Check an x402 endpoint before you pay it: verdict, risk score and what is wrong. $0.005 in USDC.
io.github.plus8bit/deadchannel (MCP) Server
The io.github.plus8bit/deadchannel MCP server checks whether an x402 endpoint is alive before it is called. It returns a verdict, a risk score, and what is wrong, for use in agentic payment flows. The service is paid per call in USDC at a price of $0.005.
🛠️ Key Features
x402 endpoint health checks
Verdict on whether the endpoint is alive
Risk score and diagnostic output (“what is wrong”)
Per-call pricing in USDC ($0.005)
🚀 Use Cases
Preflight verification before paying an x402 endpoint
Agent decision-making to avoid unsafe or incorrect endpoint calls
⚡ Developer Benefits
No signup, API key, or subscription required; an agent calls, pays, and receives an answer
Fits TypeScript-based agent tooling via MCP
⚠️ Limitations
Described functionality is focused on endpoint liveness and safety (“alive, honestly priced and safe to call”)
Pricing information provided only for deadchannel ($0.005) and does not include other services
Two services that sell to AI agents over x402, paid per call
in USDC. No signup, no API key, no subscription — an agent calls, pays, and gets
an answer.
what it sells
price
Hosaka
which third-party vendors a company uses, proven from its own DNS, plus contacts
$0.005 – $0.40
deadchannel
whether an x402 endpoint is alive, honestly priced and safe to call
$0.005
Agents can install Hosaka as a skill, which tells them what it is for and when
to reach for it:
HOSAKA_PRIVATE_KEY is a wallet holding a little USDC on Base. Four tools at
four prices, so a cheap question never pays for an expensive answer:
tool
price
what you get
hosaka_lookup
$0.005
domain age, registrar, mail and DNS provider, DMARC, HTTPS, vendor count
hosaka_contacts
$0.02
the dossier, plus the emails and phones the company publishes about itself
hosaka_dossier
$0.02
every third-party vendor the company can be proven to use, each with its proof
hosaka_people
$0.35
the dossier, plus named people who work there
Why the dossier is worth having. A company proves it owns its domain to
every SaaS product it buys by placing a DNS verification record, and authorises
every sender it uses in its SPF record. Those two lists are a purchase history
the company published itself.
Asking for figma.com returns Anthropic, OpenAI, Adobe, Atlassian, MongoDB
Atlas, Greenhouse, Docusign, Stripe, Notion, Dropbox and Zendesk — each with the
exact record that proves it, so a buyer can check rather than trust.
Page fingerprints require a loaded script or CDN host, never a mention: a site
listing a vendor's logo among its integrations is not a site that uses it.
Give it a URL, it tells an agent whether that endpoint is alive, honestly priced,
and safe to call — without spending a cent.
Roughly 17% of probed x402 endpoints are dead or traps, and the Bazaar discovery
layer ships no ranking, quality, or reputation signal by its own admission. An
agent picking from that catalog is guessing with real money.
What it checks
Every verdict comes from unpaid 402 responses, which is what makes it cheap
enough to run across a whole catalog.
Signal
What it catches
reachable
Endpoint answers at all, consistently
bot-gate
A bot wall answers agents while browsers get a clean 402 — the endpoint is invisible to indexers
speaks-402
Returns parseable payment requirements (v1 body and v2 payment-required header)
gate-closed
Advertises a price it does not enforce — anyone can take the content free
price-sane
Price sits inside $0.0001–$5; above the ceiling one call can drain a budget
price-stable
Quote does not move between probes taken seconds apart
pay-to-valid
Payout address is well formed for its chain and is not a burn address
network-mainnet
Settles somewhere that can hold real value, not testnet only
network-known
Chain identifier is recognizable (CAIP-2 or friendly name)
schema-advertised
Agent can know the response shape before paying
bazaar-metadata
Publishes serviceName / tags so topic search can find it
latency
p99 inside the 5s budget agents typically allow
spec-clean
Payload matches the documented shape; deviations are reported, not swallowed
Verdicts: live, degraded, trap, testnet, dead, unknown, plus a
bounded 0–100 risk score.
Use
Requires Node 22+. There are no runtime dependencies — types are stripped
natively, so there is no build step and nothing to audit but this repo.
Exit code is non-zero when any target is a trap or dead, so it drops into CI
as a guard against shipping an agent pointed at a bad endpoint.
code
TESTNET risk 80 $0.01 355ms p99 https://x402.org/protected
x network-mainnet Only testnet networks offered (base-sepolia, solana-devnet).
This endpoint cannot accept real value.
! schema-advertised No input or output schema. An agent has to pay before it
can find out what it gets back.
First full catalog scan — 20 Aug 2026
node src/scan.ts --live 150 pulls every resource the public Bazaar facilitators
publish and audits it. Results over 14,979 resources:
catalog held by the top 3 payout addresses
18.4%, receiving 1 call in 80
publish no discovery tags
40.9% — an agent searching by topic never finds them
pass every check
56.8%
of the 150 busiest, live right now
91.3%
of the busiest, genuinely dead
2.0%
Median price $0.01, range $0 to $1,000, 316,927 paid calls in 30 days.
