IBM PASE for i
PASE for i is the AIX runtime built into IBM i, and it is where the open-source software behind most AI work on the platform actually runs. It ships as option 33 of 5770-SS1, has been a no-charge option since V5R2M0, and it hosts the yum-installed Node.js and Python builds under /QOpenSys/pkgs, including the Mapepire server that IBM's IBM i MCP Server connects through on port 8076.
What PASE for i does
It runs AIX software inside IBM i. IBM calls it an integrated runtime environment for AIX applications, and says it does not have the drawbacks of an environment that only emulates the machine instructions. Many AIX programs run in it with little or no change. Picture one room in your house furnished exactly like an AIX machine. Programs built for AIX feel at home in that room, and they are still inside the same house as your Db2 for i data.
Why PASE matters for AI on IBM i
Most AI tooling for this platform is not written in RPG. IBM's own IBM i MCP Server, which lets AI agents talk to the machine using the Model Context Protocol, is written in TypeScript and needs Node.js 18 or newer. The Mapepire server it queries Db2 for i through is installed with yum. IBM's open source documentation groups yum, Node.js, Python, Ruby and PHP together as PASE software. So when an AI tool says it runs on IBM i, PASE is usually the part of IBM i it lands on.
Where the pieces live
Open source AI plumbing on IBM i
| Piece | Where it sits | Detail |
|---|---|---|
| yum packages | /QOpenSys/pkgs | IBM: all software provided by the RPMs installs into the /QOpenSys/pkgs prefix |
| Node.js and Python | /QOpenSys/pkgs/bin | 64-bit runtimes; the older 5733-OPS product does not need to be installed |
| Mapepire server | /QOpenSys/pkgs/bin/mapepire | Installed with yum install mapepire-server; listens on port 8076 |
| IBM i MCP Server | Off the machine | TypeScript on Node.js 18 or newer; connects in to Mapepire on port 8076 |
RPM means Red Hat Package Manager, the package format IBM uses here; yum is the installer that fetches those packages.
Which AIX level do I get?
PASE AIX level by IBM i release
| IBM i release | PASE AIX level |
|---|---|
| 7.6 | AIX 7.3 TL1 |
| 7.5 | AIX 7.2 TL5 |
| 7.4 | AIX 7.2 TL2 |
| 7.3 | AIX 7.1 TL4 |
TL means Technology Level, IBM's update stream for AIX. The level matters when you port an AIX binary or build one from source. Source: IBM's ibmi-oss-docs porting notes.
How do I turn it on?
Three steps to install PASE for i
- Run GO LICPGMSign on to the system and run the GO LICPGM command.
- Pick option 11Choose option 11 to install licensed programs.
- Select option 33Select option 33 of 5770-SS1, Portable Application Solutions Environment.
PASE for i is an optionally installable component of the operating system, so check first; on many systems it is already installed.
PASE for i does not ship a compiler of its own. IBM says you can install a supported compiler product into PASE for i and build there, and the yum packages already carry GCC and the usual build tools such as automake, autoconf, m4 and libtool.
Related Terms
IBM i
IBM's operating system for Power servers running traditional AS/400-lineage business applications, with Db2 for i built directly into the OS.
AS/400
IBM's original 1988 midrange business computer platform; the term is still used informally to refer to IBM i systems and shops even though IBM has rebranded the hardware and OS multiple times since.
OS/400
OS/400 is the original name of the operating system IBM now calls IBM i. It shipped with the AS/400 on August 26, 1988, became i5/OS in 2004 and IBM i in 2008, so the RPG, COBOL and Db2 for i objects that today's AI tools read sit on one unbroken operating system line.
Db2 for i
The relational database management system built into every IBM i operating system, tightly integrated with IBM i rather than a separately installed database product.
Mapepire
An open-source database access layer for Db2 for i, created by IBM and introduced in an August 2024 IBM blog post as a lighter, cloud-friendly alternative to ODBC and JDBC. A server daemon runs on IBM i and Node.js, Python, Java, and .NET Core clients connect to it over Secure WebSockets.
IBM i MCP Server
An open-source, IBM-published server implementing the Model Context Protocol (MCP), letting AI agents and LLMs query Db2 for i data and take defined actions on IBM i using natural language. In beta since October 2025.