Transaction

A transaction is a signed message that says: take these existing coins, and lock up new coins like this instead.

The coins it takes are its inputs. Each input points at an output of an earlier transaction. The coins it creates are its outputs, each one an amount and a lock. Proof that the sender may unlock the inputs travels alongside in a section called the witness. That’s the whole idea; the rest of this page is where each piece sits in the bytes.

Try it

Paste a raw transaction, or pick a real Pearl one, and hover any byte to see what it is.

What does a raw transaction look like?

Like this. It’s a real payment from block 130,825: one input, two outputs (2 PRL to the recipient, the rest back to the sender as change), signed with one 64-byte signature. Hover a field to name it.

A typical payment: 1 input, 2 outputs 205 bytes Copy

01000000 00 01 01 5939557091bae792be66f26cbd83fc78f16a690a854109e8a1d115e253812133 ab020000 00 ffffffff 02 b0359f1100000000 22 5120d7ab02c96a342bdddb5d07b9f3ebd6c04e077ff41418110b9a1e5997439416b2 00c2eb0b00000000 22 512062e9da3682aab288392cf7218bafc36287288abb3ce200c5d1a50aa234073b2b 01 40 4686c7014749649b25555874c7772ecb7a44e85454893ed5888db11ebcdc82a22d74ce1a1671d02810f5ba1dca3277409e95a653ba9644099f7da26be7a86ba2 00000000

Hover or focus the bytes to name each field Version bytes 0–3 1 Marker bytes 4 0x00 Flag bytes 5 0x01 Input count bytes 6 1 Previous txid bytes 7–38 33218153e215d1a1e80941850a696af178fc83bd6cf266be92e7ba9170553959 Output index bytes 39–42 683 scriptSig length bytes 43 0 Sequence bytes 44–47 0xffffffff Output count bytes 48 2 Amount bytes 49–56 295,646,640 grains (2.95646640 PRL) Script length bytes 57 34 Locking script bytes 58–91 prl1p674s9jt2xs4amk6aq7ul867kcp8qwll5zsvpzzu6revewsu5z6eqv9d5z4 Amount bytes 92–99 200,000,000 grains (2.00000000 PRL) Script length bytes 100 34 Locking script bytes 101–134 prl1pvt5a5d5z42egswfv7uscht7rv2rj3z4m8n3qp3w35592ydq88v4seuhn70 Witness items bytes 135 1 Schnorr signature length bytes 136 64 Schnorr signature bytes 137–200 4686c7014749649b25555874c7772ecb7a44e85454893ed5888db11ebcdc82a22d74ce1a1671d02810f5ba1dca3277409e95a653ba9644099f7da26be7a86ba2 Locktime bytes 201–204 0

