StackOne

UK-based unified API connecting AI agents to HR, CRM and recruiting systems securely

Quick Overview

Company StackOne Technologies LTD
Category Automation & Integration
Headquarters Newbury, United Kingdom
EU Presence United Kingdom (adequacy decision, outside the EEA)
Open Source No
Compliance SOC 2 Type II (stated)
Pricing Free Starter (1,000 credits/seat/month) / Team $600/month / Enterprise and OEM on request
Free Option Free trial, no credit card required
Replaces Merge, Paragon, building unified APIs in-house

Detailed Review

Pros and Cons

Pros

  • Built specifically for AI agents, not human-driven automation
  • Free tier with no credit card required
  • 520+ connectors across HR, CRM, ATS and IAM systems
  • Prompt-injection defence and full audit logging built in
  • UK entity, English law, EU adequacy decision

Cons

  • Also operates a US office, so check which entity is contracting
  • Team plan pricing published but Enterprise is quote-only
  • Newer entrant than the established iPaaS vendors in this category
  • Credit-based pricing needs modelling before volume is predictable

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Frequently Asked Questions

What is StackOne?

StackOne exists because an AI agent calling a CRM or an HR system needs something a human clicking through a UI does not: a stable, permissioned, auditable set of actions it can call without a prompt injection turning a support ticket into a data export.

StackOne's pitch is integration infrastructure for agents specifically — 520-plus connectors surfaced as more than 32,000 discrete actions, with permission scoping, prompt-injection defence and complete audit logging built around the assumption that the caller is a language model rather than a person.

Where is StackOne based?

StackOne operates from Newbury, United Kingdom, which places it under United Kingdom (adequacy decision, outside the EEA). Compliance: SOC 2 Type II (stated).

What does StackOne cost?

Free Starter (1,000 credits/seat/month) / Team $600/month / Enterprise and OEM on request. Free trial, no credit card required.

Who is StackOne best for?

Teams building AI agents that need to call business systems. Designed for a caller that is a language model, not a person: StackOne is the only platform here built around AI agents rather than human-triggered workflows.

What are the drawbacks of StackOne?

Also operates a US office, so check which entity is contracting. Team plan pricing published but Enterprise is quote-only. Newer entrant than the established iPaaS vendors in this category. Credit-based pricing needs modelling before volume is predictable.

Who worked on this review

Three people touch every tool page: one writes it, a second edits it, and a third checks the compliance and pricing claims against the vendor's own documentation.

Ingrid Halvorsen
Written by

Ingrid Halvorsen

Managing Editor · Oslo, Norway

Runs the review process and decides when a page is ready to publish or needs another pass.

Daniel Brandt
Edited by

Daniel Brandt

Privacy & Compliance Researcher · Berlin, Germany

Checks the compliance claims: where the company is established, where the data sits, and what the DPA actually says.

Sebastiaan Smits
Fact-checked by

Sebastiaan Smits

Founder & Editor · Netherlands

Selects the tools, writes the reviews, and checks where each company is actually established.

Read our editorial process for how we source, verify and update these pages — and how we keep affiliate income separate from what we recommend.

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