Current mainnet EL — Osaka

Status: Ready for the public MCP (not launched). baselineForkId in the probe — today’s mainnet execution-layer rules.

This page tracks whatever fork mainnet EL is on right now. Today that is Osaka (Fusaka; aliases fusaka, mainnet-el). After Amsterdam activates on mainnet, this doc (and probe metadata) will switch to Amsterdam as current / baselineForkId, and the next preview fork moves under Preview forks.

Osaka today

ModExp repricing (7883), secp256r1 precompile (7951), and related Fusaka EL changes are active on mainnet. Predecessor in lineage: Prague (historical table). Preview successor: Amsterdam.

Activated EIP numbers are in the probe (namedForks[].activatedEips, eipIntroductions). PeerDAS and blob-sidecar behaviour are not fully observable in this lab.

Runnable FYP twins on Osaka

7883, 7951 — Coverage.

Compare

Goal	Run twice
One Osaka EIP vs before it existed	Prague → Osaka (from derived module comparison or eipIntroductions)
Upcoming fork vs mainnet today	Osaka → Amsterdam

What you can ask your agent

• “Run this under current mainnet EL (Osaka / mainnet-el).”
• “Compare ModExp gas: Prague then Osaka.”
• “Same transfer on Osaka vs Amsterdam.”

Pass { "baseHardfork": "osaka", "eips": [] } (or alias mainnet-el). Osaka is not the default lab fork — Amsterdam is.

Provenance on a generic Osaka run lists advertised modules 7883 and 7951 with eips: [].

Related

Preview (Amsterdam)	Default lab / upcoming
Historical forks	Paris → Prague
Fork timeline	External reference

Changelog

Current Mainnet Fork Changelog

1. v0.32026-09-16Doc framed as rotating mainnet section (Osaka now; updates when mainnet fork changes).
2. v0.22026-09-16Lineage and predecessor compare pattern.
3. v0.12026-09-16Named fork capability — generic Osaka runs.