No-std usage among rust-lightning dependents #4314
Description
Summary
This issue tracks the usage of rust-lightning in no_std environments to help inform decisions about continued no_std support.
Rationale
Supporting no_std adds complexity to the development process. Notable pain points include:
- Time access: No access to system time, requiring alternative approaches
- Send/Sync requirements: Additional constraints on types and trait bounds
A recent example of no_std-related complexity: #4309
Is it worth supporting no_std?
To answer this question, we need visibility into who actually uses rust-lightning in no_std mode.
Methodology
Determining reverse dependencies for no_std specifically isn't straightforward—GitHub's dependency graph doesn't distinguish between feature configurations. I vibe-coded a tool to scan dependents and check their Cargo.toml files for default-features = false without std re-enabled:
https://github.com/joostjager/rust-lightning/tree/ldk-dep-scanner
Note: Not all items in the table below necessarily use no_std in an unavoidable way—some projects may work fine with std enabled but simply haven't changed their configuration.
Direct no_std dependents
The table below shows all direct dependents of rust-lightning that use it in no_std mode, sorted by stars:
| Repository | Stars | Last Updated | Cargo.toml |
|---|---|---|---|
| p2pderivatives/rust-dlc | 157 | 2025-12-13 | Cargo.toml |
| Blockstream/lwk | 93 | 2026-01-14 | Cargo.toml |
| BoltzExchange/boltz-client | 76 | 2026-01-13 | Cargo.toml |
| bennyhodl/dlcdevkit | 33 | 2026-01-08 | Cargo.toml |
| MutinyWallet/bitcoin-waila | 30 | 2025-09-01 | Cargo.toml |
| lightning-signer/validating-lightning-signer | 14 | 2026-01-07 | Cargo.toml |
| rust-bitcoin/bitcoin-payment-instructions | 10 | 2026-01-07 | Cargo.toml |
| akitamiabtc/yuv-lightning | 5 | 2025-09-21 | Cargo.toml |
| BoltzExchange/bolt12-wasm | 4 | 2026-01-08 | Cargo.toml |
| lightning-signer/vls | 1 | 2025-10-17 | Cargo.toml |
| benthecarman/rust-dlc | 1 | 2023-12-13 | Cargo.toml |
| TheBlueMatt/libbtcwallet | 0 | 2025-03-26 | Cargo.toml |
| TheBlueMatt/ln-routing-replay | 0 | 2025-05-12 | Cargo.toml |
| fedibtc/fedimint | 0 | 2024-07-24 | Cargo.toml |