System contract types

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Prerequisites

Transactions

Accounts

A TRON transaction carries exactly one contract payload — raw_data.contract is a list, but the protocol always populates only contract[0]. That payload is a Contract message whose type is a value of the ContractType enum and whose parameter is the corresponding protobuf. This page covers the most commonly used values of ContractType, the protobuf payload each one carries, and the key validation rules each one enforces.

Source enum: enum ContractType in protocol/src/main/protos/core/Tron.proto — the authoritative definition of every value referenced on this page.

Where a value depends on chain state (issuance fees, SR upgrade cost, unstake delay, etc.), the relevant chain parameter is named — query wallet/getchainparameters for the live value rather than hard-coding numbers.

Account & balance

TransferContract — enum 1

Plain TRX transfer.

Field	Type	Description
`owner_address`	bytes	Sender
`to_address`	bytes	Recipient
`amount`	int64	Amount in sun

If the recipient address is not yet activated on-chain, the transfer pays the activation fee in addition to the transfer amount — see AccountCreateContract below.

AccountCreateContract — enum 0

Creates a new on-chain account. Most callers do not invoke this directly — sending TRX to an unactivated address triggers the activation flow automatically.

Field	Type	Description
`owner_address`	bytes	Creator
`account_address`	bytes	New account address
`type`	enum	Account type: `Normal=0`, `AssetIssue=1`, `Contract=2`

Cost: chain parameter getCreateNewAccountFeeInSystemContract (currently 1 TRX on Mainnet; defaults to 0 in DynamicPropertiesStore.java:497 — the live value is the post-proposal value).

AccountUpdateContract — enum 10

Sets the human-readable name of an account.

Field	Type	Description
`owner_address`	bytes	Account
`account_name`	bytes	New name (UTF-8)

Account names are currently set-once under chain parameter #14 ALLOW_UPDATE_ACCOUNT_NAME (value 0 on Mainnet). Setting the same account a second time fails unless the parameter flips to 1.

SetAccountIdContract — enum 19

Sets a custom account ID (a separate identifier from the address).

Field	Type	Description
`owner_address`	bytes	Account
`account_id`	bytes	ID (ASCII string)

WithdrawBalanceContract — enum 13

Claims accumulated rewards — SR block rewards or voter rewards — into the calling account's balance.

Field	Type	Description
`owner_address`	bytes	SR or voter address

Cooldown: once per 24 hours (verified in WithdrawBalanceActuator.java:125-128).

TRC-10 asset

TRC-10 is the protocol-level (non-VM) token standard on TRON. Most new fungible tokens use TRC-20 instead — see Token standards overview.

AssetIssueContract — enum 6

Creates a new TRC-10 token.

Field	Type	Description
`id`	string	Token ID (auto-assigned)
`owner_address`	bytes	Issuer
`name`	bytes	Token name; required, 1–32 bytes, with every byte in the printable ASCII range `0x21`–`0x7E` (spaces are not allowed)
`abbr`	bytes	Symbol; may be empty. A nonempty value must be 1–32 bytes and follow the same printable-ASCII rule as `name`
`total_supply`	int64	Total supply (≥ 1)
`frozen_supply`	FrozenSupply[]	Time-locked supply portions
`trx_num`	int32	Amount in sun exchanged for `num` raw token units
`num`	int32	Raw token units exchanged for `trx_num` sun
`precision`	int32	Decimal places (0, or 1–6; capped by `PRECISION_DECIMAL = 6`)
`start_time`	int64	Issuance window start (ms since epoch)
`end_time`	int64	Issuance window end
`description`	bytes	Description (UTF-8)
`url`	bytes	Project website URL (UTF-8)
`vote_score`	int32	Reserved
`free_asset_net_limit`	int64	Free Bandwidth each holder gets for this token (changeable later via `UpdateAssetContract.new_limit`)
`public_free_asset_net_limit`	int64	Shared free-Bandwidth pool for this token network-wide (changeable later via `UpdateAssetContract.new_public_limit`)

FrozenSupply sub-fields:

Sub-field	Type	Description
`frozen_amount`	int64	Amount of tokens frozen
`frozen_days`	int64	Lock duration in days (1–3,652; min `MinFrozenSupplyTime = 1`, max `MaxFrozenSupplyTime = 3652`)

Cost: currently 1,024 TRX on Mainnet. Chain parameter #4 getAssetIssueFee controls the amount; query wallet/getchainparameters for the selected network's current value. One issuance per account (AssetIssueActuator.java:286-288).

TransferAssetContract — enum 2

Transfers a TRC-10 token.

