These are observations, not accusations. A band of LOW, MEDIUM or HIGH describes how much of what we check we were able to confirm — it is not a judgement about the operator of an endpoint. Every signal, its weight and its rationale are published on the methodology page, and any operator can claim an endpoint, correct a fact or opt out.
What does this x402 endpoint charge?
0.010000 USDC per request
https://readx.sh/api/search/tweets
Risk band: LOW
96/100
Endpoint
| URL | https://readx.sh/api/search/tweets |
|---|---|
| Canonical | https://readx.sh/api/search/tweets |
| Endpoint id | de738638edd04ace3783ef4315e402af |
| HTTP status | 402 |
| Latency | 10 ms |
| Redirects | 0 |
| TLS | handshake okThe negotiated TLS version is not exposed to a Worker. |
| Wire form | x402 v2 — PAYMENT-REQUIRED header |
| Bytes read | 2 |
| Strict decoder | accepteddecodePaymentRequired, imported from tx402 — the same code the SDK runs before it pays. |
Payment
accepted by the decoderThese terms were accepted by the strict decoder tx402 uses before it pays.
| Price | 0.010000 USDC |
|---|---|
| Amount (atomic) | 10000 |
| Scheme | exact |
| Network | eip155:8453 in manifestRecognized means present in the tx402 signed release manifest. Nothing more is claimed. |
| Asset | USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 in manifestRecognized means present in the tx402 signed release manifest. Nothing more is claimed. |
| Pay to | 0x13E060ADcc6F4b731Da8382B333027B8B2bfF707 |
| Pay to declared dynamic | nox402 v2 has no on-the-wire declaration of a dynamic payTo, so this is usually unobservable. |
| Authorization window | 300s |
| Resource | https://readx.sh/api/search/tweets |
| MIME type | application/json |
| Description | Search for tweets by query (optional product filter; paginate with cursor). Example: GET /api/search/tweets?q=typescript |
| Facilitator | not observed |
This endpoint offers 2 ways to pay. The card above describes the first, which is the order the server stated its own preference in.
| Alternative 2 | 10000 (atomic units) · solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp · exact |
|---|
Risk
Band: LOW 96/100 · v1 · static_onlyA band describes how much of what we check we were able to confirm. It is not a judgement about the operator of an endpoint.
- Result: pass 25 The challenge decodes under the strict x402 decoder tx402 uses before paying. challenge_decodes
- Result: pass 15 The challenge describes the endpoint that served it. resource_origin_match
- Result: pass 12 The amount is a canonical atomic integer. amount_canonical
- Result: pass 12 The recipient is a well-formed address for the declared network. pay_to_wellformed
- Result: pass 8 The network is in the tx402 signed release manifest. network_recognized
- Result: pass 8 The asset is in the tx402 signed release manifest for this network. asset_recognized
- Result: skip — The challenge named no facilitator. facilitator_known
- Result: pass 6 The payment scheme is one tx402 can route. scheme_known
- Result: pass 5 The endpoint was reached over a valid TLS connection. tls_ok
- Result: warn 4 The authorization window is outside the maximum tx402 will sign for. timeout_sane
- Result: pass 3 No redirect downgraded the connection. redirect_scheme_downgrade
- Result: pass 3 The endpoint serves the x402 v2 header form. wire_form
- Result: pass 2 The amount is within the range we see for x402 endpoints. amount_magnitude_band
Security
1 to look at
A check that could not run reports skip, and a skip is never counted as a pass.
- Result: pass wire_form_detected Served as v2-header.
- Result: pass base64_strict The strict decoder accepted the header's base64 framing.
- Result: pass json_wellformed
- Result: pass x402_version_known Declared x402Version 2.
- Result: pass accepts_present The challenge offers 2 ways to pay.
- Result: pass size_within_limit Read 2 bytes, within the probe's cap.
- Result: pass network_caip2_wellformed network: eip155:8453
- Result: pass network_recognized Recognized means present in the tx402 signed release manifest.
- Result: pass asset_recognized Recognized means present in the tx402 signed release manifest.
- Result: pass amount_atomic_canonical
- Result: pass amount_positive
- Result: pass pay_to_wellformed
- Result: warn max_timeout_sane Authorization window 300s exceeds the tx402 maximum of 60s.
- Result: pass resource_origin_match
- Result: pass scheme_known
- Result: skip facilitator_known The challenge named no facilitator.
- Result: pass mime_type_wellformed mimeType: application/json
- Result: pass extra_wellformed `extra` carries 2 field(s), preserved verbatim.
- Result: skip amount_within_observed_range needs our data No prior observations of this endpoint.
- Result: skip recipient_matches_observed needs our data No prior observations of this endpoint.
Observed
| First seen | 2026-08-15T04:00:12Z |
|---|---|
| Last seen | 2026-08-15T14:35:16Z |
| Scans recorded | 2 |
| Availability (30d) | not measured yet |
| Latency p50 | not measured yet |
| 2026-08-15T05:00:40Z | first_seen: challenge_hash — → 0a1f3f490a7ec26f68c77daf626f6ebe608a2399704733fb0b2d74c730e56f5b |
|---|
Test with tx402 →
Pre-filled with this endpoint's real terms. Your signer stays in your process — this service never sees a key, never asks for one, and cannot build a payment.
