Signed, attributed payment events for AI agents. HalvorAI records each payment an agent makes, with the agent, the owner it acted for, the instruction it followed and the network proof that came with it. It is never in the payment path: it cannot slow or block a payment.
Developer preview. The SDK works offline today: build, sign and inspect events with your own sink. Sandbox API keys go to early-access teams. Request access.
- Docs: docs.halvorai.com
- Event format: Agent Payment Event (APE) v0.1, open and Apache-2.0
- Python 3.10 or later
pip install halvorai-ingestNo account needed. Events are signed with your own Ed25519 key and handed to your sink instead of the API.
import json
from halvorai_ingest import HalvorClient, agent_context, generate_source_key
halvor = HalvorClient(
source_key=generate_source_key(), # private JWK; keep it secret
environment="test",
sink=lambda envelopes: print(json.dumps(envelopes, indent=2)),
)
with agent_context(
agent={"id": "agt_travel_12", "name": "Travel booking agent"},
owner={"id": "own_u_4410", "type": "person", "country": "US"},
instruction={"id": "task_8890", "text": "Book a return flight to Austin under $500"},
):
halvor.emit(
{
"type": "payment.settled",
"payment": {
"payment_id": "pi_3QxAbCdEfGhIjKlM",
"rail": "stripe",
"amount": {"value": "41200", "unit": "minor", "currency": "USD"},
"status": "settled",
"rail_ref": {"payment_intent": "pi_3QxAbCdEfGhIjKlM"},
},
"payee": {"type": "merchant", "name": "Example Airways"},
}
)
halvor.flush(timeout=5)emit returns at once and never raises; a background thread signs and sends events. Instruction text is hashed on your machine and never sent. Anyone with the public half of the key (the JWK without d) can check an envelope with verify_event(envelope["event"], envelope["sig"], public_key).
With a sandbox key (hk_test_…), register this machine as a source. init creates an Ed25519 key here, registers its public half, writes HALVOR_API_KEY and HALVOR_SOURCE_KEY to .env.local, sends one test event and prints a dashboard link:
halvorai-ingest init # or: python -m halvorai_ingest initIt asks for the key unless --api-key or HALVOR_API_KEY is set. Other options: --endpoint, --name, --cwd, --dashboard. The private key never leaves your machine; keep it in your secret manager.
Then load .env.local (or set the same variables) and create the client:
import os
from halvorai_ingest import HalvorClient
halvor = HalvorClient(
api_key=os.environ["HALVOR_API_KEY"],
source_key=os.environ["HALVOR_SOURCE_KEY"], # the private JWK as JSON
)- Events are sent every
flush_intervalseconds (default 1), or sooner when a batch ofbatch_sizeis full. - Network errors, 408, 425, 429 and 5xx are retried with backoff (
retry_delays, default 1, 2, 4, 8, 16, 32 s). Permanent errors (400, 401, 403, 404, 405, 409, 410, 415, 422) are not retried; the batch is reported throughon_errorwith the API'sserverCodeandrequestId. - Pass
spool_dirto keep batches that could not be delivered on disk. The nextflush()or process replays them. Rejected batches go to<spool_dir>/dead/. Limits:spool_max_bytes(50 MB) andspool_max_age(7 days), oldest first. stats()returns counts:emitted,accepted,duplicates,rejected,dropped,retries,spooled,replayed, and thedropped_*reasons.
Long-running processes need nothing else: queued events are flushed at exit (up to 2 s). In a short-lived script, a serverless handler or a worker task, flush before you return:
result = halvor.flush(timeout=5) # {"drained": True} when everything was handledOr use the client as a context manager, which closes it on exit:
with HalvorClient() as halvor:
...Put the HalvorAI transport under the httpx client your agent pays with. Payment requirements, signed payment payloads and settlement responses become events. Headers are only read; nothing in the payment path changes.
import httpx
from halvorai_ingest.x402 import AsyncHalvorX402Transport, HalvorX402Transport
client = httpx.Client(transport=HalvorX402Transport(halvor))
async_client = httpx.AsyncClient(transport=AsyncHalvorX402Transport(halvor))To keep a custom transport, pass it as inner: HalvorX402Transport(halvor, inner=my_transport). If you already have a client object, wrap_httpx(client, halvor) and wrap_httpx_async(client, halvor) observe every method except stream().
Each 402 challenge becomes a payment.requested event. The payment that answers it becomes payment.authorized, linked to the challenge with related.previous_event_id, and the settlement becomes payment.settled or payment.failed with the same payment_id. A challenge without a network or token address is reported as invalid_event and not recorded.
Stripe, MPP and MCP adapters are in the Node.js SDK, @halvorai/ingest. Guides for each: docs.halvorai.com.
uv sync --extra dev
uv run pytest
uv run mypyReport vulnerabilities privately to hello@halvorai.com.
Apache-2.0