Field	Type	Description
`asset_name`	bytes	Token ID (decimal string, e.g., `"1000001"`)
`owner_address`	bytes	Sender
`to_address`	bytes	Recipient
`amount`	int64	Amount in raw token units (no decimal-precision scaling)

ParticipateAssetIssueContract — enum 9

Buys into an active TRC-10 issuance window.

Field	Type	Description
`owner_address`	bytes	Buyer
`to_address`	bytes	Issuer
`asset_name`	bytes	Token ID
`amount`	int64	TRX paid (in sun)

The buyer receives floor(amount × num / trx_num) raw token units, where amount is the TRX payment in sun. Divide the raw token amount by 10^precision to obtain the display amount. Participation is valid only while the on-chain time satisfies start_time ≤ now < end_time; a transaction executed at end_time is rejected.

UpdateAssetContract — enum 15

Updates the description, URL, and quota fields of an existing TRC-10 token.

Field	Type	Description
`owner_address`	bytes	Issuer
`description`	bytes	New description
`url`	bytes	New project website
`new_limit`	int64	New free Bandwidth limit for each account holding this token, in Bandwidth units
`new_public_limit`	int64	New shared free Bandwidth limit for this token across the network, in Bandwidth units

Both values must be non-negative and lower than the network's one-day Bandwidth limit. They update free_asset_net_limit and public_free_asset_net_limit; they do not limit token holdings or issuance.

UnfreezeAssetContract — enum 14

Releases frozen TRC-10 supply (those defined in frozen_supply at issuance).

Field	Type	Description
`owner_address`	bytes	Token issuer

Voting and Super Representatives

VoteWitnessContract — enum 4

Casts votes for SR candidates. The caller's votes spend their TRON Power (TP) balance.

Field	Type	Description
`owner_address`	bytes	Voter
`votes`	Vote[]	List of (SR address, vote count) pairs

Vote sub-fields:

Sub-field	Type	Description
`vote_address`	bytes	SR candidate address
`vote_count`	int64	TP to allocate (1 staked TRX = 1 TP)

Maximum: 30 votes per call (Parameter.java:68 — MAX_VOTE_NUMBER = 30). The total vote_count cannot exceed the caller's TP.

WitnessCreateContract — enum 5

Registers as an SR candidate.

Field	Type	Description
`owner_address`	bytes	Applicant
`url`	bytes	SR's project website URL (UTF-8)

Cost: chain parameter #1 getAccountUpgradeCost — currently 9,999 TRX (DynamicPropertiesStore.java:382 default saveAccountUpgradeCost(9_999_000_000L)). The fee is burned (not reclaimable). Successful registration creates an entry in the SR Candidate pool; the account becomes an active SR if it ranks in the top 27 at the next scheduled maintenance update.

WitnessUpdateContract — enum 8

Updates an SR's project URL.

Field	Type	Description
`owner_address`	bytes	SR address
`update_url`	bytes	New URL; required, 1–256 bytes

UpdateBrokerageContract — enum 49

Sets an SR's brokerage rate — the percentage of total rewards the SR keeps for itself (the rest goes to voters).

Field	Type	Description
`owner_address`	bytes	SR
`brokerage`	int32	New rate, integer percent in `[0, 100]` (default 20 on Mainnet)

Stake 1.0 (legacy)

Stake 1.0 is the original time-locked staking model. New integrations should use Stake 2.0. These types remain relevant for decoding historical transactions and releasing stakes created before Stake 2.0 activated.

UnfreezeBalanceContract — enum 12

Legacy: unstake Stake-1.0 TRX. Funds are released immediately on a successful call.

Field	Type	Description
`owner_address`	bytes	Unstaker
`resource`	enum	Resource type that was originally staked
`receiver_address`	bytes	Original delegation target (must match the original stake)

Stake 2.0

Current staking model. Source: Staking on the TRON network.

FreezeBalanceV2Contract — enum 54

Stake TRX for resources. Effect is immediate.

Field	Type	Description
`owner_address`	bytes	Staker
`frozen_balance`	int64	Amount in sun
`resource`	enum	`0 = BANDWIDTH`, `1 = ENERGY` (no time parameter)

UnfreezeBalanceV2Contract — enum 55

Initiates the unstake process. Funds become available after the chain-parameter delay.

Field	Type	Description
`owner_address`	bytes	Unstaker
`unfreeze_balance`	int64	Amount in sun (≤ currently staked amount)
`resource`	enum	`0 = BANDWIDTH`, `1 = ENERGY`, `2 = TRON_POWER`

Delay: chain parameter #70 getUnfreezeDelayDays — currently 14 days on Mainnet (UnfreezeBalanceV2Actuator.java:231). After this period, call WithdrawExpireUnfreezeContract to claim the unstaked TRX.

