EventResult schema rejects cursor / hasMore fields returned by events_create

[kalyanaramansanthanam]

Environment

• vercel==0.5.8
• Python 3.12 (Vercel Lambda runtime)

The bug

The Vercel workflow service returns extra cursor and hasMore fields on events_create responses — observed on the very first RunStartedEvent create for every workflow run:

{
  "event": {...},
  "cursor": "eid:evnt_01KS1Y9HA5NR3TS7GER2VAKQK1",
  "hasMore": false
}

EventResult (src/vercel/_internal/workflow/world.py:590) inherits the SDK BaseModel's model_config = pydantic.ConfigDict(extra="forbid", ...), so validation fails:

pydantic_core._pydantic_core.ValidationError: 2 validation errors for EventResult
cursor
  Extra inputs are not permitted [type=extra_forbidden, input_value='eid:evnt_...']
hasMore
  Extra inputs are not permitted [type=extra_forbidden, input_value=False]

That 400s every workflow start, on the first SDK call after the workflow body is reached.

Suggested fix

Either:

• (a) extra="ignore" (or extra="allow") on EventResult specifically — appropriate if these are response metadata that consumers don't need; or
• (b) declare cursor: str | None = None and has_more: bool | None = Field(None, alias="hasMore") on EventResult — appropriate if they're part of the contract and worth exposing.

Context

This is the second EventResult schema-mismatch observed against the live server in vercel==0.5.8 — the first being #116 (RefDescriptor returned in event/run/step despite remoteRefBehavior=resolve). May be worth a broader audit of world.py's response schemas against the actual server contract, possibly by golden-recording a few representative responses in tests/.