Review of Spark's trust model

Unilateral-exit readiness

Blink's first documented mainnet recovery bundle was incomplete

Blink's first documented mainnet recovery bundle omitted a legacy root required for offline construction. The tool initially failed without Operator access and was changed to fetch missing roots explicitly and reject open chains before producing a corrected bundle. 12

2 sourcesEvidence reviewed through July 14, 2026

What the evidence shows

Technical and product details

  1. Documented behavior

    Blink reports that its first mainnet bundle omitted the root of each legacy tree because the bulk query_nodes(include_parents=true) response did not include that root. 1

    Supporting material shown on this page

    Blink case studyPinned source code · github.com · checked 2026-07-14
    Relevant lines from the pinned source · open raw file
    1# Case study: a real Spark unilateral exit on Bitcoin mainnet
  2. Observed result

    Offline construction failed with “Exit chain is incomplete.” 1

    Supporting material shown on this page

    Blink case studyPinned source code · github.com · checked 2026-07-14
    Relevant lines from the pinned source · open raw file
    1# Case study: a real Spark unilateral exit on Bitcoin mainnet
  3. Required fix

    The exporter was changed to walk the graph, re-fetch missing ancestors by ID while online, and reject open chains. 12

    Supporting material shown on this page

    Blink case studyPinned source code · github.com · checked 2026-07-14
    Relevant lines from the pinned source · open raw file
    1# Case study: a real Spark unilateral exit on Bitcoin mainnet
  4. Product consequence

    A saved file is not sufficient by itself: an exporter intended for outage recovery must establish that every selected leaf has a complete, closed ancestor chain before Operators become unavailable. 12

    Supporting material shown on this page

    Blink case studyPinned source code · github.com · checked 2026-07-14
    Relevant lines from the pinned source · open raw file
    1# Case study: a real Spark unilateral exit on Bitcoin mainnet

Scope control

What this does not establish

  • This is Blink's first documented mainnet bundle, not a claim that it was the first recovery bundle created by anyone. The corrected exporter addresses the recorded legacy-root failure. 12

Sources and excerpts

Primary sources

The relevant details and available source-code excerpts appear alongside the claims above. This list preserves the complete original-source trail for independent verification.

1

Blink case study

Pinned source code · github.com · Pinned or archival · checked 2026-07-14

Open original source
2

Breez fix PR 917

Repository record · github.com · Live source · checked 2026-07-14

Open original source

How sources, absence findings, and limitations were evaluated