Discussion: Contract system

  • @artch said in Discussion: Contract system:

    But automatic usage of contract templates is very unlikely. Both parties should be on the same page here, using the same conventions, agreeing on the same conditions, being neighbors in the game world, having very specific needs and demands matching each other. The chance of this happening in the real world is almost zero. Too much work for such exotic feature.

    I can see your point of view. I wonder if you know what percentage of players automatically trade on the market? Probably a hard-to-gather stat, but I imagine the number of people automatically doing contracts would be quite a bit lower, so if you wrote some clever auto-contract code, the chances of anybody else nearby having code that could understand that would be rather slim.

    On the other hand, what is the overhead of allowing automatic behaviour? I guess the traffic for a "getAllContracts" call would be quite high if it included the code string, so I guess it would probably have to just contain description/player/tick info. An one-tick-delayed call (like segments) that pulled a contract text string should work though, and I would have thought that'd be the only non-trivial thing to implement. Everything else, like checking the code against a third party template could be handled by the user. I do see drawnbacks in a system that only really works if you're also using a third party library, as I doubt many people would be able to do anything more complicated than a simple comparison but it seems like adding automation isn't a huge step having done all the work for non-automated contracts.

  • This feature sounds quite interesting, the first (and most interesting imo) use I thought of for this, is for private servers with bots that would offer contracts when they come into contact with the player, as a 'quest'. Upon fulfilment the bot could then offer more contracts. Effectively creating a 'quest line'.

    This would obviously require some degree of automation in creation/offering of contracts (though not in acceptance of contracts), and ideally the ability to add some text with the contract for the quest descriptions. (Note: I'm mostly think of individual, i.e. effectively single player, servers. But the concept could easily scale up for multiplayer private servers).

    In terms of the contracts themselves, I see them most useful if the code simply checks the criteria for completing the contract. e.g. I might offer someone a contract that simply checks that a room has no owned structures in it, other than a controller. This is obviously a contract to destroy a room, but the contractor is free to achieve this any way they want (including bribing the current owner to respawn). But to my second point, there should be a mechanism for a contract to say "I'm done, contract completed" and award the player their credits immediately (or, more likely, next tick).

    Third and final point, I was thinking of how I'd check if someone had destroyed a player with multiple rooms, one option would be require they have vision in every room I wanted taken out, but using some kind of memory would be nicer for the contractor. Would it be possible to have some kind of memory that was only modifiable by the contract code for the duration of the contract (perhaps, have an option to reserve a memory segment for a contract)?

    Just my thoughts.


  • From discussions in slack I came to the conclusion that contracts are most useful to check for conditions instead of executing code that queues intents.

    This way contracts require an implementation from the person fulfilling the contract, which not only allows the contractor to solve it in their own way and optimize it for stuff like CPU, they can be seen as some kind of quest or mission.

    I completely understand the need for manual review, but even though I'm repeating myself, limiting it to manual interaction only is a mistake in my opinion.

    When going for parameterized contracts you could easily create a checksum of the module and require to review the module at least once, after that your code is free to accept any contracts with the same checksum. Additionally your code can verify whether it actually wants to accept a contract based on those parameters.

    In the long term it would be nice being able to accept a contract without manual review, either by a well established list of tested contracts or by adding the exact same contract module to your own code.

    Example contract

    Following is a scenario of how I expect the process to look like when working with contracts.

