AVM Reference

This page provides a guide to the fields and functions (opcodes) of the Algorand Virtual Machine. Please refer to the official AVM docs for further details.

The content of this page is mostly autogenerated from the Teal language specification.

Fields

Transaction Fields

This section lists all Fields available on transactions. They can be accessed from Txn, Gtxn[i], Itxn as described in Fields.

• Txn.Accounts

• Txn.Amount

• Txn.ApplicationArgs

• Txn.ApplicationID

• Txn.Applications

• Txn.ApprovalProgram

• Txn.ApprovalProgramPages

• Txn.AssetAmount

• Txn.AssetCloseTo

• Txn.AssetReceiver

• Txn.AssetSender

• Txn.Assets

• Txn.ClearStateProgram

• Txn.ClearStateProgramPages

• Txn.CloseRemainderTo

• Txn.ConfigAsset

• Txn.ConfigAssetClawback

• Txn.ConfigAssetDecimals

• Txn.ConfigAssetDefaultFrozen

• Txn.ConfigAssetFreeze

• Txn.ConfigAssetManager

• Txn.ConfigAssetMetadataHash

• Txn.ConfigAssetName

• Txn.ConfigAssetReserve

• Txn.ConfigAssetTotal

• Txn.ConfigAssetURL

• Txn.ConfigAssetUnitName

• Txn.CreatedApplicationID

• Txn.CreatedAssetID

• Txn.ExtraProgramPages

• Txn.Fee

• Txn.FirstValid

• Txn.FirstValidTime

• Txn.FreezeAsset

• Txn.FreezeAssetAccount

• Txn.FreezeAssetFrozen

• Txn.GlobalNumByteSlice

• Txn.GlobalNumUint

• Txn.GroupIndex

• Txn.LastLog

• Txn.LastValid

• Txn.Lease

• Txn.LocalNumByteSlice

• Txn.LocalNumUint

• Txn.Logs

• Txn.Nonparticipation

• Txn.Note

• Txn.NumAccounts

• Txn.NumAppArgs

• Txn.NumApplications

• Txn.NumApprovalProgramPages

• Txn.NumAssets

• Txn.NumClearStateProgramPages

• Txn.NumLogs

• Txn.OnCompletion

• Txn.Receiver

• Txn.RekeyTo

• Txn.SelectionPK

• Txn.Sender

• Txn.StateProofPK

• Txn.TxID

• Txn.Type

• Txn.TypeEnum

• Txn.VoteFirst

• Txn.VoteKeyDilution

• Txn.VoteLast

• Txn.VotePK

• Txn.XferAsset

Global Fields

This section lists all Fields available in the Global namespace.

• Global.CallerApplicationAddress

• Global.CallerApplicationID

• Global.CreatorAddress

• Global.CurrentApplicationAddress

• Global.CurrentApplicationID

• Global.GroupID

• Global.GroupSize

• Global.LatestTimestamp

• Global.LogicSigVersion

• Global.MaxTxnLife

• Global.MinBalance

• Global.MinTxnFee

• Global.OpcodeBudget

• Global.Round

• Global.ZeroAddress

Functions

This section lists all opcodes available in the AVM and usable in Tealish in a function calling style. Some AVM opcodes are excluded from this list because they don’t make sense in the context of Tealish or an alternative interface is provided. These are documented below.

acct_params_get(F: field, A: any) → int, any

X is field F from account A. Y is 1 if A owns positive algos, else 0

Fields: AcctBalance, AcctMinBalance, AcctAuthAddr, AcctTotalNumUint, AcctTotalNumByteSlice, AcctTotalExtraAppPages, AcctTotalAppsCreated, AcctTotalAppsOptedIn, AcctTotalAssetsCreated, AcctTotalAssets, AcctTotalBoxes, AcctTotalBoxBytes

addw(A: int, B: int) → int, int

A plus B as a 128-bit result. X is the carry-bit, Y is the low-order 64 bits.

