StackOne

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Overview

StackOne is a London-based applied-AI infrastructure company founded in 2023. Its platform connects AI agents to enterprise applications through a unified interface, with support for APIs, SDKs, MCP and A2A. The company provides pre-built connectors and actions across categories including HRIS, ATS, LMS, CRM, IAM and document systems, while also allowing customers to create custom integrations.

The company is positioned between enterprise integration software and the emerging AI-agent infrastructure market. Its notable focus is on enabling agents to take actions in business systems while adding authentication, governance, observability and compliance controls. Public product information describes hundreds of connectors and tens of thousands of available actions, though counts vary by source and product update.

History

StackOne was founded in 2023 by Romain Sestier and Guillaume Lebedel, who serve as co-founder and CEO and co-founder and CTO, respectively. The company initially focused on integration infrastructure and unified APIs for connecting SaaS applications, particularly across HR and business software. It later positioned its platform around enabling AI agents to securely execute actions in enterprise applications through APIs, MCP and A2A interfaces. StackOne has raised venture funding, including a Series A led by GV with participation from Workday Ventures and other investors.

Product Lines

Product Line	Positioning	Price Range
Gateway — enterprise application connectivity	Unified gateway for AI-agent access to SaaS tools	Free starter tier; paid pricing not publicly specified
AI Connector Builder — custom integrations	Build connectors and actions for additional APIs	Included in paid Team and Enterprise plans; custom pricing
StackOne Agents — agent-to-agent workflows	Support for AI agents and A2A interactions	Included in paid Team and Enterprise plans; custom pricing
Defender — security and governance	Controls and monitoring for safer agent execution	Premium feature in paid plans; custom pricing
OEM — embedded integration infrastructure	Embed StackOne connectivity in another software product	Free OEM Core tier; custom pricing for expanded usage

Manufacturing

StackOne is a software company and does not manufacture physical products. Its platform and connectors are developed and operated as cloud software, with customers able to use pre-built integrations or build custom connectors for other APIs.

Notable Products

StackOne Platform - AI-agent infrastructure for connecting enterprise applications through a unified interface and executing actions across SaaS systems.
Gateway - A gateway providing access to StackOne's pre-built enterprise application connectors and action library.
AI Connector Builder - A tool for creating and managing custom integrations and actions for APIs not covered by pre-built connectors.
StackOne Agents - Agent capabilities supporting agent-to-agent workflows and enterprise application actions.
Defender - Security and control features for governing AI-agent activity, including protection and monitoring functions.

Reputation

StackOne is generally presented by customers and industry directories as an integration infrastructure provider focused on AI agents rather than a conventional middleware vendor. Reported strengths include broad connector coverage, a unified API approach, responsive support and support for newer agent protocols such as MCP. Reported criticisms include occasional API or SDK limitations, bugs after updates, incomplete coverage for some systems and limited filtering in certain workflows. Public employee estimates vary substantially, with directory sources ranging from roughly 11–50 employees to much larger unverified bands; the lower estimate is more consistent with available company-profile data.

Sources (10)