Mr Key said Mr Obama's message in the closed-door meeting was that there was "no need for alarm."
The president ran through the "shopping list" of outstanding issues and Mr Key said there was nothing on it that was alarming for New Zealand.
He said one or two countries would have a specific issues that was challenging.
"The question for leaders really will be will they allow a particular country to have a particular carve-out in one area."
If it happened, it would not necessarily be in areas he might worry about. That's a hint it that Japan and the US might have a special deal for rice and the automotive goods.
Mr Key didn't name the countries or good but said "it may be in New Zealand's interests...to find a way through that.
"None of them are of such significance that I can see that New Zealanders would even notice or be overly bothered by it."
That suggests that the United States and Japan will be looking for exemptions to protect rice and automotive vehicle production.
Meanwhile, New Zealand businesses are planning a "fighting fund" for a pro-TPP campaign once a deal is finished and in the public arena.
ANZCO meat exporters Sir Graeme Harrison revealed his plan in comments thanking the Prime Minister for a speech to an Apec New Zealand business delegation in Beijing.
Sir Graeme made mention of the street protests against TPP around New Zealand on Saturday.
"What we saw in the weekend on TPP, we have to engage like it or not," he said "so we in business will be there to help and we will put our hands in our pocket as well for a fighting fund because it is really necessary."