How to Connect AI Agents to ERP Systems Without an API in 2026: Deck, iPaaS, RPA, and Native APIs Compared

Most ERP systems make API access difficult by design. Some require a formal partnership agreement before any API access is granted. Others expose read-only endpoints for a fraction of the modules a business actually uses, leaving core workflows like purchase order approval, vendor record updates, and invoice reconciliation unreachable by machine. For teams building AI agents that need to both read from and write back into ERP systems like SAP, Oracle, and NetSuite, the API is often not the path.

This guide covers the main approaches to connecting AI agents to ERP systems, including cases where the vendor API does not exist or does not cover the workflow: Deck, iPaaS platforms like Workato and MuleSoft, DIY RPA scripts, and native ERP APIs. We assessed each on whether it works without a partner agreement, whether it supports write-back, how it handles authentication, and how it holds up when the ERP’s interface changes.

How We Evaluated These Approaches

This comparison reflects Deck’s own evaluation framework, informed by vendor technical documentation and publicly available information about enterprise ERP integration deployments. We assessed each approach across five criteria:

• API or partner agreement requirement: Whether the approach requires a vendor partnership or certified API access before it can be used.
• Write-back support: Whether the approach can complete actions inside the ERP (submitting approvals, updating records) in addition to reading data.
• Authentication handling: How the approach manages login flows, MFA, and session state at production scale.
• Structured JSON output: Whether data comes back in a consistent, machine-readable format without additional engineering per ERP.
• Resilience to UI changes: Whether the approach survives an ERP vendor updating their interface.

Why ERP Systems Are Hard to Connect Agents To

ERP platforms manage some of the most business-critical data a company has: inventory, procurement, HR, and more. Getting programmatic access to that data is harder than it should be.

Native ERP APIs exist on major platforms, but access is often restricted. SAP requires a formal partnership or certified integration before its API tiers are accessible. Oracle and NetSuite expose APIs that cover some modules but leave others (particularly UI-only admin workflows) without any programmatic equivalent. For a team that needs an agent to approve a purchase order, update a vendor record, or reconcile an invoice inside the ERP, the API frequently does not cover that workflow.

iPaaS platforms like Workato and MuleSoft solve this problem for ERPs that do have accessible APIs. They provide pre-built connectors, managed authentication, and visual workflow builders. When the ERP API covers the needed workflow, these tools are the right call. When it does not, they have nothing to connect to.

DIY RPA scripts (Playwright, Selenium) and enterprise RPA platforms (UiPath, Automation Anywhere) can operate ERP interfaces without an API, but they are selector-based: they follow a hardcoded sequence of steps and break when the ERP vendor updates their UI. ERP interfaces change more often than most teams expect, especially across major version upgrades.

Comparison Table

Per-Approach Evaluation

Deck

Deck is built for the case where the ERP vendor’s API does not exist, does not cover the specific workflow, or requires a partnership agreement that has not been established. Deck’s agents operate the ERP’s own interface directly, the same screens a human employee would navigate, and expose the result as a structured API that downstream AI agents can call.

This works in both directions.

Reading data from the ERP. Deck agents navigate to the relevant ERP screens, extract inventory levels, vendor data or HR records and return it as structured JSON. The output format is consistent regardless of which ERP the data came from.

Writing data back into the ERP. Deck agents can complete actions inside the ERP interface: submitting a purchase order approval, updating a vendor record, entering a transaction, or reconciling an invoice. If a human employee can do it through the ERP’s UI, a Deck agent can be directed to do it as well. This is the capability that native ERP APIs and iPaaS connectors frequently cannot provide, because the API often does not expose write access to UI-only workflows.

Authentication and credential handling. Deck manages the full login flow including MFA challenges and session state. Credentials are stored in an encrypted Vault and never touch application code, which is the requirement most enterprise security teams apply before approving a production ERP integration.

Audit trails. Every agent action is logged: what was accessed, what was changed, and when. For ERP workflows tied to procurement approvals, this audit trail is often a compliance requirement.

Resilience to ERP interface changes. ERP vendors update their interfaces regularly, particularly across version upgrades. Deck’s agents interpret the interface visually rather than following hardcoded selectors, so a UI change does not break the integration the way it would with an RPA script.

Best for: AI agents that need to read from and write into ERP systems where the native API does not cover the workflow, does not exist, or requires a partnership agreement the team does not have.

Native ERP APIs (SAP, Oracle, NetSuite)

When API access is available and covers the needed workflow, native ERP APIs are the cleanest technical path. They are purpose-built for machine-to-machine communication, return structured data reliably, and do not depend on scraping or interface interpretation.

The constraints are practical rather than technical. SAP’s API tiers frequently require a formal partner certification before access is granted, which means a procurement and legal process before any integration work begins. Oracle and NetSuite APIs cover many modules but leave others accessible only through the UI. For teams that have cleared the partnership requirements and whose workflows fall within the API’s coverage, native APIs are the right starting point.

