// Copyright 2019-2022 Parity Technologies (UK) Ltd. // This file is dual-licensed as Apache-2.0 or GPL-3.0. // see LICENSE for license details. //! Subxt is a library to **sub**mit e**xt**rinsics to a [substrate](https://github.com/paritytech/substrate) node via RPC. //! //! The generated Subxt API exposes the ability to: //! - [Submit extrinsics](https://docs.substrate.io/v3/concepts/extrinsics/) (Calls) //! - [Query storage](https://docs.substrate.io/v3/runtime/storage/) (Storage) //! - [Query constants](https://docs.substrate.io/how-to-guides/v3/basics/configurable-constants/) (Constants) //! - [Subscribe to events](https://docs.substrate.io/v3/runtime/events-and-errors/) (Events) //! //! # Initializing the API client //! //! To interact with a node, you'll need to construct a client. //! //! ```no_run //! use subxt::{OnlineClient, PolkadotConfig}; //! //! # #[tokio::main] //! # async fn main() { //! let api = OnlineClient::::new().await.unwrap(); //! # } //! ``` //! //! This default client connects to a locally running node, but can be configured to point anywhere. //! Additionally, an [`crate::OfflineClient`] is available to perform operations that don't require a //! network connection to a node. //! //! The client takes a type parameter, here [`crate::PolkadotConfig`], which bakes in assumptions about //! the structure of extrinsics and the underlying types used by the node for things like block numbers. //! If the node you'd like to interact with deviates from Polkadot or the default Substrate node in these //! areas, you'll need to configure them by implementing the [`crate::config::Config`] type yourself. //! //! # Generating runtime types //! //! Subxt can optionally generate types at compile time to help you interact with a node. These types are //! generated using metadata which can be downloaded from a node using the [subxt-cli](https://crates.io/crates/subxt-cli) //! tool. These generated types provide a degree of type safety when interacting with a node that is compatible with //! the metadata that they were generated using. We also do runtime checks in case the node you're talking to has //! deviated from the types you're using to communicate with it (see below). //! //! To generate the types, use the `subxt` macro and point it at the metadata you've downloaded, like so: //! //! ```ignore //! #[subxt::subxt(runtime_metadata_path = "metadata.scale")] //! pub mod node_runtime { } //! ``` //! //! For more information, please visit the [subxt-codegen](https://docs.rs/subxt-codegen/latest/subxt_codegen/) //! documentation. //! //! You can opt to skip this step and use dynamic queries to talk to nodes instead, which can be useful in some cases, //! but doesn't provide any type safety. //! //! # Interacting with the API //! //! Once instantiated, a client exposes four core functions: //! - `.tx()` for submitting extrinsics/transactions. See [`crate::tx::TxClient`] for more details, or see //! the [balance_transfer](../examples/examples/balance_transfer.rs) example. //! - `.storage()` for fetching and iterating over storage entries. See [`crate::storage::StorageClient`] for more details, or see //! the [fetch_staking_details](../examples/examples/fetch_staking_details.rs) example. //! - `.constants()` for getting hold of constants. See [`crate::constants::ConstantsClient`] for more details, or see //! the [fetch_constants](../examples/examples/fetch_constants.rs) example. //! - `.events()` for subscribing/obtaining events. See [`crate::events::EventsClient`] for more details, or see: //! - [subscribe_all_events](../examples/examples/subscribe_all_events.rs): Subscribe to events emitted from blocks. //! - [subscribe_one_event](../examples/examples/subscribe_one_event.rs): Subscribe and filter by one event. //! - [subscribe_some_events](../examples/examples/subscribe_some_events.rs): Subscribe and filter event. //! //! # Static Metadata Validation //! //! If you use types generated by the [`crate::subxt`] macro, there is a chance that they will fall out of sync //! with the actual state of the node you're trying to interact with. //! //! When you attempt to use any of these static types to interact with a node, Subxt will validate that they are //! still compatible and issue an error if they have deviated. //! //! Additionally, you can validate that the entirety of the statically generated code aligns with a node like so: //! //! ```no_run //! use subxt::{OnlineClient, PolkadotConfig}; //! //! #[subxt::subxt(runtime_metadata_path = "../artifacts/polkadot_metadata.scale")] //! pub mod polkadot {} //! //! # #[tokio::main] //! # async fn main() { //! let api = OnlineClient::::new().await.unwrap(); //! //! if let Err(_e) = polkadot::validate_codegen(&api) { //! println!("Generated code is not up to date with node we're connected to"); //! } //! # } //! ``` //! ## Opting out of static validation //! //! The static types that are used to query/access information are validated by default, to make sure that they are //! compatible with the node being queried. You can generally call `.unvalidated()` on these static types to //! disable this validation. //! //! # Runtime Updates //! //! The node you're connected to may occasionally perform runtime updates while you're connected, which would ordinarily //! leave the runtime state of the node out of sync with the information Subxt requires to do things like submit //! transactions. //! //! If this is a concern, you can use the `UpdateClient` API to keep the `RuntimeVersion` and `Metadata` of the client //! synced with the target node. //! //! Please visit the [subscribe_runtime_updates](../examples/examples/subscribe_runtime_updates.rs) example for more details. #![deny( bad_style, improper_ctypes, missing_docs, non_shorthand_field_patterns, no_mangle_generic_items, overflowing_literals, path_statements, patterns_in_fns_without_body, private_in_public, unconditional_recursion, unused_allocation, unused_comparisons, unused_parens, while_true, trivial_casts, trivial_numeric_casts, unused_crate_dependencies, unused_extern_crates, clippy::all )] #![allow(clippy::type_complexity)] // Suppress an unused dependency warning because tokio is // only used in example code snippets at the time of writing. #[cfg(test)] use tokio as _; pub use subxt_macro::subxt; // Used to enable the js feature for wasm. #[cfg(target_arch = "wasm32")] pub use getrandom as _; #[cfg(all(feature = "jsonrpsee-ws", feature = "jsonrpsee-web"))] std::compile_error!("Both the features `jsonrpsee-ws` and `jsonrpsee-web` are enabled which are mutually exclusive"); pub mod blocks; pub mod client; pub mod config; pub mod constants; pub mod dynamic; pub mod error; pub mod events; pub mod metadata; pub mod rpc; pub mod storage; pub mod tx; pub mod utils; // Expose a few of the most common types at root, // but leave most types behind their respective modules. pub use crate::{ client::{ OfflineClient, OnlineClient, }, config::{ Config, PolkadotConfig, SubstrateConfig, }, error::Error, metadata::Metadata, }; /// Re-export external crates that are made use of in the subxt API. pub mod ext { pub use codec; pub use frame_metadata; pub use scale_bits; pub use scale_value; pub use sp_core; pub use sp_runtime; }