Function dump_params

src/mcp/shared/peer.py:44–62

Serialize a params model to a wire dict, merging `meta` into `_meta`. Shared by `ClientPeer` and `Connection` so every typed convenience method gets the same `_meta` handling. `meta` keys take precedence over any `_meta` already present on the model. `meta` is serialized through `R

(model: BaseModel | None, meta: Meta | None = None)

def dump_params(model: BaseModel | None, meta: Meta | None = None) -> dict[str, Any] | None:
    """Serialize a params model to a wire dict, merging `meta` into `_meta`.

    Shared by `ClientPeer` and `Connection` so every typed convenience method
    gets the same `_meta` handling. `meta` keys take precedence over any
    `_meta` already present on the model.

    `meta` is serialized through `RequestParams` so Python field names emit
    their wire aliases: an inbound `ctx.meta` carries `progress_token` (the
    key `_extract_meta` validation produces), and forwarding it outbound via
    `meta=ctx.meta` must put `progressToken` back on the wire. Keys not
    declared on `RequestParamsMeta` pass through unchanged.
    """
    out = model.model_dump(by_alias=True, mode="json", exclude_none=True) if model is not None else None
    if meta:
        wire_meta = RequestParams(_meta=cast(RequestParamsMeta, meta)).model_dump(by_alias=True, mode="json")["_meta"]
        out = dict(out or {})
        out["_meta"] = {**out.get("_meta", {}), **wire_meta}
    return out


class ClientPeer: