Supabase Common Errors

What it does

When your agent uses it

• Encountering error codes like PGRST301
• Debugging failed queries
• RLS policy violations
• HTTP 4xx/5xx responses

Example prompts

• “supabase error”
• “fix supabase”
• “supabase 403”
• “/supabase-common-errors”

Requirements

• Node.js
• A credential in SUPABASE_ANON_KEY
• A credential in SUPABASE_SERVICE_ROLE_KEY
• Compatibility (from SKILL.md): Designed for Claude Code
• Pre-approved tools (allowed-tools): Read, Grep, Bash(curl:*), Bash(supabase:*), Bash(npx:*)

Workflow steps

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

1. 1Capture the Error Object
2. 2Identify the Error Layer and Code
3. 3Apply the Fix and Verify

What it can do on your machine

Read from SKILL.md and the folder at commit 80f86df. 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
  • Grep
  • Bash(curl:*)
  • Bash(supabase:*)
  • Bash(npx:*)

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • supabase
  • npm
  • npx

  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
  • postgrest.org
  • postgresql.org
  • status.supabase.com

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

• Credentials

  Names these keys or tokens, usually read from environment variables:

  • SUPABASE_ANON_KEY
  • SUPABASE_SERVICE_ROLE_KEY

  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 Common Errors loads about 2.1k tokens when it runs, and up to ~5.9k if it reads all its reference files. Until then it costs about 110 tokens; SKILL.md has 823 words of instructions outside code blocks.

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

~110

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

~2.1k

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

~5.9k

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 80f86df, republished under its MIT licence (© jeremylongshore). 823 words, ~2,129 tokens.

name

supabase-common-errors

description

Diagnose and fix Supabase errors across PostgREST, PostgreSQL, Auth, Storage, and Realtime. Use when encountering error codes like PGRST301, 42501, 23505, or auth failures. Use when debugging failed queries, RLS policy violations, or HTTP 4xx/5xx responses. Trigger with "supabase error", "fix supabase", "PGRST", "supabase 403", "RLS not working", "supabase auth error", "unique constraint", "foreign key violation".

allowed-tools

Read, Grep, Bash(curl:*), Bash(supabase:*), Bash(npx:*)

compatibility

Designed for Claude Code

version

1.54.0

license

MIT

author

Jeremy Longshore <jeremy@intentsolutions.io>

tags

saas, supabase, debugging, errors, postgrest, rls, auth

const { data, error } = await supabase.from('todos').select('*')
if (error) {
  console.error(`[${error.code}] ${error.message}`)
  return  // data is null here — do not touch it
}
console.log(`Found ${data.length} rows`)

// BAD — throws PGRST116 when the user has no profile row
const { data: profile } = await supabase
  .from('profiles').select('*').eq('user_id', userId).single()

// GOOD — returns null instead of erroring
const { data: profile, error } = await supabase
  .from('profiles').select('*').eq('user_id', userId).maybeSingle()

if (!profile) {
  await supabase.from('profiles').insert({ user_id: userId, display_name: 'New User' })
}

© 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 4 other files (references) in skills/.curated/supabase-common-errors of jeremylongshore/tons-of-skills-marketplace.

• SKILL.md
• references/error-reference.md
• references/errors.md
• references/examples.md
• references/implementation.md

Open the folder on GitHubat commit 80f86df