EIP 7702, EIP-7691, and x402: How Pectra and Beyond Shape Rollup Design

Ethereum’s May 7, 2025 Pectra upgrade changed what’s possible for rollups and wallets in very practical ways: EIP‑7691 doubled target blob throughput and retuned blob fee dynamics, while EIP‑7702 made “smart EOAs” real. Add the emerging x402 “HTTP 402 payments” standard and you’ve got a clear blueprint for cheaper L2 DA, programmable wallets, and machine‑to‑machine monetization. (blog.ethereum.org)

Who this is for

Decision‑makers at startups and enterprises evaluating whether to build on Ethereum L2s (or run their own rollup) and how to design wallet, billing, and data‑publishing pipelines after Pectra.

What actually shipped in Pectra (and why it matters to rollups)

EIP‑7691 raised the blob target from 3 to 6 per block and the max from 6 to 9, and adjusted the blob base‑fee sensitivity via a new update fraction. Result: more blobspace, faster price decay when demand is under target, and smoother peaks when demand spikes. (eips.ethereum.org)
EIP‑7702 introduced a new type‑4 transaction so EOAs can set contract code via signed authorizations, effectively delegating execution to audited wallet logic. This unlocks batching, sponsored gas, and granular permissions while keeping a user’s address. (eips.ethereum.org)
EIP‑7623 increased calldata floor pricing for data‑heavy transactions to reduce worst‑case block size and nudge DA to blobs, stabilizing network bandwidth as blobs scale up. (eips.ethereum.org)
EIP‑7840 standardized a “blobSchedule” in client configs so software can track per‑fork blob parameters (Cancun vs Prague) without brittle Engine API handshakes—useful for fee estimation and simulations. (eip.info)

Ethereum activated Pectra on mainnet at epoch 364032 on May 7, 2025; planning and operations should reference that date for any before/after comparisons. (blog.ethereum.org)

Quantifying your new DA budget after EIP‑7691

Blobs are 4096 field elements at 32 bytes each → 131,072 bytes (128 KiB). Pectra’s new target/max (6/9 blobs) translates to:

Target capacity ≈ 6 blobs × 128 KiB × ~7,200 blocks/day ≈ 5.27 GiB/day
Max capacity ≈ 9 blobs × 128 KiB × ~7,200 blocks/day ≈ 7.91 GiB/day

This is a straight derivation from EIP‑4844 and EIP‑7691 parameters, and is the baseline for rollup DA planning. (eips.ethereum.org)

Two knock‑on effects you should model:

Asymmetric fee dynamics: under 6‑blob target, blob base‑fee falls faster than it rises above target (≈‑14.5%/block vs ≈+8.2%/block in the reference configuration), which lowers average costs and smooths spikes. Your guardrails for max_fee_per_blob_gas should be widened upward less aggressively than pre‑Pectra while lowering tripwires for opportunistic posting during lulls. (eips.ethereum.org)
Calldata is a worse fallback: with EIP‑7623’s higher floor for data‑heavy txs, it’s harder for calldata to beat blobs on a per‑byte basis except during extreme blob surges. Budget your “fall back to calldata” policy only for rare spike windows. (eips.ethereum.org)

Implementation detail: expose Pectra’s blob parameters via your fee estimator and simulations by reading the per‑fork blobSchedule (target, max, update fraction) instead of hardcoding values, to remain future‑proof. (eip.info)

EIP‑7702 in practice: from EOAs to programmable wallets (without new addresses)

EIP‑7702 lets EOAs “set code” using an authorization list of tuples [chain_id, address, nonce, y_parity, r, s]; clients write a delegation indicator (0xef0100 || address) to the account’s code so execution resolves to that contract until changed again. It’s compatible with ERC‑4337 flows and can coexist with bundlers and paymasters. (eips.ethereum.org)

Security gotchas you must handle (all called out in the spec):

Initialization front‑running: you don’t get initcode execution during delegation; ensure the first‑time setup calldata is signed by the EOA (ecrecover) so nobody can initialize your storage with malicious values. (eips.ethereum.org)
Storage migrations: when rotating delegates, prevent storage collisions between old/new implementations; adopt namespaced storage like ERC‑7201 patterns in your delegate contracts. (eips.ethereum.org)
Sponsored relays: a user can invalidate or drain assets after you prepay; require bonds or reputation if you run a relayer. (eips.ethereum.org)

Developer‑level integration is getting simpler. MetaMask’s Smart Accounts Kit ships quickstarts to authorize 7702 delegation and request advanced ERC‑7715 permissions (e.g., “10 USDC/day for 30 days”) with built‑in session accounts—handy for subscriptions and agent workflows. (docs.metamask.io)

