Historical forks (Berlin → Prague)

Status: Ready for the public MCP (not launched). One catalogue page for past execution-layer hardforks.

Why this page exists

The probe exposes the Berlin→Amsterdam lineage so agents can answer “when did this EIP appear?” and run predecessor compares. Human docs use three buckets:

Bucket	Doc page	Probe role
Preview / upcoming	Amsterdam (later e.g. Hegota)	preview
Current mainnet EL	Osaka	current
History	This page (Berlin → Prague)	historical

Historical forks are generic run targets: { "baseHardfork": "<id>", "eips": [] } on the three run tools. Use eipIntroductions from Describe Capabilities for facts and compare pairs.

Not in the catalogue: difficulty-bomb delay forks (Arrow Glacier, Gray Glacier, Muir Glacier, …) and blob-parameter-only upgrades — the lineage jumps Berlin → London → Paris on mainnet.

Compare pattern

1. Look up the EIP or keyword in eipIntroductions.
2. Note introducedAt.
3. Run the same verb on predecessorFork(introducedAt) and on introducedAt.

Examples:

• EIP-1559 → london → compare berlin then london on the same Run transaction (fee market / paid gasUsed).
• PUSH0 (3855) → shanghai → compare paris then shanghai (0x5f00 on bytecode).
• ModExp repricing (7883) → osaka → compare prague then osaka (EIP-7883).

Lineage table (historical rows)

Order	baseHardfork	Aliases	Notable activations (full lists in probe)
0	berlin	—	2565 ModExp, 2718 typed txs, 2929 cold/warm gas, 2930 access lists
1	london	—	1559 fee market, 3198 BASEFEE, 3529 refunds, 3541 initcode prefix
2	paris	merge, the-merge	3675 Merge (not replayable here), 4399 PREVRANDAO
3	shanghai	shapella	3855 PUSH0, 3860 initcode, 4895 withdrawals (limited in lab)
4	cancun	dencun	1153 transient storage, 5656 MCOPY, 4844 blobs (no blob txs in lab)
5	prague	pectra	7702 set-code, 2537 BLS precompiles, 7623 calldata

Floor: Berlin — Istanbul and earlier hardforks are out of scope for this MCP round.

Honesty

The lab does not replay Merge consensus, beacon withdrawals, blob sidecars, or PeerDAS. Those EIPs still appear in eipIntroductions with honest summaries.

What you can ask your agent

• “Compare the same transfer on Berlin vs London — when did 1559 activate?”
• “Run BASEFEE opcode bytecode on London vs Berlin.”
• “When did PUSH0 activate — Paris vs Shanghai?”

Changelog

Historical Forks Catalogue Changelog

1. v0.22026-09-16Berlin and London added to lineage floor; glacier delay forks excluded from catalog.
2. v0.12026-09-16Combined historical doc; preview / mainnet / history trio.