WithdrawExpireUnfreezeContract — enum 56

Withdraws TRX whose unstake delay has elapsed.

Field	Type	Description
`owner_address`	bytes	Account address

CancelAllUnfreezeV2Contract — enum 59

Cancels all Stake 2.0 unstake requests for the account. TRX from requests that are still within the waiting period is returned to its original stake and restores the corresponding resource quota and TRON Power. Amounts whose waiting period has already elapsed are withdrawn to the account balance in the same transaction. The transaction information reports these outcomes in cancel_unfreezeV2_amount and withdraw_expire_amount.

Field	Type	Description
`owner_address`	bytes	Account address

DelegateResourceContract — enum 57

Delegates resources from your stake to another address. The receiver gets resource quota but no TP and no ownership of the underlying TRX.

Field	Type	Description
`owner_address`	bytes	Resource owner
`resource`	enum	`0 = BANDWIDTH`, `1 = ENERGY`
`balance`	int64	Amount of staked TRX whose resources to delegate (in sun)
`receiver_address`	bytes	Recipient
`lock`	bool	Whether to lock the delegation
`lock_period`	int64	Lock period in blocks (1 block ≈ 3 seconds — `BLOCK_PRODUCED_INTERVAL = 3000`); only valid when `lock = true`

Maximum lock_period: chain parameter #78 getMaxDelegateLockPeriod. The protocol default is 86,400 blocks (about 3 days), the theoretical maximum is 10,512,000 blocks (about 365 days), and the current Mainnet value is 864,000 blocks (about 30 days).

UnDelegateResourceContract — enum 58

Reclaims resources from an unlocked delegation, or from a locked delegation after its lock period has expired. For a locked delegation, java-tron treats the balance as reclaimable only when its expiration time is earlier than the current block timestamp.

Field	Type	Description
`owner_address`	bytes	Original delegator
`resource`	enum	Must match the delegation's resource
`balance`	int64	Amount to undelegate (≤ originally delegated)
`receiver_address`	bytes	Must match the delegation's receiver

Governance and proposals

ProposalCreateContract — enum 16

Creates a chain-parameter-change proposal. Submittable by any SR, SR Partner, or SR Candidate.

Field	Type	Description
`owner_address`	bytes	Creator
`parameters`	map<int64, int64>	Parameter ID → new value pairs

No hard limit on the number of parameter changes per proposal exists in source (ProposalCreateActuator.java:110-116 only rejects empty proposals). The voting window is controlled by chain parameter #92 getProposalExpireTime (currently 3 days). The first maintenance-triggering block at or after expiry counts approvals from the active SR set in effect before that block's maintenance update. A proposal passes with at least 18 eligible approvals; its parameter values are then written to chain state and apply to subsequent blocks.

ProposalApproveContract — enum 17

A registered SR candidate adds or withdraws an approval for a pending proposal.

Field	Type	Description
`owner_address`	bytes	Registered SR candidate submitting the approval operation
`proposal_id`	int64	Target proposal ID
`is_add_approval`	bool	`true` = add approval; `false` = withdraw a prior approval

Any registered SR candidate may submit or withdraw an approval before expiration. When the proposal expires, only approvals from the 27 active SRs in the eligible set are counted.

ProposalDeleteContract — enum 18

Cancels a proposal before it expires. Source ProposalDeleteActuator.java:116-118 blocks deletion only if the proposal has already passed its expiration time — there is no 24-hour minimum delay.

Field	Type	Description
`owner_address`	bytes	Must be the proposal creator
`proposal_id`	int64	Target proposal

Smart contracts

CreateSmartContract — enum 30

Deploys a new smart contract.

Field	Type	Description
`owner_address`	bytes	Deployer
`new_contract`	SmartContract	Contract definition (see below)
`call_token_value`	int64	TRC-10 amount sent to the new contract (optional)
`token_id`	int64	TRC-10 token ID (when `call_token_value > 0`)

SmartContract sub-fields:

Field	Type	Description
`origin_address`	bytes	Deployer (same as `owner_address`)
`contract_address`	bytes	Generated contract address
`abi`	ABI	Optional ABI (queryable later via `wallet/getcontract`)
`bytecode`	bytes	Compiled TVM bytecode
`call_value`	int64	TRX (in sun) sent to the constructor
`consume_user_resource_percent`	int64	Caller-pays percent, range `[0, 100]`. protobuf default is 0 (caller pays 0%, deployer 100%); SDKs such as TronWeb fill 100 when the field is unset
`name`	string	Contract name (maximum 32 bytes after UTF-8 encoding; checked at validation)
`origin_energy_limit`	int64	Deployer's per-call Energy cap; must be `> 0` (`VMActuator.java:387`, no upper limit)

For the Energy / fee_limit / origin_energy_limit interactions in detail, see FeeLimit & Energy cost.

