OpenTrain AI
LLM & Agent Solutions / Function Calling

Find Expert AI Trainers for Function Calling

Post a job and connect with specialists who can create tool-use training data, label correct function calls, and evaluate whether your agents select the right tools with valid arguments. Our network includes 100,000+ AI training specialists.

127,000+ vetted AI data experts
Why Choose Us

One place to find AI Trainers who understand tool-use workflows and can deliver schema-valid training data.

Technical Vetting

Pre-screened for structured outputs, schema accuracy, and agent workflow experience

Any Stack

Work in your agent framework, eval platform, or custom tooling

Domain Expertise

Real experience with APIs in finance, healthcare, e-commerce, and more

Integrations

Hire for Any Function Calling Tool

View All Integrations

Have your own tooling? Our talent works directly in your platform.

127,000+

Pre-Vetted Experts

180+

Countries

110+

Languages

How It Works

How OpenTrain Works for Function Calling

Step 01

Post a Job and Receive Pre-Vetted Proposals

Describe your tools, schemas, and workflow requirements. Receive proposals from AI Trainers who have already been screened for structured output work and agent experience.

Step 02

Hire and Add to Your Tooling

Review candidates, make your hires, and invite them to your agent framework, eval platform, or custom tooling.

Step 03

Communicate and Pay in One Place

Share instructions, message your team, and handle global payments from a single dashboard.

Start Building Your Function Calling Team Today

Post your first job and connect with pre-vetted AI Trainers who have the structured output experience and technical depth your project requires.

Self-Service

Post Your Function Calling Job

Describe your requirements and receive a curated shortlist of domain experts matched to your project. 15% flat fee, no hidden markups.

Most popular
Managed Service

Full-Service, End-to-End

  • Recruiting & live vetting
  • Onboarding & training
  • Daily management & QA
  • Dedicated program lead
Global Talent Network

The #1 Talent Network for Function Calling

Tool selection, argument validation, multi-step orchestration, error recovery — whatever your agent architecture requires, we have specialists who've built and evaluated real tool-use systems.

127,000+
Pre-Vetted Specialists
110+
Languages
50+
API Frameworks Supported
FAQ

FAQs About Hiring for Function Calling

Common questions about hiring AI Trainers to create function calling training data and evaluate agent tool use.