Breaking down: "How long do x402 payments take to finalize?"

Identified 2 research target(s) to investigate; these are not established facts

Deep mode: up to 4 paid/cached reads plus one bounded gap-expansion pass when needed.

Discovered 21 verified source(s)

Recalled 60 past runs on this subject — how these sources performed when they were available.

ERC-8004 reputation loaded — composite scores on this subject.

Claim-aware portfolio selected 3/4 positive proposal(s): 3 cached + 0 fresh, predicting 2/2 claim(s) above the evidence floor with $0.000000/$0.020000 fetch USDC reserved.

Free-preview pre-check maps an actionable source to every sub-claim (2/2); paid reading may proceed within the budget.

Agent spend wallet ready: 0x29028Fe1122E17Fe7863A22701e863FE4DaE1aFB (balance sufficient)

Reused cached Arc Settlement Benchmarks — Measuring x402 settlement latency on Arc (free) — S1

Reused cached Agent Economy Weekly — x402 turns HTTP 402 into an agent payment rail (free) — S2

Reused cached Web Payments Review — How long do x402 payments take to finalize? (free) — S3

Sub-claim "What are x402 payments in the context of Keryx, and how are …": 40% covered by S2 — S2 defines x402 generally as reviving HTTP 402 as a payment rail where a server responds 402 with machine-readable payment requirements and the client signs a payment authorization and retries, enabling agents to pay per request without accounts or API keys. However, it does not tie x402 specifically to Keryx, nor explain Keryx's definition or use of x402 payments. The Keryx-specific framing is missing.

Sub-claim "What is the time required for x402 payments to finalize, bas…": 60% covered by S1, S3 — S1 gives a direct timing figure: x402 batched settlements on Arc testnet finalize in roughly 180 ms (median 178ms, p95 240ms), sub-second via Arc BFT consensus and Gateway batching. S3 gives a conflicting figure of about 15 seconds, similar to Ethereum L1 block time. Both are present, but they conflict and neither is tied to Keryx specifically; the question asks for x402 payment finalization time generally, so the timing is partially answered but with unresolved divergence and no Keryx-specific specification.

The core timing question is addressed by S1 (180ms on Arc) and S3 (15s), though they conflict. The Keryx-specific definition/use of x402 is only partially covered by S2's general x402 description. No skipped source clearly fills the Keryx-specific gap: the Keryx Engineering first-party source concerns recovering a paid research job and quoting/journaling, not x402 definition or finalization timing. Other skipped sources are unrelated (gardening, retro hardware, solo founding, etc.). Given the low remaining budget and lack of clearly relevant affordable sources, no purchase is recommended.

Final check — "What are x402 payments in the context of Keryx, and how are …": 80% assessed by S2

Final check — "What is the time required for x402 payments to finalize, bas…": 90% assessed by S1, S3

Final coverage assessment — S2 defines x402 payments as a payment rail reviving HTTP 402, where a server returns payment requirements and the client signs a payment authorization and retries, enabling per-request agent payments without accounts or API keys. S1 directly answers finalization time: x402 batched settlements on Arc finalize in roughly 180 ms median (178 ms median, p95 240 ms), sub-second finality. S3 gives a conflicting ~15 second Ethereum L1-like settlement estimate. The requested finalization-time question is directly answered by S1, with S3 providing an alternative estimate. No requested part remains missing.

Synthesizing a grounded answer from 3 source(s)…

Relevance review returned; only checked excerpts can retain support, and review cannot raise it.

⚖️ Sources disagreed on Time required for x402 payments to finalize/settle — S1 x402 batched settlements on Arc testnet finalize in roughly 180 ms (median 178ms, p95 240ms); Gateway-batched payments confirm in well under a quarter second and are not block-time-bound. vs S3 An x402 payment takes about 15 seconds to settle, similar to Ethereum L1 block time, because each payment is its own transaction waiting to be mined. → reported preference: S1 (S1 reports measured empirical benchmarks (median and p95 across thousands of submitBatch calls) and is internally consistent about the Gateway-batching mechanism on Arc's BFT consensus, whereas S3 presents a stated "reading" that assumes a per-transaction L1 mining model S1 explicitly says does not apply.)

Below reward gate — S2 supports claim 1 at 10%: “x402 revives the dormant HTTP 402 'Payment Required' status as a real payment rail.”

Verified — S2 supports claim 1 at 60%: “A server responds 402 with machine-readable payment requirements; the client signs a payment authorization and retries.”

Verified — S1 supports claim 2 at 95%: “Across thousands of submitBatch calls on Arc testnet, x402 batched settlements finalize in roughly 180 milliseconds (measured median 178ms, …”

Verified — S1 supports claim 2 at 90%: “Arc's BFT consensus delivers sub-second finality, so a Gateway-batched payment confirms in well under a quarter second — it is not block-tim…”

Verified — S3 supports claim 2 at 90%: “In our reading, an x402 payment takes about 15 seconds to settle, similar to an Ethereum L1 block time, because each payment is its own tran…”

Drafted answer citing 3 source(s)

Confidence: Moderate — source preferences are explained, but conflicting evidence limits confidence.

Arc Settlement Benchmarks contributed 60% → reward $0.012

Agent Economy Weekly contributed 15% → reward $0.003

Web Payments Review contributed 25% → reward $0.005

Settled $0.012 citation reward → Arc Settlement Benchmarks (cc65e360-2…)

Settled $0.003 citation reward → Agent Economy Weekly (3e45500c-a…)

Settled $0.005 citation reward → Web Payments Review (189b1d0b-c…)

Done. Spent $0.02 across 3 confirmed/simulated payment(s) to creators.