ADR 0003: No-delete fossils

• Status: accepted
• Date: 2026-08-01

Context

Deleting dead ideas destroys the reasoning that often matters more than the idea itself — why something was abandoned, what was tried, what might resurface later.

Decision

Hypar has no delete operation for embryos. Ideas close as fossils with a required reason (optional kind: ill-defined / wrong path / superseded). Fossils retain seed, history, and connections. PATCH and agent calls on fossils return 409. Resurrection creates a new LATENT embryo linked with RESURRECTS; the fossil stays closed.

Consequences

• Fossilization UX always captures why an idea ended.
• Garden includes strata navigation for fossils; agent context may include a small fossil sample.
• Silent delete and silent un-fossilize are out of scope.

Sources

• Fossils & Memory
• Architecture — “No delete”
• README — “No delete”
• The Lifecycle