Supabase Migration Deep Dive

What it does

When your agent uses it

• Creating database migrations
• Performing zero-downtime schema changes
• Backfilling data in production
• Managing schema versions

Example prompts

• “supabase migration”
• “supabase schema change”
• “supabase zero downtime”
• “/supabase-migration-deep-dive”

Requirements

• Node.js
• Compatibility (from SKILL.md): Designed for Claude Code
• Pre-approved tools (allowed-tools): Read, Write, Edit, Bash(npx supabase:*), Bash(supabase:*), Bash(psql:*), Grep, Glob

Workflow steps

3 steps, taken from the step headings in SKILL.md.

1. 1Create and Manage Migrations
2. 2Zero-Downtime Migration Patterns
3. 3Data Backfill, Versioning, and Rollback

What it can do on your machine

Read from SKILL.md and the folder at commit cfae287. It shows what the files ask for, not the result of running them.

• Tool permissions

  Pre-approves these tools, so the agent can use them without asking each time:

  • Read
  • Write
  • Edit
  • Bash(npx supabase:*)
  • Bash(supabase:*)
  • Bash(psql:*)
  • Grep
  • Glob

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • npx
  • supabase
  • npm

  From the folder's file list and the shell code blocks in SKILL.md.

• Network

  Links to these hosts (documentation or services it may open):

  • supabase.com
  • postgresql.org

  From URLs in SKILL.md, links to its own repository left out.

• Credentials

  Names no API keys, tokens, secrets or passwords.

  From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

• Compatibility

  Designed for Claude Code

  From compatibility in the SKILL.md frontmatter.

Context cost

Supabase Migration Deep Dive loads about 1.9k tokens when it runs, and up to ~7.2k if it reads all its reference files. Until then it costs about 139 tokens; SKILL.md has 658 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it

~139

When it runs · the whole SKILL.md, loaded when a task matches

~1.9k

With references · SKILL.md plus every file in references/, read only if the agent opens them

~7.2k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from jeremylongshore/tons-of-skills-marketplace at commit cfae287, republished under its MIT licence (© jeremylongshore). 658 words, ~1,946 tokens.

name

supabase-migration-deep-dive

description

Database migration patterns with the Supabase CLI: npx supabase migration new, zero-downtime migrations, data backfill strategies, schema versioning, rollback strategies, and TypeScript type generation. Use when creating database migrations, performing zero-downtime schema changes, backfilling data in production, managing schema versions, or planning rollback strategies. Trigger with "supabase migration", "supabase schema change", "supabase zero downtime", "supabase rollback", "supabase db push", "supabase migration new".

allowed-tools

Read, Write, Edit, Bash(npx supabase:*), Bash(supabase:*), Bash(psql:*), Grep, Glob

compatibility

Designed for Claude Code

version

1.54.0

license

MIT

author

Jeremy Longshore <jeremy@intentsolutions.io>

tags

saas, supabase, migration, database, schema, zero-downtime, rollback

npx supabase migration new add_profiles_table   # create timestamped SQL file
npx supabase migration list                      # show applied/pending status
npx supabase db reset                            # apply + seed locally (destructive)
npx supabase gen types typescript --local > lib/database.types.ts
npx supabase link --project-ref "<ref>" && npx supabase db push   # promote to remote

-- Nullable column with a default does NOT lock the table in Postgres 11+
ALTER TABLE public.orders ADD COLUMN status text DEFAULT 'pending';
-- Then, in a separate -- supabase:disable-transaction migration:
CREATE INDEX CONCURRENTLY IF NOT EXISTS idx_orders_status ON public.orders(status);

npx supabase migration new add_tags_to_projects
cat > supabase/migrations/20260322150000_add_tags_to_projects.sql << 'SQL'
ALTER TABLE public.projects ADD COLUMN tags text[] DEFAULT '{}';
CREATE INDEX idx_projects_tags ON public.projects USING GIN(tags);
SQL
npx supabase db reset
npx supabase gen types typescript --local > lib/database.types.ts
npx supabase link --project-ref <staging-ref> && npx supabase db push

© jeremylongshore, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

SKILL.md and 7 other files (references) in skills/.curated/supabase-migration-deep-dive of jeremylongshore/tons-of-skills-marketplace.

• SKILL.md
• references/backfill-versioning-rollback.md
• references/creating-migrations.md
• references/errors.md
• references/examples.md
• references/implementation-plan.md
• references/pre-migration-assessment.md
• references/zero-downtime-patterns.md

Open the folder on GitHubat commit cfae287