As in a friendly sort of theft.
As in, when you went through the kitchen you kiped (kayped? caiped? keiped?) a cookie. When you went through the office lunchroom you kyped a donut.
I am a good speller, really I am. I have heard this word but I don’t think I’ve ever seen it. It’s giving me agita.
Sure you’re not thinking of swipe?
I’m sure. It does rhyme though.
It’s also possible you’re hearing kike, as in meaning #12 here, a verb meaning “steal.” It’s highly offensive, by the way. I never heard it until I moved to the western U.S., and I’m sad to say that I hear it frequently there, often with no ill intent on the speaker’s part, as well as no understanding that it’s a slur. Clearly “kike,” in my experience, not “kipe.” You might want to check this out since we have two words with similar sounds used in approximately the same way.
I had always heard it as kife
From my memory, and a swift examination of online resources, it appears that “kipe” is the correct spelling, with “kype” an idiomatic or regional variation; “kife” does not appear to be in very common use, and may be a mistake, and “kike” as a synonym or variant of “kipe” is just too bizarre for words.
Doesn’t “cop” work, too?
My experience is kipe = nick.
I’ve always thought it is spelled kype (but can’t recall ever actually writing the word). Alas, Webster’s Ninth Collegiate has nothing on it (I looked for several variations).
I wonder if it originated as a dialectical past participle of cop; or perhaps a portmanteau of cop and swipe.
And yet, I assure you that it is actively used.
Not really. I remember “jew” being used as a verb meaning the same thing when I was at school. “Who’s jewed my ruler?” Nasty and offensive, sure, but then so are schoolkids. 
Other racial or social-class-related nouns were used as verbs in the same way, e.g. “chav” and “pikey” (“chavved” and “pikied” being the inflected forms).
Never heard “kipe”, though, so sorry about the hijack…
I think if “kike” is being used in that way, it’s off a variant of “kipe”, though. That meaning doesn’t come from anti-Semitism.
Always heard/used kipe to mean snatch; never heard kike used as a verb. (50s & 60s California.)
Not necessarily - see my post directly above yours.
It’s conditional on where you live, innit? Some of our Celtic brothers spell it “cope,” as in, “I absolutely cannot kipe with alla different brands of mustard here.” Some other folks spell it “cape,” as in, “Ama drive ta Kipe Canivverrl Satdy. Wanna go?” 
Same here. Used in late 50- early 60s in California.
I’ve never heard this. Obviously it’s a regionalism, but where are you located? Other posters who have heard it all seem to be from California or the Western US.
In the context of taking some donuts from a table as I passed by, I would say I “swiped” or “poached” them to indicate that I was not, in fact, originally expected or entitled to take them by whoever laid them out, and that said person was not there to see me do it.
I’ve rarely heard the term “Jew” used as a verb; when I have it’s always been in the context of haggling or bargaining with a negative result for the speaker, and clearly anti-Semitic in origin (“I tried to get <X dollars> for it, but the guy jewed me down to <85% of X>”). When called on it, the speakers generally express surprise that it’s offensive, much like the use of “gyp” to mean cheat or deceive is so commonly used that not everyone realizes it’s an ethnic reference to Gypsies.
In fact, the last two people I called on it claimed it was as much a compliment as anything else, since “they” (the Jews) “pride themselves on getting the best deal, don’t they?”
Heard and used kipe. Not so much a friendly swiping of something as a spur of the moment thing. Grabbing on the way by. Minnesota.