✓
Tool
Category
Pricing
Free?
Updated
Thoughtly
AI Agents
Freemium
✓
Mar 2026
→
AI voice agent platform for building phone agents for sales and support
Best for: voice-agent
Nooks AI
AI Agents
From $1/mo
—
Mar 2026
→
AI sales platform with autonomous dialer and real-time coaching for SDR teams
Best for: sales-acceleration
Bland AI
AI Agents
From $0.09/mo
—
Mar 2026
→
AI phone call agent platform for automating inbound and outbound calls at scale
Best for: voice-agent
Helicone
AI Agents
Freemium
✓
Mar 2026
→
Open-source LLM proxy for logging, monitoring, and analyzing all AI API calls
Best for: LLM-proxy
PromptLayer
AI Agents
Freemium
✓
Mar 2026
→
Prompt management platform with logging and analytics for LLM API calls
Best for: prompt-management
OpenAI Assistants API
AI Agents
Paid
—
Mar 2026
→
OpenAI managed API for building stateful AI agents with tools and persistent threads
Best for: OpenAI
PolyAI
AI Agents
From $1/mo
—
Mar 2026
→
Enterprise voice AI agents for contact centers with human-like conversation quality
Best for: voice-AI
Weights & Biases Weave
AI Agents
Freemium
✓
Mar 2026
→
W&B toolkit for tracing, evaluating, and improving AI agent applications
Best for: W&B
Observe.AI
AI Agents
From $1/mo
—
Mar 2026
→
AI contact center platform with real-time agent coaching and conversation intelligence
Best for: contact-center
Fixie AI
AI Agents
Freemium
✓
Mar 2026
→
Platform for building conversational AI agents with memory, tools, and deployable hosting
Best for: conversational
Amazon Bedrock Agents
AI Agents
Paid
—
Mar 2026
→
AWS-native AI agent builder using foundation models with enterprise security
Best for: AWS
Langfuse
AI Agents
Freemium
✓
Mar 2026
→
Open-source LLM observability platform for tracing, debugging, and monitoring AI agents
Best for: observability
Smolagents
AI Agents
Free
✓
Mar 2026
→
Lightweight Hugging Face agent framework where LLMs write code to use tools
Best for: Hugging Face