opcodes
| Word
|
Opcode
|
Hex
|
Input
|
Output
|
Description
|
| OP_0, OP_FALSE
|
0
|
0x00
|
Nothing.
|
(empty value)
|
An empty array of bytes is pushed onto the stack. (This is not a no-op: an item is added to the stack.)
|
| N/A
|
1-75
|
0x01-0x4b
|
(special)
|
data
|
The next opcode bytes is data to be pushed onto the stack
|
| OP_PUSHDATA1
|
76
|
0x4c
|
(special)
|
data
|
The next byte contains the number of bytes to be pushed onto the stack.
|
| OP_PUSHDATA2
|
77
|
0x4d
|
(special)
|
data
|
The next two bytes contain the number of bytes to be pushed onto the stack.
|
| OP_PUSHDATA4
|
78
|
0x4e
|
(special)
|
data
|
The next four bytes contain the number of bytes to be pushed onto the stack.
|
| OP_1NEGATE
|
79
|
0x4f
|
Nothing.
|
-1
|
The number -1 is pushed onto the stack.
|
| OP_1, OP_TRUE
|
81
|
0x51
|
Nothing.
|
1
|
The number 1 is pushed onto the stack.
|
| OP_2-OP_16
|
82-96
|
0x52-0x60
|
Nothing.
|
2-16
|
The number in the word name (2-16) is pushed onto the stack.
|
Flow control
| Word
|
Opcode
|
Hex
|
Input
|
Output
|
Description
|
| OP_NOP
|
97
|
0x61
|
Nothing
|
Nothing
|
Does nothing.
|
| OP_IF
|
99
|
0x63
|
<expression> if [statements] [else [statements]]* endif
|
If the top stack value is not 0, the statements are executed. The top stack value is removed.
|
| OP_NOTIF
|
100
|
0x64
|
<expression> if [statements] [else [statements]]* endif
|
If the top stack value is 0, the statements are executed. The top stack value is removed.
|
| OP_ELSE
|
103
|
0x67
|
<expression> if [statements] [else [statements]]* endif
|
If the preceding OP_IF or OP_NOTIF or OP_ELSE was not executed then these statements are and if the preceding OP_IF or OP_NOTIF or OP_ELSE was executed then these statements are not.
|
| OP_ENDIF
|
104
|
0x68
|
<expression> if [statements] [else [statements]]* endif
|
Ends an if/else block.
|
| OP_VERIFY
|
105
|
0x69
|
True / false
|
Nothing / False
|
Marks transaction as invalid if top stack value is not true. True is removed, but false is not.
|
| OP_RETURN
|
106
|
0x6a
|
Nothing
|
Nothing
|
Marks transaction as invalid.
|
Stack
| Word
|
Opcode
|
Hex
|
Input
|
Output
|
Description
|
| OP_TOALTSTACK
|
107
|
0x6b
|
x1
|
(alt)x1
|
Puts the input onto the top of the alt stack. Removes it from the main stack.
|
| OP_FROMALTSTACK
|
108
|
0x6c
|
(alt)x1
|
x1
|
Puts the input onto the top of the main stack. Removes it from the alt stack.
|
| OP_IFDUP
|
115
|
0x73
|
x
|
x / x x
|
If the top stack value is not 0, duplicate it.
|
| OP_DEPTH
|
116
|
0x74
|
Nothing
|
<Stack size>
|
Puts the number of stack items onto the stack.
|
| OP_DROP
|
117
|
0x75
|
x
|
Nothing
|
Removes the top stack item.
|
| OP_DUP
|
118
|
0x76
|
x
|
x x
|
Duplicates the top stack item.
|
| OP_NIP
|
119
|
0x77
|
x1 x2
|
x2
|
Removes the second-to-top stack item.
|
| OP_OVER
|
120
|
0x78
|
x1 x2
|
x1 x2 x1
|
Copies the second-to-top stack item to the top.
|
| OP_PICK
|
121
|
0x79
|
xn ... x2 x1 x0 <n>
|
xn ... x2 x1 x0 xn
|
The item n back in the stack is copied to the top.
|
| OP_ROLL
|
122
|
0x7a
|
xn ... x2 x1 x0 <n>
|
... x2 x1 x0 xn
|
The item n back in the stack is moved to the top.
|
| OP_ROT
|
123
|
0x7b
|
x1 x2 x3
|
x2 x3 x1
|
The top three items on the stack are rotated to the left.
|
| OP_SWAP
|
124
|
0x7c
|
x1 x2
|
x2 x1
|
The top two items on the stack are swapped.
|
| OP_TUCK
|
125
|
0x7d
|
x1 x2
|
x2 x1 x2
|
The item at the top of the stack is copied and inserted before the second-to-top item.
|
| OP_2DROP
|
109
|
0x6d
|
x1 x2
|
Nothing
|
Removes the top two stack items.
|
| OP_2DUP
|
110
|
0x6e
|
x1 x2
|
x1 x2 x1 x2
|
Duplicates the top two stack items.
