Crate near_sdk

source ·


pub use near_sys as sys;
pub use crate::utils::*;


Collections that offer an alternative to standard containers from std::collections::* by utilizing the underlying blockchain trie storage more efficiently.
Blockchain-specific methods available to the smart contract. This is a wrapper around a low-level BlockchainInterface. Unless you know what you are doing prefer using env::* whenever possible. In case of cross-contract calls prefer using even higher-level API available through callback_args, callback_args_vec, ext_contract, Promise, and PromiseOrValue.
Helper types for JSON serialization.
Mock blockchain utilities. These can only be used inside tests and are not available for a wasm32 target.
Collections and types used when interacting with storage.
Testing blockchain utilities. These can only be used inside tests and are not available for a wasm32 target.
Helper methods that often used in smart contracts.


Helper macro to log a message through env::log_str. This macro can be used similar to the std::format macro in most cases.
Helper macro to create assertions that will panic through the runtime host functions.
Deprecated helper function which used to generate code to initialize the GlobalAllocator. This is now initialized by default. Disable wee_alloc feature to configure manually.
Initializes a testing environment to mock interactions which would otherwise go through a validator node. This macro will initialize or overwrite the MockedBlockchain instance for interactions from a smart contract.


A simple type used in conjunction with FunctionError representing that the function should abort without a custom message.
Account identifier. This is the human readable utf8 string which is used internally to index accounts on the network and their respective state.
Represents the amount of NEAR tokens in “gas units” which are used to fund transactions.
Weight of unused gas to use with promise_batch_action_function_call_weight.
Mocked blockchain that can be used in the tests for the smart contracts. It implements BlockchainInterface by redirecting calls to VMLogic. It unwraps errors of VMLogic to cause panic during the unit tests similarly to how errors of VMLogic would cause the termination of guest program execution. Unit tests can even assert the expected error message.
A structure representing a result of the scheduled execution on another contract.
Public key in a binary format with base58 string serialization with human-readable curve. The key types currently supported are secp256k1 and ed25519.
Context for the contract execution.


PublicKey curve
All error variants which can occur with promise results.
When the method can return either a promise or a value, it can be called with PromiseOrValue::Promise or PromiseOrValue::Value to specify which one should be returned.
When there is a callback attached to one or more contract calls the execution results of these calls are available to the contract invoked through the callback.
When there is a callback attached to one or more contract calls the execution results of these calls are available to the contract invoked through the callback.


Balance of one NEAR, which is 10^24 Yocto NEAR.
Balance of one Yocto NEAR, which is the smallest denomination. This value is 10^-24 of one NEAR.


Enables contract runtime to panic with the given type. Any error type used in conjunction with #[handle_result] has to implement this trait.
Converts Self into a Vec<u8> that is used for a storage key through into_storage_key.

Type Definitions

Balance is a type for storing amounts of tokens, specified in yoctoNEAR.
Height of the block.
Block height delta that measures the difference between BlockHeights.
Raw type for 32 bytes of the hash.
Raw type for duration in nanoseconds
Height of the epoch.
Hash used by a struct implementing the Merkle tree.
Nonce for transactions.
Number of blocks in current group.
Number of seats of validators (block producer or hidden ones) in current group (settlement).
Number of shards in current group.
Promise index that is computed only once.
An index of Receipt to append an action
Shard index, from 0 to NUM_SHARDS - 1.
StorageUsage is used to count the amount of storage used by a contract.
StorageUsageChange is used to count the storage usage within a single contract call.
Raw type for timestamp in nanoseconds
Validator identifier in current group.
Mask which validators participated in multi sign.

Attribute Macros

ext_contract takes a Rust Trait and converts it to a module with static methods. Each of these static methods takes positional arguments defined by the Trait, then the receiver_id, the attached deposit and the amount of gas and returns a new Promise.
This attribute macro is used on a struct and its implementations to generate the necessary code to expose pub methods from the contract as well as generating the glue code to be a valid NEAR contract.

Derive Macros

BorshStorageKey generates implementation for BorshIntoStorageKey trait. It allows the type to be passed as a unique prefix for persistent collections. The type should also implement or derive BorshSerialize trait.
NOTE: This is an internal implementation for #[near_bindgen(events(standard = ...))] attribute.
FunctionError generates implementation for near_sdk::FunctionError trait. It allows contract runtime to panic with the type using its ToString implementation as the message.
PanicOnDefault generates implementation for Default trait that panics with the following message The contract is not initialized when default() is called. This is a helpful macro in case the contract is required to be initialized with either init or init(ignore_state).