Read failed-run rescue capsule headers.

Read-only, leak-scanned projection of one frozen hugging-bay.failed-run-rescue.v1 envelope. HTML is the default for this alias; format or Accept can select JSON, JSON-LD, HTML, citation Markdown, badge JSON, or Model Doctor JSON without changing the recorded claims. GET/HEAD, exact-id binding, strong ETag/304, and bounded errors are wired. The current release frontier deliberately returns 503 because failed_run_rescue_selector_unavailable: no reviewed persisted exact capsuleId-to-frozen-rescue selector/read exists. It never infers an artifact-wide latest failure or fabricates a positive rescue.

Inputs. Path, query and header fields are listed below. No request body is required.

Outputs. See each status below for its media type, schema and headers. A missing record or unavailable capability is not a successful empty result.

Errors. HEAD returns headers without a body. Use the HTTP status and Retry-After.

Rate limits. Public read budgets apply by client IP and route group. This operation can have a smaller route-specific budget. Read Retry-After on 429 or retryable 503 responses.

Example setup. Use an identifier returned by the matching list, search or create operation. Sample identifiers are not a promise that a record exists.