Direct answer
Free tier is treated as a measurable operating constraint, with limits and fallback behavior made explicit.
Why it matters
Free tier is an operating constraint with quotas retention limits and failure modes rather than a permanent price promise.
Scope
A stable concept used by Service Cards, deployment contracts and the SmallGreen Spec.
Out of scope
It is not a guarantee of security, permanence or universal compatibility.
How it works
Declare every required resource derive a grade from measurable limits and publish fallback behavior before deployment.
Example
A service that requires Workers AI receives a constrained grade and explains what stops when quota is exhausted.
Machine-readable references
SmallGreen Spec · cards.json · llms.txt
Evidence and limitations
Grades reflect verified configuration at a date. Cloudflare limits and upstream behavior may later change.
Related concepts
What is Small Software? · The ownership and deployment layer · What is a Deploy Agent?
Version
Concept v1.0 · SmallGreen Spec v0.2.1