docs: add REDIS_URL and API v2 variables to root .env.example

[shockzinfinity]

What does this PR do?

Adds missing API v2 environment variables to the root .env.example that are required for Docker Compose self-hosting.

Problem

When self-hosting with Docker Compose, docker-compose.yml configures the calcom-api service using env_file: .env (root env) and explicitly passes variables like REDIS_URL, JWT_SECRET, and WEB_APP_URL to the container. However, none of these were documented in the root .env.example, causing the API v2 server to fail silently on startup with a missing REDIS_URL validation error.

Changes

Improved the # api v2 section in root .env.example:

• Added REDIS_URL (required — primary fix for the silent startup failure)
• Added JWT_SECRET (required for API v2 authentication)
• Added WEB_APP_URL (required for API v2)
• Added optional variables: REDIS_PORT, LOG_LEVEL, API_KEY_PREFIX, REWRITE_API_V2_PREFIX
• Improved comments explaining Docker Compose vs local dev setup
• Added cross-reference to apps/api/v2/.env.example for local development

Note

apps/api/v2/.env.example already contains REDIS_URL (added in #27290). This PR addresses the root .env.example for Docker Compose self-hosters who use that file as their configuration reference.

Fixes #25195
Related to #24987

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Chore (formatting, documentation, refactoring)

How has this been tested?

This is a documentation-only change (.env.example). No code behavior is affected.

• Verified against docker-compose.yml that the added variables match what the calcom-api service reads from root .env
• Verified against apps/api/v2/src/env.ts that the variables are required by the API v2 runtime

Checklist

• My changes are < 500 lines and affect < 10 files
• I have added "Allow edits from maintainers"
• .env.example changes do not affect application code

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[cubic-dev-ai]

No issues found across 1 file

[romitg2]

i don't think we're publishing api/v2 docker image for self-hosters.

[hthetiot]

i don't think we're publishing api/v2 docker image for self-hosters.

Why not? If I may ask ?
That supper useful for any environment including working on source for development. If that a commercial/licence issue ?

Best regards,

Harold

[hthetiot]

Super useful 👌

[romitg2]

i don't think we're publishing api/v2 docker image for self-hosters.

Why not? If I may ask ? That supper useful for any environment including working on source for development. If that a commercial/licence issue ?

Best regards,

Harold

i might be wrong here wrong here, checking!

[romitg2]

.