CLI — dry run, nothing is signed
npx tx402 call "https://readx.sh/api/search/tweets" \
--max-spend "0.010000 USDC" \
--network "eip155:8453" \
--dry-run
# --dry-run stops after the policy decision. Nothing is signed and nothing is spent.
TypeScript
import { createTx402Client } from "tx402";
// Your signer stays in your process. tools.tx402.io never sees a key,
// never asks for one, and cannot build a payment.
import { signers } from "./signers.js";
const tx402 = createTx402Client({
signers,
policy: {
maxPerRequest: "0.010000 USDC",
allowedDomains: ["readx.sh"],
allowedNetworks: ["eip155:8453"],
},
});
// Policy and budget are committed before the signer is reachable, so a
// refusal here is a payment that was never authorized.
const response = await tx402.fetch("https://readx.sh/api/search/tweets");
Python
from tx402 import Tx402Client, Policy
# Your signer stays in your process. tools.tx402.io never sees a key,
# never asks for one, and cannot build a payment.
tx402 = Tx402Client(
evm_signer=evm,
policy=Policy(
max_per_request="0.010000 USDC",
allowed_domains=["readx.sh"],
allowed_networks=["eip155:8453"],
),
)
# Policy and budget are committed before the signer is reachable, so a
# refusal here is a payment that was never authorized.
response = tx402.fetch("https://readx.sh/api/search/tweets")
This report, as JSON or Markdown
curl -sS 'https://tools.tx402.io/api/v1/inspect?url=https%3A%2F%2Freadx.sh%2Fapi%2Fsearch%2Ftweets'
# The same result as Markdown, for a terminal or an agent:
curl -sS -H 'Accept: text/markdown' 'https://tools.tx402.io/inspect?url=https%3A%2F%2Freadx.sh%2Fapi%2Fsearch%2Ftweets'
The challenge, as served
Public data: the endpoint serves this to anyone who asks. It is shown exactly as it arrived, truncated to the documented cap.
raw challenge
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SHA-256 of the canonicalized challenge: 1736d3b70fb6c0b5ccb9ac642040e6d907e5ef68471f6fe27eb986ed867b0dbc
Raw signals
The exact input the scoring function was given. A signal we could not determine has
observed: false and contributes nothing to the score — it is never counted as a failure.
signals
[
{
"id": "probe_ok",
"value": true,
"observed": true,
"detail": null
},
{
"id": "challenge_served",
"value": true,
"observed": true,
"detail": null
},
{
"id": "challenge_decodes",
"value": true,
"observed": true,
"detail": null
},
{
"id": "wire_form",
"value": "v2-header",
"observed": true,
"detail": null
},
{
"id": "x402_version",
"value": 2,
"observed": true,
"detail": null
},
{
"id": "tls_ok",
"value": true,
"observed": true,
"detail": null
},
{
"id": "tls_protocol",
"value": null,
"observed": false,
"detail": "The negotiated TLS version is not exposed to the probe."
},
{
"id": "redirect_count",
"value": 0,
"observed": true,
"detail": null
},
{
"id": "redirect_scheme_downgrade",
"value": false,
"observed": true,
"detail": "Cross-scheme redirects are refused."
},
{
"id": "resource_origin_match",
"value": true,
"observed": true,
"detail": null
},
{
"id": "network_recognized",
"value": true,
"observed": true,
"detail": "Recognized means present in the tx402 signed release manifest."
},
{
"id": "asset_recognized",
"value": true,
"observed": true,
"detail": "Recognized means present in the tx402 signed release manifest."
},
{
"id": "facilitator_known",
"value": null,
"observed": false,
"detail": "The challenge named no facilitator."
},
{
"id": "amount_canonical",
"value": true,
"observed": true,
"detail": null
},
{
"id": "amount_magnitude_band",
"value": "small",
"observed": true,
"detail": null
},
{
"id": "pay_to_wellformed",
"value": true,
"observed": true,
"detail": null
},
{
"id": "pay_to_declared_dynamic",
"value": false,
"observed": true,
"detail": null
},
{
"id": "timeout_sane",
"value": false,
"observed": true,
"detail": "Authorization window 300s exceeds the tx402 maximum of 60s."
},
{
"id": "scheme_known",
"value": true,
"observed": true,
"detail": null
},
{
"id": "requirement_count",
"value": 2,
"observed": true,
"detail": null
},
{
"id": "challenge_size_bytes",
"value": 2,
"observed": true,
"detail": null
},
{
"id": "first_seen_age_days",
"value": null,
"observed": false,
"detail": "No history yet."
},
{
"id": "scan_count",
"value": null,
"observed": false,
"detail": "No history yet."
},
{
"id": "availability_30d",
"value": null,
"observed": false,
"detail": "No history yet."
},
{
"id": "latency_p50_ms",
"value": null,
"observed": false,
"detail": "No history yet."
},
{
"id": "price_changes_90d",
"value": null,
"observed": false,
"detail": "No history yet."
},
{
"id": "recipient_changes_90d",
"value": null,
"observed": false,
"detail": "No history yet."
},
{
"id": "recipient_unstable_undeclared",
"value": null,
"observed": false,
"detail": "No history yet."
},
{
"id": "terms_changed_within_24h",
"value": null,
"observed": false,
"detail": "No history yet."
}
]