    Player A: contractee Player B: contractor

    1. The contractee create a contract module, in this case it's a module that requires a nuke to be sent by the contractor to a specific position:
    const { x, y, roomName } = Game.contract.parameters;
    const pos = new RoomPosition(x, y, room);
    const hasVision = roomName => roomName in Game.rooms;
    const isMyRoom = roomName => _.get(Game.rooms, [roomName, 'controller', 'my'], false);
    module.exports.loop = function() {
    	if (!hasVision(roomName)) {
    		return false;
    	const nukes = pos.lookFor(LOOK_NUKE);
    	if (!nukes) {
    		return false;
    	return nukes.some(({ launchRoomName }) => isMyRoom(launchRoomName));
    1. The contractee creates a contract based on this module:
    function requestNuke(pos, reward) {
    	const { x, y, roomName } = pos;
    	return Game.contracts.create('contract-nuke.js', reward, { x, y, roomName });
    requestNuke(new RoomPosition(25, 25, 'N0E0'), 100000);
    1. The potential contractor ( Player B ) views all of the available contracts in the UI, reviews the contract's code and approves it, the checksum is then added to their list of allowed contracts.

    2. Player B's code views a list of available contracts and chooses appropriately, afterwards every accepted contract is getting executed (contracts won't be accepted until the next tick). If the contract hasn't been reviewed yet an appropriate error code will get returned.

    const CHECKSUM = '1b1774169003e863931fa3c5ddbfa7f1';
    const MINIMUM_REWARD = 80000;
    const myRoom = room => _.get(room, ['controller', 'my'], false);
    const getNuker = room => room.find(FIND_STRUCTURES, { filter: { structureType: STRUCTURE_NUKER }});
    const hasNuker = room => !!getNuker(room);
    const inNukeRange = (room, target) => Game.map.getRoomLinearDistance(room.name, target) <= NUKE_RANGE;
    function getFirstNukerInRange(targetRoom) {
    	return _.first(_.values(Game.rooms), room => myRoom(room) && hasNuker(room) && inNukeRange(room, targetRoom));
    const isNukeContract = contract => contract.checksum === CHECKSUM;
    const isNukeContractValuable = contract => contract.reward >= MINIMUM_REWARD;
    const isNukeContractInRange = contract => !!getFirstNukerInRange(contract.parameters.roomName);
    function acceptNukeContracts(contract) {
    	if (!isNukeContract(contract)) {
    	if (!isNukeContractValuable(contract)) {
    	if (!isNukeContractInRange(contract)) {
    function executeNukeContracts(contract) {
    	if (!isNukeContract(contract)) {
    	const { x, y, roomName } = contract.parameters;
    	const nuker = getFirstNukerInRange(roomName);
    	nuker.launchNuke(new RoomPosition(x, y, roomName));
    module.exports.loop = function loop() {
    	_.forEach(Game.contracts.available, acceptNukeContracts);
    	_.forEach(Game.contracts.accepted, executeNukeContracts);

    This is a fairly simple implementation (but devastating none the less!) but I hope this example shows how automation would be able to handle contracts.

    Contracts API Draft

    The following is a little draft of how the contract API could look like, it's probably a good idea to replace the properties under Game.contracts with a function similar to Game.market.getAllOrders.

    • Contract object
    property type description
    id string A unique identifier, can be used to interact with a contract
    checksum string Checksum of the contained code, each checksum will have to be allowed manually once by reviewing the associated code
    contractee string The player of which the contract was created
    contractor optional string The player that accepted the contract, might not be set yet
    reward number The amount of credits that the contractee pays the contractor once the contract has been fulfilled
    parameters otpional object Any valid json object that can be used to modify the modules behaviour
    • Game.constract: Is only available from within a contract, contains the currently executed Contract object.

    • Game.contracts.available: Array of available Contract objects.

    • Game.contracts.accepted: Array of Contract objects that you accepted.

    • Game.contracts.created: Array of Contract objects that you created but are not accepted yet.

    • Game.contracts.running: Array of Contract objects that you created any were accepted by someone else.

