Speed up an unconfirmed attach

POST

/v1/attach-templates/speed-up

curl --request POST \
  --url https://api.digirare.com/v1/attach-templates/speed-up \
  --header 'Content-Type: application/json' \
  --header 'x-session-token: <x-session-token>' \
  --data '{ "owner": "example", "txid": "example", "fee_rate": 1 }'

Returns an unsigned CPFP child for the session owner’s own unconfirmed attach. The server reads the attach from Bitcoin, proves from its bytes that it is a Counterparty attach whose unit lands on its first spendable output, finds the owner’s change output after it (never the asset UTXO), checks that the change is unspent, and sizes a one-input, one-output child back to the same owner so the package (the attach, its unconfirmed ancestors, and the child) reaches fee_rate (default: the next-block rate). Nothing is stored. Sign input 0 with DEFAULT|ALL and relay the finalized child with POST /transactions. Refusals carry a reason: confirmed, no_change, change_spent (with spent_by), fee_sufficient, ancestor_limit, not_attach, or insufficient_change (code insufficient_funds with need_sats, have_sats and shortfall_sats).

Authorizations

• session

Request Body^required

Media typeapplication/json

object

owner

required

The session address whose change pays for the speed-up.

string

txid

required

The unconfirmed attach to speed up. For a chain of attaches, the newest one: its change is the unspent one, and its package carries every ancestor.

string

/^[0-9a-f]{64}$/

fee_rate

number

>= 0.1 <= 500

Example^generated

{
  "owner": "example",
  "txid": "example",
  "fee_rate": 1
}

Responses

200

One unsigned speed-up child, never stored

Media typeapplication/json

object

result

required

object

parent_txid

required

string

/^[0-9a-f]{64}$/

owner

required

Mainnet P2TR or P2WPKH address. The SIGNING capability: every signature is verified by reconstructing a BIP-143/BIP-341 witness sighash.

string

fee_rate

required

number

>= 0.1 <= 500

change

required

The attach’s plain-BTC change output the child spends. Never the asset UTXO.

object

txid

required

string

/^[0-9a-f]{64}$/

vout

required

integer

>= 1

value_sats

required

integer

>= 1 <= 9007199254740991

script_pub_key_hex

required

string

/^[0-9a-f]+$/

child

required

object

psbt_hex

required

string

/^[0-9a-f]+$/

expected_txid

required

string

/^[0-9a-f]{64}$/

signing

required

object

signer_address

required

Mainnet P2TR or P2WPKH address. The SIGNING capability: every signature is verified by reconstructing a BIP-143/BIP-341 witness sighash.

string

inputs_to_sign

required

Array

>= 1 items <= 1 items

sighash

required

Allowed value: DEFAULT|ALL

fees

required

object

parent_fee_sats

required

The attach plus every unconfirmed ancestor it waits on.

integer

>= 1 <= 9007199254740991

parent_vsize

required

integer

>= 1

unconfirmed_ancestors

required

integer

child_fee_sats

required

integer

>= 1 <= 9007199254740991

child_vsize

required

integer

>= 1

package_fee_sats

required

integer

>= 1 <= 9007199254740991

package_vsize

required

integer

>= 1

package_fee_rate

required

number

> 0

final_change_sats

required

What the child returns to the owner: change minus the child fee.

integer

>= 1 <= 9007199254740991

Example

{
  "result": {
    "child": {
      "signing": {
        "inputs_to_sign": [
          0
        ],
        "sighash": "DEFAULT|ALL"
      }
    }
  }
}

4XX

Stable machine-readable failure

Media typeapplication/json

object

error

required

string

code

required

string

Allowed values: invalid_request unsupported_address_type unauthenticated forbidden not_found method_not_allowed state_changed expired invalid_transaction rate_limited internal_error upstream_unavailable service_unavailable checkout_changed target_unavailable signature_invalid template_mismatch mempool_rejected broadcast_unknown conflict_spend duplicate_funding_slot offer_selection_unavailable attached_delivery_single_item_only insufficient_funds insufficient_asset_balance price_below_minimum listing_price_above_maximum counter_price_invalid self_trade offer_capacity_full open_offer_limit policy_offer_refused

retryable

boolean

mempool_policy

On 422 mempool_rejected from a broadcast: which deterministic node policy refused the bytes. Retrying the same bytes fails the same way. fee_floor: re-quote at a higher fee_rate. chain_too_long: too many unconfirmed ancestors; wait for a confirmation, then retry. truc: a version-3 (TRUC) package rule, such as spending an unconfirmed version-3 output; wait for a confirmation, then retry.

