Invoking Edge Functions from client in Supabase - Step-by-Step Execution

Process Flow - Invoking Edge Functions from client

Client triggers function call

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Send HTTP request to Edge Function URL

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Edge Function receives request

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Edge Function processes logic

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Edge Function sends response

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Client receives response and handles it

The client sends a request to the Edge Function URL, the function runs its logic, then returns a response back to the client.

Execution Sample

Supabase

const { data, error } = await supabase.functions.invoke('hello');
if (error) console.error(error);
else console.log(data.message);

Client calls the Edge Function named 'hello' and logs the response or error.

Process Table

Step	Action	Request Status	Response Data	Client Output
1	Invoke 'hello' Edge Function	Request sent	N/A	Waiting for response
2	Edge Function receives request	Processing	N/A	Waiting for response
3	Edge Function runs logic	Processing	{"message":"Hello from Edge!"}	Waiting for response
4	Edge Function sends response	Completed	{"message":"Hello from Edge!"}	Waiting for response
5	Client receives response	Completed	{"message":"Hello from Edge!"}	Logs: Hello from Edge!
6	End	N/A	N/A	Process complete

💡 Client received response and logged the message, ending the invocation process.

Status Tracker

Variable	Start	After Step 1	After Step 3	After Step 5	Final
data	undefined	undefined	undefined	{"message":"Hello from Edge!"}	{"message":"Hello from Edge!"}
error	undefined	undefined	undefined	undefined	undefined

Key Moments - 2 Insights

Why does the client wait after sending the request before logging the data?

Because the request is asynchronous, the client must wait for the Edge Function to process and respond before data is available, as shown between steps 1 and 5 in the execution table.

What happens if the Edge Function returns an error?

The error variable will be set and the client can handle it, for example by logging it. This is implied in the sample code where error is checked after invocation.

Visual Quiz - 3 Questions

Look at the execution table, what is the client output at step 5?

A Logs: Hello from Edge!

B Waiting for response

C Request sent

D Process complete

💡 Hint

Check the 'Client Output' column at step 5 in the execution table.

At which step does the Edge Function send its response back to the client?

A Step 2

B Step 5

C Step 4

D Step 3

💡 Hint

Look at the 'Action' and 'Request Status' columns to find when the response is sent.

If the Edge Function returned an error, which variable would hold that information?

A response

B error

C data

D status

💡 Hint

Refer to the variable_tracker where 'error' is used to capture issues.

Concept Snapshot

Invoke Edge Functions from client using supabase.functions.invoke('functionName').
The call sends a request to the Edge Function URL.
The function runs and returns a response.
Client awaits response asynchronously.
Handle errors by checking the error variable.
Use the returned data as needed.

Full Transcript

This visual execution shows how a client calls a Supabase Edge Function named 'hello'. The client sends a request asynchronously and waits. The Edge Function receives the request, runs its logic, and sends back a JSON response with a message. The client receives this response and logs the message. Variables 'data' and 'error' track the response and any errors. Key moments include understanding asynchronous waiting and error handling. The quiz tests knowledge of client output timing, response sending step, and error variable usage.