Regions

Data residency pinning at rest and at inference.

Residency is an invocation rule, not only a disk policy. Eridian pins Customer Data at rest and, on Enterprise, primary inference processing to the region on the project. Routing still selects GPT or Gemini; both families are offered in every published region.

Published Regions

Region	Code	Alignment
United States	`us-east-1`	Default for US-booked tenants
European Union	`eu-west-1`	GDPR; SCCs as documented in the DPA
United Arab Emirates	`me-central-1`	UAE PDPL; RENEDOR LLC processing
Asia-Pacific	`ap-southeast-1`	APAC residency option on the order form

Account, billing, email, and security telemetry may be processed outside the pinned region as described in the privacy policy.

Pin a Project

http

PUT /v1/projects/prj_legal_001/residency
Authorization: Bearer eridian_sk_...

PUT /v1/projects/prj_legal_001/residency
Authorization: Bearer eridian_sk_...

json

{
  "region": "eu-west-1",
  "inference_pin": true,
  "cache_scope": "region",
  "fail_closed": true
}

{
  "region": "eu-west-1",
  "inference_pin": true,
  "cache_scope": "region",
  "fail_closed": true
}

Field	Meaning
`inference_pin`	GPT and Gemini hops must run in-region. If the family cannot, the call fails closed
`cache_scope`	`region` (default) or `project`. Embeddings never leave the pin
`fail_closed`	If true, HTTP 403 `residency_violation` instead of failing open to another region

Required scope: governance:manage. Changing region after data exists requires dual control.

Per-Request Override

json

{
  "model": "auto",
  "project_id": "prj_legal_001",
  "region": "eu-west-1",
  "messages": [{ "role": "user", "content": "Summarize." }]
}

{
  "model": "auto",
  "project_id": "prj_legal_001",
  "region": "eu-west-1",
  "messages": [{ "role": "user", "content": "Summarize." }]
}

If region disagrees with the project pin and fail_closed is true, Eridian returns 403 residency_violation. It does not silently re-route.

Headers

Header	Description
`X-Eridian-Region`	Region that processed the call
`X-Eridian-Residency-Pin`	`true` when inference was pinned

Zero-Data-Retention

Enterprise ZDR means prompts are not stored after the response is returned. Residency still governs the in-flight path. Retrieve-by-id returns record_not_retained. Audit events keep counts, route (gpt / gemini), and cost, not prompt text.

Multi-Region Tenants

A tenant may hold one project per region. Do not share RAG collections across regions. Semantic cache keys include region; a EU prompt cannot hit a US cache entry.

Python

python

client = Eridian(api_key="eridian_sk_...", region="eu-west-1")
response = client.inference.create(
    model="auto",
    project_id="prj_legal_001",
    messages=[{"role": "user", "content": "Draft the notice."}],
)
print(response.eridian.region)

client = Eridian(api_key="eridian_sk_...", region="eu-west-1")
response = client.inference.create(
    model="auto",
    project_id="prj_legal_001",
    messages=[{"role": "user", "content": "Draft the notice."}],
)
print(response.eridian.region)

See Projects, PII Redaction, and the DPA.

Production API credentials are issued with an institution workspace. Contact sales if you need access.