Legacy ERP customers are no longer weighing one decision. As maintenance deadlines, third-party support, and agentic interfaces collide, the choice is becoming whether to migrate the core, extend its life, or place a new AI-driven experience layer on top of it.
In a June 16 interview, Rimini Street CEO Seth Ravin described a headless ERP architecture and framed it as a broader enterprise shift, pointing to Salesforce’s parallel move in CRM. A headless system separates the interface from the engine, so the front end is replaced by a custom layer while the ERP keeps running underneath through APIs.
SAPinsider benchmark research found that while 55% of organizations have deployed SAP S/4HANA, only 34% have fully completed the transition, leaving much of the customer base still weighing its next move.
Headless ERP Splits Interface from the Core
Ravin describes ERP breaking into microservices connected by APIs, with a custom agentic UX layered on top. An agentic UX is an interface driven by AI agents, so a user states an intent and software carries out the steps. Because that layer sits over APIs rather than being welded to the core, the ERP underneath becomes “headless.”
Salesforce made a similar turn with Headless 360, exposing every capability as an API, a Model Context Protocol tool, or a command-line call with the browser optional.
Ravin says business data can eventually move to open-source databases, such as PostgreSQL and MongoDB. That step marks the most radical part of the thesis.
Still, the idea attracts pushback. Deloitte argues the future is modernization rather than replacement, a modular, API-driven agentic ERP where rules and workflows stay in the core while agents act as the interface. That keeps the core as the system of record.
SAP becomes the clearest test case because its ECC customer base faces the sharpest combination of migration deadlines, third-party support options, and AI-access negotiations. The headless ERP debate is broader than SAP, but SAP holdouts show how the trade-off plays out when legacy support, cloud migration, and agentic interfaces all land in the same buying decision.
AI Access Moves to the Migration Bargain
SAP shifted its cloud-only AI stance in May 2026, agreeing to bring a significant share of Joule assistants and agents to hybrid landscapes that connect to on-premises SAP ECC and SAP S/4HANA. SAP frames the access as an interim bridge for customers who have committed their landscape to RISE with SAP.
SAP Chief Strategy Officer Sebastian Steinhaeuser presented the change at Sapphire 2026, softening the cloud-only position CEO Christian Klein set in July 2023 around RISE with SAP. SAP positions Joule, SAP Business Technology Platform, SAP S/4HANA, and SAP Business Data Cloud as a single semantic layer over business data.
Rimini Street reads the reversal differently. It characterizes on-prem AI access as gated behind two commercial conditions: redirecting at least half of SAP spend to the cloud under a RISE with SAP commitment, and enrolling in SAP’s Max Success Plan. Rimini Street calls that a contractual and financial dependency.
Support Deadlines Force a Three-Way Choice
Mainstream maintenance for SAP ERP (ECC 6.0) enhancement packages 0 through 5 ended December 31, 2025. Maintenance for packages 6 through 8 ends December 31, 2027, with extended support at roughly a two-percentage-point premium through 2030.
Rimini Street offers Rimini Support and Rimini Agentic UX for SAP ECC and Business Suite, positioning its Agentic AI ERP approach to layer AI over existing systems without replatforming. Rimini Street reports it will extend support beyond 2040 and cut annual SAP support fees by up to 50%.
For holdouts, the maintenance deadline sets up a clear trade-off. Third-party support may buy time and cut costs, but staying on SAP ECC past 2027 means forgoing SAP’s standard security patches and legal-change updates, which accrues technical debt and compliance exposure. These risks weigh against the cost of migrating.
What This Means for ERP Insiders
Legacy ERP teams need to price optionality. Headless ERP, third-party support, and cloud migration each carry different costs, risks, and timelines. CIOs should compare them across support exposure, integration complexity, security updates, compliance obligations, AI access, and long-term platform control rather than treating migration as the only variable.
AI access can shape the ERP contract decision. Vendor AI capabilities are increasingly tied to cloud commitments, support tiers, and platform roadmaps. ERP buyers should model the commercial terms around AI access before signing multiyear modernization agreements, especially when independent support or decoupled architectures remain on the table.
Headless models shift risk into architecture. A custom agentic interface can extend the useful life of a legacy core, but it also changes who owns security, support, integration, data flows, and compliance. ERP leaders should test whether the architecture reduces migration pressure or simply moves complexity into a new layer.
Editor’s note: A version of this article was originally published on SAPinsider on 6/24.
