is mandatory.

Image 1: The Info Tab

Source tab

Mandatory and optional parameters for the Source tab are outlined below (Image 2).

Source Details

Parameter	Description	Example
Source	Mandatory. Select your source from the drop down menu.	REST API
HTTP Method	Mandatory.	This will be either GET or POST.
API Response Format	Mandatory. Use this field to specify a response format of the endpoint. Currently, the Connections UI only supports JSON responses.	JSON
Records Root JSONPath	Mandatory. Specify the JSON path for the results. The root of a JSON object is $. If the top-element of the response is an array, Cinchy places the array under a "data" key in a new JSON object. See Best practices for more info.	$.data, $, $.ResponseObject
Path to Iterate	The path to select an array of records for capturing elements inside. A record is created for each element which you can use as the input in a source schema. The path is relative to the root JSONPath.
API Endpoint URL	Mandatory. API endpoint, including URL parameters like API key	https://www.quandl.com/api/v3/datatables/CLS/IDHP?fx_business_date=2024-01-01&api_key=@API_KEY
Next Page URL JSONPath	Specify the path for the next page URL. This is only relevant for APIs that use cursor pagination

Schema

The Schema section is where you define which source columns you want to sync in your connection. You can repeat the values for multiple columns.

Parameter	Description	Example
Name	Mandatory. The name of your column as it appears in the source.	Name
Alias	Optional. You may choose to use an alias on your column so that it has a different name in the data sync.
Data Type	Mandatory. The data type of the column values.	Text
Description	Optional. You may choose to add a description to your column.

Select Show Advanced for more options for the Schema section.

Parameter	Description	Example
Mandatory	- If both 'Mandatory' and 'Validated': empty rows rejected. - If only 'Mandatory': rows synced but marked as failed with 'Mandatory Rule Violation'.
Validate Data	- If both 'Mandatory' and 'Validated': empty rows rejected. - If only 'Validated': all rows synced.
Trim Whitespace	Optional for text data. Choose to trim whitespace.
Max Length	Optional for text data. Set max length; exceeding values get rejected.

You can choose to add in a Transformation > String Replacement by inputting the following:

Parameter	Description	Example
Pattern	Mandatory when using a Transformation. The pattern for your string replacement.
Replacement	What you want to replace your pattern with.

Note that you can have more than one String Replacement

Other Sections

More options are available to you under the "Add a Section" drop down.

Note that adding a Pagination Block is mandatory.

You can learn more about these sections in Appendix A - Other Sections.

Image 2: The Source Tab

Best practices

Retrieve nested fields

To get fields in a nested array, you can either set the nested array as the root, or you can use Path to Iterate to expand the array.

Examples

Here is a sample JSON response:

  {
  "groupId": 111,
  "users": [{
      "userID": 1,
      "name": "Jack"
  },
  {
      "userID": 2,
      "name": "Jill"
  }
  ]
}

Records Root JSONPath: $.users Schema:

• $.userId for ID

• $.name for Name

You can't reference "groupId" as it's one level above the specified root scope.

JSON array handling

Use $.data in Records Root JSONPath if the API returns a top-level JSON array.

Examples

Here is a sample JSON response:

[
  {
  "name": "John Doe",
  "age": 21,
},
{"name": "Jane Doe",
  "age": 21
}
]

Records Root JSONPath: $.data

Schema:

• $.name for Name

• $.age for Age

Path to Iterate

Use Path to Iterate to expand on an array. It allows you to target nested keys within the array. This only applies if the records within an array are objects.

If the record within the path to iterate is an array, each item within the array gets placed under an "item" key in a new JSON object.

Example

For example, here is a sample JSON response:

{
  "name": "John",
  "transactions": [{ "transactionId": 1 }, { "transactionId": 2 }]
}

In this example, we want to iterate over the "transactions" array and capture the records for "transactionid" and assign them to the "Transaction ID" column, and then add the parent "name" key to a Name column .

Records Root JSONPath: $ Path to iterate: $.transactions

Schema:

• $.name for Name

• $.transactions.id for Transaction ID

Next steps

• Configure your Destination

• Define your Sync Actions.

• Add in your Post Sync Scripts, if required.

• To run a batch sync, select Jobs > Start Job

Resources

Auth Request

For more information, see the page about auth requests.

Request Headers

For more information, see the page about request headers.

Body

You are able to use this section to add body content.

Pagination

A pagination block is mandatory. Review the documentation here for more on pagination blocks.

Retry Configuration

Retry Configuration automatically retries HTTP Requests on failure based on a defined set of conditions. This provides a mechanism to recover from transient errors, such as network disruptions or temporary service outages.

Note: the maximum number of retries is capped at 10.

To set up a retry specification:

1. Under the REST API source tab, select API Specification > Retry Configuration

1. Select your Delay Strategy.

• Linear Backoff: Defines a delay of approximately n seconds where n = current retry attempt.

• Exponential Backoff: A strategy where every new retry attempt is delayed exponentially by 2^n seconds, where n = current retry attempt.

  • Example: you defined Max Attempts = 3. Your first retry is going to be in 2^1 = 2, second: 2^2 = 4, third: 2^3 = 8 sec.

3. Input your Max Attempts. The maximum number of retries allowed is 10.

1. Define your Retry Conditions. You must define the conditions under which a retry should be attempted. For the Retry to trigger, at least one of the "Retry Conditions" has to evaluate to true.

Retry conditions are only evaluated if the response code isn't 2xx Success.

Each Retry Condition contains one or more "Attribute Match" sections. This defines a regex to evaluate against a section of the HTTP response. The following are the three areas of the HTTP response that can be inspected:

• Response Code

• Header

• Body

If there are multiple "Attribute Match" blocks within a Retry Condition, all have to match for the retry condition to evaluate to true.

Note that the Regex value should be entered as a regular expression. The Regex engine is .NET and expressions can be tested by using this online tool. In the below example, the Regex is designed to match any HTTP 5xx Server Error Codes, using a Regex value of 5[0-9][0-9]. For Headers, the format of the Header string which the regex is applied against is {Header Name}={Header Value}. For example "Content-Type=application/json".

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