agent-skills: Instructions file for Codex

AGENTS.md

agent-skills AGENTS.md is an instructions file for Codex, OpenCode from powersync-ja/agent-skills. It costs 286 tokens per session, scanned A, original, MIT.

Project instructions for PowerSync agent skills, including required setup questions, command-line procedures, backend choices, and verification steps. PowerSync synchronizes data between applications and databases.

In plain words
What is it for?
Use them when building or modifying PowerSync skills, choosing Cloud or self-hosted deployment, following setup procedures, or verifying changes.
Why use it?
They prevent agents from making incorrect hosting or backend assumptions and require changes to pass the project's security and validation checks.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md. Also seen: mentions AGENTS.md.

This is powersync-ja/agent-skills's own configuration. It tells Codex and OpenCode how to work on agent-skills itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything agent-skills configures →

Reuse

Borrowing it

Nothing to install: this file belongs to powersync-ja/agent-skills. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/powersync-ja/agent-skills/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/powersync-ja/agent-skills

Made for: Codex, OpenCode.

Wrote 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.

agentmods badge for agent-skills AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/powersync-ja/agent-skills/agents-md/github.svg)](https://agentmods.dev/instructions/powersync-ja/agent-skills/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/powersync-ja/agent-skills/agents-md"><img src="https://agentmods.dev/badge/instructions/powersync-ja/agent-skills/agents-md/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.

agentmods 80×15 button for agent-skills AGENTS.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/powersync-ja/agent-skills/agents-md"><img src="https://agentmods.dev/badge/instructions/powersync-ja/agent-skills/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 286 This file is loaded in full into every session.
When invoked 286 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00286 $0.00286
Opus 5.5 $0.00114 $0.00114
Sonnet 5.5 $0.00057 $0.00057
Haiku 4.5 $0.00029 $0.00029

Measured 1mo ago against content hash e517b5f71d2a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

agent-skills AGENTS.md 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 1mo 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.

AGENTS.md · 19 lines

What it actually says

PowerSync Agent Skills

If you are building or modifying anything that uses PowerSync, you must follow the playbook in skills/powersync/AGENTS.md — not a condensed summary.

That file includes:

  • Agent compliance (non-negotiable): ask Cloud vs self-hosted, ask backend if unspecified, CLI-first, no silent shortcuts.
  • Full onboarding sequence, setup paths, SDK references, and debugging.

Do not assume Supabase, assume self-hosted Docker, or skip CLI steps unless the user explicitly opts out.

powersync login is PowerSync Cloud only. Self-hosted does not use it — see skills/powersync/references/powersync-cli.md § “Authentication”.

When editing files under skills/powersync/, preserve and strengthen playbook language so agents cannot reasonably treat references as optional recipes.

Verifying changes

After changing any file under skills/, you must verify the skill still passes Snyk's security scanner (snyk-agent-scan) before considering the work done. Run the scan as described in "Verifying changes with snyk-agent-scan" in README.md and confirm it reports zero issues. Also run node scripts/validate.mjs, which CI enforces.

Changes

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.

  1. 1mo ago First seen · 19 lines · 286 tokens per session scan A e517b5f71d2a

Subscribe to this mod's changes

agent-skills AGENTS.md is an instructions file published in the GitHub repository powersync-ja/agent-skills (21 stars, last pushed 5d ago), licensed MIT. It adds 286 tokens to every session, about $0.0011 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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