Azure Key Vault vs Phase

Azure Key Vault

Access runs on Microsoft Entra ID tokens and Azure roles that can be scoped to one secret, with soft delete, a 99.99 per cent SLA and a public OpenAPI contract. Secret rotation needs an Event Grid trigger and a function the owner writes, audit logging is off until enabled, and an Azure subscription needs a person and a payment card.

Phase

Service account tokens can be minted with an expiry over the API, every secret read is logged, and the CLI redacts values when it detects an AI agent. No OpenAPI document or pagination was found in the reviewed documentation, and the Free plan keeps audit logs for 24 hours.

Azure Key Vault

1. Request a token for the resource https://vault.azure.net and send it as a Bearer header. Every call must carry api-version, such as 2025-07-01, because there is no default
2. Ask for the Key Vault Secrets User role on the vault or the single secret. Key Vault Reader returns metadata only, not values
3. Cache secret values in memory. A vault allows 4,000 reads and 300 secret creations per 10 seconds, and a subscription five times that
4. On 429 wait 1, 2, 4, 8 then 16 seconds. Throttled requests do not count against the limit
5. Don't retry Set Secret blindly. Each successful call creates a new version of the secret

Phase

1. Enable server-side encryption on the app before calling /v1/secrets. Without it the REST API cannot read or write that app's secrets
2. Send Authorization: Bearer ServiceAccount <token> for a service account and Bearer User <token> for a personal access token. The token type is part of the header
3. Stay under 120 requests a minute per account on Free and 240 on Pro, and wait the seconds in the retry-after header on a 429
4. Treat a 409 on POST /v1/secrets as the key already existing at that path, and use PUT to change it. Rotating secrets reject PUT and DELETE
5. Have a person run phase ai enable and choose masked values. The CLI blocks an agent from running phase ai enable or phase ai disable itself