exists

Deterministic package existence for PyPI and npm, built from real published artifacts (never LLM guesses).

Deterministic package existence for PyPI and npm, built from real published artifacts (never LLM guesses). Negative answers and typosquat-adjacency flags carry signed proof. $0.002 USDC per check.

UNRATEDListed

Overview

Grade?

UNRATED

0 of 30 paid calls toward a letter

Price

$0.002 per call

Paid calls

none yet

delivery unknown until someone pays

More info

Seller?

0x57407d69…a87467dd

URL

https://attester.dev/v1/package/exists

MCP server on this host: io.github.maminihds/attester-mcp

Seen

first 34 days ago · last 11 hr ago

64 free handshakes

Payment

Pays through

x402

Offered on?

Base USDC

Listed on?

Base

Score, from free handshakes onlyweights 2026.09.6

UN
RATED

0.719 liveness verified, no letter

To a letter · 30 paid calls

0 of 30

Held down by latency p95 · gap to 1.000 is 0.281: 0.067 uncertain ? + 0.213 short ? · 0.081 to B

How the composite of 0.719 is made up, part by part
Component	Weight	Measured	Lower bound ?		Adds	Short ?	Uncertain ?
latency p95costs the most it answered as fast as its class	0.20	0.00	0.000		0.000	−0.200	0
liveness it answered at all	0.60	0.98	0.866		0.519	−0.013	−0.067
price stability the price stayed where it was listed	0.20	1.00	1.000		0.200	0	0
Composite	1.00		0.719	gap to 1.000 = 0.281 · 0.213 short · 0.067 uncertain	0.719	−0.213	−0.067

Not measured: correctness · nobody paid; honesty · nobody paid; schema conformance · no answer had a published shape to check

The multiplication, written out

  0.200 × 0.000   latency p95    
+ 0.600 × 0.866   liveness       
+ 0.200 × 1.000   price stability
= 0.719           → UNRATED: 56 of 30 paid calls      weights 2026.09.6 · 56 samples · seed cap_01M1A51P7VYVWV4Y0BM8F6RDZX|2026-09-03T14:22:48.128Z|2026.09.6

Verify it yourselfnpx teppi-check https://attester.dev/v1/package/existscurl -s https://api.teppi.xyz/v1/trust/cap_01M1A51P7VYVWV4Y0BM8F6RDZX