Claude Code Hooks and Automation Guide: A complete tutorial on event-driven AI workflows

1. What are Hooks? How is it different from Skills?

• Skills: User Active Trigger (Input/Command Or Natural Language) → Claude Executes The Preset Process
• Hooks: Events Are Automatically Triggered (Tools Are Called, Messages Are Sent, Instructions Are Completed, Etc.) → The System Automatically Executes Shell Instructions
• Combined Power: /Deploy Skill Executes Deployment → Deployment Is Completed → Hook Automatically Runs Smoke Test → Smoke Test Passes → Hook Sends Slack Notification

2. Hook event type

3. Setting method: settings.json

• Configuration File Location: ~/.Claude/Settings.Json (Global) Or .Claude/Settings.Json (Project Level)
• Basic Structure: Hooks Objects Are Grouped By Event Type, Each Event Can Be Bound To Multiple Hooks
• Each Hook Contains: Type (Command), Command (Shell Instruction To Be Executed), Description (Description)
• Optional Fields: Matcher (Only Triggered For Specific Tool Names), Timeout (Timeout Setting)
• Priority: Project-Level Settings Will Override Global Settings

4. Example 1-3: Development process automation

• Example 1 - Automatically Lint After File Modification: Posttooluse + Matcher: Write/Edit → Execute Eslint --Fix Or Black To Automatically Format The Newly Modified File
• Example 2 - Load Project Status At The Beginning Of The Session: Sessionstart → Execute Git Status And Docker Ps To Bring The Results Into The Session Context
• Example 3 - Interception Before Dangerous Operations: Pretooluse + Matcher: Bash → Check Whether The Command Contains Dangerous Operations Such As Rm -Rf, Git Push --Force, Etc., And Prevent Execution If Any

5. Example 4-6: Quality Assurance Automation

• Example 4 - Automatically Run Tests Before Submission: Pretooluse + Matcher: Bash (When The Command Includes Git Commit) → Run Pytest First, And Then Submit After Passing The Test
• Example 5 - Translation Safety Check: Posttooluse + Matcher: Write (When Modifying .Po Or Locale Files) → Automatically Execute Python3 Scripts/Check_Translations.Py --Js-Safety
• Example 6 - Automatic Verification After Json Modification: Posttooluse + Matcher: Write (When Modifying The File Under Data/Guides/) → Automatically Execute ./Scripts/Validate_Json.Sh

6. Example 7-8: Notifications and Records

• Example 7 — Automatic Notification On Completion: Stop → Send A Summary Of Claude’S Final Response To Slack Or Telegram To Let Team Members Know The Task Is Completed
• Example 8 - Operation Record: Posttooluse → Record The Type And Parameters Of Each Tool Call To The Log File To Facilitate Subsequent Tracking Of "What Claude Did"

7. Hooks + Skills combination mode

• Mode 1 - Pre-Check: Hook (Pretooluse) Confirms That The Environment Is Normal → Skill Performs The Main Work. For Example, Hook Checks Whether Ci Passes Before Deployment.
• Mode 2 — Post-Processing Chain: Skill Does The Main Work → Hook (Stop) Performs Post-Processing Automatically. For Example, After /Content-Pipeline Creates Content, Hook Automatically Commits And Notifies
• Mode 3 - Quality Access Control: Skill Modifies The Program Code → Hook (Posttooluse) Automatically Runs Lint And Tests → Continue Only If All Pass. Ensure That The Code Produced By Ai Meets Quality Standards

8. Debugging and Best Practices

• Hook Is Not Triggered: Confirm Whether The Event Type And Matcher Are Correct. Use The Echo Command To Test Whether The Hook Is Called
• Hook Blocks Operation: Check The Hook'S Exit Code. A Non-Zero Exit Code Blocks The Operation
• Hook Is Too Slow: Add Timeout Settings To Prevent Hook From Blocking The Entire Workflow. Default Timeout 60 Seconds
• Best Practice 1: Keep Hook Instructions Simple—One Hook Does One Thing
• Best Practice 2: Use Description To Clearly Explain The Purpose Of Hook To Facilitate Team Members’ Understanding.
• Best Practice 3: Test In Personal Settings First, And Then Push To Project Settings After Confirming It Is Correct.
• Best Practice 4: Be Especially Cautious When Using Hooks For Sensitive Operations (Such As Automatic Push And Automatic Deployment). It Is Recommended To Add A Confirmation Step.