Dependency-Based Parallelization
Install this skill
npx skills add vercel-labs/agent-skillsWorks across Claude Code, Cursor, Codex, Copilot & Antigravity
Dependency-Based Parallelization optimizes task execution flows that contain mixed sequential and independent operations. Standard JavaScript primitives like Promise.all force developers to choose between flat parallelization or nested serial waterfalls, often creating unnecessary idle time. This skill uses the better-all pattern to define task graphs where child operations resolve as soon as their specific upstream dependencies finish, rather than waiting for every sibling task to complete. By mapping dependencies within an execution object, the agent initiates I/O-bound requests at the earliest moment technically feasible. This results in shorter total execution duration for complex data fetching logic where some attributes depend on early identifiers while others remain isolated from the primary chain. It effectively flattens complex request trees into a single, efficient concurrent operation while maintaining strict data integrity.
When to Use This Skill
- •Fetching user account settings and profile details simultaneously
- •Loading related blog post data after initial user ID resolution
- •Running independent API configuration tasks alongside dependent data requests
- •Aggregating dashboard widgets with varied dependency trees
How to Invoke This Skill
Example prompts that trigger this skill in Claude Code, Cursor, or Antigravity:
- “Refactor this waterfall into a parallel dependency graph
- “How can I run these promises concurrently if one depends on the other?
- “Optimize this slow data fetching flow to use better-all
- “Reduce execution time by parallelizing these dependent API calls
- “Fix this sequential bottleneck using dependency-based parallelization
What this skill does
- •Maps task dependencies to maximize concurrency
- •Triggers dependent tasks immediately upon input resolution
- •Eliminates waterfall delays in nested data fetching
- •Provides a unified interface for mixed parallel-serial logic
- •Automatically manages promise resolution order based on defined keys
When not to use it
- ✕When tasks have no dependencies and simple Promise.all suffices
- ✕When task operations perform side effects that require strict global ordering
- ✕When memory constraints prevent simultaneous execution of all tasks
Example workflow
- Identify current sequential code blocks causing latency
- Map out which functions require previous function outputs
- Initialize the better-all structure with independent task definitions
- Inject dependencies using the context-aware reference pattern
- Execute and verify that total runtime matches the longest single dependency chain
Prerequisites
- –Node.js environment
- –better-all dependency installed
- –Async/await understanding
Pitfalls & limitations
- !Over-engineering simple promise chains
- !Misdefining dependency keys leading to runtime errors
- !Ignoring error propagation differences compared to native Promise.all
FAQ
How it compares
Unlike manual Promise.all chains which create rigid waterfalls, this approach builds an execution graph that calculates the shortest possible time to completion for interdependent tasks.
📄 Full skill instructions — original source: vercel-labs/agent-skills
For operations with partial dependencies, use
better-all to maximize parallelism. It automatically starts each task at the earliest possible moment.**Incorrect (profile waits for config unnecessarily):**
const [user, config] = await Promise.all([
fetchUser(),
fetchConfig()
])
const profile = await fetchProfile(user.id)**Correct (config and profile run in parallel):**
import { all } from 'better-all'
const { user, config, profile } = await all({
async user() { return fetchUser() },
async config() { return fetchConfig() },
async profile() {
return fetchProfile((await this.$.user).id)
}
})Reference: [https://github.com/shuding/better-all](https://github.com/shuding/better-all)
How to Use This Skill Unit
Option A: Project-Specific (Recommended)
- Click "Download" above
- In your project, create the directory:
.agent/skills/async-dependencies/ - Save the file as
SKILL.md - The agent will automatically discover the skill based on its description.
Option B: Global Installation (All Agents)
Save the file to these locations to make it available across all projects:
- Claude Code:
~/.claude/skills/vercel-labs/agent-skills/async-dependencies/SKILL.md - Cursor:
~/.cursor/skills/vercel-labs/agent-skills/async-dependencies/SKILL.md - Antigravity:
~/.gemini/antigravity/skills/vercel-labs/agent-skills/async-dependencies/SKILL.md
🚀 Install with CLI:npx skills add vercel-labs/agent-skills
