skills/redis-development/rules/json-partial-updates.md

title	impact	impactDescription	tags	description	alwaysApply
Use JSON Paths for Partial Updates	MEDIUM	Avoids fetching and rewriting entire documents	json, partial-updates, paths, atomic	Use JSON Paths for Partial Updates	true

Use JSON Paths for Partial Updates

Use JSON path syntax to update specific fields without fetching the entire document.

Correct: Use JSON paths for targeted updates.

# Store JSON document
redis.json().set("user:1001", "$", {
    "name": "Alice",
    "email": "alice@example.com",
    "preferences": {"theme": "dark", "notifications": True}
})

# Update nested field without fetching entire document
redis.json().set("user:1001", "$.preferences.theme", "light")

# Get specific field
theme = redis.json().get("user:1001", "$.preferences.theme")

# Increment numeric field atomically
redis.json().numincrby("user:1001", "$.preferences.volume", 5)

# Append to array
redis.json().arrappend("user:1001", "$.tags", "premium")

Incorrect: Storing JSON as a string and parsing client-side.

# Bad: Loses queryability and atomic updates
redis.set("user:1001", json.dumps(user_data))

# Must fetch, parse, modify, serialize, and rewrite
data = json.loads(redis.get("user:1001"))
data["preferences"]["theme"] = "light"
redis.set("user:1001", json.dumps(data))

Reference: Redis JSON Path