# Aguasto API versioning and deprecation policy

Policy for the anonymous public research and educational calculation interfaces at https://www.aguasto.com. Effective October 27, 2026.

## Current version

REST catalog and calculator operations use /api/v1. The /ask endpoint implements NLWeb 0.55. MCP protocol versions are negotiated independently during initialize. There are no deprecated operations and no scheduled shutdowns.

## Compatible changes

New optional fields may be added within v1. Clients should ignore unknown response fields. Breaking request or response changes require a new major REST URL version. The v1 calculator formula contract preserves deterministic results for the same canonical inputs.

## Deprecation and Sunset

Before retiring an operation, Aguasto will publish its replacement, migration instructions and a specific removal date at least 90 days before removal. Deprecated operations will send a Deprecation header and a Sunset header with the announced removal date. Active operations do not emit misleading retirement dates.

Retirement notices will appear in this policy and at https://www.aguasto.com/developers#versioning. The OpenAPI description at https://www.aguasto.com/openapi.json links this policy. No change to the absence of GPU provisioning, inference, accounts, billing or payment interfaces is implied.

## Client responsibilities

Follow typed error codes, honor Retry-After on HTTP 429 and use the published per-instance rate-limit window. Calculator retry keys bind to canonical inputs; the server stores neither keys nor request bodies. See the developer guide for limits and examples. Do not send confidential inputs.

HTML policy: https://www.aguasto.com/developers/versioning. The /api/v1/sandbox test operations follow the same versioning rules.

Questions: contact@aguasto.com. Website inquiry delivery remains disabled; use your own email application to send a message.