HACP (HTTP AICC Communication Protocol)

What is HACP in e-learning?

HACP (HTTP AICC Communication Protocol) is the technical protocol that defines how an e-learning course and a learning management system (LMS) exchange data over HTTP. It was developed by the AICC committee in 1998 as part of its specification for digital training, and for many years it served as the standard mechanism for content to report learner progress to the LMS — whether the course had been completed, the learner’s score, or time spent.

In the context of corporate e-learning, HACP was a relevant solution at a time when SCORM did not yet exist and organisations needed a reliable way to connect training content with their platforms. Unlike later standards such as SCORM — which uses JavaScript for communication — HACP bases its data exchange on HTTP requests between servers, making it the only mechanism among the e-learning standards that does not depend on sharing the same domain to function.

How HACP works: communication between course and LMS

The HACP mechanism is conceptually straightforward. When a learner launches an AICC course, the LMS passes the content a special URL (known as the AICC URL) along with a session identifier. From that point on, the course uses that URL to send HTTP POST requests to the LMS, reporting events such as session start, learner progress, or module completion.

All data travels as plain text structured as name-value pairs, similar to classic HTML forms. The LMS processes those text strings, updates the learner record, and can send data back to the course. There is no JavaScript or embedded API involved: communication happens server to server, which is technically different from how SCORM works.

This architecture has one important consequence: AICC content can reside on a completely different server from the LMS. This allowed content providers such as Skillsoft to distribute their courses to multiple organisations without handing over the files — simply by enabling HACP communication between their servers and the client’s LMS. In the 2000s, this represented a significant logistical and commercial advantage.

HACP, JavaScript API, and xAPI: differences between communication mechanisms

To understand what HACP does and why it was relevant, it helps to compare it with the other mechanisms that have defined communication between content and LMS throughout the history of e-learning.

When HACP is still relevant in corporate training

Although the AICC committee dissolved in 2014 and the standard no longer receives updates, HACP has not disappeared entirely. There are still contexts where L&D teams encounter it:

• Legacy content from classic providers. Libraries such as Skillsoft or OpenSesame distributed their courses in AICC/HACP format for many years. Organisations that acquired that content may still be running it if their LMS maintains compatibility.
• Regulated industries with strict requirements. Civil aviation, defence, and some government agencies adopted AICC as their corporate standard. In those environments, a full migration to modern standards can require lengthy validation and approval processes.
• Legacy system migrations. When an organisation changes LMS and needs to audit its existing content, it is common to find AICC courses using HACP. Knowing what this protocol is helps decide whether to migrate the content or rebuild it.
• Third-party content integration. Some external providers still deliver content in AICC format. Verifying whether your LMS supports HACP — and at what level — is a technical requirement before contracting that content.

In any of these scenarios, the general L&D industry recommendation is to plan a progressive migration towards xAPI or cmi5, which offer granular tracking, mobile learning compatibility, and active ongoing support.

HACP limitations compared to current standards

Understanding HACP’s limitations is just as important as knowing what it does well. For a training manager assessing whether to keep or migrate AICC content, these are the constraints that have the greatest practical impact:

• Very limited tracking. HACP only records whether the course was completed, the final score, and time spent. It does not capture interaction data — which questions the learner answered, which sections they visited, or where they dropped off. This limitation makes the kind of deep pedagogical analysis possible with xAPI or SCORM impossible.
• No native mobile learning support. HACP’s architecture does not account for mobile devices, offline experiences, or learning outside the LMS. In an environment where over 70% of digital content is consumed on mobile (Statista, 2024), this is a structural limitation.
• Plain text over HTTP. Data travels without structured encryption, which contrasts with current protocols that use HTTPS with robust authentication by default.
• A standard with no evolution. Since the AICC committee dissolved in 2014, no organisation updates or maintains HACP. Known issues go unresolved and new training needs — microlearning, simulations, social learning — have no place in this protocol.
• Variable compatibility across LMS platforms. Not all LMS platforms implement HACP at the same level. Some only support protocol version 2.2; others add version 3.5/4.0. This can create incompatibilities when migrating content between systems.

These limitations explain why the industry standard roadmap is to progressively migrate from AICC/HACP to SCORM or xAPI, or to rebuild content using modern authoring tools.

HACP and modern LMS platforms: what to expect

Most modern LMS platforms retain HACP support as a backward-compatibility feature for legacy content, but they prioritise it behind SCORM, xAPI, and cmi5. Before assuming your platform supports AICC/HACP, it is worth verifying two specific things: which protocol version is supported (2.2, 3.5, or 4.0) and which data elements the platform can read and record.

If your organisation is evaluating an LMS integration or migration, this is a good moment to audit which content is still in AICC/HACP format and plan a transition. isEazy LMS is built for current standards — SCORM, xAPI, and cmi5 — and allows you to centralise all corporate training with full tracking and compatibility with the most widely used authoring tools. If you need to migrate AICC courses to a modern environment, comparing LMS platforms compatible with current standards is a good first step.