feat(workflow): add hook support

[fantix]

Demo code from docs, workflow:

from vercel.workflow import HookMixin, workflow


# Human approval for AI-generated drafts
class Approval(BaseModel, HookMixin):
    decision: Literal["approved", "changes"]
    notes: str | None


@workflow
async def ai_approval_workflow(topic: str):
    draft = await generate_draft(topic)

    # Wait for human approval events
    events = Approval.wait(token="draft-123")

    async for event in events:
        if event["decision"] == "approved":
            await publish_draft(draft)
            break
        else:
            revised = await refine_draft(draft, event.get("notes"))
            await publish_draft(revised)
            break

App:

@app.post("/api/resume")
async def resume_workflow(approval: Approval):
    await approval.resume("draft-123")

    return {"ok": True}

[vercel]

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Project	Deployment	Actions	Updated (UTC)
vercel-py	Ready	Preview	Mar 28, 2026 3:38am