Feature Gates

Saturday’s API features progress through launch stages. This system controls feature visibility, access, and stability guarantees as the platform matures.

Why feature gates?

Not all API features ship at the same time. When you integrate Saturday, some features may be in early access (alpha), some in public beta, and some fully stable (GA). Feature gates tell you exactly what to expect from each feature. If an endpoint returns a 404 when you expect it to work, check the feature stage — it may be in STEALTH or require alpha access.

Launch stages

Stage	What happens	Who can access	Stability
STEALTH	Endpoint returns 404 (indistinguishable from nonexistent)	Nobody	Not available
ALPHA	Works for allowlisted partners	Specific partners by invitation	May change without notice
BETA	Works for all authenticated partners	All partners	May have breaking changes with notice
GA	Production-stable	All partners	Stable, backward compatible
DEPRECATED	Still works but being phased out	All partners	12-month sunset notice

STEALTH

Features in stealth are completely invisible. The endpoint returns a standard 404 that is byte-identical to a request for a path that doesn’t exist. No auth headers, no CORS headers, no logging. This is intentional — stealth features don’t exist yet from the outside world.

ALPHA

Alpha features are available to specific partners who have been invited. If you try to access an alpha feature without being on the allowlist, you’ll get a 403 response:

{
  "error": {
    "type": "authorization_error",
    "code": "feature_alpha_access_required",
    "message": "This feature is in alpha. Contact api@saturday.fit to request access.",
    "documentation_url": "https://api.saturday.fit/docs/feature-gates"
  }
}

When you are on the alpha allowlist, responses include a notice header:

X-Saturday-Feature-Stage: ALPHA
X-Saturday-Alpha-Notice: This feature is in alpha and may change without notice. Contact api@saturday.fit with feedback.

BETA

Beta features work for all authenticated partners. They may have breaking changes with advance notice. Responses include:

X-Saturday-Feature-Stage: BETA
X-Saturday-Beta-Notice: This feature is in beta. Breaking changes may occur with 14 days notice.

GA (General Availability)

GA features are production-stable with backward compatibility guarantees. Breaking changes go through a deprecation cycle.

DEPRECATED

Deprecated features still work but will be removed. A 12-month notice period starts when deprecation is announced:

X-Saturday-Feature-Stage: DEPRECATED
Deprecation: true

Current feature stages

Feature	What it controls	Stage
`nutrition`	Fuel/hydration/electrolyte calculation, prep, inference	ALPHA
`products`	Curated product database (186+ products)	STEALTH
`gear`	Gear management CRUD (bottles, flasks)	STEALTH
`ai_coach`	AI coaching with SSE streaming	STEALTH
`ai_data`	AI-generated insights, churn risk, ML bias	STEALTH

Feature stages are updated in Saturday’s configuration without requiring a deploy. Stage changes propagate within 5 minutes.

Feature groups

Features are organized into groups for coordinated stage transitions:

Group	Features	Example transition
`core`	nutrition, products	”Move core to BETA” — all partners get nutrition + products
`advanced`	ai_coach, ai_data	”Move advanced to ALPHA” — select partners get AI features
`all`	All 5 features	”Move all to GA” — launch day

Getting alpha access

Alpha access is by invitation. To request access:

Email api@saturday.fit with your platform name, use case, and expected volume
Saturday vets the request and adds your partner ID to the alpha allowlist
Within 5 minutes, your API key works on alpha-stage endpoints

Alpha partners get:

Early access to new features before public beta
Direct support channel for integration questions
Influence on API design decisions
No additional cost

Checking feature availability

The API root endpoint shows which features are available at each stage:

GET /v1/

The response includes feature discovery information. Features in STEALTH are intentionally omitted — they don’t appear in discovery, error catalogs, or documentation.

Response headers reference

Header	When sent	Value
`X-Saturday-Feature-Stage`	ALPHA, BETA, DEPRECATED	Stage name
`X-Saturday-Alpha-Notice`	ALPHA (on allowlist)	Stability warning + support contact
`X-Saturday-Beta-Notice`	BETA	Breaking changes warning
`Deprecation`	DEPRECATED	`true` (RFC 8594)

Getting Started

Core Guides

Integration Guides

Coach API

Platform

Feature Gates

Feature Gates

Why feature gates?

Launch stages

STEALTH

ALPHA

BETA

GA (General Availability)

DEPRECATED

Current feature stages

Feature groups

Getting alpha access

Checking feature availability

Response headers reference

​Feature Gates

​Why feature gates?

​Launch stages

​STEALTH

​ALPHA

​BETA

​GA (General Availability)

​DEPRECATED

​Current feature stages

​Feature groups

​Getting alpha access

​Checking feature availability

​Response headers reference

Feature Gates

Why feature gates?

Launch stages

STEALTH

ALPHA

BETA

GA (General Availability)

DEPRECATED

Current feature stages

Feature groups

Getting alpha access

Checking feature availability

Response headers reference