...there's a first time for everything.

The standard spiel, as told to people who have normal problems in this genre, starts by saying that alignment is a shortcut. Just because Law is an ideal to aspire to doesn't mean it actually does anything in negotiations other than tell you a little bit about how the other person thinks. (Not even all that much! Someone can project "Lawful" and have that name mean all sorts of specific things, after all, and some of them are Razmir.) If you're working cross-alignment you can't instantly trust your counterparty on questions like "a fair split of profits," but you can't always do that anyway. You're doing without the shortcut and that's fine.

The good specialists, such as the ones here at Swift 4.8.3.3, won't give Cam the standard spiel. They can avoid assuming most people are Lawful Neutral and like it. (He might still notice the Lawful Neutral baseline hanging around in the background.) For Chaotic Good people, it sometimes helps to think of this whole "Lawful" construct as less a fundamental force of the universe and more just a bunch of people doing their own thing, except that it's the same thing and they're doing it because it scales well.

...although some people can get very annoying about how everyone else should be Lawful. Other people might make it a pillar of their personal identity, and it sounds like Carissa might be doing that one. Not to armchair speculate, but Carissa might have been thinking of Law as the source of every good thing because in Cheliax that was basically true. That particular issue tends to get less pronounced with exposure to. Like. The universe.

But yes! People in Carissa's position thinking Cams are fundamentally untrustworthy is a common problem! The most basic thing that needs doing from Cam's side is showing the Lawful person that it is actually possible to form expectations around his future actions at all. Convincing her of specific choices Cam would or wouldn't (or could or couldn't) make-- it's hard for that to be reassuring without a shared foundation of "it matters to this person whether things are logical." Which Lawful types sometimes conflate with alignment.

When any miscommunication can sound like something unexpected and anything unexpected can pattern-match to "this person is Fundamentally Unpredictable," the usual solution is to go through intermediaries. You can talk to your lawyers talk to my lawyers talk to me. A trained mediator will respond to things like "is pointing out you could already communicate with Lastwall a threat" with either "no" or "let me confer with my principal" and then "no." Or "yes, and here's what it was trying to accomplish and why it seemed like the best option," but it's usually no.

They can work out the communication problems easily enough, especially since Iomedae already handled some unknown amount of that. Assuming the process is taken care of, what does Cam substantively want from an agreement? Ability to conjure on his own recognizance, ability to directly oppose Cheliax, a promise that Carissa won't banish him?

"I don't even have a plan for directly opposing Cheliax at this time! I want to, uh, indirectly oppose Cheliax, by giving its enemies stuff. I would appreciate very much the ability to make everyday objects - replace my computer, get a change of clothes now and then, conjure reference materials - going through her about stuff like massive amounts of diamond isn't fundamentally unreasonable but it does reduce my ability to react in an emergency if something comes up - and I can understand why she would be freaking out about my ability to make everyday objects given what happened with the potato letters, but it remains really inconvenient and nerve-wracking to be without, right now I can't even replace my computer if something befalls it."

He'd also really like to not be banished, but like, not under all possible circumstances, like if someone has mind-controlled him and is using him to let Rovagug out or something.

Broader existing permissions are the kind of thing that's easier to negotiate at one remove. If they say "this permission will not allow any harm Cam can't already do through the medium of potatoes" then it won't come across as threatening.

In Axis this would involve a lot of representations by Cam that this is actually true, or when something does remove a meaningful constraint they can agree to limitation on what he'll use the new permissions for. A conjuration "for informational purposes only" would be understood to let him make whatever scale models are most convenient and have it actually not matter whether the material is specified not to be diamond or a critical mass of something extremely deadly, because using it to enrich or destroy someone would be outside the agreement. People outside Axis usually prefer to think in terms of what they can and can't do, more than what purposes they can use which things for, but they may end up having to do both.

They can almost certainly at least get advance permission for duplicates of anything Cam currently has. Possibly with time limitations, depending on Carissa's current paranoia level about things he can do with a network of computers that he can't do with one. Beyond that, one possible plan is to negotiate for blanket permission to make anything in common use by human civilians in Cheliax, or some other Golarion country. That would probably allow enriching countries without further permission, while also preventing anything exotic if Carissa is still worried about that. Anything commonly used by human civilians in Cam's world of origin would be far better, but that they'd be asking Carissa to agree to blind.

...the everyday objects problem might just be solvable with money. Cam could create a duplicate of his normal living space, plus duplicates of some everyday objects exactly as he previously conjured them, and with written explanations if those exist for anything where the function isn't obvious. They could get people to inspect them (possibly involving magic unknown to Cam) and confirm they are what they appear to be. This might not catch everything, if at home Cam has a toothbrush that is also a death ray, but truth magic might cover that gap. Could be worth trying; if having a whitelisted supply of normal items would make Cam less nerve-wracked that's genuinely very important.

