Choose the smallest action surface that fits the workflow.

Start with a supported API when it is complete

A supported API is usually the cleanest boundary for a defined operation. It avoids presentation-layer dependencies, often provides structured authentication and errors, and may be covered by the application vendor’s compatibility commitments.

Its presence does not end the evaluation. Confirm that the endpoint exposes the exact action, deployed module, business semantics, permissions, and evidence required. An API that retrieves records but cannot perform the approved status transition leaves the operational gap unresolved.

• Best fit: stable, documented operations that fully cover the workflow.
• Watch for: incomplete modules, mismatched business paths, broad credentials, rate limits, and missing verification data.

Use RPA for deterministic orchestration when it already fits

RPA is effective for known sequences across applications, especially when an organization already has operating standards, monitoring, credentials, and people who maintain those automations. It can be the right foundation for a repeated process with predictable screens and exceptions.

For agent use, ask whether the automation is available as a callable capability with a clear input contract, authorization boundary, structured result, and source-system verification. Existing automation does not need to be discarded merely because an agent is now the requester. It may need a safer, narrower interface.

• Best fit: stable, rules-driven sequences with established automation operations.
• Watch for: brittle selectors, hidden credentials, opaque failures, duplicate retries, and a gap between bot completion and business completion.

Use computer use where flexibility is the point

Computer-use systems can inspect and navigate unfamiliar or changing interfaces without a prepared integration for every step. That makes them useful for exploration, assisted work, and variable tasks where the next action depends on information discovered in the interface.

The same flexibility increases the execution surface. For recurring consequential writes, decide whether the agent should rediscover the path each time or whether the learned action should become a governed capability. Supervision, session isolation, and explicit confirmation may remain appropriate when open-ended interaction is necessary.

• Best fit: variable, exploratory, low-frequency, or supervised interface work.
• Watch for: excessive autonomy, prompt-based permissions, inconsistent recovery, sensitive screen exposure, and weak business-effect evidence.

Use a governed agent tool for a repeatable business action

A governed tool presents a stable action schema to the agent while hiding the implementation path. The underlying action may use an API, an existing automation, an interface adapter, or a combination. What distinguishes the tool is the contract around inputs, policy, effects, failures, evidence, and versions.

Graft is focused on creating this boundary for workflows whose complete action remains in a browser, desktop, or internal interface. It is not a claim that an interface-backed adapter should replace a supported API or a dependable automation asset.

• Best fit: repeated, understood actions that need reuse across agents and a narrow execution boundary.
• Watch for: overbroad tool schemas, source roles that exceed tool scope, unmodeled exceptions, and conformance claims detached from a tested environment.

Hybrid architectures are normal

One workflow may retrieve data through an API, apply a policy in an agent, request human approval, invoke an interface-backed write, and verify the record through an export. The goal is not to select one category for every step. It is to use the most direct supported path for each action while maintaining coherent authorization and evidence across the workflow.

Avoid architectural purity that increases risk. Reuse a stable RPA asset if it already performs the operation well. Keep a person in the loop where judgment is irreducible. Use a governed tool where repeated agent access needs a contract.

A decision worksheet

• Is the task exploratory or is the business action already known?
• Does a supported API expose the complete action in this deployment?
• Does an existing automation already have reliable operations and ownership?
• How much execution freedom does the task genuinely require?
• Which identity, record, field, value, and approval boundaries apply?
• Can the outcome be verified in the source system?
• What changes will require maintenance or recertification?
• Who handles exceptions and uncertain completion?

Frequently asked questions

Is a governed agent tool an alternative to every RPA workflow?

No. An established RPA process may remain the best execution mechanism. It can potentially sit behind a narrower tool contract if agents need to invoke it.

Is computer use always less reliable?

Reliability depends on the task, environment, controls, and evidence. Open-ended flexibility is valuable for some work; a repeated consequential action usually benefits from less freedom and more explicit structure.

Can a tool use both APIs and interfaces?

Yes. The contract can remain stable while the implementation uses the most suitable supported path for each part of the operation, provided authorization and verification remain coherent.

Which approach is fastest to evaluate?

A fast happy path is not the same as the safest operating choice. Compare the effort to authorize, verify, maintain, and recover the workflow, not only the effort to complete one successful run.

What if no approach can prove the outcome?

Keep an explicit human verification or reconciliation step. An agent should not report business completion when the system of record cannot provide trustworthy evidence.