    • Game.contracts.create(moduleName, reward, [parameters]): Create a new contract

    parameter type description
    moduleName string Name of the module you want to create as a contract
    reward number The amount of credits that the contractee pays the contractor once the contract has been fulfilled
    parameters otpional object Any valid json object that can be used to modify the modules behaviour
    • Game.contracts.accept(id): Accept an available contract
    parameter type description
    id string A unique identifier of the contract you want to accept

  • @artch

    Can be both. Code is proposed by the party creating the offer, and an offer can be created by any party. When you create an offer, you write code and choose one of two options:

    I am the client (I pay) I am the contractor (I execute the code)

    Glad to hear. Is there any plan to support "catalog" contracts? (i.e. the contractor creates a "catalog entry" for remote mine defense), and players are free to accept that offer with certain terms (e.g. {room: "W12N14", whitelist:["Alice","Bob","James"]}), and the contract module contains a function to calculate the cost for different parameter sets.

    Little example pseudocode I wrote for a module:

    //@param options.room: string (Room name of room to be defended)
    //@param options.whitelist: string[] (People to not shoot at)
    module.exports.loop = function(options) {
    	if no creep exists
    		spawn creep
    		return false
    	if creep.room != options.room
    		moveTo room
    		return false
    		hostiles=find creeps not in options.whitelist
    		if (hostiles.length>0)
    		return true
    module.exports.bid = function(options) {
    	myroom=find my closest room to options.room
    	range=distance between myroom and options.room
    	if (range>10) {
    		return false; //No-bid on this one.
    	} else {
    		//bid 100*range credits as a contractor's fee.
    		return 100*range;

    Without at least automating simple contracts like this with variable parameters, I can't see contracts becoming very useful. (This lowers the barrier to entry so that even small 1000-tick-long contracts could be practical. If 2 people need to be online at the same time and negotiating, working with contracts would be a massive effort and inconvenience.)

    While I understand that automated code-review is not something that you would be interested in allowing, if a module like that could be setup as a non-editable offer in a player's "catalog", then other players could manually review the code, and have their code automatically request quotes/bids for tasks.

    I don't see contracts being very useful if you have to negotiate them every time. Imagine if you had to negotiate the price of food with the manager every time you went to the store! Trade would be impossible.

    It is handled as usual, you will see an error in your console.

    But if contracts are "read-only", is there any way to fix this error? Perhaps have something like: if a contract fails an assert(), then it dies at no cost to either player?

  • I have to agree with some others. I can see that it is interesting concept. But I think it will see little uptake for the amount of development effort, I could well be wrong. But it seems to me other areas should have a higher priority.

    Wasn’t there a battle arena planned? πŸ™‚

    Battleground type matches between geographically distant players would be awesome and allow low level GCL players to get experience with battle in a safe β€˜non-ganky’ way and give high level players the ability to show off their prowess as they wish to.

    Anyway. Veering widely off-topic.


  • @artch said in Discussion: Contract system:

    @w4rl0ck My only concern of what you have mentioned is modifying prototypes. We're still debating on how to handle that. All other things could (and should) be covered by contract conditions.

    That's what worry me the most. Looking at a code snippet doesn't account for prototypes and global changes.

    Example with the code given in first message: what if I change creep.prototype.harvest() to always return OK ? Or what if I change _.find() to return a custom object (with similar methods to Creep) ?

    If I cannot ensure that the code is reliable, it's very dangerous.

    Regards, Hiryus

  • @kraiik said in Discussion: Contract system:

    This feature sounds quite interesting, the first (and most interesting imo) use I thought of for this, is for private servers with bots that would offer contracts when they come into contact with the player, as a 'quest'. Upon fulfilment the bot could then offer more contracts. Effectively creating a 'quest line'.

    Thats the most interesting think i read in today. I for myself wish more casual npc elements, like events of spawning raiders (a little bit more than the normal invaders, maybe a small base, like a playerroom at rc3-6), other biomes, bosses, small quests/instance shards. Maybe the contract system is a way to more active gameplay. Sharing code can be interessting, but i am not sure how usefull it could be. It can bring more player interaction, but i think a kind of ingame "clan system" would be better/easier for this.

