Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add JustineDevs/premortem --skill supabase-postgres-best-practicesgit clone --depth 1 https://github.com/JustineDevs/premortemWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/justinedevs/premortem/supabase-postgres-best-practices)<a href="https://agentmods.dev/skills/justinedevs/premortem/supabase-postgres-best-practices"><img src="https://agentmods.dev/badge/skills/justinedevs/premortem/supabase-postgres-best-practices/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/justinedevs/premortem/supabase-postgres-best-practices"><img src="https://agentmods.dev/badge/skills/justinedevs/premortem/supabase-postgres-best-practices.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00041 | $0.00565 |
| Opus 5 | $0.00020 | $0.00282 |
| Sonnet 5 | $0.00008 | $0.00113 |
| Haiku 4.5 | $0.00004 | $0.00056 |
Grade A, and why
supabase-postgres-best-practices scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
This is a copy
83% identical to supabase-postgres-best-practices — 2 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
What it actually says
Supabase Postgres Best Practices
Comprehensive performance optimization guide for Postgres, maintained by Supabase. Contains rules across 8 categories, prioritized by impact to guide automated query optimization and schema design.
When to Apply
Reference these guidelines when:
- Writing SQL queries or designing schemas
- Implementing indexes or query optimization
- Reviewing database performance issues
- Configuring connection pooling or scaling
- Optimizing for Postgres-specific features
- Working with Row-Level Security (RLS)
Rule Categories by Priority
| Priority | Category | Impact | Prefix |
|---|---|---|---|
| 1 | Query Performance | CRITICAL | query- |
| 2 | Connection Management | CRITICAL | conn- |
| 3 | Security & RLS | CRITICAL | security- |
| 4 | Schema Design | HIGH | schema- |
| 5 | Concurrency & Locking | MEDIUM-HIGH | lock- |
| 6 | Data Access Patterns | MEDIUM | data- |
| 7 | Monitoring & Diagnostics | LOW-MEDIUM | monitor- |
| 8 | Advanced Features | LOW | advanced- |
How to Use
Read individual rule files for detailed explanations and SQL examples:
references/query-missing-indexes.md
references/query-partial-indexes.md
references/_sections.md
Each rule file contains:
- Brief explanation of why it matters
- Incorrect SQL example with explanation
- Correct SQL example with explanation
- Optional EXPLAIN output or metrics
- Additional context and references
- Supabase-specific notes (when applicable)
References
What ships with it
35 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- CHANGELOG.md 2.0 KB
- references/_contributing.md 4.0 KB
- references/_sections.md 1.6 KB
- references/_template.md 1.0 KB
- references/advanced-full-text-search.md 1.4 KB
- references/advanced-jsonb-indexing.md 1.4 KB
- references/conn-idle-timeout.md 1.3 KB
- references/conn-limits.md 1.3 KB
- references/conn-pooling.md 1.3 KB
- references/conn-prepared-statements.md 1.5 KB
- references/data-batch-inserts.md 1.3 KB
- references/data-n-plus-one.md 1.3 KB
- references/data-pagination.md 1.3 KB
- references/data-upsert.md 1.4 KB
- references/lock-advisory.md 1.5 KB
- references/lock-deadlock-prevention.md 1.8 KB
- references/lock-short-transactions.md 1.3 KB
- references/lock-skip-locked.md 1.3 KB
- references/monitor-explain-analyze.md 1.4 KB
- references/monitor-pg-stat-statements.md 1.4 KB
- references/monitor-vacuum-analyze.md 1.5 KB
- references/query-composite-indexes.md 1.4 KB
- references/query-covering-indexes.md 1.3 KB
- references/query-index-types.md 1.5 KB
- references/query-missing-indexes.md 1.2 KB
- references/query-partial-indexes.md 1.3 KB
- references/schema-constraints.md 1.8 KB
- references/schema-data-types.md 1.4 KB
- references/schema-foreign-key-indexes.md 1.6 KB
- references/schema-lowercase-identifiers.md 1.7 KB
- references/schema-partitioning.md 1.5 KB
- references/schema-primary-keys.md 1.8 KB
- references/security-privileges.md 1.5 KB
- references/security-rls-basics.md 1.3 KB
- references/security-rls-performance.md 2.1 KB
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 8d ago First seen · 65 lines · 41 tokens per session scan A ccd6e4596bd5
supabase-postgres-best-practices is a skill published in the GitHub repository JustineDevs/premortem (2 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 41 tokens to every session and 565 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 83% identical to supabase-postgres-best-practices, differing in 2 lines, and is treated as a copy.
Other skills, from other repositories
azure-resource-manager-postgresql-dotnet
Azure PostgreSQL Flexible Server SDK for .NET. Database management for PostgreSQL Flexible Server deployments. Use for creating servers, databases, firewall rules, configurations, backups, and high availability. Triggers: "PostgreSQL", "PostgreSqlFlexibleServer", "PostgreSQL Flexible Server", "Azure Database for…
azure-postgres-ts
Connect to Azure Database for PostgreSQL Flexible Server from Node.js/TypeScript using the pg (node-postgres) package. Use for PostgreSQL queries, connection pooling, transactions, and Microsoft Entra ID (passwordless) authentication. Triggers: "PostgreSQL", "postgres", "pg client", "node-postgres", "Azure PostgreSQL…
neon
Use when you have picked Neon (serverless Postgres) and need to connect correctly from a serverless or edge runtime, wire database branching into dev, preview and CI, or stop being burned by scale-to-zero cold starts and pooler limits — including choosing HTTP versus WebSocket connections and pooled versus direct…
postgresdb
Use when PostgreSQL engine behaviour decides the answer — schema and type design, index choice, reading EXPLAIN on a slow query, zero-downtime DDL and backfills, or ops (roles, RLS, pooling, vacuum, partitioning, PITR). PG16, ORM-agnostic. NOT portable query logic (that is sql), NOT a managed provider's platform…
diesel-guard
Lints Diesel and SQLx Postgres migrations for unsafe schema changes that lock tables or cause downtime, and authors custom Rhai checks. Use when reviewing, writing, or fixing SQL migrations, when diesel-guard reports a violation, when configuring diesel-guard.toml, or when the user mentions migration safety, table…
srtd-cli
This skill should be used when the user mentions "srtd", "sql templates", "migrations-templates", "live reload sql", "supabase functions", when working with files in supabase/migrations-templates/, when .buildlog.json or srtd.config.json is detected, or when writing Postgres functions/views/triggers for Supabase.