Discover / http-header-checker.underscoredone.com

HTTP Header Checker

■ Challenge detected

Sends a request to a web address you provide and reports back everything the server said in response: the status code, all the response headers, how many times it got redirected, and how long the whole thing took.

x402
Base
Solana
USDC

Listed price: $0.01
Challenge detected: 10 of the last 10 checks
Median response: 128 ms
Last checked: 17 Oct, 08:59 UTC
In our index since: 26 Sept 2026

Endpoint

curl -i https://http-header-checker.underscoredone.com/check
# 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://http-header-checker.underscoredone.com/check$0.01Sends a request to a web address you provide and reports back everything the server said in response: the status code, all the response headers, how many times it got redirected, and how long the whole thing took.

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/http-header-checker.underscoredone.com

Recent checks

30 Sept 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.17 Oct 2026

All 10 checks

When (UTC)	Result	HTTP	Response
17 Oct, 08:59 UTC	Challenge detected	402	224ms
16 Oct, 08:13 UTC	Challenge detected	402	129ms
14 Oct, 23:56 UTC	Challenge detected	402	127ms
13 Oct, 10:39 UTC	Challenge detected	402	223ms
11 Oct, 10:02 UTC	Challenge detected	402	100ms
9 Oct, 21:31 UTC	Challenge detected	402	95ms
8 Oct, 18:39 UTC	Challenge detected	402	202ms
7 Oct, 15:42 UTC	Challenge detected	402	135ms
6 Oct, 15:34 UTC	Challenge detected	402	118ms
30 Sept, 05:03 UTC	Challenge detected	402	73ms

Questions

Did our last probe detect a payment challenge?

At our last probe on 17 Oct, 08:59 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 HTTP Header Checker?

Its listed price is $0.01.

What payment terms does HTTP Header Checker advertise?

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

Where is HTTP Header Checker listed?

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

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