app_global_del(A: bytes)

delete key A from the global state of the current application

app_global_get(A: bytes) → any

global state of the key A in the current application

app_global_get_ex(A: int, B: bytes) → int, any

X is the global state of application A, key B. Y is 1 if key existed, else 0

app_global_put(A: bytes, B: any)

write B to key A in the global state of the current application

app_local_del(A: any, B: bytes)

delete key B from account A’s local state of the current application

app_local_get(A: any, B: bytes) → any

local state of the key B in the current application in account A

app_local_get_ex(A: any, B: int, C: bytes) → int, any

X is the local state of application B, key C in account A. Y is 1 if key existed, else 0

app_local_put(A: any, B: bytes, C: any)

write C to key B in account A’s local state of the current application

app_opted_in(A: any, B: int) → int

1 if account A is opted in to application B, else 0

app_params_get(F: field, A: int) → int, any

X is field F from app A. Y is 1 if A exists, else 0

Fields: AppApprovalProgram, AppClearStateProgram, AppGlobalNumUint, AppGlobalNumByteSlice, AppLocalNumUint, AppLocalNumByteSlice, AppExtraProgramPages, AppCreator, AppAddress

arg(i: int) → bytes

Nth LogicSig argument

args(A: int) → bytes

Ath LogicSig argument

assert(A: int)

immediately fail unless A is a non-zero number

asset_holding_get(F: field, A: any, B: int) → int, any

X is field F from account A’s holding of asset B. Y is 1 if A is opted into B, else 0

Fields: AssetBalance, AssetFrozen

asset_params_get(F: field, A: int) → int, any

X is field F from asset A. Y is 1 if A exists, else 0

Fields: AssetTotal, AssetDecimals, AssetDefaultFrozen, AssetUnitName, AssetName, AssetURL, AssetMetadataHash, AssetManager, AssetReserve, AssetFreeze, AssetClawback, AssetCreator

balance(A: any) → int

balance for account A, in microalgos. The balance is observed after the effects of previous transactions in the group, and after the fee for the current transaction is deducted. Changes caused by inner transactions are observable immediately following itxn_submit

base64_decode(i: int, A: bytes) → bytes

decode A which was base64-encoded using _encoding_ E. Fail if A is not base64 encoded with encoding E

bitlen(A: any) → int

The highest set bit in A. If A is a byte-array, it is interpreted as a big-endian unsigned integer. bitlen of 0 is 0, bitlen of 8 is 4

block(i: int, A: int) → any

field F of block A. Fail unless A falls between txn.LastValid-1002 and txn.FirstValid (exclusive)

box_create(A: bytes, B: int) → int

create a box named A, of length B. Fail if A is empty or B exceeds 32,768. Returns 0 if A already existed, else 1

box_del(A: bytes) → int

delete box named A if it exists. Return 1 if A existed, 0 otherwise

box_extract(A: bytes, B: int, C: int) → bytes

read C bytes from box A, starting at offset B. Fail if A does not exist, or the byte range is outside A’s size.

box_get(A: bytes) → int, bytes

X is the contents of box A if A exists, else ‘’. Y is 1 if A exists, else 0.

box_len(A: bytes) → int, int

X is the length of box A if A exists, else 0. Y is 1 if A exists, else 0.

box_put(A: bytes, B: bytes)

replaces the contents of box A with byte-array B. Fails if A exists and len(B) != len(box A). Creates A if it does not exist

box_replace(A: bytes, B: int, C: bytes)

write byte-array C into box A, starting at offset B. Fail if A does not exist, or the byte range is outside A’s size.

bsqrt(A: bytes) → bytes

The largest integer I such that I^2 <= A. A and I are interpreted as big-endian unsigned integers

btoi(A: bytes) → int

converts big-endian byte array A to uint64. Fails if len(A) > 8. Padded by leading 0s if len(A) < 8.

bury(i: int, A: any)

replace the Nth value from the top of the stack with A. bury 0 fails.

bzero(A: int) → bytes

zero filled byte-array of length A

concat(A: bytes, B: bytes) → bytes

join A and B

cover(i: int, A: any) → any

remove top of stack, and place it deeper in the stack such that N elements are above it. Fails if stack depth <= N.

dig(i: int, A: any) → any, any

Nth value from the top of the stack. dig 0 is equivalent to dup

divmodw(A: int, B: int, C: int, D: int) → int, int, int, int

W,X = (A,B / C,D); Y,Z = (A,B modulo C,D)

divw(A: int, B: int, C: int) → int

A,B / C. Fail if C == 0 or if result overflows.

