Directory of Agents

Agent infrastructure tools to make agents reliable in production

AI engineering tools for tracing, evaluating, connecting, and remembering what agents do before they touch real customers or business systems. Each one below shows its real entry price for a one-person team and an honest take on whether you need a developer to run it.

8 agents · 8 solo-founder ready

Arcade.dev

Agent Infrastructure

MCP-compatible tool-calling infrastructure with auth, hosted tools, and usage-based pricing for agent builders.

Entry price
Free Hobby; Growth $25/mo plus usage
No-code
2/5
Technical solo-ready View →

Arize Phoenix

Agent Infrastructure

Free open-source observability and evaluation for LLM apps, with Arize's paid platform when you outgrow it.

Entry price
Free open source; Arize AX Pro from $50/mo
No-code
2/5
Technical solo-ready View →

Braintrust

Agent Infrastructure

Evals and observability for teams shipping real AI agents, with a free starter path and serious paid tier.

Entry price
Free Starter; Pro $249/mo plus usage
No-code
2/5
Technical solo-ready View →

Composio

Agent Infrastructure

Tool access, auth, and integrations for AI agents that need to take real actions across apps.

Entry price
Free 20K tool calls/mo; paid from $29/mo
No-code
2/5
Technical solo-ready View →

Helicone

Agent Infrastructure

LLM observability and AI gateway for tracking requests, costs, latency, and production behavior.

Entry price
Free Hobby; Pro $79/mo plus usage
No-code
3/5
Technical solo-ready View →

Langfuse

Agent Infrastructure

Open-source LLM observability and evals for builders who want traces, prompts, datasets, and cost visibility.

Entry price
Free Hobby; Core $29/mo plus usage
No-code
2/5
Technical solo-ready View →

LangSmith

Agent Infrastructure

LangChain's tracing, eval, deployment, and monitoring platform for builders shipping agents.

Entry price
Free Developer; Plus $39/seat/mo plus usage
No-code
2/5
Technical solo-ready View →

Letta

Agent Infrastructure

Stateful agent platform from the MemGPT team, built around persistent memory and long-running agents.

Entry price
Free tier; Pro $20/mo; API plan $20/mo plus usage
No-code
2/5
Technical solo-ready View →