vercel-connect

Python SDK for Vercel Connect, a credential broker for third-party APIs.

You exchange your deployment's token for a short-lived credential for an upstream service. Your project never stores provider secrets, and Connect owns the OAuth client, PKCE, refresh, and revocation server-side.

pip install vercel-connect

Usage

import httpx
from vercel.connect import ConnectAppTokenSubject, get_token

token = await get_token("github/my-app", subject=ConnectAppTokenSubject())

async with httpx.AsyncClient() as client:
    await client.get(
        "https://api.github.com/user/repos",
        headers={"Authorization": f"Bearer {token}"},
    )

The same surface is available synchronously, with identical names and arguments:

from vercel.connect.sync import ConnectAppTokenSubject, get_token

token = get_token("github/my-app", subject=ConnectAppTokenSubject())

Use a plain with block and vercel.connect.sync together; mixing an async call into a sync session, or the reverse, is rejected.

Subjects

Whose authority the credential carries:

app is one shared credential per installation: simple, always available, but ambient authority. user preserves the provider's own permission model per person and names them in the provider's audit log, at the cost of a consent flow.

Subjects are typed values rather than plain strings because three of the four carry their own fields, so subject="user" could not say which user:

ConnectUserTokenSubject(id="u_123", issuer="https://idp.example.com")
ConnectJwtBearerTokenSubject(sub="u_123", additional_claims={"tenant": "acme"})

Value types

Every type on this surface is a frozen Pydantic model, so you get validation on construction, autocompletion, exact match/case narrowing, model_dump() for logging, and immutability, which means a subject cannot be mutated after a credential has been cached against it:

detail = ConnectGitHubAppInstallationAuthorizationDetail(permissions=["contents:read"])
detail.model_dump()                    # {'org': None, 'permissions': ('contents:read',), ...}
detail.permissions = ["admin"]         # ConnectValidationError: frozen

Construction is by keyword, a misspelled field is an error rather than a silently dropped value, and every rejection raises ConnectValidationError, so you never need to catch Pydantic's own error type. Containers of strings accept any container and store a tuple; a bare string is rejected rather than expanded into one entry per character:

get_token(..., scopes="repo:read")     # ConnectValidationError, and a type error
get_token(..., scopes=["repo:read"])   # correct

Authorization as control flow

The two "required" errors are not bugs, they are states with a remedy:

from vercel.connect import (
    ConnectUserTokenSubject,
    UserAuthorizationRequiredError,
    get_token,
    start_authorization,
)

subject = ConnectUserTokenSubject(id=user_id)
try:
    token = await get_token("linear/my-app", subject=subject)
except UserAuthorizationRequiredError:
    authorization = await start_authorization(
        "linear/my-app", subject=subject, return_url="https://myapp.com/cb"
    )
    return redirect(authorization.url)

A CLI or headless process has nowhere to redirect to, so it asks for a device code and polls. Each outcome is its own error, so the loop never inspects an error code:

import anyio
from vercel.connect import (
    AuthorizationDeniedError,
    AuthorizationExpiredError,
    AuthorizationPendingError,
    ConnectOptions,
)

authorization = await start_authorization(
    "linear/my-app", subject=subject, device_code=True
)
print(f"Enter {authorization.device_code} at {authorization.url}")

while True:
    try:
        token = await get_token(
            "linear/my-app", subject=subject, options=ConnectOptions(force_refresh=True)
        )
        break
    except AuthorizationPendingError:
        await anyio.sleep(5)
    except (AuthorizationDeniedError, AuthorizationExpiredError):
        raise  # terminal: nothing to wait for

force_refresh=True is what makes the poll reach the server; without it a cached credential would be returned. slow_down is reported as AuthorizationPendingError too, so a fixed interval stays correct.

Inbound triggers

A connector with triggers enabled forwards provider webhooks to your project with a Vercel OIDC token attached, so you verify one thing instead of a different signature scheme per provider:

from vercel.connect import verify_connect_webhook

claims = await verify_connect_webhook(request.headers)

Verification pins the issuer to Vercel's OIDC service, accepting both https://oidc.vercel.com and the team-scoped https://oidc.vercel.com/<team>, allows only RS256, and fails closed when the expected project and environment cannot be resolved. It accepts any valid Vercel OIDC token for this project and environment; it is not pinned to a specific connector or deployment.

Configuration

To configure advanced options, use a session context manager, and pass ConnectServiceOptions:

from vercel.api import session
from vercel.connect import ConnectAppTokenSubject, ConnectServiceOptions, get_token

async with session(
    service_options=[ConnectServiceOptions(base_url="https://staging.example.com")]
):
    token = await get_token("github/my-app", subject=ConnectAppTokenSubject())

Local development

On Vercel the OIDC token is injected automatically. Locally:

vercel link
vercel env pull    # writes VERCEL_OIDC_TOKEN into .env.local

The connector must be attached to your project and enabled for the target environment, or every call fails.