Emergency clauses are a good idea. Obviously the binding doesn't know or care what's an emergency, but could Carissa authorize creating a chunk of diamond once, without specifying a time? If it's nonmagically agreed to be for paying people in emergencies, Cam would at least have to report it or go without next time he needs it. Then he could betray Carissa and do damage up to one Wish, which is a lot, but since the stakes they're playing for are much bigger than that she might consider the information worth it. Or just actively want him to have the resource in case she gets Dominated or similar. If she thinks she's more likely than Cam to have that problem.

If he makes diamond dioramas they could be stolen - presumably this is unlikely in Aktun, but it seems worth mentioning.

Duplicates permission would be good, it'd let him change clothes and not be so protective of his computer and violin. Uh, in the interest of full disclosure, this would without some careful phrasing allow him to install chiplock computers in people, which he frankly cannot think of any reason whatsoever to do without their consent but might reasonably want to do without Carissa's.

He doesn't know what is in common use where in Golarion but the peanut gallery can help with that.

His toothbrush is not a death ray; duplicating his house would be slightly complicated because he does have a black hole and a swimming pool but not in a way that can't be worked around pretty straightforwardly. He doesn't keep all the things he might need around in his house, though, because when he's in his house, he doesn't need anyone's permission to make a dustcloth or a dish to replace one he drops or anything like that. Duplicates of things he already has and maybe a few electronic peripherals he can swear are equivalent in function to the ones built into the shuttle they abandoned on the moon would do the trick.

Carissa is, to the best of Cam's understanding of how his current binding is functioning, able to authorize creation of one diamond of a particular size at an unspecified time.

The way they'd pitch a duplicate-household-items permission to Carissa--well, to a generic person who cares a lot about their Lawful identity; Carissa herself currently has a lot of question marks--is that both sides should try to be the kind of negotiating partner who reliably makes their counterparty better off. Even in a case like this one, where making each other better off compared to doing nothing at all is pretty trivial, a good Lawful person isn't going to impose costs for no reason. They expect they can have Lawful people convince her of that if she doesn't already agree.

Wanting comfortable or familiar things is pretty normal! Carissa seems likely to see it as unimportant, maybe even as weak (because Cheliax). But a perfectly Lawful person who had those opinions would still agree this is a cost she's imposing on Cam and would stop doing that if she could. Then they'll just have to show her it isn't trading off against any new risk of malfeasance or world-destruction if Cam conjures his... everything except his black hole, that's worse than a death ray actually.

It's also strategically useful, right, for Carissa to see more of what kinds of material prosperity are available. She probably has a better guess than Cam's of which household objects would be tempting as luxuries to people like Razmir, or life-changing for ordinary people on Golarion. So it's not just trading a side project for vague human comfort. If doing it once would make them better at their goals then they might as well check for detectable risks and whitelist things afterward. Having it be specifically Cam's stuff shouldn't be strictly necessary, if having his house and effects examined sounds privacy-violating; it's just that "duplicates of things that have been in Cam's house in the last however long" should get him the permissions he needs while being obvious that it's at least not selected for any hidden dangers.

Cam's diary is chiplocked and his house per se isn't particularly private! Well, he does have a drawer of sex toys but maybe these will be life-changing for ordinary people on Golarion, who knows, at any rate he is not particularly private about their existence.

Convenient. Carissa has already agreed in principle to conjuring things only Cam recognizes to pay Razmir with, so it Wouldn't Be Very Lawful Of Her to object to the safest possible version of allowing it. What limitations she asks for will be pretty informative about what they're even negotiating with right now. Getting from there to a whitelist is hopefully achievable.

Aside from his active Worldwound-closing efforts, Cam's other obvious bargaining chip is refusing to make things. Right now most of what they're doing is pursuing common goals, but at what level of frustration would he just quit? Hare off to do whatever, with the limited conjuration ability he has, and take the risk of being banished about it?
(If the answer isn't never, they should make sure to phrase it in a way that doesn't come across as a threat. It's not obvious whether Carissa understands decision theory.)

It's... probably not never but he's actually having a hard time thinking of situations where it would get to that point. He would have to be running pretty low on common goals but somehow confident that he could get something worth doing accomplished in the time before being banished and unable with all the lawyers material objects can buy to get Carissa to come around on it.

