Zero Data Retention

Zero data retention (ZDR) means the upstream provider that serves your request does not keep the prompt or the completion after returning it. Use it when a prompt carries data you cannot leave on a third party’s disk. Two surfaces implement it:

GET /v1/models?zdr=true lists the models a ZDR request can reach.
provider: {"zdr": true} in a request body restricts routing for that request.

The two agree by construction. A model listed under ?zdr=true is one that provider: {"zdr": true} can route.

Route a request under zero data retention

Add the provider block to the request. Every inference endpoint accepts it: /v1/chat/completions, /v1/messages, /v1/responses, /v1/embeddings, and /v1/completions.

curl https://api.redpill.ai/v1/chat/completions \
  -H "Authorization: Bearer $REDPILL_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "google/gemma-3-27b-it",
    "messages": [{"role": "user", "content": "Summarize this contract clause."}],
    "provider": {"zdr": true}
  }'

If no provider for that model operates under zero data retention, the request fails before the prompt is sent:

{
  "error": {
    "message": "No zero-data-retention providers are available for the selected model.",
    "type": "not_found_error"
  }
}

The status is 404. This is a fail-closed check: the gateway does not fall back to a non-ZDR provider, and failover retries stay inside the ZDR set. Setting "zdr": false, or omitting the field, applies no retention constraint and behaves exactly as a request with no provider block.

List the models you can use

curl -s "https://api.redpill.ai/v1/models?zdr=true" \
  -H "Authorization: Bearer $REDPILL_API_KEY" \
  | jq -r '.data[].id'

Embedding models have their own catalog, which takes the same parameter:

curl -s "https://api.redpill.ai/v1/embeddings/models?zdr=true" \
  -H "Authorization: Bearer $REDPILL_API_KEY" \
  | jq -r '.data[].id'

true is the only accepted value. Any other value, including false, returns 400. Omit the parameter for the full catalog. Rejecting other values is deliberate: a typo cannot silently return an unfiltered list that looks filtered. A model object has no zdr field. The filter is how you read this property, so query the filtered catalog rather than inspecting individual model objects.

How zero data retention differs from confidential inference

These are different properties and you may need either, or both.

	What it constrains	How to select it	How to verify it
Confidential inference (`is_tee`)	Who can read memory while the model runs. The upstream is attested and the channel is bound before the prompt is sent.	`is_tee: true` on a model object	The per-response receipt records `upstream.verified.result`
Zero data retention (`zdr`)	Whether the upstream stores prompt and completion content after serving.	`?zdr=true`, `provider: {"zdr": true}`	Provider contract and published policy

The distinction matters because a TEE constrains execution, not storage. A provider could run a model inside an enclave and still write request logs to disk. RedPill tracks the two properties separately for that reason.

Today the two filters happen to select the same models, because every confidential provider RedPill routes to also operates under zero data retention, and the routed third-party providers do not. Do not depend on that. Filter with ?zdr=true when you need the retention property, rather than inferring it from is_tee.

Zero data retention is a property of the upstream provider, backed by its contract or published policy. It is not proven by the attestation report or the receipt, which cover workload identity and response integrity. Confidential inference is the property the receipt does prove. See Verify a response.

The gateway’s own retention

The gateway does not store request or response bodies at any point, for ZDR and non-ZDR requests alike. Receipts hold hashes, not content. See Trust boundary. Setting zdr changes which upstream serves the request. It does not change gateway behavior.

List Models

The zdr query parameter and model object fields.

Chat Completions

The provider routing block.

Providers

What each upstream provider attests.

Compliance

How retention maps to GDPR and HIPAA obligations.

Core

Privacy

Migration

Integrations

Route a request under zero data retention

List the models you can use

How zero data retention differs from confidential inference

The gateway’s own retention

List Models

Chat Completions

Providers

Compliance

​Route a request under zero data retention

​List the models you can use

​How zero data retention differs from confidential inference

​The gateway’s own retention

​Related

List Models

Chat Completions

Providers

Compliance

Route a request under zero data retention

List the models you can use

How zero data retention differs from confidential inference

The gateway’s own retention

Related