A Spark unilateral exit is a staged recovery procedure, not a single emergency broadcast

What the evidence shows

Technical and product details

1. Confirm-and-continue

   Blink's recovery loop reconstructs package state, signs a CPFP bump, submits one package per leaf chain, waits for confirmation, and repeats. 1

   Supporting material shown on this page

   Blink confirm-and-continue loopPinned source code · github.com · checked 2026-07-14

   138```
   139
   140Each round it rebuilds packages from live chain state, signs the CPFP bump
   141with the seed, submits **one package per leaf chain**, waits for confirmation,
   142and repeats. Already-confirmed transactions are skipped on reconstruction, so
   143the loop is stateless: rate limits, crashes, and reboots cost nothing — re-run
   144and it resumes. Esplora hiccups are retried with exponential backoff instead

2. Durable progress

   Confirmed transactions are skipped when the tool is rerun, allowing recovery after rate limits, crashes, or reboots. 1

   Supporting material shown on this page

   Blink confirm-and-continue loopPinned source code · github.com · checked 2026-07-14

   138```
   139
   140Each round it rebuilds packages from live chain state, signs the CPFP bump
   141with the seed, submits **one package per leaf chain**, waits for confirmation,
   142and repeats. Already-confirmed transactions are skipped on reconstruction, so
   143the loop is stateless: rate limits, crashes, and reboots cost nothing — re-run
   144and it resumes. Esplora hiccups are retried with exponential backoff instead

3. Timelock stage

   The refund that hands each leaf to the user's key is deferred until its CSV lock matures; the recovery command must be rerun afterward to broadcast it. 3

   Supporting material shown on this page

   Blink timelock and sweep stagesPinned source code · github.com · checked 2026-07-14

   189After the loop finishes, each economical leaf's refund waits out its CSV
   190timelock. Re-running the same `make recover` after maturity broadcasts the
   191refunds; once they confirm, `make sweep` builds and signs one-input Taproot
   192key-path spends from the refund outputs to any destination address, and
   193`broadcast-sweep` pushes them as ordinary transactions. At the time of
   194writing, this wallet's four economical exits are through their chains and
   195waiting on refund maturity.

4. Finalization stage

   After refunds confirm, separate sweep construction, signing, and broadcasting move the outputs to the chosen destination. 3

   Supporting material shown on this page

   Blink timelock and sweep stagesPinned source code · github.com · checked 2026-07-14

   189After the loop finishes, each economical leaf's refund waits out its CSV
   190timelock. Re-running the same `make recover` after maturity broadcasts the
   191refunds; once they confirm, `make sweep` builds and signs one-input Taproot
   192key-path spends from the refund outputs to any destination address, and
   193`broadcast-sweep` pushes them as ordinary transactions. At the time of
   194writing, this wallet's four economical exits are through their chains and
   195waiting on refund maturity.

5. Parallelism limit

   Under Blink's documented standard-mempool relay path, funding fan-out can advance independent leaf chains concurrently, but it does not remove within-chain confirmation ordering or the refund timelock. 23

   Supporting material shown on this page

   Blink parallelism mechanicsPinned source code · github.com · checked 2026-07-14

   161### What fan-out would have changed here
   162
   163We ran this recovery sequentially (the default). With `FAN_OUT=1` the loop
   164would first have broadcast **one extra transaction with 4 outputs** — the
   165single 9,388-sat funding UTXO split into one UTXO per economical leaf, each
   166sized to that leaf's remaining CPFP fees plus a 1,000-sat buffer, the last

   Blink timelock and sweep stagesPinned source code · github.com · checked 2026-07-14

   189After the loop finishes, each economical leaf's refund waits out its CSV
   190timelock. Re-running the same `make recover` after maturity broadcasts the
   191refunds; once they confirm, `make sweep` builds and signs one-input Taproot
   192key-path spends from the refund outputs to any destination address, and
   193`broadcast-sweep` pushes them as ordinary transactions. At the time of
   194writing, this wallet's four economical exits are through their chains and
   195waiting on refund maturity.

Scope control

What this does not establish

• Blink's tooling automates and resumes this operatorless process once the required bundle and fee funds exist. The staged workflow demonstrates operational burden; it does not establish technical impossibility or that a mobile implementation can never be built. 123

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.