Field	Bytes	Value
Version version	4 @0	1 int32 little-endian. Pearl wallets and pearld coinbases use version 1; relay policy accepts 1-2.
Marker marker	1 @4	0x00 Segwit marker (BIP-144): says witness data follows the outputs.
Flag flag	1 @5	0x01 Witness flag; 0x01 is the only value Pearl accepts.
Input count vin.length	1 @6	1 CompactSize number of inputs.
Previous txid vin[0].txid	32 @7	33218153e215d1a1e80941850a696af178fc83bd6cf266be92e7ba9170553959 The transaction being spent, stored byte-reversed (internal order); shown here in normal display order.
Output index vin[0].vout	4 @39	683 Which output of that transaction is spent (uint32 LE).
scriptSig length vin[0].scriptSig.length	1 @43	0 Always 0 for non-coinbase inputs in Pearl: every spend uses the witness instead.
Sequence vin[0].sequence	4 @44	0xffffffff Final (0xffffffff): no RBF signal, no relative locktime, and locktime is ignored for this input. Pearl wallets use this.
Output count vout.length	1 @48	2 CompactSize number of outputs.
Amount vout[0].value	8 @49	295,646,640 grains (2.95646640 PRL) int64 little-endian, in grains (1 PRL = 100,000,000 grains).
Script length vout[0].scriptPubKey.length	1 @57	34 CompactSize length of the locking script.
Locking script vout[0].scriptPubKey	34 @58	prl1p674s9jt2xs4amk6aq7ul867kcp8qwll5zsvpzzu6revewsu5z6eqv9d5z4 OP_1 OP_PUSHBYTES_32 <output key Q>: a Taproot output.
Amount vout[1].value	8 @92	200,000,000 grains (2.00000000 PRL) int64 little-endian, in grains (1 PRL = 100,000,000 grains).
Script length vout[1].scriptPubKey.length	1 @100	34 CompactSize length of the locking script.
Locking script vout[1].scriptPubKey	34 @101	prl1pvt5a5d5z42egswfv7uscht7rv2rj3z4m8n3qp3w35592ydq88v4seuhn70 OP_1 OP_PUSHBYTES_32 <output key Q>: a Taproot output.
Witness items witness[0].length	1 @135	1 Number of witness stack items for input 0.
Schnorr signature length witness[0][0].length	1 @136	64 CompactSize length of this witness item.
Schnorr signature witness[0][0]	64 @137	4686c7014749649b25555874c7772ecb7a44e85454893ed5888db11ebcdc82a22d74ce1a1671d02810f5ba1dca3277409e95a653ba9644099f7da26be7a86ba2 64-byte BIP-340 signature (R.x ‖ s) with SIGHASH_DEFAULT: a Taproot key-path spend.
Locktime locktime	4 @201	0 0: no time lock.

txid

d919e02a4adfd739ceef31d98803f0ddd24e1b1fa67b0fe572cdec42c1b384c9

Size

205 bytes · 154 vbytes

Block

130,825

Fee

7,915 grains

205 bytes in all. Read it left to right and every field sits at a fixed spot, or right after a small length prefix that says how long the next part is.

What is the structure?

Every Pearl transaction has these fields, in this order:

Numbers are stored little-endian, smallest byte first. Counts and lengths are CompactSize numbers: one byte below 253, more only when needed.

Version

Size

4 bytes

Type

Signed integer

Format

Little-endian

01000000 = 1. Oyster always writes version 1, and so does pearld’s own block template. Version 2 also appears on chain: block 130,825’s coinbase, from the Kryptex pool, uses it, as does the OP_RETURN example in this group. Consensus doesn’t check the number; relay policy accepts 1 and 2. The one thing it changes: relative locktimes only work at version 2 or above.

Marker and flag

Size

1 byte each

Type

Constants

Format

00 then 01

A 00 where the input count should be can’t be a real count (a transaction needs inputs), so it marks the segwit format, and 01 is the flag. Pearl rejects any other flag value, and rejects a flag whose witnesses are all empty. Pearl’s mempool only accepts transactions with a witness, so every normal transaction has these two bytes.

Inputs

Size

41 bytes each (with an empty scriptSig)

Type

Outpoint ‖ scriptSig ‖ sequence

Each input names an earlier output by its transaction ID and output number, then an empty scriptSig, then a sequence number. The payment above spends output 683 of transaction 33218153…553959. See inputs.

Outputs

Size

43 bytes each (Taproot or P2MR)

Type

Amount ‖ locking script

Each output is an 8-byte amount in grains and a locking script. The payment’s outputs are 295,646,640 grains (change) and 200,000,000 grains (2 PRL to the recipient). See outputs.

Witness

Size

Varies

Type

One stack of items per input

For each input, in order: how many items, then each item’s length and bytes. A normal Taproot spend has one item, the 64-byte Schnorr signature. See witness.

Locktime

Size

4 bytes

Type

Unsigned integer

Format

Little-endian

Range

0 = none; below 500,000,000 = a height; from 500,000,000 = a Unix time

00000000 = no lock. Pearl wallets always write 0. See locktime and sequence.

How is a transaction identified?

By its txid: SHA256d of the transaction without the marker, flag and witness, shown with its bytes reversed. For the payment above, that’s d919e02a…b384c9. Leaving the witness out means a signature can’t change the ID. The txid page does the hashing step by step.

