Unilateral-exit readiness
The documented self-operated exit requires external on-chain fee funding before Spark value is available
The documented independent exit requires external on-chain fee funding before the Spark value becomes spendable on chain. A third party could sponsor the UTXO, but doing so replaces the user's funding requirement with a service dependency. 123
What the evidence shows
Technical and product details
- Documented mechanism
In the current procedure, pre-signed Spark exit and refund transactions pay zero fee and are relayed with fee-paying CPFP children. 12
Supporting material shown on this page
Spark unilateral-exit manualOfficial documentation · docs.spark.money · checked 2026-07-14 Spark package constructorPinned source code · github.com · checked 2026-07-14 Relevant lines from the pinned source · open raw file 1// unilateral-exit.ts - Manual requirement
Spark tells mainnet users to bring sufficient L1 UTXOs and use Bitcoin Core v29 submitpackage. 1
Supporting material shown on this page
Spark unilateral-exit manualOfficial documentation · docs.spark.money · checked 2026-07-14 - Timing consequence
The Spark value is not yet available as an ordinary spendable L1 output when those fee children must be funded. 12
Supporting material shown on this page
Spark unilateral-exit manualOfficial documentation · docs.spark.money · checked 2026-07-14 Spark package constructorPinned source code · github.com · checked 2026-07-14 Relevant lines from the pinned source · open raw file 1// unilateral-exit.ts - Independent-user consequence
A user relying only on the documented independent path cannot begin with a Spark balance alone; an external fee source must first supply a suitable UTXO. 13
Supporting material shown on this page
Spark unilateral-exit manualOfficial documentation · docs.spark.money · checked 2026-07-14 Blink funding transactionOn-chain transaction · mempool.space · checked 2026-07-14
Scope control
What this does not establish
- The external UTXO need not always be personally supplied by the user. A wallet or sponsor could provide fee funding, but that replaces the user-funding requirement with dependency on that sponsor. It does not remove the documented standard-relay path's requirement for a fee-paying input outside the Spark balance. 4
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.
Spark unilateral-exit manual
Official documentation · docs.spark.money · Live source · checked 2026-07-14
Spark package constructor
Pinned source code · github.com · Pinned or archival · checked 2026-07-14
Blink funding transaction
On-chain transaction · mempool.space · Pinned or archival · checked 2026-07-14
Blink mobile integration plan
Pinned source code · github.com · Pinned or archival · checked 2026-07-14
How sources, absence findings, and limitations were evaluated