Supabase Advanced Troubleshooting

What it does

When your agent uses it

• Standard troubleshooting fails
• Investigating performance regressions
• Debugging race conditions
• Building evidence for a Supabase support escalation

Example prompts

• “supabase deep debug”
• “supabase slow query”
• “supabase lock contention”
• “/supabase-advanced-troubleshooting”

Requirements

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

Workflow steps

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

1. 1pg_stat_statements and slow query analysis
2. 2lock debugging and connection leak detection
3. 3RLS conflicts, Edge Function cold starts, and Realtime drops

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
  • Grep
  • Bash(npx supabase:*)
  • Bash(supabase:*)
  • Bash(curl:*)
  • Bash(psql:*)

  From allowed-tools in the SKILL.md frontmatter.

• Runs code

  Shell commands in SKILL.md call:

  • supabase

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

• Network

  Hosts in commands or code, which the agent is likely to contact:

  • supabase.com

  Also links to:

  • postgresql.org

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

• Credentials

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

  • 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 Advanced Troubleshooting loads about 2.8k tokens when it runs, and up to ~9.1k if it reads all its reference files. Until then it costs about 146 tokens; SKILL.md has 781 words of instructions outside code blocks.

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

~146

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

~2.8k

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

~9.1k

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). 781 words, ~2,783 tokens.

name

supabase-advanced-troubleshooting

description

Deep Supabase diagnostics: pg_stat_statements for slow queries, lock debugging with pg_locks, connection leak detection, RLS policy conflicts, Edge Function cold starts, and Realtime connection drop analysis. Use when standard troubleshooting fails, when investigating performance regressions, when debugging race conditions, or when building evidence for a Supabase support escalation. Trigger with "supabase deep debug", "supabase slow query", "supabase lock contention", "supabase connection leak", "supabase RLS conflict", "supabase cold start".

allowed-tools

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

compatibility

Designed for Claude Code

version

1.54.0

license

MIT

author

Jeremy Longshore <jeremy@intentsolutions.io>

tags

saas, supabase, debugging, advanced, performance, troubleshooting

CREATE EXTENSION IF NOT EXISTS pg_stat_statements;

SELECT queryid, calls,
  round(total_exec_time::numeric, 2) AS total_ms,
  round(mean_exec_time::numeric, 2)  AS avg_ms,
  left(query, 150) AS query_preview
FROM pg_stat_statements
ORDER BY total_exec_time DESC
LIMIT 10;

SELECT blocked.pid AS blocked_pid, blocking.pid AS blocking_pid,
  bl.mode AS lock_mode, left(blocked.query, 80) AS blocked_query
FROM pg_stat_activity blocked
JOIN pg_locks bl ON bl.pid = blocked.pid AND NOT bl.granted
JOIN pg_locks kl ON kl.relation = bl.relation AND kl.granted AND kl.pid != bl.pid
JOIN pg_stat_activity blocking ON blocking.pid = kl.pid
WHERE blocked.state = 'active';

-- Run this query to get a snapshot of database health
SELECT
  'Connections' AS metric,
  count(*)::text AS value
FROM pg_stat_activity WHERE datname = current_database()
UNION ALL
SELECT 'Cache hit ratio',
  round(100.0 * sum(heap_blks_hit) / nullif(sum(heap_blks_hit + heap_blks_read), 0), 2)::text || '%'
FROM pg_statio_user_tables
UNION ALL
SELECT 'Table bloat (dead tuples)',
  sum(n_dead_tup)::text
FROM pg_stat_user_tables
UNION ALL
SELECT 'Longest running query',
  coalesce(max(age(now(), query_start))::text, 'none')
FROM pg_stat_activity WHERE state = 'active' AND query NOT LIKE '%pg_stat%';

import { createClient } from '@supabase/supabase-js';

const supabase = createClient(url, serviceRoleKey, {
  auth: { autoRefreshToken: false, persistSession: false },
});

async function buildDiagnosticBundle() {
  const bundle: Record<string, any> = {
    timestamp: new Date().toISOString(),
    projectRef: process.env.SUPABASE_PROJECT_REF,
  };

  // Connection stats
  const { data: connHealth } = await supabase.rpc('get_connection_health');
  bundle.connections = connHealth;

  // Table sizes
  const { data: tableSizes } = await supabase.rpc('get_table_sizes');
  bundle.tableSizes = tableSizes;

  // Recent errors from application logs
  const { data: recentErrors } = await supabase
    .from('error_logs')
    .select('message, count, last_seen')
    .order('last_seen', { ascending: false })
    .limit(10);
  bundle.recentErrors = recentErrors;

  console.log(JSON.stringify(bundle, null, 2));
  // Submit with your support ticket at https://supabase.com/dashboard/support
}

import { createClient } from '@supabase/supabase-js';

const supabase = createClient(url, serviceRoleKey, {
  auth: { autoRefreshToken: false, persistSession: false },
});

async function checkSlowQueries(thresholdMs = 1000) {
  const { data: slowQueries } = await supabase.rpc('get_slow_queries', {
    threshold_ms: thresholdMs,
  });

  if (slowQueries && slowQueries.length > 0) {
    console.warn(`Found ${slowQueries.length} queries averaging > ${thresholdMs}ms`);
    for (const q of slowQueries) {
      console.warn(`  [${q.avg_ms}ms avg, ${q.calls} calls] ${q.query_preview}`);
    }
  }
}

// Database function:
// CREATE OR REPLACE FUNCTION get_slow_queries(threshold_ms numeric DEFAULT 1000)
// RETURNS TABLE(queryid bigint, avg_ms numeric, calls bigint, query_preview text) AS $$
//   SELECT queryid, round(mean_exec_time::numeric, 2), calls, left(query, 150)
//   FROM pg_stat_statements
//   WHERE mean_exec_time > threshold_ms AND calls > 10
//   ORDER BY mean_exec_time DESC LIMIT 10;
// $$ LANGUAGE sql SECURITY DEFINER;

© 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 8 other files (references) in skills/.curated/supabase-advanced-troubleshooting of jeremylongshore/tons-of-skills-marketplace.

• SKILL.md
• references/errors.md
• references/evidence-collection-framework.md
• references/examples.md
• references/lock-connection-diagnostics.md
• references/rls-edge-functions-realtime.md
• references/slow-query-analysis.md
• references/systematic-isolation.md
• references/timing-analysis.md

Open the folder on GitHubat commit cfae287