  • Don't know if this was mentioned, but running contracts at the end of the tick might be problematic. More flexible way would be allowing contracts to be listed and executed as part of main tick (maybe as an option, default being at the end of the tick). This will allow better CPU handling (especially in the context of an OS). Contracts can then make executing frequency to be a requirement if it matters. Host can run contracts before own optional and expensive code.

    An option for exposing some clearly separated host code would be nice too. Then players can define and implement interfaces for basic things like creep spawning. We already have POSIS (a solution waiting for a problem currently :)) that is implemented by several people and can be easily implemented by anyone running an OS.

    For example contract can take in a context object provided by the host. It would be up to contact writer and host to negotiate exact details.

    let context = {};

    Game.contracts.forEach((c) => c.execute(context));

  • Quick thoughts (@o4kapuk here you go):

    1. Contract versioning so that you can run a contract you've verified before without having to check for changes.

    2. Contracts where you pay to run them so that you can rent code. Eg buying defense code from someone when you're under attack or renting room startup code for intershard portals. Also automated room planner would be great for contracts. Basically contracts could be NPM modules that you could run for a fee.

    3. Automation is a must.

    4. Barebones autoreview for contracts that checks for unclaiming/respawn/evals/infinite loops etc will be made either by the community or packaged with it

    5. Contract entrance/exit functions. Graceful ways to start and end contracts, eg if a contract stores things in memory to have it clean up after itself and make sure its not overwriting. Eg accept contract, start contract, run contract, end contract.

    6. Contract specific memory segment would make contracts cleaner to write and run.

    7. Contract permissions: allow for limiting contracts access (eg app permissions) like sandboxing memory to that segment or locking market.


  • I think finishing what is already drafted... like power creeps.. should be a priority. Before even drafting new features.

    Just my 2 cents though.

  • This seems like a cool feature with some fun possibilities but I do worry about it leading to some undesirable outcomes.

    There is already a situation where newbie players can use open source code developed by veterans and have an extreme advantage over other new players.

    These re-used code bases can be large and complex. This proposed contract system would incentivize the creation of highly modularized, highly reusable code that is built for highly specialized tasks. There will also be incentive for these contracts to be optimized at some reasonable level if they are to be accepted by those who will be executing them. These pieces of code are intended to be executed for pay and create interesting exchanges between players and in a way expand the reach of every player by using other willing players. This is a fun idea and I think it would be used in some fun and interesting ways that would make the game more enjoyable, but I also see it being used in a much less desirable way.

    It doesn't seem an unlikely future where you recognize the way you are getting attacked because you read the code for it in a popular contract, or you destroy a players room and it gets built back up faster and more efficiently than the rest of their code has ever behaved because they copy pasted another popular contract for rebuilding a room.

    I personally haven't been super active for a while now but when i was more active I always tried to write my own code for things except for small snippets shared back and forth on slack. I enjoyed the challenge of trying to improve my own code or come up with solutions for things. I also enjoyed being attacked by other players who I could learn from. It is fun to see how others solve similar issues. Conversely, there is little to no fun in being bested by a player who is obviously using known open source code that they did not write themselves.

    I can see this contract system making this a bigger issue and causing more copy-paste playing and for that reason I am against the feature in spite of the possible fun uses it could have.

    I know that many players do not share my views on this topic. Some may like the idea of being able to copy paste in code for specialized tasks. There are many games out there that are fun and require creativity but eventually become a game where if you want to be successful with little to no effort, you can just look online for popular "builds" pioneered by veteran players and copied by many in the community. I would hate for Screeps to head in that direction regardless of intent.

    This is just my personal view and the way I feel about Screeps and what makes it fun for me. I know there are many who have opposing views and thats fine by me, the opposing views are valid. Not looking to spark any debates, I just want to present my opinion on the matter solely as my personal feedback in relation to the contract system.

  • int_max

    @dignissi Imagine if you had to negotiate the price of food with the manager every time you went to the store! Trade would be impossible. We do that at the market here in Thailand, trade works fine.

