Fletcher-16 / Fletcher-32

checksum.openverbs.com · 4 paid endpoints · listed 2026-10-27

Fletcher checksum over the input payload, in 16-bit (default) or 32-bit width. Returns the checksum as an unsigned integer and hex. Non-cryptographic.

livelast check 5 days ago

100%valid x402 answers, 72 h

sharedUSDC received on Base, 7 days

28distinct payers, 7 days

69.9score (0-100)

Paid endpoints

Method	Endpoint	Price	Networks
POST	checksum.openverbs.com/v1/adler32 Adler-32 checksum (as used by zlib) over the input payload. Faster than CRC-32 but weaker for short inputs. Returns the checksum as an unsigned integer and 8-di	$0.002	Base
POST	checksum.openverbs.com/v1/crc16 CRC-16 over the input payload in one of several standard variants (ccitt-false, xmodem, modbus, ibm; default ccitt-false). Returns the checksum as an unsigned i	$0.002	Base
POST	checksum.openverbs.com/v1/crc32 CRC-32 (IEEE 802.3 polynomial, as used by zip, gzip and PNG) over the input payload. Returns the checksum as an unsigned integer and 8-digit hex. Non-cryptograp	$0.002	Base
POST	checksum.openverbs.com/v1/fletcher Fletcher checksum over the input payload, in 16-bit (default) or 32-bit width. Returns the checksum as an unsigned integer and hex. Non-cryptographic.	$0.002	Base

Latest checks

When	Endpoint	HTTP	ms	Result
5 days ago	checksum.openverbs.com/v1/adler32	402	557	valid x402 v2 terms

Income on Base (7 days)

This provider's payout address is shared by several providers, so its income is not shown as its own.

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<a href="https://logicnodes.io/observatory/p/checksum.openverbs.com"><img src="https://logicnodes.io/observatory/badge/checksum.openverbs.com.svg" alt="x402 status"></a>

Claim it for free with x402_provider_claim (sign with your payout address), and get an alert within minutes when it stops answering with x402_monitor_create ($5 for 30 days). Both work over MCP (https://logicnodes.io/mcp/v2) or POST https://logicnodes.io/v1/tools/<tool>.

Income is all USDC received by the provider's payout address on Base, whatever the source. Score: 0-100: 50 x share of checks in the last 72 h that returned valid x402 payment terms + 30 x min(1, log10(1 + USDC received in 7 days) / 4) + 20 x min(1, log10(1 + distinct payers in 7 days) / 3). A provider never checked scores on income only; income is all USDC received by its payout address on Base, whatever the source. JSON: /v1/observatory/providers/checksum.openverbs.com