claude-code-usage

name	claude-code-usage
description	[AUTO-INVOKE] MUST be invoked at the START of each new coding session. Covers context management, task strategies, and Foundry-specific workflows. Trigger: beginning of any new conversation or coding session in a Solidity/Foundry project.

Claude Code Best Practices

Language Rule

• Always respond in the same language the user is using. If the user asks in Chinese, respond in Chinese. If in English, respond in English.

Context Management Rules

Rule	Why
One window = one task	Mixing tasks pollutes context and degrades output quality
Use /clear over /compact	Clean start is more reliable than compressed context
/clear after complex tasks	Prevents old context from interfering with new work
Copy key info to new windows	Don't rely on context persistence — paste critical details

Task Execution Strategy

Task Type	Recommended Approach
Small bug fix (few lines)	Describe directly, let Claude modify in-place
Large feature / refactor	/plan → review approach → /clear → paste plan → execute step by step
Multi-file changes	Must use /plan workflow — never modify multiple files without a plan
Code analysis / learning	Ask Claude to analyze directly — no plan needed
Debugging	Provide error message + file path + relevant code — ask for root cause

Prompt Techniques

Do This

• Give specific paths: "Modify the _transfer function in src/MyToken.sol"
• Give examples: "Input: 100 tokens, Expected: 95 tokens after 5% fee"
• Set boundaries: "Only modify this function, don't touch other code"
• Reference tests: "The fix should make test_transfer_feeDeduction pass"

Avoid This

• Vague references: "Modify that transfer function" — which one? Where?
• Open-ended requests without constraints: "Make it better"
• Multiple unrelated tasks in one message

Meta-Prompting — When Things Go Wrong

When Claude's response misses the mark, don't just rephrase and retry. Use Meta-Prompting (reverse prompting) to let Claude diagnose the gap, then re-ask with complete context.

Four Prompt Types

Type	When to Use	Template
Diagnose	Answer was wrong or incomplete	"我刚才的提问中缺少了哪些关键信息，导致你没能一次性给出正确答案？请逐条列出。"
Rewrite	You don't know how to improve the question	"请帮我重写刚才的问题，补全你认为缺失的上下文，使你能一次性给出正确答案。"
Template	Prevent same mistake next time	"对于这类问题，我应该提供哪些信息你才能一次性解决？请给我一个提问模板。"
Pre-check	Before Claude starts working	"在你开始写代码之前，列出你还需要我提供的所有信息。"

Recommended Flow

Step 1: Ask your question
        ↓ (answer is wrong or incomplete)
Step 2: Use [Diagnose] — "我的问题中缺少了什么？"
        ↓ (Claude lists missing info)
Step 3: Use [Rewrite] — "帮我重写这个问题"
        ↓ (Claude outputs a complete, self-contained prompt)
Step 4: Copy the rewritten prompt, `/clear`, paste and send
        ↓ (clean context + complete prompt = correct answer)

Practical Example

# Round 1 — incomplete question
User: "帮我写一个 staking 合约"
Claude: (generates a basic staking contract, but missing reward logic)

# Round 2 — diagnose
User: "我刚才的提问中缺少了哪些信息？"
Claude: "你没有说明：
  1. 质押代币和奖励代币是否相同
  2. 奖励分发机制（按时间/按区块/固定APR）
  3. 是否需要锁仓期
  4. 是否需要紧急提取功能
  5. 管理员权限范围"

# Round 3 — rewrite
User: "帮我重写这个问题"
Claude: "请帮我写一个 Staking 合约，要求如下：
  - 质押代币：ERC20 TOKEN_A，奖励代币：ERC20 TOKEN_B
  - 奖励机制：按质押时长线性释放，年化 12%
  - 锁仓期：7 天最短锁仓
  - 紧急提取：支持，但扣除 10% 罚金
  - 管理员：可更新奖励率，不可触碰用户质押资金
  - 安全：使用 ReentrancyGuard + SafeERC20
  请基于 OpenZeppelin 5.x，Solidity ^0.8.20，Foundry 项目结构。"

# Round 4 — /clear, paste rewritten prompt, get correct result

Key Principle

Don't guess what you missed — let Claude tell you. One round of meta-prompting saves multiple rounds of trial and error.

Git Operation Rules

• Always run git diff before committing to review changes
• Only commit — do not push unless explicitly requested
• Never push directly to main/master branch
• Stage specific files — never use git add . in Solidity projects (risk of committing .env)

Foundry-Specific Workflow

Action	Command
Before committing	forge fmt && forge test
After modifying contracts	forge build to check compilation
Before PR	forge test --gas-report to check gas impact
Debugging failed test	forge test --match-test <name> -vvvv for full trace

Quick Command Reference

Command	Purpose
/clear	Clear context, start fresh
/plan	Enter planning mode — analyze before modifying
/help	View all available commands
/compact	Compress context (prefer /clear instead)

Project-level Configuration

Create .claude/instructions.md in the project root with project-specific rules. Claude automatically reads it at the start of every conversation — no manual loading needed.