Registry stack documentation: machine-readable Markdown.
Index of all pages: https://docs.registrystack.org/preview/llms.txt
Full corpus: https://docs.registrystack.org/preview/llms-full.txt

# When Registry Stack fits

> Decide whether Registry Stack matches the access problem your institution needs to solve.

Use Registry Stack when an institution already manages authoritative data and
needs a controlled way for another system to read selected records or receive
a bounded answer. Registry Stack adds an access layer. It does not replace the
system that owns the data.

## Registry Stack is a good fit when

- The source must remain authoritative and under the institution's control.
- Callers need a reviewed interface instead of direct database or file access.
- Each caller must have an explicit purpose, permission, and limited result.
- The institution needs to test source behavior with synthetic fixtures before
  connecting a runtime environment.
- Operators need separate control over endpoints, credentials, trust, and
  deployment.

## Choose the result you need

| Caller needs | Use | Result |
| --- | --- | --- |
| Selected records or fields | Registry Relay | A protected, read-only API response |
| A bounded answer or status | Registry Notary | A claim result without the source record |

The two products can work together. Registry Relay obtains a limited source
result, and Registry Notary evaluates a reviewed claim over that result.

## Registry Stack is not the right tool when

- You need a new system of record.
- A caller must create, update, or delete source records.
- You need a workflow, eligibility, ranking, or case-management engine.
- You need Registry Stack to decide legal authority, data ownership, or
  institutional approval.
- You want to publish unrestricted open data.

Registry Stack makes these boundaries visible, but the responsible
institutions still make and approve the underlying decisions.

## What you need to adopt it

Before moving beyond a local sample, identify:

- The source owner and update process.
- The fields and operations the integration is allowed to use.
- The callers, purposes, and fields each service may disclose.
- The operator responsible for endpoints, credentials, trust, deployment,
  monitoring, recovery, and audit retention.

Start with non-personal data. A successful local tutorial is not production
approval.

## Next

- [Run your first registry API](../../tutorials/publish-spreadsheet-secured-registry-api/)
- [Connect your own spreadsheet](../../tutorials/use-your-spreadsheet/)
- [Read the architecture overview](../../explanation/architecture/)
- [Review the security boundaries](../../security/)