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Announcing StackOne Defender: leading open-source prompt injection guard for your agent Read More

About

We fuel innovation by connecting AI agents to software.

We created StackOne so any AI agent — whether you built it or just use one — can act across the business applications you or your customers rely on.

Leadership

Been there. Done that.

Having worked together for over 10 years at several SaaS companies, we saw how integration complexity held back product innovation. With AI agents now redefining how software operates, we created StackOne to make sure they can act across any application.

Romain Sestier

Romain Sestier

Co-Founder & CEO

Guillaume Lebedel

Guillaume Lebedel

Co-Founder & CTO

Team Experience

OracleJP MorganCoinbaseGoogleMicrosoftOutsystemsBCGOttaMastercardSiemensVodafoneContentSquare

Want to join the team?

View Open Positions

Our Mission

StackOne is the
integration infrastructure
AI agents need.

Whether you're building AI agents into your product or connecting off-the-shelf agents like Claude Code to your stack, StackOne provides the real-time infrastructure, connectivity, optimized execution, and security, companies need to scale.

200+

Agent Integrations

10,000+

Actions

10+ Million

API Calls

SOC2 II Certified
CCPA Compliant
GDPR Compliant
HIPAA Compliant

Investors

Backed by greatness.

StackOne is backed by exceptional founders and investors at:

Sequoia
GitHub
GV (Google Ventures)
XTX Ventures
Episode One
Playfair
MuleSoft
Blissgrowth
OpenAI
DeepMind
Workday Ventures
Microsoft

Timeline

Our journey so far

One of the fastest growing AI agent infrastructure platforms in the world.

Q1, 2023

Launched out of stealth

Q2, 2023

Investment from Co-Founder of GitHub

Q3, 2023

100m API Calls, 20 Integrations available

Q4, 2023

$3.6M Seed Round, 50+ Integrations available

Q2, 2024

100+ Integrations, 6 Categories, Customers in 3 Continents

Today

$20M Series A, 200+ Integrations, 10 Categories, 10,000+ AI Actions

Frequently Asked Questions

StackOne provides real-time integration infrastructure purpose-built for AI agents acting across business SaaS applications. The platform optimizes execution by reducing context bloat and token spend, and protects agent actions with open-source prompt injection detection and guardrails. Unlike retrofitted iPaaS tools, StackOne was designed from day one for agent-to-application connectivity.
Two groups: teams building AI agents into their products who need to connect them to customers' enterprise stacks — HRIS, ATS, CRM, LMS — at scale, and teams using off-the-shelf agents like Claude Code or ChatGPT who need those agents to act across their own business applications. If your agents only need a handful of read-only connectors with simple requirements, you can use brand MCPs. Once write operations, custom integrations and actions, customer counts, and tenants grow, managed infrastructure pays off.
StackOne is SOC2 Type II, HIPAA, and GDPR certified with managed permissions that limit each agent's scope. Agent-consumed data is scanned by Defender, an open-source prompt injection library that detects threats in under 4ms with 88.7% accuracy — higher than models 81x its size like DistilBERT. Authentication, credential storage, and access control are managed by the platform.
A free Starter tier includes 200+ pre-built connectors, 10,000+ actions, managed auth, and up to 1,000 action calls per month. Core adds premium connectors, unlimited custom connectors via the connector builder, A2A protocol, and SOC2 certification. Enterprise includes custom SLAs and professional services. Full breakdown on the pricing page.
StackOne Technologies Limited is incorporated in England and Wales (company 14684360) with registered offices at 2 Communications Road, Newbury, Berkshire, RG19 6AB. The team operates globally across Europe and the United States.
Yes. The team is distributed across Europe and the United States and hires across engineering, product, and go-to-market. Open roles are listed on the careers page.

Put your AI agents to work

All the tools you need to build and scale AI agent integrations, with best-in-class connectivity, execution, and security.