Why this matters to a rollup: you can standardize user UX around one canonical address, enable sponsored/gasless flows at the L2, and still bundle/route via ERC‑4337 where it makes sense. This reduces address churn, simplifies KYC/CRM mapping, and makes AI/agent‑driven commerce feasible without custom wallet forks. (ethereum.org)

x402, not “EIP‑402”: the HTTP 402 payments layer for agents and APIs

There is no Ethereum “EIP‑402.” The relevant standard is x402, which turns the long‑reserved HTTP 402 Payment Required status into an on‑chain payment handshake—clients request a resource; servers reply 402 with payment requirements; clients pay and retry with a payment proof in headers; servers verify locally or via a facilitator and return 200. x402 V2 adds wallet‑based identity, multi‑chain CAIP identifiers, and standardized headers. (docs.cdp.coinbase.com)

Key pieces you can deploy now:

Headers and flow: server returns 402 with PAYMENT‑REQUIRED details; client retries with PAYMENT‑SIGNATURE; server replies 200 with PAYMENT‑RESPONSE after verification/settlement (often via a facilitator’s /verify, /settle endpoints). (docs.cdp.coinbase.com)
Chain‑agnostic design: CAIP‑2 network IDs (e.g., eip155:8453 for Base) in the payment payloads let you accept USDC on L2s your users already use. (docs.cdp.coinbase.com)
V2 improvements: reusable sessions, dynamic recipients, and extensible schemes make it viable for AI agents hitting high‑QPS endpoints without “pay per call” friction. (x402.org)

x402 pairs cleanly with EIP‑7702: grant a session permission (ERC‑7715) on a user’s EOA‑addressed account, sponsor gas where needed, and let agents pay per request via HTTP—with on‑chain settlement your finance team can reconcile. (docs.metamask.io)

A practical L2 architecture after Pectra

Here’s a design that we’ve seen work well for post‑Pectra conditions.

Blob‑first DA pipeline with adaptive batching

Target a blob “fill” of 70–90% to amortize per‑blob overhead while avoiding fragmentation. Keep two lanes:
- Fast lane (latency‑sensitive): post every N seconds or when buffer hits 0.7 blob; pays a small premium for UX.
- Bulk lane (throughput‑optimized): post when 0.9–1.0 blob or when time cap elapses.
Re‑tune guardrails: widen your acceptable blob base‑fee band upward more slowly (spikes rise ≈8.2%/block at full usage) and lower “post aggressively” thresholds during lulls (fees decay ≈14.5%/block when below target). Automate bids from historical demand. (eips.ethereum.org)
Use EIP‑7840 blobSchedule to drive sim/ops configs; avoid hard‑coding 3/6 vs 6/9. (eip.info)

Fallback logic without surprises

Calldata fallback should be reserved for rare spike windows; pre‑compute break‑even curves for your compression ratio and include the EIP‑7623 floor in gas estimates. Consider multi‑DA (Celestia/EigenDA/DAC) only if your threat model tolerates it. (eips.ethereum.org)

Sequencer/Batcher settings (Nitro‑style example)

Lower max posting delay for the “fast lane” to 5–15 minutes; keep a larger cap (30–60 minutes) for bulk lane to maximize compression. This reduces reorder risk and reorg exposure without spamming tiny batches. (docs.arbitrum.io)
Enable EIP‑4844 blob posting (ArbOS ≥ 20; verify presence of ExcessBlobGas/BlobGasUsed in parent headers). (docs.arbitrum.io)

Wallet and payments

Adopt EIP‑7702 delegates that use namespaced storage to allow safe upgrades (ERC‑7201‑style layout). For recurring charges, request ERC‑7715 permissions and run a paymaster for sponsored gas where needed. Tie x402 into your API gateway to let agents and users pay per call over HTTP. (eips.ethereum.org)

Metrics you should watch weekly

Blob “fill” distribution, base‑fee time‑to‑double/halve, average MiB/tx batch vs compression ratio, calldata fallback count and cost deltas, settlement latency and reorg windows, and x402 authorization→verification success rates.

Worked example: designing a blob budget and fallback

Assume:

Average batch after compression = 0.78 blobs (≈100 KiB ops + headers)
Target SLA: ≤ 10 minutes to “finalize” DA on L1
Blob base‑fee today = B; your max bid = 2.5B; you’ll post if fee ≤ 2.0B

Policy:

Fast lane posts at 0.7 blobs or 8 minutes, whichever comes first
Bulk lane posts at 0.95 blobs or 30 minutes

What happens during a spike?

With a 2:3 target:max and the update fraction from EIP‑7691, two consecutive full blocks increase blob base‑fee by roughly 1.082² ≈ 1.17×; your 2.0B trigger still hits reliably across a short spike—no thrash between lanes. If blocks go empty post‑surge, base‑fee decays ≈0.855 per block; within 5–7 blocks you’re back near baseline and can flush bulk lane cheaply. (eips.ethereum.org)

What if blobs surge above your cap?

