Claude Code vs Aider Comparison

// .claude/settings.json — permission rules only (MCP config is NOT written here)
{
  "permissions": {
    "allow": ["Bash(git status)", "Bash(git diff)"]
  }
}

// .mcp.json — at the project root; MCP servers are defined here and committed to the repo
{
  "mcpServers": {
    "postgres": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-postgres"],
      "env": { "DATABASE_URL": "${DATABASE_URL}" }
    }
  }
}

// You can also add the same definition via the command line:
// $ claude mcp add-json postgres '{"command":"npx","args":["-y","@modelcontextprotocol/server-postgres"]}' --scope project

// .claude/agents/reviewer.md — custom subagent definition
---
name: reviewer
description: A read-only subagent that reviews code
tools: Read, Grep, Glob
model: claude-sonnet-5
---
You are a code review specialist. Only read and report, never modify files.

# Invoking from the terminal
$ claude "Scan this PR for edge cases with the reviewer subagent" \
    --permission-mode plan

# Aider — running with a local model (Ollama) + auto-commit
# 1) Pull the local model and point it at the Ollama endpoint
$ ollama pull qwen2.5-coder:32b
$ export OLLAMA_API_BASE=http://127.0.0.1:11434

# 2) Start the server with an 8k context — the default 2k window SILENTLY drops overflow context
$ OLLAMA_CONTEXT_LENGTH=8192 ollama serve

# 3) Point Aider at the local model (ollama_chat/ is recommended, not ollama/)
$ aider --model ollama_chat/qwen2.5-coder:32b \
    --edit-format diff \
    src/api/users.py src/api/auth.py

# 4) One-off script mode (not a subagent, one command → one result)
$ aider --message "shorten the token expiry in auth.py to 15 minutes" \
    --yes-always src/api/auth.py

# .aiderignore — to narrow context in a large monorepo
node_modules/
dist/
*.lock
legacy/

# Auto-commit is ON by default (--auto-commits, default: True):
# $ git log --oneline -1
# a1b2c3d aider: shorten token expiry to 15 minutes