FRAME pallets

The FRAME development environment provides modules—called pallets—and support libraries that you can use, modify, and extend to build the runtime logic to suit the needs of your blockchain.

This section provides an overview of the predefined pallets and links to the Rust API reference documentation, where you can find details about each pallet's interfaces.

System pallets

The FRAME system pallets are integral to the Substrate runtime and provide core functionality that all other pallets depend on.

System pallet name	What it's for
frame_benchmarking	Contains common runtime patterns for benchmarking and testing purposes.
frame_executive	Orchestrates incoming function calls by sending them to the appropriate pallets in the runtime.
frame_support	Provides Rust macros, types, traits, and modules that generate boilerplate code for the pallet structure when compiled.
frame_system	Defines low-level types for Substrate primitives, storage items, and core functions for the blockchain. All other pallets depend on the frame_system crate.

Functional pallets

The Substrate development framework includes many functional pallets that provide features you might find generally useful as composable components of your blockchain. These functional pallets are prebuilt and freely available to enable the community to share, reuse, and improve the interfaces to address common use cases.

The following table highlights some of the most commonly used pallets available. However, the number of pallets that provide specialized functionality and how they provide that functionality changes frequently. You should check the Rust documentation for the most up-to-date listing of pallets and for details about using them.

Prebuilt pallet name	What it's for
pallet_alliance	Initializes a collective for community members to join in an effort to establish rules against bad behavior and to provide recognition and influence for teams that contribute to the ecosystem.
pallet_assets	Provides simple and secure methods for dealing with fungible assets.
pallet_atomic_swap	Enables sending funds from an origin to a target. A proof is used to allow the target to claim the swap. If the swap is not claimed within a specified duration of time, the sender may cancel it.
pallet_aura	Extends the authority round (Aura) consensus model by managing offline reporting.
pallet_authority_discovery	Retrieves the current set of authorities, learns its own authority ID, and signs and verifies messages to and from other authorities.
pallet_authorship	Tracks the current author of the block and recent uncles.
pallet_babe	Extends BABE consensus by collecting on-chain randomness from VRF outputs and managing epoch transitions.
pallet_balances	Provides functionality for handling accounts and balances.
pallet_bounties	Manages rewards for performing specified work or for achieving a specified set of objectives.
pallet_collective	Allows a set of account IDs to make their collective feelings known through dispatched calls from specialized origins.
pallet_contracts	Provides functionality for the runtime to deploy and execute WebAssembly smart contracts.
pallet_contracts_primitives	Provides common definitions that are used by the pallet_contracts crate for smart contracts.
pallet_democracy	Provides a democratic system that handles administration of general stakeholder voting.
pallet_election_provider_multi_phase	Enables an election provider to conduct an election consisting of signed and unsigned phases.
pallet_elections_phragmen	Provides an election module based on sequential Phragmén.
pallet_example_basic	Demonstrates concepts, APIs, and structures that are applicable for most pallets.
pallet_example_offchain_worker	Demonstrates concepts, APIs, and structures that are applicable for most offchain workers.
pallet_grandpa	Extends the GRANDPA consensus by managing the GRANDPA authority set ready for the native code.
pallet_identity	Enables a federated naming system that allows multiple registrars to be added from a specified origin. Registrars can set a fee to provide identity-verification service.
pallet_im_online	Allows validators to gossip a heartbeat transaction with each new session to signal that the node is online.
pallet_indices	Allocates indices for newly created accounts. An index is a short form of an address.
pallet_lottery	Configures a lottery that enables network participants to purchase tickets.
pallet_membership	Allows control of membership of a set of AccountIds, useful for managing the membership of a collective.
pallet_multisig	Enables multi-signature dispatches.
pallet_nicks	Demonstrates simplified account naming on-chain. It makes no effort to create a name hierarchy, be a DNS replacement, or provide reverse lookups.
pallet_offences	Tracks reported offences.
pallet_proxy	Allows accounts to give permission to other accounts to dispatch types of calls from their signed origin.
pallet_randomness_collective_flip	Provides a random function that can be used in tests and generates low-influence random values based on the block hashes from the previous 81 blocks. This pallet is not intended for use in production.
pallet_recovery	Provides a social recovery tool for users to gain access to their accounts if their private key or other authentication mechanism is lost. This pallet enables an account owner to identify trusted parties who can act on the owner's behalf to recover access to an account.
pallet_scheduler	Exposes capabilities for scheduling dispatches to occur at a specified block number or at a specified period. These scheduled dispatches can be named or anonymous and can be canceled.
pallet_scored_pool	Maintains a scored membership pool where the highest scoring entities are made members.
pallet_session	Allows validators to manage their session keys, provides a function for changing the session length, and handles session rotation.
pallet_society	Provides economic incentives for users to participate and maintain a membership society.
pallet_staking	Manages funds that have been staked by network maintainers.
pallet_sudo	Allows for a single account—called the sudo key—to execute dispatchable functions that require a Root origin or designate a new account to replace them as the sudo key.
pallet_timestamp	Provides functionality to get and set the on-chain time.
pallet_transaction_payment	Provides the basic logic to compute pre-dispatch transaction fees.
pallet_treasury	Provides a reserve of funds that can be managed by stakeholders in the system and a structure for making spending proposals from this reserve.
pallet_uniques	Provides methods for managing non-fungible collections and items.
pallet_utility	Provides a stateless helper module for managing dispatches.
pallet_vesting	Places a linear curve on an account's locked balance. This module ensures that there is a lock in place to prevent the balance to drop below the unvested amount for any reason other than transaction fee payment.

Parachain pallets

In addition to the functional pallets that are generally useful for any blockchain, there are prebuilt pallets that provide features specifically for blockchains that are intended to connect to a relay chain. The following pallets provide features for parachain development.

Prebuilt pallet name	What it's for
cumulus-pallet-aura-ext	Provides AURA consensus for parachains.
pallet-collator-selection	Manages collators in a parachain.
cumulus-pallet-dmp-queue	Implements a message queue for receiving messages from the relay chain.
cumulus-pallet-parachain-system	Provides basic functionality for cumulus-based parachains.
cumulus-pallet-solo-to-para	Enables migration from a solo chain to a parachain.
cumulus-pallet-xcm	Adds support for cross-chain message passing (XCMP) to a parachain.
cumulus-pallet-xcmp-queue	Enables the XCMP transport layer to handle both incoming and outgoing message sending and dispatch, queuing, signalling, and backpressure.

Additional information

For detailed information about any pallet, refer to the Rust-generated API documentation or the source code for the individual pallet.