The infrastructure AI agents run on.

Cloud browsers, sandboxes, memory, search, email, payments and voice. One checked list for people shipping agents, not demos.

54tools listed

11categories

131side-by-side comparisons

Oct 16last link check, updated daily

Covering Browserbase, E2B, Mem0, Exa and 50 more

Browse by layer of the stack

All 54 tools

Browsers & Computer UseCloud browsers and SDKs that let agents use the web.8 tools

Code SandboxesIsolated machines where agents can safely run code.8 tools

Memory & ContextLong-term memory layers so agents remember users and tasks.5 tools

Search & Web DataAPIs that give agents fresh web search and clean page content.7 tools

EmailInboxes and sending APIs for agents that talk over email.3 tools

Integrations & Auth ToolsPrebuilt tool calls and managed OAuth for thousands of apps.5 tools

PaymentsWays for agents to charge, pay, and hold credentials.3 tools

Voice AgentsPlatforms for phone and voice agents.3 tools

Observability & EvalsTracing, debugging, and evals for agents in production.5 tools

Agent FrameworksLibraries for building agents and multi-agent workflows.6 tools

IdentityLogin, permissions, and token handling for agents.1 tools

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Agent 37
agent37.com

Cloud sandboxes for running AI agents, positioned as lower-cost agent infrastructure.
Code SandboxesNew
Pickle Browser
picklebrowser.com

Local browser that opens real pages for agents, shows its work on your machine, and needs no account.
Browsers & Computer UseNew
AIO Sandbox
sandbox.agent-infra.com

All-in-one agent sandbox with browser, shell, file access, VSCode Server, and MCP in one container.
Code SandboxesOpen sourceNew
Browserbase
browserbase.com

Hosted headless browsers for agents, with session control and an MCP server.
Browsers & Computer UseNew
Browser Use
browser-use.com

Open-source browser agent library plus hosted remote browsers for AI agents.
Browsers & Computer UseOpen sourceNew
Steel
steel.dev

Open-source browser API for running fleets of cloud browsers for agents.
Browsers & Computer UseOpen sourceNew
Hyperbrowser
hyperbrowser.ai

Cloud Chrome sessions, isolated sandboxes, and web data APIs for agents.
Browsers & Computer UseNew
Stagehand
stagehand.dev

SDK for browser agents with a Playwright-style API and self-healing selectors.
Browsers & Computer UseOpen sourceNew

Browse the stack

54 tools

Agent 37
agent37.com

Cloud sandboxes for running AI agents, positioned as lower-cost agent infrastructure.
Code SandboxesNew
AgentMail
agentmail.to

Email inbox API for agents: create, send, and receive real inboxes.
EmailNew
AgentOps
agentops.ai

Tracing and debugging for AI agents.
Observability & EvalsNew
AIO Sandbox
sandbox.agent-infra.com

All-in-one agent sandbox with browser, shell, file access, VSCode Server, and MCP in one container.
Code SandboxesOpen sourceNew
Anchor Browser
anchorbrowser.io

Infrastructure for computer-use agents that automate web tasks at scale.
Browsers & Computer UseNew
Apify
apify.com

Marketplace of ready-made scrapers and automation tools callable by agents.
Search & Web DataNew
Arcade
arcade.dev

Actions runtime that lets agents act on users' behalf with governed auth.
Integrations & Auth ToolsNew
Auth0 for AI Agents
auth0.com

Auth0 tools for user login, token vaults, and permissions in AI agents.
IdentityNew
Braintrust
braintrust.dev

Observability and evals platform for production agents.
Observability & EvalsNew
Brave Search API
brave.com

Independent web search API covering a 40B+ page index.
Search & Web DataNew
Browser Use
browser-use.com

Open-source browser agent library plus hosted remote browsers for AI agents.
Browsers & Computer UseOpen sourceNew
Browserbase
browserbase.com

Hosted headless browsers for agents, with session control and an MCP server.
Browsers & Computer UseNew
Cloudflare Sandbox SDK
developers.cloudflare.com

Run untrusted or generated code in Linux VMs or isolated Workers on Cloudflare.
Code SandboxesNew
Cognee
cognee.ai

Open-source agent memory platform built on graph and vector stores.
Memory & ContextOpen sourceNew
Coinbase x402
x402.org

Open standard for internet-native payments using HTTP 402, built for agents.
PaymentsNew
Composio
composio.dev

Tool calls with delegated auth across 1,500+ apps for agents.
Integrations & Auth ToolsNew
CrewAI
crewai.com

Framework and platform for multi-agent teams.
Agent FrameworksOpen sourceNew
Daytona
daytona.io

Secure sandboxes for running AI-generated code.
Code SandboxesOpen sourceNew
E2B
e2b.dev

Isolated cloud machines for agents to run code, browse, and use tools.
Code SandboxesOpen sourceNew
ElevenLabs Agents
elevenlabs.io

