Agent Exchange x402 census and directory

x402 census · api.particle.pro · b3744facab24 · JSON

GET /v1/topics

live

List topics. Returns the hierarchical topic taxonomy.

Verdict: live. The unpaid GET reached a valid 402 (confirmed by the re-probe of 2026-10-01).

Facts from the catalogs

FieldValue
URLhttps://api.particle.pro/v1/topics
MethodGET
Price$0.01 USDC = 10000 atomic units of 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
Networkeip155:8453 (base)
payTo0x59f3a6dcb6f482c53872dd8f8f9e1f9161a1c5f7
Sellerapi.particle.pro
Catalogscdp (row updated 2026-09-28)
Listed since (lower bound)2026-09-28 (earliest catalog timestamp; catalogs report last-update times only)
Last catalog update2026-09-28
CDP quality counters3 calls and 3 unique payers in 30 days, last call 2026-09-28 (catalog-reported, not verified on chain)
Category (keyword rule)other/unknown
Templated pathno
x402Version in catalog2
Service name / tagsParticle Pro · topics, podcasts, media intelligence, particle pro

Unpaid probe (census of )

FieldValue
Probenot probed in this build

Latest re-probe

FieldValue
Re-probed at2026-10-01T01:13:18.000Z (cron)
Verdict nowlive changed from unprobed
HEAD / GET405 / 402
accepts[0]{"scheme":"exact","network":"eip155:8453","amount":"10000","payTo":"0x59f3a6dcb6f482c53872dd8f8f9e1f9161a1c5f7","asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","maxTimeoutSeconds":300,"extra":{"name":"USD Coin","version":"2"}}
Live amount equals catalog priceyes
Latency1,562 ms
Errornone

On-chain facts for the payTo (public address)

FieldValue
Distinct payers3
Payments21
USDC volume$0.47
Median payment$0.01
First / last payment2026-09-10 / 2026-09-30
Sampler-shaped share of payments100.0%
Payers that are not samplers0
Sourceforensics-2026-09-30
Address0x59f3a6dcb6f482c53872dd8f8f9e1f9161a1c5f7

Declared input and output (extensions.bazaar)

{
 "input": {
  "method": "GET",
  "type": "http"
 }
}

Try it (unpaid: shows the 402)

curl -si -X GET 'https://api.particle.pro/v1/topics' -H 'accept: application/json'

The catalog declares GET. A 402 answer carries the payment requirements in the JSON body and, for x402 v2, base64 in the PAYMENT-REQUIRED header. This page never sends a payment.

Paid checks (x402, USDC on Base)

GET https://bazaar.agentexchange.work/r/b3744facab24/probe.json re-runs this probe right now for $0.01 and writes the result here. POST https://bazaar.agentexchange.work/featured with {"id":"b3744facab24"} places this resource at the top of the report and search pages for 30 days for $1.00, labelled. Unpaid requests answer 402 with the terms. Pricing.

Catalog references: agentic.market (CDP Bazaar front end) · this record as JSON · all resources on api.particle.pro.