TriggerSmartContract — enum 31

Invokes a function on an existing contract.

Field	Type	Description
`owner_address`	bytes	Caller
`contract_address`	bytes	Target contract
`data`	bytes	ABI-encoded call (4-byte selector + 32-byte-padded arguments)
`call_value`	int64	TRX sent with the call (in sun)
`call_token_value`	int64	TRC-10 sent with the call (in raw token units)
`token_id`	int64	TRC-10 token ID

See Parameter encoding and decoding for the ABI encoding rules.

UpdateSettingContract — enum 33

Updates a contract's consume_user_resource_percent (the caller/deployer Energy split).

Field	Type	Description
`owner_address`	bytes	Contract deployer
`contract_address`	bytes	Target contract
`consume_user_resource_percent`	int64	New value, `[0, 100]`

UpdateEnergyLimitContract — enum 45

Updates a contract's origin_energy_limit.

Field	Type	Description
`owner_address`	bytes	Contract deployer
`contract_address`	bytes	Target contract
`origin_energy_limit`	int64	New value; must be `> 0` (no documented upper bound)

ClearABIContract — enum 48

Clears the on-chain ABI of a contract. The contract continues to execute normally; only the ABI lookup via wallet/getcontract returns empty afterward.

Field	Type	Description
`owner_address`	bytes	Contract deployer
`contract_address`	bytes	Target contract

GetContract — enum 32

GetContract is a reserved protocol enum value with no transaction actuator. It cannot be used to build an executable Transaction.Contract; query contract metadata through wallet/getcontract or another node query API.

Account Permission Management

AccountPermissionUpdateContract — enum 46

Updates the multi-sign permission structure of an account — owner permission, optional witness permission (only for SRs), and 1–8 active permissions.

Field	Type	Description
`owner_address`	bytes	Account
`owner`	Permission	Owner permission
`witness`	Permission	Witness permission (SR-signing, optional, only for SRs)
`actives`	Permission[]	Complete updated list; an account must retain at least 1 and may have at most 8 active permissions

Each Permission carries a threshold, a list of (address, weight) keys, and an operations bitmap that gates which contract types this permission can sign. See Multi-signature for the full schema.

Quick lookup

Enum	Type	Group
0	`AccountCreateContract`	Account & balance
1	`TransferContract`	Account & balance
2	`TransferAssetContract`	TRC-10
4	`VoteWitnessContract`	Voting
5	`WitnessCreateContract`	Voting
6	`AssetIssueContract`	TRC-10
8	`WitnessUpdateContract`	Voting
9	`ParticipateAssetIssueContract`	TRC-10
10	`AccountUpdateContract`	Account & balance
12	`UnfreezeBalanceContract`	Stake 1.0 (legacy)
13	`WithdrawBalanceContract`	Account & balance
14	`UnfreezeAssetContract`	TRC-10
15	`UpdateAssetContract`	TRC-10
16	`ProposalCreateContract`	Governance
17	`ProposalApproveContract`	Governance
18	`ProposalDeleteContract`	Governance
19	`SetAccountIdContract`	Account & balance
30	`CreateSmartContract`	Smart contracts
31	`TriggerSmartContract`	Smart contracts
32	`GetContract`	Smart contracts (query)
33	`UpdateSettingContract`	Smart contracts
45	`UpdateEnergyLimitContract`	Smart contracts
46	`AccountPermissionUpdateContract`	Permissions
48	`ClearABIContract`	Smart contracts
49	`UpdateBrokerageContract`	Voting
54	`FreezeBalanceV2Contract`	Stake 2.0
55	`UnfreezeBalanceV2Contract`	Stake 2.0
56	`WithdrawExpireUnfreezeContract`	Stake 2.0
57	`DelegateResourceContract`	Stake 2.0
58	`UnDelegateResourceContract`	Stake 2.0
59	`CancelAllUnfreezeV2Contract`	Stake 2.0

Enum values 7, 21–29, 34–40, 47, 50 are unused in the current proto and reserved for future contract types or have been historically retired.

Related resources

Transactions — transaction structure and lifecycle
Accounts — account model and key derivation
Multi-signature — Account Permission Management schema
Staking on the TRON network — Stake 2.0 lifecycle
Network parameters — values referenced above (getAssetIssueFee, getAccountUpgradeCost, getUnfreezeDelayDays, etc.)
Token standards overview — TRC-10 / TRC-20 / TRC-721 / TRC-1155