corepc

Bitcoin Core JSON-RPC support for Rust. Replaces the archived rust-bitcoincore-rpc.

Repo: github.com/rust-bitcoin/corepc. As of September 2026 the GitHub README carries a "This repository has moved" banner pointing at the org's own Forgejo instance, git.rust-bitcoin.org/rust-bitcoin/corepc; issues and PRs belong there, crates still publish to crates.io as normal.

Read the upstream guidance first

The README is explicit and unusual, so do not skip it:

If you require a JSON RPC client in production software it is expected you write your own and only use the corepc-types crate in your dependency graph.

Please do not use corepc-client in production and raise bugs, issues, or feature requests.

So the supported split is: corepc-types is the production dependency; corepc-client exists to exercise those types and to drive nodes in tests. Meanwhile the archived rust-bitcoincore-rpc README (archived 25 November 2025) tells its users to switch to corepc-client. Both statements are upstream; reconcile them by taking the types crate plus a thin client of your own for a service, and corepc-client for tests and tooling.

Crates (versions as of September 2026)

MSRV across the workspace is Rust 1.75.0; the crates build against bitcoin = "0.32.0". Releases came roughly fortnightly from April to June 2026 (client 0.11.0 → 0.16.0); nothing has been tagged since the 18 June 2026 wave.

Version-aware design

The whole point of the repo is that a Core RPC response shape depends on which Core you are talking to. corepc-types therefore has one module per Core major - v17 through v31 - holding the literal JSON shape that version returns, plus a model module of version-agnostic types. Convert with into_model():

use corepc_client::client_sync::v31::Client;
use corepc_client::client_sync::Auth;

// cargo add corepc-client --features client-sync
let client = Client::new_with_auth(
    "http://127.0.0.1:8332",
    Auth::UserPass("user".into(), "pass".into()),
)?;

let json = client.get_blockchain_info()?;   // corepc_types::v31 shape
let info = json.into_model()?;              // corepc_types::model shape
println!("{} at height {}", info.chain, info.blocks);

Client::new(url) exists for unauthenticated endpoints. Features: client-sync (blocking) and client-async; neither is on by default.

The v31 client asserts the server version it was built for (impl_client_check_expected_server_version!({ [310000] })), so pointing a v31::Client at a v29 node fails loudly instead of mis-deserialising. No crate here sniffs the peer's version for you - picking the right module is the application's job.

Integration testing with bitcoind

[dev-dependencies]
bitcoind = { version = "0.41", features = ["latest", "download"] }

use bitcoind::BitcoinD;

let node = BitcoinD::from_downloaded()?;    // needs the `download` feature
let info = node.client.get_blockchain_info()?;
assert_eq!(info.chain, "regtest");
// node killed on drop; datadir is a tempfile::TempDir

BitcoinD::new(exe) / BitcoinD::with_conf(exe, &conf) use a binary already on the host instead. The crate re-exports version-specific types as vtype and the model types as mtype.

Version features select which Core the harness expects, and they cascade downwards:

• default = ["0_17_2"], latest = ["31_0"].
• One pinned Core binary per supported major: 31_0 → 31.0, 30_2 → 30.2, 29_0 → 29.0, then 28_2, 27_2, 26_2, ... back to 0_17_2 (as of bitcoind 0.41.0, June 2026). There is no 30_0 or 30_1 feature, excluded upstream because of a wallet migration bug.
• No feature exists for Core 29.1-29.4, 30.3 or 31.1, although all of those tags shipped (as of September 2026). Upstream's Cargo.toml comment about supporting every minor of the latest three majors is stale; bitcoind/src/versions.rs is the authority.
• Enabling several version features is not an error; the highest wins.

Migrating from rust-bitcoincore-rpc

rust-bitcoin/rust-bitcoincore-rpc was archived on 25 November 2025 with bitcoincore-rpc frozen at 0.19.0 (May 2024) and its README recommending corepc-client. The bitcoind crate name is the same crate lineage: it was renamed to corepc-node and then renamed back to bitcoind in 0.37.0 (16 April 2026, PR #542), with the version number bumped past the old standalone bitcoind releases. corepc-node is frozen at 0.12.0 (April 2026) - move to bitcoind 0.37.0+.

Shape differences to expect when porting:

• Responses are per-version types, not one universal struct. Add an into_model() hop, or read the v3x fields directly.
• into_model() is fallible - Core returns -1 in fields typed as numeric, and amounts have to survive the float round trip.
• Method coverage is deliberately exhaustive - every documented RPC since client 0.9.0 (September 2025), plus hidden ones added in client 0.11.0 (April 2026) - so missing-method workarounds can go.

Common pitfalls

• Shipping corepc-client in a production service. Upstream says not to and will not take bug reports for it.
• Mixing crate versions from different release waves. corepc-client 0.16.0 pins corepc-types 0.15.0 and bitcoind 0.41.0 pins corepc-client 0.16.0 - take one wave.
• Assuming bitcoind's default feature targets a modern node: the default is 0_17_2. Pass latest or an explicit version feature.
• download pulls a Core binary over the network at build time, which most sealed CI images will refuse. Pre-fetch and use BitcoinD::new(exe) there.
• Choosing the client module by guesswork. Read getnetworkinfo once at startup and fail fast if the node is not the major you compiled for.

See also

• rust-bitcoin/SKILL.md
• bdk/SKILL.md
• bitcoin-kernel/SKILL.md
• ../../core/rpc/SKILL.md