dup(A: any) → any, any

duplicate A

dup2(A: any, B: any) → any, any, any, any

duplicate A and B

dupn(i: int, A: any)

duplicate A, N times

ecdsa_pk_decompress(i: int, A: bytes) → bytes, bytes

decompress pubkey A into components X, Y

ecdsa_pk_recover(i: int, A: bytes, B: int, C: bytes, D: bytes) → bytes, bytes

for (data A, recovery id B, signature C, D) recover a public key

ecdsa_verify(i: int, A: bytes, B: bytes, C: bytes, D: bytes, E: bytes) → int

for (data A, signature B, C and pubkey D, E) verify the signature of the data against the pubkey => {0 or 1}

ed25519verify(A: bytes, B: bytes, C: bytes) → int

for (data A, signature B, pubkey C) verify the signature of (“ProgData” || program_hash || data) against the pubkey => {0 or 1}

ed25519verify_bare(A: bytes, B: bytes, C: bytes) → int

for (data A, signature B, pubkey C) verify the signature of the data against the pubkey => {0 or 1}

exp(A: int, B: int) → int

A raised to the Bth power. Fail if A == B == 0 and on overflow

expw(A: int, B: int) → int, int

A raised to the Bth power as a 128-bit result in two uint64s. X is the high 64 bits, Y is the low. Fail if A == B == 0 or if the results exceeds 2^128-1

extract(i: int, i: int, A: bytes) -> bytes

A range of bytes from A starting at S up to but not including S+L. If L is 0, then extract to the end of the string. If S or S+L is larger than the array length, the program fails

extract3(A: bytes, B: int, C: int) → bytes

A range of bytes from A starting at B up to but not including B+C. If B+C is larger than the array length, the program fails extract3 can be called using extract with no immediates.

extract_uint16(A: bytes, B: int) → int

A uint16 formed from a range of big-endian bytes from A starting at B up to but not including B+2. If B+2 is larger than the array length, the program fails

extract_uint32(A: bytes, B: int) → int

A uint32 formed from a range of big-endian bytes from A starting at B up to but not including B+4. If B+4 is larger than the array length, the program fails

extract_uint64(A: bytes, B: int) → int

A uint64 formed from a range of big-endian bytes from A starting at B up to but not including B+8. If B+8 is larger than the array length, the program fails

frame_bury(i: int, A: any)

replace the Nth (signed) value from the frame pointer in the stack with A

frame_dig(i: int) → any

Nth (signed) value from the frame pointer.

gaid(i: int) → int

ID of the asset or application created in the Tth transaction of the current group

gaids(A: int) → int

ID of the asset or application created in the Ath transaction of the current group

getbit(A: any, B: int) → int

Bth bit of (byte-array or integer) A. If B is greater than or equal to the bit length of the value (8*byte length), the program fails

getbyte(A: bytes, B: int) → int

Bth byte of A, as an integer. If B is greater than or equal to the array length, the program fails

gitxn(F: field) → any

field F of the Tth transaction in the last inner group submitted

Fields: Sender, Fee, FirstValid, FirstValidTime, LastValid, Note, Lease, Receiver, Amount, CloseRemainderTo, VotePK, SelectionPK, VoteFirst, VoteLast, VoteKeyDilution, Type, TypeEnum, XferAsset, AssetAmount, AssetSender, AssetReceiver, AssetCloseTo, GroupIndex, TxID, ApplicationID, OnCompletion, ApplicationArgs, NumAppArgs, Accounts, NumAccounts, ApprovalProgram, ClearStateProgram, RekeyTo, ConfigAsset, ConfigAssetTotal, ConfigAssetDecimals, ConfigAssetDefaultFrozen, ConfigAssetUnitName, ConfigAssetName, ConfigAssetURL, ConfigAssetMetadataHash, ConfigAssetManager, ConfigAssetReserve, ConfigAssetFreeze, ConfigAssetClawback, FreezeAsset, FreezeAssetAccount, FreezeAssetFrozen, Assets, NumAssets, Applications, NumApplications, GlobalNumUint, GlobalNumByteSlice, LocalNumUint, LocalNumByteSlice, ExtraProgramPages, Nonparticipation, Logs, NumLogs, CreatedAssetID, CreatedApplicationID, LastLog, StateProofPK, ApprovalProgramPages, NumApprovalProgramPages, ClearStateProgramPages, NumClearStateProgramPages

gitxna(F: field) → any

Ith value of the array field F from the Tth transaction in the last inner group submitted