You switch to calldata only if the all‑in per‑MiB cost (including EIP‑7623 floor) beats your 2.5B max. That will be rare; simulate with your actual compression and per‑byte costs before enabling automatic fallback. (eips.ethereum.org)

Account abstraction decisions in 2026: “smart EOA,” ERC‑4337, or both?

“Smart EOA” via 7702: best when you need the same canonical address, minimal infra, and straightforward permissions/sponsorship. Use audited delegate code and keep upgrades simple. (eips.ethereum.org)
ERC‑4337: needed for complex multi‑tenant flows, custom validation, or when you want to lean on existing bundler/paymaster ecosystems. EntryPoint v0.8 is current across most providers. (eip.info)
Hybrid: 7702 delegates that point to ERC‑4337 wallet code let you share modules and paymasters across both worlds—smooth migrations and less duplicated UX. (eips.ethereum.org)

Emerging standardization around modular smart accounts (ERC‑7579) makes your modules—validators, hooks, passkeys—portable across stacks. Favor wallets and delegates aligning with 7579 to reduce future lock‑in. (eips.ethereum.org)

Near‑term roadmap: PeerDAS and “BPO” forks

Pectra is not the ceiling. PeerDAS (EIP‑7594) enables data‑availability sampling so not every node must download every blob; EF’s “Fusaka” upgrade (scheduled Dec 3, 2025) introduces Blob Parameter Only forks—config‑only changes that raise blob targets safely after PeerDAS. Expect further blob increases and more stable fees; design your estimators and dashboards to ingest new blobSchedule entries automatically. (eips-wg.github.io)

How x402 changes your go‑to‑market

Price your API per call in USDC on an L2 your users already hold; advertise via PAYMENT‑REQUIRED, verify via a facilitator, and return PAYMENT‑RESPONSE on success. This replaces API keys, accounts, and card processors for usage‑based endpoints while remaining HTTP‑native. (docs.cdp.coinbase.com)
Combine with 7702 + ERC‑7715 to enable “set‑and‑forget” subscriptions and agent budgets with human‑visible limits (e.g., $10/day), payable on L2s and settled on‑chain without custom relayers. (docs.metamask.io)
x402 V2’s wallet‑based identity and sessions remove the need to repay on every request—latency and costs drop for high‑frequency AI workloads. (x402.org)

Implementation checklist (30/60/90 days)

30 days
- Enable blob posting if not already; verify ArbOS/parent chain compatibility; set dual‑lane batcher timers/thresholds. (docs.arbitrum.io)
- Update estimators and dashboards to read blobSchedule and log blob base‑fee elasticity metrics. (eip.info)
60 days
- Ship a 7702 delegate with namespaced storage, audits, and a rollback plan; pilot sponsored flows for key journeys (onboarding, swaps). (eips.ethereum.org)
- Add an x402 pilot endpoint with USDC on Base/your L2; instrument verification/settlement latencies. (docs.cdp.coinbase.com)
90 days
- Roll out ERC‑7715 permissions for subscriptions/agents; set org‑wide limits and abuse detection. (docs.metamask.io)
- Simulate PeerDAS‑era capacity and cost envelopes; pre‑approve thresholds for BPO forks so you can move fast when blob targets rise. (eips-wg.github.io)

The bottom line

Pectra’s EIP‑7691 gives your rollup more DA headroom today and a gentler, more forgiving blob fee curve—take advantage with blob‑first batching and smarter triggers. (eips.ethereum.org)
EIP‑7702 makes “smart EOAs” real, so you can deliver gasless UX, subscriptions, and agent‑driven transactions without forcing new addresses. Design your delegates like you’d design a wallet: namespaced storage, explicit initialization, upgrade playbooks. (eips.ethereum.org)
x402 turns HTTP itself into your payments rail—pair it with 7702/4337 and stablecoins on L2 to monetize APIs and agent usage with minimal friction. (docs.cdp.coinbase.com)

If you align your rollup pipeline, wallet stack, and billing around these shifts, you’ll ship cheaper transactions, cleaner UX, and a business model that scales with the next wave of agentic and enterprise‑grade use cases.

References and specs worth bookmarking

Pectra mainnet announcement; blob scaling and dates. (blog.ethereum.org)
EIP‑7691: blob throughput increase and fee sensitivity. (eips.ethereum.org)
EIP‑7702: set code for EOAs; security considerations. (eips.ethereum.org)
EIP‑7623: calldata floor pricing. (eips.ethereum.org)
EIP‑7840: blobSchedule in client config. (eip.info)
EIP‑4844: blob size and fee mechanics. (eips.ethereum.org)
PeerDAS and Fusaka/BPO previews. (eips-wg.github.io)
Arbitrum batcher/DA docs for concrete settings. (docs.arbitrum.io)
MetaMask Smart Accounts Kit and ERC‑7715 permissions. (docs.metamask.io)
x402 docs and V2 updates. (docs.cdp.coinbase.com)