How big is it?

Witness bytes count a quarter. Fees are paid per vbyte: this payment paid 7,915 grains, about 51.4 grains per vbyte. The fees and vsize page has the details and the limits (a block holds 1,000,000 vbytes).

What other shapes are there?

The same format carries every kind of Pearl transaction. Each of these is real and has its own page:

• Two inputs: each input has its own outpoint and its own one-signature witness. (inputs)
• Coinbase: one input pointing at nothing, a height in the scriptSig, a witness commitment output. (coinbase)
• P2MR spend: a witness with four items: two signatures, a 71-byte script and a 1-byte control block. (P2MR)
• OP_RETURN: an output that carries 37 bytes of data and can never be spent. (OP_RETURN)

Show the two-input payment

A payment from block 130,822: two inputs, each with its own 64-byte signature in the witness.

2 inputs, 2 outputs 312 bytes Copy

01000000 00 01 02 207decc85aaf210383704c39294c193864bf8e4255984abab5fe19a891ea0fc5 00000000 00 ffffffff d5da316cc9db4a367ce18ef27fb76809601a7fde2d111844962fc7584fceadf7 00000000 00 ffffffff 02 782d7c0700000000 22 51206f03b8c53fff74f0b22844a62fb29f822fda5f4e062d492f1d91bf567361a340 c07fdc0b00000000 22 5120e407fefe99e7ae5957da27b1565b4c9568fcd0a7c1b01ee8b79e694f0ec52fbd 01 40 bcdee9e8c70a956f0faf3f19324ff7595aa9d6d377010f12a392d5dfb8a20b05076090f11d7d6523f995c316c40b5c4c635853491a29dd5367e54e899e460638 01 40 9c9a3f1689bc718d7cbf2639e1433e7bb0f01896c7f2c14a565d515c41a5b5cd0e4a748978492d8dbda559088b66ef79003d421098cc25ef4ab05b39256790b8 00000000

Hover or focus the bytes to name each field Version bytes 0–3 1 Marker bytes 4 0x00 Flag bytes 5 0x01 Input count bytes 6 2 Previous txid bytes 7–38 c50fea91a819feb5ba4a9855428ebf6438194c29394c70830321af5ac8ec7d20 Output index bytes 39–42 0 scriptSig length bytes 43 0 Sequence bytes 44–47 0xffffffff Previous txid bytes 48–79 f7adce4f58c72f964418112dde7f1a600968b77ff28ee17c364adbc96c31dad5 Output index bytes 80–83 0 scriptSig length bytes 84 0 Sequence bytes 85–88 0xffffffff Output count bytes 89 2 Amount bytes 90–97 125,578,616 grains (1.25578616 PRL) Script length bytes 98 34 Locking script bytes 99–132 prl1pdupm33flla60pv3ggjnzlv5lsgha5h6wqck5jtcajxl4vump5dqq3mvacr Amount bytes 133–140 199,000,000 grains (1.99000000 PRL) Script length bytes 141 34 Locking script bytes 142–175 prl1pusrlal5eu7h9j476y7c4vk6vj450e598cxcpa69hne557rk9977skn6lrw Witness items bytes 176 1 Schnorr signature length bytes 177 64 Schnorr signature bytes 178–241 bcdee9e8c70a956f0faf3f19324ff7595aa9d6d377010f12a392d5dfb8a20b05076090f11d7d6523f995c316c40b5c4c635853491a29dd5367e54e899e460638 Witness items bytes 242 1 Schnorr signature length bytes 243 64 Schnorr signature bytes 244–307 9c9a3f1689bc718d7cbf2639e1433e7bb0f01896c7f2c14a565d515c41a5b5cd0e4a748978492d8dbda559088b66ef79003d421098cc25ef4ab05b39256790b8 Locktime bytes 308–311 0