That is exactly the kind of thing that's objectively a very conciliatory answer but also might sound terrifying. It might come across to the counterparty like "it's not my first resort, but no promises I won't eventually have an ultimatum and end up seeing what I can get away with." If they're Lawful and wrong. They'd have to be pretty hostilely predisposed, but, well.

On the less-in-need-of-translation side, it sounds like Cam would be judging possible deals here in terms of goals and accomplishing things worth doing? As opposed to whim or aesthetics or personal dignity. Especially that last one; a lot of people in Cam's position would object to the baseline assumption Carissa shared with many other summoners that Cam should be controlled and any deviation from that is a threat. Anyway, there's any number of perfectly valid desiderata that people sometimes base their thinking on. But if Cam's first thought is about what he can achieve then that's a very familiar language to many Lawful people.

It is not ridiculous for summoners to want to control their summonses! Cam has been on many such summonses and kept coming back for more. It's just adversarial and inefficient in all the ways adversarial relationships usually are. Uh, having had a little while longer to mull on it he thinks all situations where he would quit and run off would be information-disclosure-type situations, that being the sort of thing that can be accomplished very fast and without much conjuration freedom. Inconveniently that is also kind of the thing that Carissa is most intensely jumpy about. He'd really like an updated list of who she considers her enemies and what interactions with/about them are okay.

Agreed. Hard to negotiate properly without knowing what the other side wants, but at least it's obviously not in Carissa's interests to withhold that list.

The usual solution for secrecy problems is an NDA. Obviously there's the problem that any situation where Cam is considering an attempt to just leave is one where mo agreement can really be enforced, but does he think he'd hold to one voluntarily? Relatedly, are there things Carissa might say or do that would provoke him into spilling relevant beans, that she could agree not to do?

Inconveniently Cam has to acknowledge about himself that he might be the sort of person who'd get incredibly cute with any NDA that he wouldn't instead break by accident - either it's trying to hermetically seal information such that he can't act on it at all and he doesn't think he can, in fact, do that, or he's allowed to stare at people making helpful facial expressions and occasionally reminding them that he's under an NDA, he's not aware of a really clever way around that but maybe the Axis lawyers are?

The hypotheticals are getting pretty abstract for him, can they give him some toy problems to hook his intuitions to?

Suppose Carissa resolves her current situation in favor of being uncomplicatedly Asmodean, at least as much as that's possible for a philosophy that's sometimes opposed to people being uncomplicatedly things. They negotiate an agreement that covers closing the Worldwound and doing absolutely nothing else. As soon as they pull that off, Carissa announces she's not interested in any further deal and has made resurrection arrangements, and immediately stabs herself.

If Cam had previously agreed to secrecy on some topic, would he at that point follow the agreement? Or would he use Carissa's last moments to hand Lastwall and Sothis and Razmir a pile of information- and calorie-dense material goods?

If so, that's equivalent to not being able to make the agreement, which is what the Lawful people think of as the problems with Chaos.

...if she kills herself he probably won't have time? Also, uh, the First Vault now contains all that information. But if he imagines that she accidentally misses and dies a more lingering death he - okay, maybe tries to administer medical attention, but supposing he can't do that for some reason... he would certainly be tempted to do the chaos thing but he does not actually have prepared a care package appropriate for that situation and doesn't have to prepare one.

So that sounds like he's not approaching an agreement as really giving up the future option. And that's fine. No one here is going to try to convert Cam into being Lawful enough to go "well, the deal was worth it in expectation, so now I have to just let her banish me." That still leaves them in the situation where everyone expects the last move to be defecting in any way available. At least if there ever is a clear last move, which hopefully they can avoid with an agreement that lasts indefinitely.

Standard procedure here is to find anything at all where they can trust each other-- usually at least that he'll reliably pursue his own interests, and that that includes following whatever deal they make. That can work in specific cases, maybe even lots of specific cases, probably more than Carissa expects with her Law-related blinders.

He's already thinking along the right lines of how that might work for an NDA. If Cam can't easily mass-spread information, they can probably fill that gap with a verified statement that violating secrecy would take work he has not done, has no intention of doing without notice, and maybe an estimate of how much. Probably repeated regularly to confirm nothing changed. This could maybe work as long as Cam values the continued ability to do things directly more than he wants Lastwall-or-whoever to have a complete set of whatever technology and textbooks Cam could get them.

Yeah, he is willing to verify that he has not done the curation and format conversion work that it would take to render down the Library of Hell into something more useful, has no intention of doing it without notice, has not commissioned or sought directions to a completed form of this work from another apsel, and would take, say, at least fifteen minutes to have something more useful than dangerous to drop on an ally? It wouldn't take that long if summoning worked here but it seems it does not so it'd all have to be technology stuff.