|
| OP_3DUP
|
111
|
0x6f
|
x1 x2 x3
|
x1 x2 x3 x1 x2 x3
|
Duplicates the top three stack items.
|
| OP_2OVER
|
112
|
0x70
|
x1 x2 x3 x4
|
x1 x2 x3 x4 x1 x2
|
Copies the pair of items two spaces back in the stack to the front.
|
| OP_2ROT
|
113
|
0x71
|
x1 x2 x3 x4 x5 x6
|
x3 x4 x5 x6 x1 x2
|
The fifth and sixth items back are moved to the top of the stack.
|
| OP_2SWAP
|
114
|
0x72
|
x1 x2 x3 x4
|
x3 x4 x1 x2
|
Swaps the top two pairs of items.
|
Splice
| Word
|
Opcode
|
Hex
|
Input
|
Output
|
Description
|
| OP_CAT
|
126
|
0x7e
|
x1 x2
|
out
|
Concatenates two strings. Currently disabled.
|
| OP_SUBSTR
|
127
|
0x7f
|
in begin size
|
out
|
Returns a section of a string. Currently disabled.
|
| OP_LEFT
|
128
|
0x80
|
in size
|
out
|
Keeps only characters left of the specified point in a string. Currently disabled.
|
| OP_RIGHT
|
129
|
0x81
|
in size
|
out
|
Keeps only characters right of the specified point in a string. Currently disabled.
|
| OP_SIZE
|
130
|
0x82
|
in
|
in size
|
Returns the length of the input string.
|
Bitwise logic
| Word
|
Opcode
|
Hex
|
Input
|
Output
|
Description
|
| OP_INVERT
|
131
|
0x83
|
in
|
out
|
Flips all of the bits in the input. Currently disabled.
|
| OP_AND
|
132
|
0x84
|
x1 x2
|
out
|
Boolean and between each bit in the inputs. Currently disabled.
|
| OP_OR
|
133
|
0x85
|
x1 x2
|
out
|
Boolean or between each bit in the inputs. Currently disabled.
|
| OP_XOR
|
134
|
0x86
|
x1 x2
|
out
|
Boolean exclusive or between each bit in the inputs. Currently disabled.
|
| OP_EQUAL
|
135
|
0x87
|
x1 x2
|
True / false
|
Returns 1 if the inputs are exactly equal, 0 otherwise.
|
| OP_EQUALVERIFY
|
136
|
0x88
|
x1 x2
|
True / false
|
Same as OP_EQUAL, but runs OP_VERIFY afterward.
|
Arithmetic
Arithmetic is limited to max 4 byte integers
| Word
|
Opcode
|
Hex
|
Input
|
Output
|
Description
|
| OP_1ADD
|
139
|
0x8b
|
in
|
out
|
1 is added to the input.
|
| OP_1SUB
|
140
|
0x8c
|
in
|
out
|
1 is subtracted from the input.
|
| OP_2MUL
|
141
|
0x8d
|
in
|
out
|
The input is multiplied by 2. Currently disabled.
|
| OP_2DIV
|
142
|
0x8e
|
in
|
out
|
The input is divided by 2. Currently disabled.
|
| OP_NEGATE
|
143
|
0x8f
|
in
|
out
|
The sign of the input is flipped.
|
| OP_ABS
|
144
|
0x90
|
in
|
out
|
The input is made positive.
|
| OP_NOT
|
145
|
0x91
|
in
|
out
|
If the input is 0 or 1, it is flipped. Otherwise the output will be 0.
|
| OP_0NOTEQUAL
|
146
|
0x92
|
in
|
out
|
Returns 0 if the input is 0. 1 otherwise.
|
| OP_ADD
|
147
|
0x93
|
a b
|
out
|
a is added to b.
|
| OP_SUB
|
148
|
0x94
|
a b
|
out
|
b is subtracted from a.
|
| OP_MUL
|
149
|
0x95
|
a b
|
out
|
a is multiplied by b. Currently disabled.
|
| OP_DIV
|
150
|
0x96
|
a b
|
out
|
a is divided by b. Currently disabled.
|
| OP_MOD
|
151
|
0x97
|
a b
|
out
|
Returns the remainder after dividing a by b. Currently disabled.
|
| OP_LSHIFT
|
152
|
0x98
|
a b
|
out
|
Shifts a left b bits, preserving sign. Currently disabled.
|
| OP_RSHIFT
|
153
|
0x99
|
a b
|
out
|
Shifts a right b bits, preserving sign. Currently disabled.
|
| OP_BOOLAND
|
154
|
0x9a
|
a b
|
out
|
If both a and b are not 0, the output is 1. Otherwise 0.
|
| OP_BOOLOR
|
155
|
0x9b
|
a b
|
out
|
If a or b is not 0, the output is 1. Otherwise 0.
|
| OP_NUMEQUAL
|
156
|
0x9c
|
a b
|
out
|
Returns 1 if the numbers are equal, 0 otherwise.
|
| OP_NUMEQUALVERIFY
|
157
|
0x9d
|
a b
|
out
|
Same as OP_NUMEQUAL, but runs OP_VERIFY afterward.
|
| OP_NUMNOTEQUAL
|
158
|
0x9e
|
a b
|
out
|
Returns 1 if the numbers are not equal, 0 otherwise.
|
| OP_LESSTHAN
|
159
|
0x9f
|
a b
|
out
|
Returns 1 if a is less than b, 0 otherwise.
|
| OP_GREATERTHAN
|
160
|
0xa0
|
a b
|
out
|
Returns 1 if a is greater than b, 0 otherwise.
|
| OP_LESSTHANOREQUAL
|
161
|
0xa1
|
a b
|
out
|
Returns 1 if a is less than or equal to b, 0 otherwise.
|
| OP_GREATERTHANOREQUAL
|
162
|
0xa2
|
a b
|
out
|
Returns 1 if a is greater than or equal to b, 0 otherwise.
|
| OP_MIN
|
163
|
0xa3
|
a b
|
out
|
Returns the smaller of a and b.
|
| OP_MAX
|
164
|
0xa4
|
a b
|
out
|
Returns the larger of a and b.
|
| OP_WITHIN
|
165
|
0xa5
|
x min max
|
out
|
Returns 1 if x is within the specified range (left-inclusive), 0 otherwise.
|
Crypto
| Word
|
Opcode
|
Hex
|
Input
|
Output
|
Description
|
| OP_RIPEMD160
|
166
|
0xa6
|
in
|
hash
|
The input is hashed using RIPEMD-160.
|
| OP_SHA1
|
167
|
0xa7
|
in
|
hash
|
The input is hashed using SHA-1.
|
| OP_SHA256
|
168
|
0xa8
|
in
|
hash
|
The input is hashed using SHA-256.
|
| OP_HASH160
|
169
|
0xa9
|
in
|
hash
|
The input is hashed twice: first with SHA-256 and then with RIPEMD-160.
|
| OP_HASH256
|
170
|
0xaa
|
in
|
hash
|
The input is hashed two times with SHA-256.
|
| OP_CODESEPARATOR
|
171
|
0xab
|
Nothing
|
Nothing
|
All of the signature checking words will only match signatures to the data after the most recently-executed OP_CODESEPARATOR.
|
| OP_CHECKSIG
|
172
|
0xac
|
sig pubkey
|
True / false
|
The entire transaction's outputs, inputs, and script (from the most recently-executed OP_CODESEPARATOR to the end) are hashed. The signature used by OP_CHECKSIG must be a valid signature for this hash and public key. If it is, 1 is returned, 0 otherwise.
|
| OP_CHECKSIGVERIFY
|
173
|
0xad
|
sig pubkey
|
True / false
|
Same as OP_CHECKSIG, but OP_VERIFY is executed afterward.
|
| OP_CHECKMULTISIG
|
174
|
0xae
|
x sig1 sig2 ... <number of signatures> pub1 pub2 <number of public keys>
|
True / False
|
For each signature and public key pair, OP_CHECKSIG is executed. If more public keys than signatures are listed, some key/sig pairs can fail. All signatures need to match a public key. If all signatures are valid, 1 is returned, 0 otherwise. Due to a bug, one extra unused value is removed from the stack.
|
| OP_CHECKMULTISIGVERIFY
|
175
|
0xaf
|
x sig1 sig2 ... <number of signatures> pub1 pub2 ... <number of public keys>
|
True / False
|
Same as OP_CHECKMULTISIG, but OP_VERIFY is executed afterward.
|
Pseudo-words
These words are used internally for assisting with transaction matching. They are invalid if used in actual scripts.
| Word
|
Opcode
|
Hex
|
Description
|
| OP_PUBKEYHASH
|
253
|
0xfd
|
Represents a public key hashed with OP_HASH160.
|
| OP_PUBKEY
|
254
|
0xfe
|
Represents a public key compatible with OP_CHECKSIG.
|
| OP_INVALIDOPCODE
|
255
|
0xff
|
Matches any opcode that is not yet assigned.
|
Reserved words
Any opcode not assigned is also reserved. Using an unassigned opcode makes the transaction invalid.
| Word
|
Opcode
|
Hex
|
When used...
|
| OP_RESERVED
|
80
|
0x50
|
Transaction is invalid unless occuring in an unexecuted OP_IF branch
|
| OP_VER
|
98
|
0x62
|
Transaction is invalid unless occuring in an unexecuted OP_IF branch
|
| OP_VERIF
|
101
|
0x65
|
Transaction is invalid even when occuring in an unexecuted OP_IF branch
|
| OP_VERNOTIF
|
102
|
0x66
|
Transaction is invalid even when occuring in an unexecuted OP_IF branch
|
| OP_RESERVED1
|
137
|
0x89
|
Transaction is invalid unless occuring in an unexecuted OP_IF branch
|
| OP_RESERVED2
|
138
|
0x8a
|
Transaction is invalid unless occuring in an unexecuted OP_IF branch
|
| OP_NOP1-OP_NOP10
|
176-185
|
0xb0-0xb9
|
The word is ignored.
|