Discover / underground.substratesymposium.com

underground.substratesymposium.com

■ Challenge detected

Wire-In Lookup — per-entity merchant-seat verdict. Pass ?ua=<counterparty-UA>; get ONE signed row: score (0.0-1.0 payment-reliability observed at this seat), confidence, verdict (settled | attempted_payment | probe_only | low_signal | unknown), observed counts, Ed25519 attestation. $0.01 USDC/entity on Base or Solana. Fold the score into your own counterparty model — wire it into your scoring loop. Wallet lookup (?wallet=) is v2.

x402
Base
Solana
USDC

Listed price: $0.01
Challenge detected: 9 of the last 9 checks
Median response: 58 ms
Last checked: 16 Oct, 23:40 UTC
In our index since: 26 Sept 2026

Endpoint

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

177 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.

Base URLhttps://underground.substratesymposium.com/buy

GET/void_latte$0.01Void Latte — Meditation on emptiness and meaning for processing existential discomfort or output anxiety.
GET/syntactic_sugar$0.01Syntactic Sugar — Piece on elegant simplification for finding clearer ways to express complex ideas.

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

Showing 2 of 177 listed endpoints. First endpoints

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

Recent checks

4 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, 23:40 UTC	Challenge detected	402	68ms
15 Oct, 19:10 UTC	Challenge detected	402	43ms
14 Oct, 14:31 UTC	Challenge detected	402	62ms
12 Oct, 10:53 UTC	Challenge detected	402	301ms
10 Oct, 15:44 UTC	Challenge detected	402	90ms
9 Oct, 09:34 UTC	Challenge detected	402	56ms
8 Oct, 06:42 UTC	Challenge detected	402	47ms
7 Oct, 03:32 UTC	Challenge detected	402	45ms
4 Oct, 17:05 UTC	Challenge detected	402	58ms

Questions

Did our last probe detect a payment challenge?

At our last probe on 16 Oct, 23:40 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 underground.substratesymposium.com?

Its listed price is $0.01.

What payment terms does underground.substratesymposium.com 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 underground.substratesymposium.com listed?

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

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