alter-sdk 0.18.0

Alter Vault Python SDK - OAuth token management with policy enforcement

Alter SDK for Python

Official Python SDK for Alter Vault — credential and authorization layer for apps and AI agents that call third-party APIs.

Tokens stay in the vault. The SDK injects the credential, refreshes it, and writes the audit row — application code only calls vault.request() (or vault.proxy_request() when the backend should make the outgoing call instead of the SDK).

Install

pip install alter-sdk

Requires Python 3.10+.

Quick example

Make an authenticated API call — no token ever touches application code.

import asyncio
from alter_sdk import App, HttpMethod

async def main():
    async with App(api_key="<api-key>") as vault:
        response = await vault.request(
            HttpMethod.POST,
            "https://api.example.com/resource",
            grant_id="<grant-id>",
            json={"example": "payload"},
        )
        print(response.status_code, response.json())

asyncio.run(main())

For a full walkthrough — sign-up, key minting, OAuth — see the Quickstart.

Two runtime modes

The SDK exposes two ways to reach a third-party API:

• vault.request(...) — retrieve mode. The SDK fetches the token from the backend and makes the outgoing call itself. Returns the third-party response.
• vault.proxy_request(...) — proxy mode. The backend holds the token, makes the outgoing call, and returns the result. Application code and the SDK never observe the token. Required for any grant configured with human-in-the-loop approval; available for any other grant when wire-level audit, strong token isolation, or backend-side policy enforcement matter.

See runtime modes for the tradeoffs and when to pick each.

Recovering from missing-grant errors

When a request fails because the user hasn't authorized the provider yet, the SDK exposes recovery context on the typed error so you can drive a re-consent flow without re-deriving anything from the call site:

from alter_sdk import NoDelegatedGrantError

try:
    await vault.request(provider="<provider-id>", user_token=jwt, url=..., method=...)
except NoDelegatedGrantError as e:
    session = await vault.create_connect_session_for_error(
        e,
        allowed_origin="https://app.example.com",
    )
    # Surface session.connect_url to the user — popup, redirect,
    # out-of-band message, whatever your framework does.
    results = await vault.poll_connect_session(session.session_token)
    # Retry with the freshly-minted grant_id.
    response = await vault.request(grant_id=results[0].grant_id, url=..., method=...)

create_connect_session_for_error and poll_connect_session are available on both App and Agent so the catch block can recover from whichever client raised.

NoDelegatedGrantError and GrantNotFoundError carry provider_id / agent_id / app_user_id recovery context when the original lookup was identity-mode; CredentialRevokedError carries provider_id / app_user_id. See the error reference for the full surface.

Documentation

Full docs are at https://docs.alterauth.com.

Topic	Page
Getting started end-to-end	Quickstart
The mental model	How Alter works
Calling APIs on behalf of users (OAuth + JWT)	Guide
Identity provider setup	Auth0 / Clerk / Okta / Custom OIDC
Provisioning backend secrets	Guide
Scoped credentials for AI agents	Guide
Human-in-the-loop approvals	Guide
Runtime modes (retrieve vs proxy)	Concept
Integrating with Claude Code (MCP)	Guide
Per-method API reference	Python SDK reference
Errors	Error reference

License

MIT. See LICENSE.

Support

Email [e-mail] or open an issue at https://github.com/alter-ai/alter-vault.