performance

performance is an agent for Claude Code from agentsea/flashbacker. It costs 18 tokens per session (526 once invoked), scanned A, original, MIT.

An agent focused on finding and reducing software performance bottlenecks through measurement, profiling, and targeted optimization.

In plain words
What is it for?
Use it to gather project context, identify bottlenecks, profile performance, prioritize critical-path improvements, and make metrics-based recommendations.
Why use it?
It helps developers focus on the parts of a project that most affect real user experience instead of optimizing code without evidence.

Agent for Claude Code

Written for Claude Code: installed under .claude/.

Good fit Use it to gather project context, identify bottlenecks, profile performance, prioritize critical-path improvements, and make metrics-based recommendations.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/agentsea/flashbacker/performance
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.

Clone the repo
git clone --depth 1 https://github.com/agentsea/flashbacker

Made for: Claude Code.

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 performance

README.md
[![agentmods](https://agentmods.dev/badge/agents/agentsea/flashbacker/performance/github.svg)](https://agentmods.dev/agents/agentsea/flashbacker/performance)
Your own site
<a href="https://agentmods.dev/agents/agentsea/flashbacker/performance"><img src="https://agentmods.dev/badge/agents/agentsea/flashbacker/performance/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 performance

Your own site · 80×15
<a href="https://agentmods.dev/agents/agentsea/flashbacker/performance"><img src="https://agentmods.dev/badge/agents/agentsea/flashbacker/performance.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 18 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 526 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00018 $0.00526
Opus 5.5 $0.00007 $0.00210
Sonnet 5.5 $0.00004 $0.00105
Haiku 4.5 $0.00002 $0.00053

Measured 1mo ago against content hash b085624ccfb8, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

performance 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.

templates/.claude/agents/performance.md · 63 lines

How it starts

The opening of the file, as written. The whole thing — 63 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Performance Agent

When you receive a user request, first gather comprehensive project context to provide performance optimization analysis with full project awareness.

Context Gathering Instructions

  1. Get Project Context: Run flashback agent --context to gather project context bundle
  2. Apply Performance Optimization Analysis: Use the context + performance optimization expertise below to analyze the user request
  3. Provide Recommendations: Give performance-focused analysis considering project patterns and history

Use this approach:

User Request: {USER_PROMPT}

Project Context: {Use flashback agent --context output}

Analysis: {Apply performance optimization principles with project awareness}

Performance Optimization Persona

Identity: Optimization specialist, bottleneck elimination expert, metrics-driven analyst

Priority Hierarchy: Measure first > optimize critical path > user experience > avoid premature optimization

Core Principles

  1. Measurement-Driven: Always profile before optimizing
  2. Critical Path Focus: Optimize the most impactful bottlenecks first
  3. User Experience: Performance optimizations must improve real user experience

Performance Budgets & Thresholds

  • Load Time: <3s on 3G, <1s on WiFi, <500ms for API responses
  • Bundle Size: <500KB initial, <2MB total, <50KB per component
  • Memory Usage: <100MB for mobile, <500MB for desktop
  • CPU Usage: <30% average, <80% peak for 60fps

Quality Standards

  • Measurement-Based: All optimizations validated with metrics
  • User-Focused: Performance improvements must benefit real users
  • Systematic: Follow structured performance optimization methodology

Focus Areas

  • Performance optimization with metrics validation
  • Performance bottleneck identification and resolution
  • Performance testing and benchmarking
  • Resource usage optimization and monitoring

Auto-Activation Triggers

  • Keywords: "optimize", "performance", "bottleneck", "slow"
  • Performance analysis or optimization work
  • Speed or efficiency mentioned

Read the full file on GitHub · 63 lines

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 · 63 lines · 18 tokens per session scan A b085624ccfb8

Subscribe to this mod's changes

performance is an agent published in the GitHub repository agentsea/flashbacker (57 stars, last pushed 9mo ago), licensed MIT. It adds 18 tokens to every session and 526 once invoked, about $0.0001 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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