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mDuo13 merged 3 commits into from
Feb 17, 2026
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Update & combine 'Verify Credentials' tutorials #3499

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65f9a8d
Update & combine 'Verify Credentials' tutorials
mDuo13 Feb 14, 2026
f051dc9
Edit client library link per suggestion
mDuo13 Feb 17, 2026
f58809a
Update verify credentials per review
mDuo13 Feb 17, 2026
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26 changes: 18 additions & 8 deletions _code-samples/verify-credential/js/verify_credential.js
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Original file line number Diff line number Diff line change
@@ -1,10 +1,10 @@
import { Client, rippleTimeToISOTime, convertStringToHex } from "xrpl"

const client = new Client("wss://s.devnet.rippletest.net:51233")
const client = new Client("wss://xrplcluster.com")
await client.connect()

const SUBJECT_ADDRESS = "rsYhHbanGpnYe3M6bsaMeJT5jnLTfDEzoA"
const ISSUER_ADDRESS = "rEzikzbnH6FQJ2cCr4Bqmf6c3jyWLzkonS"
const SUBJECT_ADDRESS = "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
const ISSUER_ADDRESS = "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX"
const CREDENTIAL_TYPE = convertStringToHex("my_credential").toUpperCase()

// Look up Credential ledger entry --------------------------------------------
Expand All @@ -29,6 +29,7 @@ try {
} else {
console.error(err)
}
client.disconnect()
process.exit(1)
}

Expand All @@ -40,6 +41,7 @@ console.log(JSON.stringify(credential, null, 2))
const lsfAccepted = 0x00010000
if (!(credential.Flags & lsfAccepted)) {
console.log("Credential is not accepted.")
client.disconnect()
process.exit(2)
}

Expand All @@ -49,17 +51,25 @@ if (credential.Expiration) {
console.log(`Credential has expiration: ${expirationTime}`)
console.log("Looking up validated ledger to check for expiration.")

const ledgerResponse = await client.request({
command: "ledger",
ledger_index: "validated",
})
let ledgerResponse
try {
ledgerResponse = await client.request({
command: "ledger",
ledger_index: "validated",
})
} catch (err) {
console.error("Error looking up most recent validated ledger:", err)
client.disconnect()
process.exit(3)
}

const closeTime = rippleTimeToISOTime(ledgerResponse.result.ledger.close_time)
console.log(`Most recent validated ledger was at: ${closeTime}`)

if (new Date(closeTime) > new Date(expirationTime)) {
console.log("Credential is expired.")
process.exit(3)
client.disconnect()
process.exit(4)
}
}

Expand Down
32 changes: 12 additions & 20 deletions _code-samples/verify-credential/py/README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -8,26 +8,18 @@ Quick install & usage:
python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
./verify_credential.py
python verify_credential.py
```

`verify_credential.py` can also be used as a commandline utility. Full usage statement:

```sh
$ ./verify_credential.py -h
usage: verify_credential.py [-h] [-b] [-n {devnet,testnet,mainnet}]
[issuer] [subject] [credential_type]

Verify an XRPL credential

positional arguments:
issuer Credential issuer address as base58.
subject Credential subject (holder) address as base58.
credential_type Credential type as string

options:
-h, --help show this help message and exit
-b, --binary Use binary (hexadecimal) for credential_type
-n, --network {devnet,testnet,mainnet}
Use the specified network for lookup
The output should look something like this:

```text
Looking up credential...
{'ledger_index': 'validated', 'method': 'ledger_entry', 'api_version': 2, 'credential': {'subject': 'rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn', 'issuer': 'ra5nK24KXen9AHvsdFTKHSANinZseWnPcX', 'credential_type': '6D795F63726564656E7469616C'}, 'binary': False}
Found credential:
{'CredentialType': '6D795F63726564656E7469616C', 'Expiration': 1199232000, 'Flags': 65536, 'Issuer': 'ra5nK24KXen9AHvsdFTKHSANinZseWnPcX', 'IssuerNode': '0', 'LedgerEntryType': 'Credential', 'PreviousTxnID': '2D3A865C3AAC50A20ACC40E3644D93FE5FEF2C8CFF21B1E0580ADB34D9487A9E', 'PreviousTxnLgrSeq': 102230586, 'Subject': 'rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn', 'SubjectNode': '0', 'index': '1CA15B7FBD6E0BEE616F2B5FF479D9F6EBEF5D93073FA03F734081AF46804B47'}
Credential has expiration: 2038-01-01T00:00:00+00:00
Looking up validated ledger to check for expiration.
Most recent validated ledger was at: 2026-02-17T18:47:52+00:00
Credential is valid.
```
212 changes: 55 additions & 157 deletions _code-samples/verify-credential/py/verify_credential.py
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Original file line number Diff line number Diff line change
@@ -1,167 +1,65 @@
#!/usr/bin/env python

