Attesto

SDKs

Python and TypeScript SDKs

Both SDKs default to https://verify.attesto.eu, validate system-key shape locally, set idempotency headers, and retry transient failures with jittered exponential backoff.

Python

pip install attesto
import os
from attesto import AttestoClient

attesto = AttestoClient(api_key=os.environ["ATTESTO_API_KEY"])
ack = attesto.log_event(
    type="inference",
    status="verified",
    source_ref="case-2026-0001:decision-1",
    payload={
        "model": "risk-service-v4",
        "score": 0.91,
        "policy_id": "policy-2026-01",
    },
)
print(ack.id)

Python async

import os
from attesto import AsyncAttestoClient

async with AsyncAttestoClient(api_key=os.environ["ATTESTO_API_KEY"]) as attesto:
    ack = await attesto.log_event(
        type="ai.decision",
        status="verified",
        source_ref="case-2026-0001:decision-1",
        payload={"decision": "manual_review", "score": 91},
    )
    print(ack.id)

TypeScript

npm install @attesto/sdk
import { AttestoClient } from "@attesto/sdk";

const attesto = new AttestoClient({
  apiKey: process.env.ATTESTO_API_KEY!,
});

const ack = await attesto.logEvent({
  type: "inference",
  status: "verified",
  sourceRef: "case-2026-0001:decision-1",
  payload: {
    model: "risk-service-v4",
    score: 0.91,
    policy_id: "policy-2026-01",
  },
});
console.log(ack.id);

Proofstream v2 client

Use AttestoV2Client when you need stream-level receipts, checkpoint consistency, witness policy visibility, verifier bundles, and offline verification helpers. 

from attesto import AttestoV2Client

with AttestoV2Client(api_key=os.environ["ATTESTO_API_KEY"]) as attesto:
    stream = attesto.create_stream(
        use_case="ai-decision-history",
        policy_id="policy-2026-01",
    )
    receipt = attesto.log_event(
        stream_id=stream.stream_id,
        source_ref="source-event-001",
        event_type="decision",
        payload={"decision": "review", "score": 91},
    )
    stored = attesto.get_receipt(receipt.stream_event_id)
    report = attesto.verify_receipt(
        receipt=stored.receipt,
        public_key_hex=os.environ["ATTESTO_RECEIPT_SIGNER_PUBLIC_KEY_HEX"],
        stream_event_id=receipt.stream_event_id,
    )
    assert report.ok

TypeScript Proofstream:

import { AttestoV2Client } from "@attesto/sdk";

const attesto = new AttestoV2Client({
  apiKey: process.env.ATTESTO_API_KEY!,
});

const stream = await attesto.createStream({
  useCase: "ai-decision-history",
  policyId: "policy-2026-01",
});

const receipt = await attesto.logEvent(stream.streamId, {
  sourceRef: "case-2026-0001:decision-1",
  eventType: "ai.decision",
  payload: { decision: "manual_review", score: 91 },
});

const report = await attesto.verifyReceipt({
  receipt: receipt.receipt,
  streamEventId: receipt.streamEventId,
  publicKeyHex: process.env.ATTESTO_RECEIPT_SIGNER_PUBLIC_KEY_HEX!,
});
if (!report.ok) throw new Error(report.problems.join("; "));

Offline and online verify helpers

SDK verification methods are useful in services that receive Attesto receipts or bundles and need to fail closed before accepting them. 

from attesto import AttestoV2Client

with AttestoV2Client(api_key=os.environ["ATTESTO_API_KEY"]) as attesto:
    report = attesto.verify_object(
        kind="bundle",
        proof_object=bundle_object,
    )
    if not report.ok:
        raise RuntimeError(report.problems)
const report = await attesto.verifyObject({
  kind: "bundle",
  object: bundleObject,
});

if (!report.ok) {
  throw new Error(report.problems.join("; "));
}

Security rules