string

Allowed values: fee_floor chain_too_long truc dust nonstandard

mempool_reason

The node’s own reject reason, on mempool_rejected (422) and on state_changed (409) when a broadcast lost to a conflicting or replacing spend.

string

wait_for_confirmation

Present and true when mempool_policy is chain_too_long or truc.

boolean

claims_released

On a checkout or accept completion refused as mempool_rejected: the journaled settlement ended and every listing, bid, and asset claim it held was released (its inputs were proven unspent). The quote or accept is replaced; request a new one.

boolean

refused_listings

Batch listing routes only: every refused item. The first sets the status and code.

Array<object>

One refused item in a batch refusal’s refused_listings array. Nothing in the batch was changed.

object

index

required

integer

listing_id

required

string

status

required

integer

code

required

string

error

required

string

key

additional properties

any

retry_after_seconds

On 429 rate_limited: the exact seconds until the oldest counted request leaves the window; a retry then is admitted (also sent as Retry-After). Limited writes are bucketed per route scope in exact sliding 60-second windows: by session address when a valid x-session-token is present, otherwise by IP, with a per-IP ceiling across sessions. Expensive writes: 20, ceiling 120. Signed completions: 120, ceiling 600. Session minting (/auth/*): 60 per IP. A request refused by any bucket is counted by none.

integer

>= 1

key

additional properties

any

Example

{
  "code": "invalid_request",
  "mempool_policy": "fee_floor"
}

5XX

Stable machine-readable failure

Media typeapplication/json

object

error

required

string

code

required

string

Allowed values: invalid_request unsupported_address_type unauthenticated forbidden not_found method_not_allowed state_changed expired invalid_transaction rate_limited internal_error upstream_unavailable service_unavailable checkout_changed target_unavailable signature_invalid template_mismatch mempool_rejected broadcast_unknown conflict_spend duplicate_funding_slot offer_selection_unavailable attached_delivery_single_item_only insufficient_funds insufficient_asset_balance price_below_minimum listing_price_above_maximum counter_price_invalid self_trade offer_capacity_full open_offer_limit policy_offer_refused

retryable

boolean

mempool_policy

On 422 mempool_rejected from a broadcast: which deterministic node policy refused the bytes. Retrying the same bytes fails the same way. fee_floor: re-quote at a higher fee_rate. chain_too_long: too many unconfirmed ancestors; wait for a confirmation, then retry. truc: a version-3 (TRUC) package rule, such as spending an unconfirmed version-3 output; wait for a confirmation, then retry.

string

Allowed values: fee_floor chain_too_long truc dust nonstandard

mempool_reason

The node’s own reject reason, on mempool_rejected (422) and on state_changed (409) when a broadcast lost to a conflicting or replacing spend.

string

wait_for_confirmation

Present and true when mempool_policy is chain_too_long or truc.

boolean

claims_released

On a checkout or accept completion refused as mempool_rejected: the journaled settlement ended and every listing, bid, and asset claim it held was released (its inputs were proven unspent). The quote or accept is replaced; request a new one.

boolean

refused_listings

Batch listing routes only: every refused item. The first sets the status and code.

Array<object>

One refused item in a batch refusal’s refused_listings array. Nothing in the batch was changed.

object

index

required

integer

listing_id

required

string

status

required

integer

code

required

string

error

required

string

key

additional properties

any

retry_after_seconds

On 429 rate_limited: the exact seconds until the oldest counted request leaves the window; a retry then is admitted (also sent as Retry-After). Limited writes are bucketed per route scope in exact sliding 60-second windows: by session address when a valid x-session-token is present, otherwise by IP, with a per-IP ceiling across sessions. Expensive writes: 20, ceiling 120. Signed completions: 120, ceiling 600. Session minting (/auth/*): 60 per IP. A request refused by any bucket is counted by none.

integer

>= 1

key

additional properties

any

Example

{
  "code": "invalid_request",
  "mempool_policy": "fee_floor"
}