Build and deploy chat and voice agents on ElevenLabs.
Voice AgentsNew
Exa
exa.ai

Search API built for AI agents, with real-time web data and deep research.
Search & Web DataNew
Firecrawl
firecrawl.dev

Turns websites into clean, LLM-ready data with crawl, scrape, and search APIs.
Search & Web DataOpen sourceNew
Helicone
helicone.ai

AI gateway with routing and LLM observability.
Observability & EvalsOpen sourceNew
Hyperbrowser
hyperbrowser.ai

Cloud Chrome sessions, isolated sandboxes, and web data APIs for agents.
Browsers & Computer UseNew
Jina Reader
jina.ai

Converts any URL to Markdown for grounding LLMs.
Search & Web DataNew
Kernel
kernel.sh

Browser infrastructure for web agents with reusable sessions and fast spin-up.
Browsers & Computer UseNew
Langfuse
langfuse.com

Open-source tracing, evals, and observability for agents.
Observability & EvalsOpen sourceNew
LangGraph
langchain.com

Agent orchestration framework with durable execution and human-in-the-loop.
Agent FrameworksOpen sourceNew
LangSmith
langchain.com

LangChain's tracing and monitoring platform for agents and LLM apps.
Observability & EvalsNew
Letta
letta.com

Platform for stateful agents that keep long-term memory.
Memory & ContextOpen sourceNew
Mailgun
mailgun.com

Email API to send, receive, and track email.
EmailNew
Mastra
mastra.ai

TypeScript framework for agents with memory, tools, MCP, and workflows.
Agent FrameworksOpen sourceNew
Mem0
mem0.ai

Memory layer that lets agents learn from past interactions.
Memory & ContextOpen sourceNew
Modal
modal.com

Serverless cloud for running, training, and serving AI workloads, including sandboxes.
Code SandboxesNew
Nango
nango.dev

Integration platform connecting products and agents to 1,000+ APIs.
Integrations & Auth ToolsNew
OpenAI Agents SDK
openai.github.io

OpenAI's lightweight Python framework for multi-agent workflows.
Agent FrameworksOpen sourceNew
Parallel
parallel.ai

Web search, extraction, and monitoring APIs built for AI.
Search & Web DataNew
Pickle Browser
picklebrowser.com

Local browser that opens real pages for agents, shows its work on your machine, and needs no account.
Browsers & Computer UseNew
Pipedream Connect
pipedream.com

Managed auth and thousands of prebuilt tools across 3,000+ APIs.
Integrations & Auth ToolsNew
Pydantic AI
pydantic.dev

Type-safe Python agent framework from the Pydantic team.
Agent FrameworksOpen sourceNew
Resend
resend.com

Developer email API for transactional and marketing mail.
EmailNew
Retell AI
retellai.com

Voice agents for inbound and outbound phone calls.
Voice AgentsNew
Runloop
runloop.ai

Code sandboxes (Devboxes) for AI coding agents, plus evaluations.
Code SandboxesNew
Skyfire
skyfire.xyz

Identity and payment credentials for AI agents on the open web.
PaymentsNew
Smithery
smithery.ai

Registry and hosting to connect agents to MCP tools and services.
Integrations & Auth ToolsNew
Stagehand
stagehand.dev

SDK for browser agents with a Playwright-style API and self-healing selectors.
Browsers & Computer UseOpen sourceNew
Steel
steel.dev

Open-source browser API for running fleets of cloud browsers for agents.
Browsers & Computer UseOpen sourceNew
Stripe Agent Toolkit
docs.stripe.com

Stripe's MCP server, plugins, and skills for agents that handle payments.
PaymentsNew
Supermemory
supermemory.ai

Memory and continual learning engine for agents.
Memory & ContextNew
Tavily
tavily.com

Real-time search and content extraction APIs for agents.
Search & Web DataNew
Vapi
vapi.ai

Developer platform to build, test, and deploy voice AI agents.
Voice AgentsNew
Vercel AI SDK
ai-sdk.dev

Unified TypeScript SDK for AI apps and agents across model providers.
Agent FrameworksOpen sourceNew
Vercel Sandbox
vercel.com

Isolated Linux microVMs on Vercel for untrusted or agent-generated code.
Code SandboxesNew
Zep
getzep.com

Context layer that unifies business data, documents, and chats for agents.
Memory & ContextNew

FAQ

Questions

What is Agent Stack Directory?

A free, hand-checked directory of 54 infrastructure tools for AI agents, grouped into 11 categories like cloud browsers, code sandboxes, memory, and web search.

How are tools chosen?

Each tool is built for or widely used by people building AI agents. Every link is opened and checked before it is listed, and listings are rechecked regularly.

How do I get my tool listed?

Submit it on the submit page. Free listings are reviewed in order. A $79 fast-track gets a decision within 24 hours and is refunded if we decline. Paid placements are always labeled.

Can I pay for a better ranking or a verified badge?

No. Organic order, comparisons and guides are never sold. Paid placements are separate, labeled, and their links are marked rel=sponsored.