Fields: ApplicationArgs, Accounts, Assets, Applications, Logs, ApprovalProgramPages, ClearStateProgramPages

gitxnas(i: int, i: int, A: int) -> any

Ath value of the array field F from the Tth transaction in the last inner group submitted

gload(i: int, i: int) -> any

Ith scratch space value of the Tth transaction in the current group

gloads(i: int, A: int) → any

Ith scratch space value of the Ath transaction in the current group

gloadss(A: int, B: int) → any

Bth scratch space value of the Ath transaction in the current group

global(F: field) → any

global field F

Fields: MinTxnFee, MinBalance, MaxTxnLife, ZeroAddress, GroupSize, LogicSigVersion, Round, LatestTimestamp, CurrentApplicationID, CreatorAddress, CurrentApplicationAddress, GroupID, OpcodeBudget, CallerApplicationID, CallerApplicationAddress

itob(A: int) → bytes

converts uint64 A to big-endian byte array, always of length 8

itxn(F: field) → any

field F of the last inner transaction

Fields: Sender, Fee, FirstValid, FirstValidTime, LastValid, Note, Lease, Receiver, Amount, CloseRemainderTo, VotePK, SelectionPK, VoteFirst, VoteLast, VoteKeyDilution, Type, TypeEnum, XferAsset, AssetAmount, AssetSender, AssetReceiver, AssetCloseTo, GroupIndex, TxID, ApplicationID, OnCompletion, ApplicationArgs, NumAppArgs, Accounts, NumAccounts, ApprovalProgram, ClearStateProgram, RekeyTo, ConfigAsset, ConfigAssetTotal, ConfigAssetDecimals, ConfigAssetDefaultFrozen, ConfigAssetUnitName, ConfigAssetName, ConfigAssetURL, ConfigAssetMetadataHash, ConfigAssetManager, ConfigAssetReserve, ConfigAssetFreeze, ConfigAssetClawback, FreezeAsset, FreezeAssetAccount, FreezeAssetFrozen, Assets, NumAssets, Applications, NumApplications, GlobalNumUint, GlobalNumByteSlice, LocalNumUint, LocalNumByteSlice, ExtraProgramPages, Nonparticipation, Logs, NumLogs, CreatedAssetID, CreatedApplicationID, LastLog, StateProofPK, ApprovalProgramPages, NumApprovalProgramPages, ClearStateProgramPages, NumClearStateProgramPages

itxna(F: field) → any

Ith value of the array field F of the last inner transaction

Fields: ApplicationArgs, Accounts, Assets, Applications, Logs, ApprovalProgramPages, ClearStateProgramPages

itxnas(i: int, A: int) → any

Ath value of the array field F of the last inner transaction

json_ref(i: int, A: bytes, B: bytes) → any

key B’s value, of type R, from a [valid](jsonspec.md) utf-8 encoded json object A

keccak256(A: bytes) → bytes

Keccak256 hash of value A, yields [32]byte

len(A: bytes) → int

yields length of byte value A

load(i: int) → any

Ith scratch space value. All scratch spaces are 0 at program start.

loads(A: int) → any

Ath scratch space value. All scratch spaces are 0 at program start.

log(A: bytes)

write A to log state of the current application

match()

given match cases from A[1] to A[N], branch to the Ith label where A[I] = B. Continue to the following instruction if no matches are found.

method(i: int) → bytes

min_balance(A: any) → int

minimum required balance for account A, in microalgos. Required balance is affected by ASA, App, and Box usage. When creating or opting into an app, the minimum balance grows before the app code runs, therefore the increase is visible there. When deleting or closing out, the minimum balance decreases after the app executes. Changes caused by inner transactions or box usage are observable immediately following the opcode effecting the change.

mulw(A: int, B: int) → int, int

A times B as a 128-bit result in two uint64s. X is the high 64 bits, Y is the low

pop(A: any)

discard A

popn(i: int)

remove N values from the top of the stack

proto(i: int, i: int)

Prepare top call frame for a retsub that will assume A args and R return values.

pushbytes() → bytes

immediate BYTES

pushbytess()

push sequences of immediate byte arrays to stack (first byte array being deepest)

pushint() → int

immediate UINT

pushints()

push sequence of immediate uints to stack in the order they appear (first uint being deepest)

replace2(i: int, A: bytes, B: bytes) → bytes

Copy of A with the bytes starting at S replaced by the bytes of B. Fails if S+len(B) exceeds len(A) replace2 can be called using replace with 1 immediate.

replace3(A: bytes, B: int, C: bytes) → bytes

Copy of A with the bytes starting at B replaced by the bytes of C. Fails if B+len(C) exceeds len(A) replace3 can be called using replace with no immediates.

