Batch create endpoint design in Rest API - Step-by-Step Execution

Concept Flow - Batch create endpoint design

Client sends batch create request

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Server receives request with multiple items

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Validate each item

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Create items

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Send response with created items and errors

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Client receives response

The client sends many items to create at once; the server checks each, creates valid ones, collects errors for invalid ones, then replies with results.

Execution Sample

Rest API

POST /items/batch
Body: [{"name":"A"},{"name":""},{"name":"B"}]

Response:
{
  "created": [{"id":1,"name":"A"},{"id":2,"name":"B"}],
  "errors": [{"index":1,"error":"Name required"}]
}

This example shows a batch create request with 3 items; one is invalid, so the response shows 2 created items and 1 error.

Execution Table

Step	Action	Item Index	Validation Result	Create Result	Response Part
1	Receive batch request	-	-	-	Items: [{"name":"A"},{"name":""},{"name":"B"}]
2	Validate item	0	Valid	Create item with id=1	Created: [{"id":1,"name":"A"}]
3	Validate item	1	Invalid (name empty)	Skip creation	Errors: [{"index":1,"error":"Name required"}]
4	Validate item	2	Valid	Create item with id=2	Created: [{"id":1,"name":"A"},{"id":2,"name":"B"}]
5	Send response	-	-	-	{"created":[{"id":1,"name":"A"},{"id":2,"name":"B"}],"errors":[{"index":1,"error":"Name required"}]}
6	Client receives response	-	-	-	Process created items and errors

💡 All items processed; response sent with created items and errors.

Variable Tracker

Variable	Start	After Item 0	After Item 1	After Item 2	Final
created_items	[]	[{"id":1,"name":"A"}]	[{"id":1,"name":"A"}]	[{"id":1,"name":"A"},{"id":2,"name":"B"}]	[{"id":1,"name":"A"},{"id":2,"name":"B"}]
errors	[]	[]	[{"index":1,"error":"Name required"}]	[{"index":1,"error":"Name required"}]	[{"index":1,"error":"Name required"}]

Key Moments - 3 Insights

Why do we continue processing items after finding an invalid one?

The execution_table rows 3 and 4 show that even after item 1 is invalid, item 2 is still processed to create all valid items in one request.

How does the server report which items failed validation?

Row 3 and the errors variable in variable_tracker show errors include the item index and error message, so the client knows exactly which item failed.

What happens if all items are valid?

If all items are valid, errors remain empty (see variable_tracker), and the response only contains created items without errors.

Visual Quiz - 3 Questions

Look at the execution_table at step 3, what is the validation result for item index 1?

A Invalid (name empty)

B Valid

C Skipped

D Created

💡 Hint

Check the 'Validation Result' column in row 3 of execution_table.

According to variable_tracker, what is the state of 'errors' after processing item 2?

A []

B [{"index":1,"error":"Name required"}]

C [{"index":2,"error":"Name required"}]

D [{"index":0,"error":"Name required"}]

💡 Hint

Look at the 'errors' row under 'After Item 2' column in variable_tracker.

If the second item was valid, how would the 'created_items' variable change after item 1?

A [{"id":1,"name":"A"}]

B [{"id":1,"name":"A"},{"id":2,"name":"B"}]

C [{"id":1,"name":"A"},{"id":2,"name":""}]

D [{"id":1,"name":"A"},{"id":2,"name":""},{"id":3,"name":"B"}]

💡 Hint

Refer to variable_tracker's 'created_items' row and imagine item 1 is valid but has empty name.

Concept Snapshot

Batch create endpoint design:
- Client sends multiple items in one request.
- Server validates each item individually.
- Valid items are created; invalid ones are reported with errors.
- Response includes created items and error details.
- This reduces multiple requests and improves efficiency.

Full Transcript

Batch create endpoint design lets clients send many items to create in one request. The server checks each item for validity. If an item is valid, it is created and added to the created list. If invalid, an error with the item's index and message is recorded. After processing all items, the server sends a response containing both the created items and any errors found. This approach helps clients create many items efficiently and handle errors clearly. The execution table shows each step: receiving the request, validating each item, creating valid items, collecting errors, and sending the response. The variable tracker shows how created items and errors grow after each item is processed. Key moments include understanding why processing continues after errors, how errors are reported, and what happens if all items are valid. The visual quiz tests understanding of validation results, error tracking, and variable changes. Overall, batch create endpoints improve API efficiency and error handling by processing multiple items in one go.