EvaluationDetails<boolean> as a downstream receipt boundary

[Rul1an]

Hi OpenFeature folks - small downstream build note, no spec change request.

We built an Assay-side compiler lane over a bounded OpenFeature EvaluationDetails<boolean> artifact: one decision detail row in, one portable evidence receipt bundle out.

The interesting bit is the negative space. The receipt is useful because of what it refuses to know. It keeps the small decision surface:

• flag key
• boolean value
• optional variant
• optional reason
• optional error code
• source artifact digest and reducer version

And it deliberately does not import provider config, evaluation context, targeting keys, targeting rules, flag metadata, provider metadata, telemetry, free-text error_message, or application correctness claims.

The larger point: a standard decision surface can become reviewable evidence without turning provider logs, rules, or runtime context into "truth".

This stays outside OpenFeature and is not an official integration or partnership claim. If it is useful context for future docs or discussions around audit/debug consumers of get*Details, great. Otherwise we will keep it as an Assay-side recipe over the existing decision-detail surface.

Links:

• P41 plan: https://github.com/Rul1an/assay/blob/main/docs/architecture/PLAN-P41-OPENFEATURE-EVALUATION-DETAILS-DECISION-RECEIPT-IMPORT-2026q2.md
• CLI docs: https://github.com/Rul1an/assay/blob/main/docs/reference/cli/evidence.md#openfeature-details-import
• Example fixture: https://github.com/Rul1an/assay/blob/main/examples/openfeature-evaluation-details-evidence/README.md#import-the-checked-in-jsonl-artifact-as-assay-receipts

[Rul1an]

Small downstream follow-up for context: I landed the Harness-side recipe for this experiment as a runnable path over the existing OpenFeature EvaluationDetails surface.

The boundary is intentionally narrow: boolean EvaluationDetails only, no provider config, evaluation context, targeting keys or rules, metadata, or error_message in the canonical receipt path. Assay compiles the bounded decision detail into an evidence bundle and Trust Basis artifact; Assay Harness only gates and projects the resulting Trust Basis diff.

Recipe: https://github.com/Rul1an/Assay-Harness/blob/main/docs/OPENFEATURE_DECISION_RECEIPT_PIPELINE.md
Assay importer docs: https://github.com/Rul1an/assay/blob/main/docs/reference/cli/evidence.md#openfeature-details-import

Keeping this outside the OpenFeature repo; sharing it here only as downstream context for the receipt-boundary idea.