Discover / kevinhoff.com

x-preflight

■ Challenge detected

X Preflight: read a draft post against X's open-sourced ranking code. Returns what is already settled before you post, whether it enters the pool strangers are drawn from, how long it stays retrievable, which filters delete it, and which gates nobody can know in advance. Every claim cites a file and line in X's published source. Never writes the post. Nothing stored.

x402
Base
USDC

Listed price: $0.01
Challenge detected: 9 of the last 9 checks
Median response: 311 ms
Last checked: 16 Oct, 18:49 UTC
In our index since: 26 Sept 2026

Endpoint

curl -i https://kevinhoff.com/api/paid/grade
# 402 Payment Required: pay with an x402 client (USDC on Base),
# then send the same request again with the payment attached.

1 listed endpoints · on x402 Bazaar

Checks and payment terms on this page refer to the endpoint above. Other listed endpoints have not been checked individually.

POSThttps://kevinhoff.com/api/paid/grade$0.01X Preflight: read a draft post against X's open-sourced ranking code. Returns what is already settled before you post, whether it enters the pool strangers are drawn from, how long it stays retrievable, which filters delete it, and which gates nobody can know in advance. Every claim cites a file and line in X's published source. Never writes the post. Nothing stored.

A dash means the listing gives no price or method. Copy buttons copy the full URL.

Showing 1 of 1 listed endpoints.

Agents can find it through the Superstables MCP server and JSON API: GET /api/v1/services/kevinhoff.com

Recent checks

2 Oct 2026One bar per check, showing up to 20 recent checks. Coloured bars show relative response time, with a minimum visible height; full-height grey bars mean no challenge was detected. “Challenge detected” means HTTP 402 or another detected payment-challenge signal.16 Oct 2026

All 9 checks

When (UTC)	Result	HTTP	Response
16 Oct, 18:49 UTC	Challenge detected	402	311ms
15 Oct, 11:37 UTC	Challenge detected	402	813ms
14 Oct, 00:19 UTC	Challenge detected	402	282ms
12 Oct, 00:34 UTC	Challenge detected	402	438ms
10 Oct, 10:04 UTC	Challenge detected	402	243ms
9 Oct, 03:33 UTC	Challenge detected	402	353ms
8 Oct, 00:44 UTC	Challenge detected	402	216ms
6 Oct, 21:30 UTC	Challenge detected	402	366ms
2 Oct, 05:04 UTC	Challenge detected	402	300ms

Questions

Did our last probe detect a payment challenge?

At our last probe on 16 Oct, 18:49 UTC, it returned HTTP 402 or another detected payment-challenge signal. This check did not test payment, delivery or compatibility with the Superstables client.

What price is recorded for x-preflight?

Its listed price is $0.01.

What payment terms does x-preflight advertise?

The listing advertises x402, Base and USDC. It names cdp as its facilitator. Check the seller's current payment challenge and authentication requirements before paying.

Where is x-preflight listed?

In x402 Bazaar. Superstables first indexed it on 26 Sept 2026.

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