Sello Python SDK

Python support lives in sdks/python/ so the repository stays easy to scan:

• sdks/typescript/ contains the TypeScript SDK and reference implementation.
• sdks/python/src/sello/ contains the Python SDK.

The Python SDK mirrors the TypeScript service-side facade:

pip install sello

import sello

receipts = sello.service()

@receipts.tool("calendar.create_event")
def create_event(request):
    return calendar.events.create(request)

The service process emits receipts. It does not need the owner private key.

Quickstart Example

From the repository root, start the local dev log in one terminal:

npx --yes sello dev

Then run the Python example in another terminal:

python -m pip install ./sdks/python
python sdks/python/examples/quickstart_tool.py
npx --yes sello actions

The example reads .sello/dev.json, wraps a mock calendar action with @receipts.tool(...), emits one encrypted receipt, and then lets the Sello CLI verify it locally.

Local Development

For contributing to the SDK from the repository root:

python3 -m venv .venv
. .venv/bin/activate
python -m pip install ./sdks/python
python -m unittest discover -s sdks/python/tests

Current Scope

The Python SDK currently focuses on service-side receipt emission:

• env-first sello.service() config,
• @receipts.tool(...) decorator support,
• compact JWS verification,
• HPKE encryption,
• COSE_Sign1 receipt signing,
• memory and HTTP log adapters,
• background submission with flush().

Owner-side viewing is still handled by the Sello CLI and lower-level protocol tooling.