40 releases (major breaking)

29.0.0 Dec 18, 2025
28.0.1 Feb 4, 2026
28.0.0 Dec 8, 2025
27.0.0 Oct 3, 2025
0.0.0 Nov 21, 2022

#2 in #relay-chain

Download history 646/week @ 2025-10-15 538/week @ 2025-10-22 278/week @ 2025-10-29 584/week @ 2025-11-05 680/week @ 2025-11-12 606/week @ 2025-11-19 424/week @ 2025-11-26 343/week @ 2025-12-03 282/week @ 2025-12-10 370/week @ 2025-12-17 235/week @ 2025-12-24 341/week @ 2025-12-31 133/week @ 2026-01-07 330/week @ 2026-01-14 315/week @ 2026-01-21 339/week @ 2026-01-28

1,177 downloads per month
Used in 19 crates (2 directly)

GPL-3.0-only

15MB
251K SLoC

Rococo: v2.1

Rococo is a testnet runtime with no stability guarantees.

How to build rococo runtime

EpochDurationInBlocks parameter is configurable via ROCOCO_EPOCH_DURATION environment variable. To build wasm runtime blob with customized epoch duration the following command shall be executed:

ROCOCO_EPOCH_DURATION=10 ./polkadot/scripts/build-only-wasm.sh rococo-runtime /path/to/output/directory/

How to run rococo-local

The Cumulus Tutorial details building, starting, and testing rococo-local and parachains connecting to it.

How to register a parachain on the Rococo testnet

The parachain registration process on the public Rococo testnet is also outlined.

Dependencies

~31–54MB
~790K SLoC