Goalkeeping coach Ludo has run the rule over the 31 year old on several occasions and says:
"I saw him a few times in the last games of the season and watched him on video; we have been looking at him for a while.
"I think he is a very agile keeper, experienced, and a good shot stopper.
"He is the sort of goalkeeper we need, he knows the first division so he is a good signing for us."
West Ham had previously taken a look at young Yeovil keeper Chris Weale on trial but Ludo explains why they went for a 30 year old instead.
"I think it is a good combination to have one young keeper and one experienced keeper," he says.
"It is quite risky to have two young keepers and it always better if there is an age gap between them."
James played 476 games for Walsall over a 10 year span which led to a testimonial.
"I think it tells how consistent he is and that is good for us," he says.
"Goalkeepers can learn until their career is finished and there is always something new to learn with new rules."
Walsall were relegated from the first division at the end of the season and Ludo adds:
"He had plenty of work to do and showed in the games that he is a good character.
"He is a good lad and I think we need someone like him."
James effectively replaces the outgoing Pavel Srnicek, who signed on a short term deal from Portsmouth towards the end of the campaign, and Ludo says of his Czech mate:
"I hope he will find a club and do well.
"Steve was very happy with working with him and says he learned a lot from him."
So will James be a number one or a number two?
"I can't tell you that!"
James, known to fans at the Bescot stadium as 'Wacka', had previously been on the books of Notts County who released him before he joined Walsall.