Best for: Teams with certified API access whose specific ERP workflows are fully covered by the vendor’s API. If either of those conditions is not met, a different approach is needed.

iPaaS Tools (Workato, MuleSoft, Boomi)

iPaaS platforms are the right call when the ERP has an accessible API and the team needs to connect it to downstream systems without building custom integration code. Pre-built ERP connectors, visual workflow builders, and managed authentication reduce the setup time significantly compared to custom development.

The limitation is the same as with native APIs: these platforms require the ERP to expose an API for the workflow in question. If the target workflow is UI-only, the connector has nothing to attach to. iPaaS tools do not operate web interfaces and cannot complete actions that exist only in the ERP’s UI.

Best for: Connecting ERPs with accessible, stable APIs to other systems in the stack. Not applicable when the ERP workflow is not covered by the vendor’s API.

DIY RPA Scripts (Playwright, Selenium)

Playwright and Selenium can interact with ERP interfaces without an API, which makes them a reasonable starting point for one-off automations against a small number of stable screens. For a team with engineering capacity and a well-understood ERP workflow, a custom script can be built quickly.

The limitation is maintenance. ERP interfaces change across version upgrades, and each change requires the script to be manually updated. Authentication flows, MFA challenges, and session management all have to be custom-built per ERP. There is no normalization of output: the developer writes the parsing logic, and every ERP produces a different format.

Best for: One-off automations against stable, well-understood ERP screens where the team controls the timeline for script updates and the ERP is not expected to change layout frequently.

Enterprise RPA Platforms (UiPath, Automation Anywhere)

Enterprise RPA platforms add governance, credential management, and bot orchestration on top of the selector-based automation model. UiPath’s Orchestrator provides audit logging, centralized bot management, and credential assets that raw scripts do not. For large enterprises with dedicated RPA teams automating stable, high-volume ERP workflows (SAP back-office processes, mainframe terminal interactions), this is a well-proven approach.

The underlying automation is still recording-based, though. When an ERP UI changes, bots break and a developer has to update the recording. Licensing costs also scale with bot count, which adds up as the number of automated ERP workflows grows.

Best for: Large enterprises with dedicated RPA teams and stable, high-volume ERP workflows where UI changes are infrequent and governance tooling (audit logs, bot management) is a requirement.

ERP Workflows This Unlocks

Connecting AI agents to ERP interfaces rather than ERP APIs opens up a specific set of workflows that the API often cannot reach.

• Purchase order creation and approval. Submitting or approving purchase orders directly inside the ERP interface, including workflows that exist only in the UI and are not exposed by the vendor’s API.
• Inventory data extraction. Pulling current inventory levels, stock movements, and warehouse data from ERP screens and returning them as structured JSON for downstream AI agent consumption.
• Vendor record management. Reading and updating vendor records, payment terms, and contact information inside the ERP without a formal API integration.
• Employee and HR data sync. Extracting employee records, payroll data, and organizational data from ERP HR modules that restrict API access to partner-tier accounts.

Frequently Asked Questions

Q: Can AI agents connect to ERP systems that don’t have a public API?

A: Yes. Platforms like Deck let AI agents operate the ERP’s own web interface directly, the same way a human employee would, so a public API is not required. The agent logs in, navigates to the relevant screens, and returns the result as structured JSON. DIY scripts (Playwright, Selenium) and RPA platforms (UiPath) can also operate ERP interfaces without an API, but they are selector-based and break when the ERP’s layout changes.

Q: Can Deck write data back into an ERP, or only read it?

A: Both. Deck agents can complete actions inside the ERP interface (submitting approvals, updating vendor records, entering transactions) as well as extracting data. Write-back is the capability that native ERP APIs and iPaaS connectors frequently cannot provide, because the API often does not expose UI-only workflows.

Q: Do we need a partnership agreement with the ERP vendor to use Deck?

A: No. Deck operates through the existing user interface rather than the vendor’s API, so no partner agreement or API certification is required. This is a meaningful difference from native ERP API access, which on platforms like SAP often requires a formal partnership before the relevant API tiers are accessible.

Q: Which ERP systems does Deck support?

A: Deck supports 30+ enterprise applications out of the box, including SAP, Oracle, and NetSuite, with broader coverage across 100,000+ portals and vendor systems.

Q: When should I use a native ERP API instead of Deck?

A: Use the native ERP API when access is available, the partnership requirements are already cleared, and the specific workflow is fully covered by the API. Native APIs are the cleanest technical path when those conditions are met. Deck is the right alternative when any of those conditions is not met: the API does not cover the workflow, access requires a partnership the team does not have, or the workflow exists only in the ERP’s UI.

Q: What happens when the ERP vendor updates their interface?

A: Deck’s agents interpret the ERP interface visually rather than following hardcoded selectors, so they adapt when the layout changes rather than breaking. DIY scripts and RPA bots are selector-based: an interface change breaks the automation and requires a developer to manually update it.