spica performance-optimization.instructions.md

The most comprehensive, practical, and engineer-authored performance optimization instructions for all languages, frameworks, and stacks. Covers frontend, backend, and database best practices with actionable guidance, scenario-based checklists, troubleshooting, and pro tips.

Instructions file for GitHub Copilot

Install

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.

agentmods
npx agentmods add instructions/spica-engine/spica/performance-optimization
Clone the repo
git clone --depth 1 https://github.com/spica-engine/spica

Made for: GitHub Copilot.

Per session 4,642 This file is loaded in full into every session.
When invoked 4,642 The same file — it is already loaded in full.
Security scan C 1 finding. Scan, not verified.
Origin unknown 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 $0.04642 $0.04642
Opus 5 $0.02321 $0.02321
Sonnet 5 $0.00928 $0.00928
Haiku 4.5 $0.00464 $0.00464

Measured today against content hash 2f742336cb67, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade C, and why

spica performance-optimization.instructions.md scanned grade C with 1 finding 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 today.

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.

Hidden instructionshighPrompt injection

Directives inside HTML comments, invisible characters or bidirectional overrides are read by the model and not by the person reviewing the file.

<!-- End of Performance Optimization Instructions -->
.github/instructions/performance-optimization.instructions.md · 421 lines

The source is not reproduced here

Licensed AGPL-3.0

The repository is licensed AGPL-3.0, which this catalogue does not treat as permission to reproduce the file. Read it at the source.

Read it on GitHub

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. today First seen · 421 lines · 4,642 tokens per session scan C 2f742336cb67

Subscribe to this mod's changes

spica performance-optimization.instructions.md is an instructions file published in the GitHub repository spica-engine/spica (100 stars, last pushed 7d ago), licensed AGPL-3.0. It adds 4,642 tokens to every session, about $0.0232 per session on Opus 5. A static security scan graded it C with 1 finding (hidden instructions). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-01.