# SierraTec Survey Developer Implementation Notes

These notes support architecture planning for the static front-end prototype. They are not a live API guarantee.

## Environments

- Maintain separate development, test, staging, and production credentials.
- Never reuse production secrets or response data in lower environments.
- Use synthetic test surveys and respondents in the developer sandbox.

## Authentication and authorization

- Store API credentials only in server-side secret management.
- Scope credentials by workspace, environment, operation, and data class.
- Enforce authorization on every resource, not only at the user-interface layer.
- Rotate credentials on schedule and immediately after suspected exposure.

## Requests and retries

- Use idempotency keys for create, publish, invitation, import, export, and other retryable write operations.
- Retry transient failures with exponential backoff and jitter.
- Respect rate-limit and retry-after headers.
- Do not retry permanent validation, authorization, or policy errors without a change.

## Pagination and synchronization

- Use cursor pagination for changing collections.
- Persist the last successfully committed cursor.
- Use updated-since filters for incremental synchronization where supported.
- Handle deleted or revoked resources explicitly.

## Webhooks

- Read and verify the raw request body before parsing.
- Validate signature, timestamp, expected source, and replay window.
- Deduplicate by event ID.
- Acknowledge quickly and process longer work asynchronously.
- Use a dead-letter queue and safe replay controls for repeated failure.

## Imports and exports

- Validate schema, encoding, data types, size, and access before processing.
- Show a preview and downloadable error file before committing an import.
- Run large files as asynchronous jobs with status and cancellation controls.
- Protect export files with short-lived links, authorization, encryption, and audit records.

## Errors and observability

- Return stable error codes, readable messages, field-level details, and correlation IDs.
- Do not expose secrets, raw stack traces, or unnecessary personal data.
- Log authentication, authorization, import, export, webhook, and privileged events.
- Monitor latency, errors, rate limits, queue age, retries, and third-party dependencies.