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
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.
The contracting entity is StackOne Technologies LTD, registered in Newbury, England, with its terms governed by English law — the company also has a San Francisco office, but the UK entity is the one a European customer contracts with.
Pricing starts free with 1,000 credits per seat per month on the Gateway Starter plan, rising to $600 a month for the Team plan with 5,000 credits, and custom pricing for Enterprise and for the OEM tier aimed at vendors embedding StackOne into their own product. A free trial needs no credit card. StackOne states SOC 2 Type II compliance for its Enterprise tier.
What StackOne does well
- 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
Where StackOne falls short
- 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
Standout feature. 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.
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
Alternatives to StackOne
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.
Is StackOne a good alternative to Merge?
StackOne is built as a European alternative to Merge: UK-based unified API connecting AI agents to HR, CRM and recruiting systems securely. It will not be a like-for-like feature match in every respect, so check the review above for where the two genuinely differ before switching.
How does StackOne compare to other Automation & Integration tools?
StackOne is one of several European Automation & Integration tools we cover. It is most often compared with Merge, Paragon, building unified APIs in-house.