  • @starwar15432 Market != store. If you did in every discounter/supermarket it would not work. If you would need to negotiate with every online trader... they would not do. And you do not need to inspect the goods as you would need to inspect the contract (the analogy would the to test the goods with a mass spectrometer, i think )

  • Personally I am not a fan of this feature, but as its so open ended its hard to see how it will be used in practice. I think there are improvements that could be made to combat. But as that seriously off topic I will put it in a new post.

  • I like the idea to pay others to do stuff but the current suggestion is filled with problems.

    First forcing the execution at the end of the tick is unacceptable, it is not like your plumber crawls out of your phone as soon as you called him.

    Second Automation is a must.

    Third any code inside a contract must run within a vanilla environment to ensure safety and consistent execution.

    So @postcrafter addresses a lot of my concerns but I like to make one big change, contract scripts should not be modules at all, they should be a function.

    Why should they be a function? Because you can give a function parameters even at runtime.

    In example the contract specifies the first three fields fixed at creation and the contractor is able to give a creep object at runtime so the script has a creep to do work with.

    This method would even allow changes of those fields from the client while it is active if the contractor agrees.

  • I think the value add to the game is less than some of the other ideas I've heard, e.g. power creeps.

    Unbreakable contracts seem to go against the idea of a war game, where you can breach contract and then get punished using whatever means your opponent has (including in the metagame, convincing other players to not trust you).

    The most interesting nugget of this idea to me is the idea of programmatically executing code on behalf of another user, but this is actually implementable using terminal messages and public memory segments, plus if I breach the contract people can "hold me accountable" however they want.

  • So it sounds interesting with a few caveats:

    With some contracts, like courier contracts, I would want to charge extra if my creep got attacked. So it makes more sense that the client puts money in an some kind of escrow and then the contract can return data on how much get's paid out (or paid back to the client).

    Additionally, if the escrow is changeable, then the duration of the contracts could be also. It would allow for potentially indefinite contracts as long as both client and contractor agree.

    Contracts explicitly allow rental of cpu. With the use of public segments between the client and contractor, the client could offload their pathfinding or other processing only tasks to the contractor.

    Also guaranteed processing should put contracts at the start of the loop rather than the end. Not only would this help guarantee enough cpu for the contract, but it might help player's code adjust to the cpu usage.

    It's certainly an interesting idea, and one I wouldn't mind getting further thought.

  • People are talking about offloading much larger pieces of code than I had first thought. Postcrafter just said on slack that "contracts are a great way to specify conditions, not execution", and I agree with him. How would people feel about a strong limit on the size of a contract. Say, 512 characters maximum. This would mean you'd be able to specify what you want done, but now how it's done.

  • Culture

    I'm on vacation so I'm not following this daily. However, if automation is being completely ruled out than it is my personal opinion that development time would be better spent on some of the already announced features (power creeps, arena) instead. Without some way to verify and automate contracts it means people will have to setup a lot of bootstrapping and custom code for each contract, as well as a lot of code review, and honestly I don't think many people will engage in that.

    Having some type of "contract catalog", "standard library", or "written by" verification would make this system far more usable, and without it I think this feature would be very niche.


  • Dev Team

    I just want to post it here again:

    In order to create some "marketplace-like" behavior to popularize contracts usage, we can develop a public offer system, where you create an offer without a direct respondent, and all interested parties can view all such public offers via special UI. When someone accepts a public offer, you're notified (both via UI and API) and should finish the deal to start the contract (again, either via UI or API).

    Thus, creation and acceptance would be manual, but dealing could be both manual and automatic.

    To make it more clear:

    1. You write code, create a contract (manually).
    2. You set up this contract to be public rather than directly invited (manually).
    3. The contract is then listed in the Public Contracts UI.
    4. An interested party views your contract and accepts it (manually).
    5. You finish the deal (either manually or automatically).
    6. The contract starts, you track the progress (either manually or automatically).

    Still looking forward to hearing some feedback on this.