Software Alternatives & Startups

HumanLayer VS Underscore Done

Compare HumanLayer VS Underscore Done and see what are their differences

HumanLayer

Human-in-the-Loop infra for AI Agents

No screenshot yet
Rating
0 reviews
Underscore Done

Real-world tasks your agent can't do alone.

Rating
0 reviews
Pricing
Paid $0.01 (Per api call)

Which is more popular?

Based on our record, HumanLayer should be more popular than Underscore Done. It has been mentioned 2 times since March 2021.

social mentions
2 vs 1
AI popularity
76% vs 24%
alternatives listed
20 vs 2

Base details

Website, pricing, platforms and company facts side by side.

HL
HumanLayer
Underscore Done
Website humanlayer.dev underscoredone.com
Pricing —
Paid $0.01 (Per api call) Official pricing
Company — Startup from the United States · 2026
Listed in

About HumanLayer and Underscore Done

In their own words, as submitted to SaaSHub.

HL
HumanLayer
Underscore Done

No description of HumanLayer yet.

Underscore Done (_done) is a suite of pay-per-call utility APIs built for AI agents. No API keys, no subscriptions - agents pay per request with USDC via the x402 protocol

Read more about Underscore Done

Features and specs

What each product offers, as listed by its team.

HL
HumanLayer 5 features
Underscore Done 0 features
  • Human-in-the-loop for AI agents
    HumanLayer provides a structured framework for incorporating human oversight and approval into AI agent workflows, ensuring that critical or sensitive actions are reviewed by a human before execution. This reduces the risk of AI making costly or irreversible mistakes.
  • Easy integration with existing agent frameworks
    HumanLayer is designed to work with popular AI agent frameworks like LangChain, CrewAI, and others, making it relatively straightforward to add human approval gates to existing agent pipelines without major architectural changes.
  • Multi-channel contact support
    HumanLayer supports human approvals through multiple channels such as Slack and email, allowing teams to integrate approval workflows into communication tools they already use, reducing friction in the review process.
  • Granular control over approval workflows
    Developers can define specific function calls or actions that require human approval, allowing fine-grained control over which agent actions need oversight and which can proceed autonomously. This enables a balanced approach between automation and human control.
  • Open source core
    HumanLayer offers an open-source SDK, making it accessible for developers to inspect the code, contribute improvements, and customize the tool for their specific needs without vendor lock-in concerns.

Possible disadvantages

  • Added latency to agent workflows
    Requiring human approval introduces delays into AI agent pipelines, as the workflow must pause and wait for a human to review and respond. This can significantly slow down time-sensitive processes or reduce the efficiency gains that agents are meant to provide.
  • Relatively early-stage project
    HumanLayer is a relatively new and emerging tool in the AI agent ecosystem. This means the documentation, community support, and feature set may not be as mature or comprehensive as more established tools, and the API may undergo breaking changes.
  • Scalability challenges with human bottlenecks
    As AI agent usage scales up, the human approval step can become a bottleneck. If many agents or many actions require approval simultaneously, it can overwhelm human reviewers and create queues that defeat the purpose of automation.
  • Limited ecosystem and integrations
    While HumanLayer supports some popular agent frameworks and communication channels, the range of supported integrations is still growing. Teams using less common frameworks or communication tools may need to build custom integrations.
  • Dependency on external services for notifications
    Relying on Slack, email, or other external channels for approval notifications introduces dependencies on third-party services. If those services experience outages or message delivery delays, agent workflows can stall without clear fallback mechanisms.

No features have been listed yet.

Analysis

An editorial look at what each product does well and who it suits.

HL
HumanLayer
Underscore Done

Overall verdict

  • HumanLayer is a solid tool for teams building AI agents that need human oversight, offering a straightforward way to add human-in-the-loop approvals and interactions to autonomous workflows.

Why this product is good

  • Provides a purpose-built API and SDK for adding human approval steps to AI agent actions, reducing the risk of unsupervised automation.
  • Integrates with popular frameworks like LangChain, CrewAI, and custom agent setups, making it flexible for different tech stacks.
  • Supports multiple communication channels such as Slack, email, and web for routing approval requests to the right humans.
  • Enables safer deployment of AI agents that perform high-stakes or irreversible operations by keeping a human in the loop.
  • Developer-friendly with clear documentation and quick setup for common use cases.

Recommended for

  • Developers and teams building autonomous AI agents that require human approval for sensitive actions
  • Companies deploying LLM-powered automation in high-stakes domains like finance, healthcare, or operations
  • Startups experimenting with agentic workflows who want to add guardrails without building oversight infrastructure from scratch
  • Engineering teams using frameworks like LangChain or CrewAI that need human-in-the-loop capabilities

No analysis of Underscore Done yet.

Videos

Walkthroughs and reviews on video.

HL
HumanLayer 3 videos + Add
Underscore Done 0 videos + Add

HumanLayer (CodeLayer): The MOST PRODUCTIVE AI Coder YET!

More videos

  • - No Vibes Allowed: Solving Hard Problems in Complex Codebases – Dex Horthy, HumanLayer
  • - How to Ship Complex Features 10x Faster with AI Agents | Dex Horthy (HumanLayer)

No Underscore Done videos yet. You could help us improve this page by suggesting one.

Category popularity

How often each product is chosen within a category, 0–100% relative to the other.

Score bands 0–20 21–40 41–50 51–60 61–100
HL
HumanLayer
Underscore Done
76% 76%
AI
24% 24%
62% 62%
38% 38%
100% 100%
0% 0%
100% 100%
0% 0%

Questions & Answers

As answered by people managing HumanLayer and Underscore Done.

What makes your product unique?

Underscore Done's answer:

We provide data and actions that AI cannot achieve.

Also we don't require accounts, registration, api keys. And we charge per usage and never charge monthly subscriptions.

How would you describe the primary audience of your product?

Underscore Done's answer:

Ai Agents that work on behalf of people.

User comments

Share your experience with using HumanLayer and Underscore Done. For example, how are they different and which one is better?

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Social recommendations and mentions

Recommendations tracked on public social media and blogs since March 2021.

HL
HumanLayer 2 mentions
Underscore Done 1 mention
  • Research Plan Implement — The Anti-Vibe-Coding Workflow
    Dex Horthy, CEO of HumanLayer, put a name to the pattern in his AI Engineer conference talk "No Vibes Allowed" (AI Engineer World's Fair, 2024). The Research → Plan → Implement (RPI) framework is a structured workflow for AI-assisted... - Source: dev.to / 6 months ago
  • How I Used RPI to Build an OpenClaw Alternative
    I realized I needed to change my approach. While I love the iterative learning process, I needed a way to give the agent a better foundation so our pair programming sessions actually made progress. I decided to try the RPI method... - Source: dev.to / 8 months ago
  • Why I'm Passionate About x402
    _done is a catalog of small, pay-per-call utility APIs aimed at AI agents: things like DNS and WHOIS lookups, screenshots, OCR, hashing, QR codes, and SEO extraction. Every call costs one cent in USDC over x402. There's no account and no... - Source: dev.to / 13 days ago

Alternatives to HumanLayer and Underscore Done

When comparing HumanLayer and Underscore Done, you can also consider the following products.