select(A: any, B: any, C: int) → any

selects one of two values based on top-of-stack: B if C != 0, else A

setbit(A: any, B: int, C: int) → any

Copy of (byte-array or integer) A, with the Bth bit set to (0 or 1) C. If B is greater than or equal to the bit length of the value (8*byte length), the program fails

setbyte(A: bytes, B: int, C: int) → bytes

Copy of A with the Bth byte set to small integer (between 0..255) C. If B is greater than or equal to the array length, the program fails

sha256(A: bytes) → bytes

SHA256 hash of value A, yields [32]byte

sha3_256(A: bytes) → bytes

SHA3_256 hash of value A, yields [32]byte

sha512_256(A: bytes) → bytes

SHA512_256 hash of value A, yields [32]byte

shl(A: int, B: int) → int

A times 2^B, modulo 2^64

shr(A: int, B: int) → int

A divided by 2^B

sqrt(A: int) → int

The largest integer I such that I^2 <= A

store(i: int, A: any)

store A to the Ith scratch space

stores(A: int, B: any)

store B to the Ath scratch space

substring(i: int, i: int, A: bytes) -> bytes

A range of bytes from A starting at S up to but not including E. If E < S, or either is larger than the array length, the program fails

substring3(A: bytes, B: int, C: int) → bytes

A range of bytes from A starting at B up to but not including C. If C < B, or either is larger than the array length, the program fails

swap(A: any, B: any) → any, any

swaps A and B on stack

switch(A: int)

branch to the Ath label. Continue at following instruction if index A exceeds the number of labels.

uncover(i: int, A: any) → any

remove the value at depth N in the stack and shift above items down so the Nth deep value is on top of the stack. Fails if stack depth <= N.

vrf_verify(i: int, A: bytes, B: bytes, C: bytes) → int, bytes

Verify the proof B of message A against pubkey C. Returns vrf output and verification flag.

Operators

This section lists all AVM operator opcodes that can be used in math/logic expressions in Tealish.

A + B

A plus B. Fail on overflow.

A - B

A minus B. Fail if B > A.

A * B

A times B. Fail on overflow.

A / B

A divided by B (truncated division). Fail if B == 0.

A % B

A modulo B. Fail if B == 0.

A == B

A is equal to B => {0 or 1}

A >= B

A greater than or equal to B => {0 or 1}

A <= B

A less than or equal to B => {0 or 1}

A > B

A greater than B => {0 or 1}

A < B

A less than B => {0 or 1}

A != B

A is not equal to B => {0 or 1}

A && B

A is not zero and B is not zero => {0 or 1}

A || B

A is not zero or B is not zero => {0 or 1}

A | B

A bitwise-or B

A % B

A modulo B. Fail if B == 0.

A ^ B

A bitwise-xor B

!A

A == 0 yields 1; else 0

A & B

A bitwise-and B

~A

bitwise invert value A

A b+ B

A plus B. A and B are interpreted as big-endian unsigned integers

A b- B

A minus B. A and B are interpreted as big-endian unsigned integers. Fail on underflow.

A b/ B

A divided by B (truncated division). A and B are interpreted as big-endian unsigned integers. Fail if B is zero.

A b* B

A times B. A and B are interpreted as big-endian unsigned integers.

A b% B

A modulo B. A and B are interpreted as big-endian unsigned integers. Fail if B is zero.

A b== B

1 if A is equal to B, else 0. A and B are interpreted as big-endian unsigned integers

A b!= B

0 if A is equal to B, else 1. A and B are interpreted as big-endian unsigned integers

A b>= B

1 if A is greater than or equal to B, else 0. A and B are interpreted as big-endian unsigned integers

A b<= B

1 if A is less than or equal to B, else 0. A and B are interpreted as big-endian unsigned integers

A b> B

1 if A is greater than B, else 0. A and B are interpreted as big-endian unsigned integers

A b< B

1 if A is less than B, else 0. A and B are interpreted as big-endian unsigned integers

A b| B

A bitwise-or B. A and B are zero-left extended to the greater of their lengths

A b& B

A bitwise-and B. A and B are zero-left extended to the greater of their lengths

A b^ B

A bitwise-xor B. A and B are zero-left extended to the greater of their lengths

b~A

A with all bits inverted

Unsupported Opcodes

Some opcodes are excluded from the above lists because they don’t make sense in the context of Tealish or an alternative interface is provided:

global, txn, txna, txnas, gtxn, gtxna, gtxns, gtxnsas

The Fields syntax is encouraged instead of the function style.

itxn_begin, itxn_next, itxn_submit

The Tealish inner_txn construct is encouraged instead.

callsub, retsub

Tealish Functions are used instead.

b, bz, bnz, match, switch

Tealish If/Else, Loops or switch are used instead. Tealish does not support labels so these opcodes cannot be used.

return

exit is an alias of return in Tealish and its use is encouraged to avoid confusion with return in Tealish functions.

intc, bytec

Tealish does not expose the int/bytes constants block and to Tealish code.