I want develop a MMORPG game and completed the pathfinding function recently.

I used navmesh map that exported from unity3d,now I want set this on client-side and find the path.after this send way point to server-side.

server side check the way points is validity.

I have no idea a few days about how to check the way points is validity

I deleted your duplicate question.

You already have a pathfinding solution.

It should be easy to check that:

1) the client that wants to pathfind is close to the reported start point of the path.

2) the path-finder can find a simple path between each waypoint