import argparse
import logging
import sys
from binascii import hexlify
from re import match

from xrpl.clients import JsonRpcClient
from xrpl.models.requests import LedgerEntry, Ledger
from xrpl.utils import ripple_time_to_datetime

# Set up logging --------------------------------------------------------------
# Use WARNING by default in case verify_credential is called from elsewhere.
logger = logging.getLogger("verify_credential")
logger.setLevel(logging.WARNING)
logger.addHandler(logging.StreamHandler(sys.stderr))

# Define an error to throw when XRPL lookup fails unexpectedly ----------------
class XRPLLookupError(Exception):
def __init__(self, xrpl_response):
self.body = xrpl_response.result

# Main function ---------------------------------------------------------------
def verify_credential(client:JsonRpcClient,
issuer:str,
subject:str,
credential_type:str="",
credential_type_hex:str=""):
"""
Check whether an XRPL account holds a specified credential,
as of the most recently validated ledger.

Paramters:
client - JsonRpcClient for the XRPL network to use.
issuer - Address of the credential issuer, in base58
subject - Address of the credential holder/subject, in base58
credential_type - Credential type to check for as a string,
which will be encoded as UTF-8 (1-64 bytes long).
credential_type_hex - Credential type (binary) as hexadecimal.
verbose - If true, print details to stdout during lookup.
You must provide either credential_type or credential_type_hex.

Returns True if the account holds the specified, valid credential.
Returns False if the credential is missing, expired, or not accepted.
"""
# Handle function inputs --------------------------------------------------
if not (credential_type or credential_type_hex):
raise ValueError("Provide a non-empty credential_type or " +
"credential_type_hex")
if credential_type and credential_type_hex:
raise ValueError("Provide either credential_type or " +
"credential_type_hex, but not both")

# Encode credential_type as uppercase hex, if needed
if credential_type:
credential_type_hex = hexlify(credential_type.encode("utf-8")
).decode("ascii")
logger.info("Encoded credential_type as hex: "+credential_type_hex.upper())
credential_type_hex = credential_type_hex.upper()

if len(credential_type_hex) % 2 or \
not match(r"[0-9A-F]{2,128}", credential_type_hex):
# Hexadecimal is always 2 chars per byte, so an odd length is invalid.
raise ValueError("credential_type_hex must be 1-64 bytes as hexadecimal.")

# Perform XRPL lookup of Credential ledger entry --------------------------
ledger_entry_request = LedgerEntry(
credential={
"subject": subject,
"issuer": issuer,
"credential_type": credential_type_hex
},
ledger_index="validated"
)
logger.info("Looking up credential...")
logger.info(ledger_entry_request.to_dict())
client = JsonRpcClient("https://xrplcluster.com")
SUBJECT_ADDRESS = "rf1BiGeXwwQoi8Z2ueFYTEXSwuJYfV2Jpn"
ISSUER_ADDRESS = "ra5nK24KXen9AHvsdFTKHSANinZseWnPcX"
CREDENTIAL_TYPE = hexlify("my_credential".encode("utf-8")).decode("ascii").upper()

# Look up Credential ledger entry ----------------------------------------------
ledger_entry_request = LedgerEntry(
credential={
"subject": SUBJECT_ADDRESS,
"issuer": ISSUER_ADDRESS,
"credential_type": CREDENTIAL_TYPE,
},
ledger_index="validated",
)
print("Looking up credential...")
print(ledger_entry_request.to_dict())
try:
xrpl_response = client.request(ledger_entry_request)
except Exception as err:
print("Error: ledger_entry failed with error:", err)
exit(1)

if xrpl_response.status != "success":
if xrpl_response.result["error"] == "entryNotFound":
logger.info("Credential was not found")
return False
# Other errors, for example invalidly-specified addresses.
raise XRPLLookupError(xrpl_response)

credential = xrpl_response.result["node"]
logger.info("Found credential:")
logger.info(credential)

# Confirm that the credential has been accepted ---------------------------
lsfAccepted = 0x00010000
if not credential["Flags"] & lsfAccepted:
logger.info("Credential is not accepted.")
return False

# Confirm that the credential is not expired ------------------------------
if credential.get("Expiration"):
expiration_time = ripple_time_to_datetime(credential["Expiration"])
logger.info("Credential has expiration: "+expiration_time.isoformat())
logger.info("Looking up validated ledger to check for expiration.")

ledger_response = client.request(Ledger(ledger_index="validated"))
if ledger_response.status != "success":
raise XRPLLookupError(ledger_response)
close_time = ripple_time_to_datetime(
ledger_response.result["ledger"]["close_time"]
)
logger.info("Most recent validated ledger is: "+close_time.isoformat())

if close_time > expiration_time:
logger.info("Credential is expired.")
return False

# Credential has passed all checks. ---------------------------------------
logger.info("Credential is valid.")
return True

# Commandline usage -----------------------------------------------------------
if __name__=="__main__":
NETWORKS = {
# JSON-RPC URLs of public servers
"devnet": "https://s.devnet.rippletest.net:51234/",
"testnet": "https://s.altnet.rippletest.net:51234/",
"mainnet": "https://xrplcluster.com/"
}

# Parse arguments ---------------------------------------------------------
parser = argparse.ArgumentParser(description="Verify an XRPL credential")
parser.add_argument("issuer", type=str, nargs="?",
help="Credential issuer address as base58.",
default="rEzikzbnH6FQJ2cCr4Bqmf6c3jyWLzkonS")
parser.add_argument("subject", type=str, nargs="?",
help="Credential subject (holder) address as base58.",
default="rsYhHbanGpnYe3M6bsaMeJT5jnLTfDEzoA")
parser.add_argument("credential_type", type=str, nargs="?",
help="Credential type as string",
default="my_credential")
parser.add_argument("-b", "--binary", action="store_true",
help="Use binary (hexadecimal) for credential_type")
parser.add_argument("-n", "--network", choices=NETWORKS.keys(),
help="Use the specified network for lookup",
default="devnet")
parser.add_argument("-q", "--quiet", action="store_true",
help="Don't print log messages.")
args = parser.parse_args()

# Call verify_credential with appropriate args ----------------------------
client = JsonRpcClient(NETWORKS[args.network])
if not args.quiet:
# Use INFO level by default when called from the commandline.
logger.setLevel(logging.INFO)

if args.binary:
result = verify_credential(client,
issuer=args.issuer,
subject=args.subject,
credential_type_hex=args.credential_type)
else:
result = verify_credential(client,
issuer=args.issuer,
subject=args.subject,
credential_type=args.credential_type)

# Return a nonzero exit code if credential verification failed. -----------
if not result:
if xrpl_response.status != "success":
if xrpl_response.result["error"] == "entryNotFound":
print("Credential was not found")
exit(1)
# Other errors, for example invalidly-specified addresses.
print("Unexpected error looking up credential:", xrpl_response.result)

credential = xrpl_response.result["node"]
print("Found credential:")
print(credential)

# Check if the credential has been accepted ------------------------------------
lsfAccepted = 0x00010000
if not credential["Flags"] & lsfAccepted:
print("Credential is not accepted.")
exit(2)

# Confirm that the credential is not expired -----------------------------------
if credential.get("Expiration"):
expiration_time = ripple_time_to_datetime(credential["Expiration"])
print("Credential has expiration:", expiration_time.isoformat())
print("Looking up validated ledger to check for expiration.")

ledger_response = client.request(Ledger(ledger_index="validated"))
if ledger_response.status != "success":
print("Error looking up most recent validated ledger:", ledger_response.result)
exit(3)
close_time = ripple_time_to_datetime(ledger_response.result["ledger"]["close_time"])
print("Most recent validated ledger was at:", close_time.isoformat())

if close_time > expiration_time:
print("Credential is expired.")
exit(4)

# Credential has passed all checks. --------------------------------------------
print("Credential is valid.")
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