Field	Bytes	Value
Version version	4 @0	1 int32 little-endian. Pearl wallets and pearld coinbases use version 1; relay policy accepts 1-2.
Marker marker	1 @4	0x00 Segwit marker (BIP-144): says witness data follows the outputs.
Flag flag	1 @5	0x01 Witness flag; 0x01 is the only value Pearl accepts.
Input count vin.length	1 @6	2 CompactSize number of inputs.
Previous txid vin[0].txid	32 @7	c50fea91a819feb5ba4a9855428ebf6438194c29394c70830321af5ac8ec7d20 The transaction being spent, stored byte-reversed (internal order); shown here in normal display order.
Output index vin[0].vout	4 @39	0 Which output of that transaction is spent (uint32 LE).
scriptSig length vin[0].scriptSig.length	1 @43	0 Always 0 for non-coinbase inputs in Pearl: every spend uses the witness instead.
Sequence vin[0].sequence	4 @44	0xffffffff Final (0xffffffff): no RBF signal, no relative locktime, and locktime is ignored for this input. Pearl wallets use this.
Previous txid vin[1].txid	32 @48	f7adce4f58c72f964418112dde7f1a600968b77ff28ee17c364adbc96c31dad5 The transaction being spent, stored byte-reversed (internal order); shown here in normal display order.
Output index vin[1].vout	4 @80	0 Which output of that transaction is spent (uint32 LE).
scriptSig length vin[1].scriptSig.length	1 @84	0 Always 0 for non-coinbase inputs in Pearl: every spend uses the witness instead.
Sequence vin[1].sequence	4 @85	0xffffffff Final (0xffffffff): no RBF signal, no relative locktime, and locktime is ignored for this input. Pearl wallets use this.
Output count vout.length	1 @89	2 CompactSize number of outputs.
Amount vout[0].value	8 @90	125,578,616 grains (1.25578616 PRL) int64 little-endian, in grains (1 PRL = 100,000,000 grains).
Script length vout[0].scriptPubKey.length	1 @98	34 CompactSize length of the locking script.
Locking script vout[0].scriptPubKey	34 @99	prl1pdupm33flla60pv3ggjnzlv5lsgha5h6wqck5jtcajxl4vump5dqq3mvacr OP_1 OP_PUSHBYTES_32 <output key Q>: a Taproot output.
Amount vout[1].value	8 @133	199,000,000 grains (1.99000000 PRL) int64 little-endian, in grains (1 PRL = 100,000,000 grains).
Script length vout[1].scriptPubKey.length	1 @141	34 CompactSize length of the locking script.
Locking script vout[1].scriptPubKey	34 @142	prl1pusrlal5eu7h9j476y7c4vk6vj450e598cxcpa69hne557rk9977skn6lrw OP_1 OP_PUSHBYTES_32 <output key Q>: a Taproot output.
Witness items witness[0].length	1 @176	1 Number of witness stack items for input 0.
Schnorr signature length witness[0][0].length	1 @177	64 CompactSize length of this witness item.
Schnorr signature witness[0][0]	64 @178	bcdee9e8c70a956f0faf3f19324ff7595aa9d6d377010f12a392d5dfb8a20b05076090f11d7d6523f995c316c40b5c4c635853491a29dd5367e54e899e460638 64-byte BIP-340 signature (R.x ‖ s) with SIGHASH_DEFAULT: a Taproot key-path spend.
Witness items witness[1].length	1 @242	1 Number of witness stack items for input 1.
Schnorr signature length witness[1][0].length	1 @243	64 CompactSize length of this witness item.
Schnorr signature witness[1][0]	64 @244	9c9a3f1689bc718d7cbf2639e1433e7bb0f01896c7f2c14a565d515c41a5b5cd0e4a748978492d8dbda559088b66ef79003d421098cc25ef4ab05b39256790b8 64-byte BIP-340 signature (R.x ‖ s) with SIGHASH_DEFAULT: a Taproot key-path spend.
Locktime locktime	4 @308	0 0: no time lock.

txid

091166043c8d93530171ca9e5ac883aaeae467934fbb8e4df1ea739c8d71b23e

Size

312 bytes · 212 vbytes

Block

130,822

Fee

10,650 grains