Environment variables and secrets in Supabase - Step-by-Step Execution

Process Flow - Environment variables and secrets

Start: Deploy Supabase Project

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Set Environment Variables

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Set Secrets (Sensitive Data)

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Supabase Reads Variables & Secrets

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Use Variables in Functions/Configs

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Run Project with Secure Config

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End

This flow shows how you set environment variables and secrets in Supabase, which the system then uses securely during project execution.

Execution Sample

Supabase

SUPABASE_URL=https://xyz.supabase.co
SUPABASE_ANON_KEY=anon-key-123

// Use in function:
const url = Deno.env.get('SUPABASE_URL');

This code sets environment variables for Supabase URL and anon key, then accesses the URL in code securely.

Process Table

Step	Action	Variable/Secret Set	Value	Effect
1	Deploy Supabase project	None	None	Project created, ready for config
2	Set environment variable SUPABASE_URL	SUPABASE_URL	https://xyz.supabase.co	URL stored for project use
3	Set secret SUPABASE_ANON_KEY	SUPABASE_ANON_KEY	anon-key-123	Secret stored securely, hidden from logs
4	Supabase reads variables	SUPABASE_URL	https://xyz.supabase.co	Variable available to runtime
5	Supabase reads secrets	SUPABASE_ANON_KEY	anon-key-123	Secret available securely to runtime
6	Code accesses SUPABASE_URL	SUPABASE_URL	https://xyz.supabase.co	Code uses URL to connect to Supabase
7	Code accesses SUPABASE_ANON_KEY	SUPABASE_ANON_KEY	anon-key-123	Code uses anon key for authentication
8	Run project	None	None	Project runs with secure config
9	Exit	None	None	All variables and secrets used securely

💡 All environment variables and secrets set and used securely; project runs with correct config

Status Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	After Step 5	Final
SUPABASE_URL	undefined	https://xyz.supabase.co	https://xyz.supabase.co	https://xyz.supabase.co	https://xyz.supabase.co	https://xyz.supabase.co
SUPABASE_ANON_KEY	undefined	undefined	anon-key-123	anon-key-123	anon-key-123	anon-key-123

Key Moments - 3 Insights

Why do we set environment variables separately from secrets?

Environment variables like URLs are less sensitive and can be visible in some logs, but secrets like keys must be stored securely and hidden from logs, as shown in steps 2 and 3 of the execution_table.

How does the code access these variables safely?

The code accesses variables via Deno.env.get('VAR_NAME'), which reads the secure environment at runtime, ensuring secrets are not hardcoded, as shown in steps 6 and 7.

What happens if a secret is missing?

If a secret is missing, the project may fail to authenticate or connect properly, causing errors at runtime, which would be evident if the value is undefined in the variable_tracker.

Visual Quiz - 3 Questions

Look at the execution_table at step 3. What is the value of SUPABASE_ANON_KEY?

A https://xyz.supabase.co

B undefined

C anon-key-123

D null

💡 Hint

Check the 'Variable/Secret Set' and 'Value' columns at step 3 in execution_table.

At which step does the code first access the SUPABASE_URL variable?

A Step 4

B Step 6

C Step 2

D Step 8

💡 Hint

Look for 'Code accesses SUPABASE_URL' in the Action column of execution_table.

If SUPABASE_ANON_KEY was not set at step 3, what would be its value at step 7?

A undefined

B anon-key-123

C null

D empty string

💡 Hint

Refer to variable_tracker to see how missing secrets appear as undefined.

Concept Snapshot

Environment variables store configuration like URLs.
Secrets store sensitive data like keys securely.
Set them in Supabase dashboard or CLI.
Access in code via Deno.env.get('VARIABLE_NAME').
Secrets are hidden from logs and safe at runtime.
Always keep secrets out of code files.

Full Transcript

This lesson shows how environment variables and secrets work in Supabase. First, you deploy your project. Then you set environment variables like SUPABASE_URL and secrets like SUPABASE_ANON_KEY. Supabase reads these securely at runtime. Your code accesses them using Deno.env.get(). This keeps sensitive data safe and your project configured correctly. The execution table traces each step from setting variables to running the project. The variable tracker shows how values change. Key moments clarify why secrets are separate and how code uses them. The quiz tests your understanding of these steps and values.