The catalog is in better shape than the folklore suggests. What it is not is
evenly distributed: three addresses list 2,750 resources between them and receive
one call in eighty, which makes them roughly 15x over-represented relative to the
demand they serve. Catalog size is not catalog depth.
catalog audit
A correction, and the guard against repeating it
An earlier version of this table claimed 89.8% of the catalog published no tags.
That was wrong. The loader read extensions.bazaar.tags only, while most
publishers put tags on the item root — the real figure is 40.9%.
The bug survived review because nothing asserted the positive count. A check
that only ever counts what is missing cannot tell "publishers omit this" apart
from "we are looking in the wrong place." test/catalog.test.ts now hand-counts
tags across all three known locations in a captured 200-item slice of the live
catalog and asserts the loader matches exactly, in both directions.
Notes from the wild
Built against live endpoints, not the spec alone:
v2 moves payment requirements into a base64 payment-required header and
leaves the body as {}. A parser that only reads the body marks the official
reference endpoint as dead.
v2 sends CAIP-2 network ids (eip155:84532, solana:EtWTRA…) where v1 sent
friendly names. Both are live simultaneously.
v2 renames maxAmountRequired to amount and hoists shared resource
metadata to the payload root.
Several servers omit the top-level x402Version the reference implementations
all send, and some nest accepts[] one level deeper than documented. Both are
parsed and reported as warnings rather than rejected.
Most resources are POST. Probing them with GET returns 404/405, which looks
exactly like a dead endpoint — it put our first live-probe dead rate at 25%
when the real figure is 2.7%. The verb comes from the catalog now, with a POST
retry when it is unknown. Any x402 index reporting a high dead rate is worth
checking for this.
Discovery metadata is scattered. The spec puts serviceName/tags on the
ResourceInfo object, the CDP catalog flattens them onto the item root, and a
minority nest them under extensions.bazaar. Read one location and you will
undercount by half.
Brokered rails exist. AWS Marketplace resources name the payee with a URN
under an aws:base network instead of a chain address. That is legitimate, but
the funds go to the broker, so it is reported as a warning rather than scored
as an invalid payout.
Selling
The service sells its own check over x402. src/server/ implements the seller
side of the v2 HTTP transport: PAYMENT-REQUIRED out, PAYMENT-SIGNATURE in,
PAYMENT-RESPONSE back, in the authorization flow — verify, run the resource,
then settle.
No private key is involved. A seller declares where settlement should land;
the buyer signs and the facilitator broadcasts. The payout address is therefore
public information and lives in deadchannel.config.json, where anyone can
audit it, rather than in a dashboard where nobody can.
Settlement runs only after the probe produced a result, so a failure on our side
costs the buyer nothing.
code
GET / service card, free
GET /health liveness, free
GET /facilitator proves credentials are accepted, free, moves no money
POST /probe the check, $0.005 in USDC on Base
GET /facilitator exists because a wrong credential otherwise stays invisible
until someone tries to pay, and the first to discover it would be a customer.
Live
The service is deployed at https://deadchannel.vercel.app, selling on Base
mainnet at $0.005 per call and settling through the Coinbase facilitator.
First settled payment: 0x6ac4a22c,
block 50230005, 20 Aug 2026. Gas was paid by the facilitator, not the buyer —
in x402 the buyer only signs, so a wallet holding nothing but USDC can pay.
npm run validate re-runs the 25 preflight checks the Bazaar applies before it
will index a resource, and reports whether the listing is currently active. It
needs no key and moves no money.
A second shop on the same payout address, selling company facts to agents.
code
POST /lookup $0.005 domain age, registrar, mail and DNS provider, DMARC, HTTPS
POST /dossier $0.02 every third-party vendor we can prove, with the proof
Profiles are assembled from four sources that need no key and no supplier: DNS
over HTTPS, the RDAP registry, the TLS handshake and the homepage. Cost per
profile is zero — the margin is in the assembly.
The interesting part is vendor detection. A company proves ownership to every
SaaS product it buys by placing a DNS verification record, and authorises every
sender it uses in its SPF record. Those two lists are a purchase history the
company published itself. Every claim carries the record that proves it, so a
buyer can check rather than trust.
Using it from Claude or ChatGPT
The Bazaar's search ignores the query and ranks by unique payers, so a new shop
is invisible there regardless of quality. MCP is the channel that works on day
one — the agent is already in a client that speaks it.
The buyer brings their own wallet: the key signs the payment locally and never
leaves the machine. Without it the tools say what is missing instead of failing
mid-conversation.
Development
code
npm install # typescript only, for typechecking
npm test # 18 tests, no network required
npm run typecheck
License
MIT
Install
Configuration
Environment variables
DEADCHANNEL_PRIVATE_KEYsecret
Private key of a wallet holding a little USDC on Base. It signs payments locally and never leaves the machine. Not needed for the free health check.
DEADCHANNEL_URL
Override the service endpoint. Defaults to https://deadchannel.vercel.app