diegosouzapw Claude Code Tools Reference
Configure tool permissions when launching parallel Claude Code agents.
Available Tools
| Tool | Description | Use Case |
|---|---|---|
Read |
Read files | Always needed for context |
Write |
Create new files | Creating new code files |
Edit |
Modify existing files | Updating existing code |
Bash |
Execute shell commands | Running tests, builds, git |
Glob |
Find files by pattern | File discovery |
Grep |
Search file contents | Code search |
WebFetch |
Fetch web content | Documentation lookup |
WebSearch |
Search the web | Research |
TodoWrite |
Manage task lists | Progress tracking |
Task |
Launch sub-agents | Delegation |
NotebookEdit |
Edit Jupyter notebooks | Data science |
mcp__<server> |
MCP server tools | External integrations |
CLI Syntax
Each tool is a separate quoted argument:
claude --allowedTools "Tool1" "Tool2" "Tool3(...)" --print "prompt"
Example with multiple tools:
claude --allowedTools "Read" "Edit" "Bash(pytest:*)" --print "implement feature"
Path-Specific Restrictions
Restrict file operations to specific directories using gitignore-style patterns.
Path Pattern Syntax
| Pattern | Meaning | Example |
|---|---|---|
//path |
Absolute filesystem path | Edit(//Users/alice/src/**) |
~/path |
Home directory relative | Read(~/.zshrc) |
/path |
Relative to settings file | Edit(/src/**/*.ts) |
path |
Relative to current directory | Read(src/**) |
Examples
# Allow editing only in src/ directory
claude --allowedTools "Edit(/src/**)" --print "..."
# Allow editing TypeScript files only
claude --allowedTools "Edit(/src/**/*.ts)" --print "..."
# Multiple path restrictions
claude --allowedTools "Read" "Edit(/apps/users/**)" "Edit(/tests/**)" --print "..."
# Absolute path restriction
claude --allowedTools "Edit(//tmp/scratch.txt)" --print "..."
Bash Command Restrictions
Restrict which shell commands can be executed using prefix matching.
Syntax
Bash(command:*)
The :* wildcard only works at the END of patterns (prefix matching).
Pattern Examples
| Pattern | Matches | Does NOT Match |
|---|---|---|
Bash(pytest:*) |
pytest, pytest apps/ |
python -m pytest |
Bash(npm run test:*) |
npm run test, npm run test:unit |
npm run build |
Bash(git log:*) |
git log --oneline |
git commit |
Bash(git status:*) |
git status |
git push |
Bash(mypy:*) |
mypy apps/ |
python -m mypy |
Bash(ruff:*) |
ruff check . |
python -m ruff |
Example
claude --allowedTools "Bash(pytest:*)" "Bash(mypy:*)" "Bash(ruff:*)" "Read" --print "run tests"
Security Note
Claude Code prevents bypass via shell operators (&&, ;, ||). Be aware:
- Different invocations may bypass patterns (
python -m pytestvspytest) - For URL restrictions, prefer
WebFetch(domain:...)overBash(curl:*)
WebFetch Domain Restrictions
Restrict web fetches to specific domains:
claude --allowedTools "WebFetch(domain:github.com)" "WebFetch(domain:docs.python.org)" --print "..."
MCP Tool Restrictions
Allow All Tools from a Server
claude --allowedTools "mcp__puppeteer" --print "..."
Allow Specific Tool Only
claude --allowedTools "mcp__puppeteer__puppeteer_navigate" --print "..."
Note: MCP permissions do NOT support wildcards (*).
Recommended Configurations
By Task Type
| Task Type | Recommended --allowedTools |
|---|---|
| Implementation | "Read" "Write" "Edit(/apps/myapp/**)" "Bash(pytest:*)" "Bash(mypy:*)" "Glob" "Grep" |
| Code Review | "Read" "Glob" "Grep" (read-only) |
| Testing Only | "Read" "Bash(pytest:*)" "Bash(npm test:*)" |
| Documentation | "Read" "Write(/docs/**)" "Edit(/docs/**)" "WebFetch" |
| Full Access | --dangerously-skip-permissions |
For Parallel Development
When using git worktrees for isolation, --dangerously-skip-permissions is safe:
- Each agent runs in an isolated worktree
- Agents can only affect files in their workspace
- Main branch remains protected until explicit merge
# Safe in isolated worktree
claude --dangerously-skip-permissions --print "$(cat prompts/task-001.txt)"
For Granular Control
When agents share a workspace, use path-scoped permissions:
claude \
--allowedTools \
"Read" \
"Write(/apps/users/**)" \
"Edit(/apps/users/**)" \
"Bash(pytest apps/users/:*)" \
"Bash(mypy apps/users/:*)" \
"Glob" \
"Grep" \
--print "$(cat prompts/task-001.txt)"
Complete Examples
Django App Implementation Agent
claude \
--allowedTools \
"Read" \
"Write(/apps/orders/**)" \
"Edit(/apps/orders/**)" \
"Bash(pytest apps/orders/:*)" \
"Bash(mypy apps/orders/:*)" \
"Bash(ruff check apps/orders/:*)" \
"Glob" \
"Grep" \
--print "Implement order management per task-004 spec"
React Component Agent
claude \
--allowedTools \
"Read" \
"Write(/src/components/Dashboard/**)" \
"Edit(/src/components/Dashboard/**)" \
"Bash(npm run test:*)" \
"Bash(npm run lint:*)" \
"Glob" \
"Grep" \
--print "Implement Dashboard components per task-003 spec"
Read-Only Analysis Agent
claude \
--allowedTools \
"Read" \
"Glob" \
"Grep" \
"WebFetch(domain:docs.python.org)" \
--print "Analyze codebase and suggest improvements"
Quick Reference
| Restriction Type | Syntax |
|---|---|
| Allow tool everywhere | "Edit" |
| Restrict to directory | "Edit(/src/**)" |
| Restrict to file type | "Edit(/src/**/*.ts)" |
| Restrict bash command | "Bash(pytest:*)" |
| Restrict web domain | "WebFetch(domain:github.com)" |
| Allow MCP server | "mcp__puppeteer" |
| Allow specific MCP tool | "mcp__puppeteer__puppeteer_navigate" |
| Skip all permissions | --dangerously-skip-permissions |
Common Patterns
Task-Scoped Permissions
Match permissions to task boundaries:
# Task owns apps/users/
--allowedTools "Edit(/apps/users/**)" "Write(/apps/users/**)"
# Task owns apps/orders/
--allowedTools "Edit(/apps/orders/**)" "Write(/apps/orders/**)"
Test Commands Only
--allowedTools "Read" "Bash(pytest:*)" "Bash(npm test:*)" "Bash(go test:*)"
Documentation Writer
--allowedTools "Read" "Write(/docs/**)" "Edit(/docs/**)" "WebFetch" "WebSearch"
Infrastructure Agent
--allowedTools "Read" "Edit(/terraform/**)" "Edit(/docker-compose.yml)" "Bash(terraform:*)" "Bash(docker:*)"