# A marketplace protocol optimized for localized trade of basic needs

Same structure for asks (queries) and bids (stores, offers)

## Usecases

* transport (rides, deliveries)
* accommodations
* store with permanent location
* store with single dynamic location
* store with routes (multiple schedules and locations)


## Core entity

* identity public key
* version (see changes below)
* location

### Location

* polygon (city boundary) or point/sphere (e.g. entrance, pick-up spot)
* origin only (e.g. store) or origin/target pair (e.g. rideshare)
* categories (entrance, delivery radius, drop-off point...)


## Optional core information

### Times

* schedules (opening hours) and one-offs (weekly market)
* ranges and point/sphere ("pick up around")
* negations ("but not between", "but not on")
* categories (store opening hours, transport time window, accomm lease time, reservation deadline ...)


### Product

* uuid (in the domain of the entity identity key)
* rdf schemas
* should be loosely defined so that entry can be "groceries" and price ranges
* extrapolate price to citing price on reference products against a price oracle, (but still instantiate)
* each article can be stated in both spot and range in multiple currencies


### Contact:

* URN (email, msisdn, im...)


## Auxiliary information

Client itself chooses and assembles providers / indexers.

* Entity description
* Linked resources (website, social media...)
* Municipality data (e.g. street address)
* Ratings
* Trust graphs
* Payment providers


## Datatypes

### Point/sphere
 
* optional progressive distance weighting formula, e.g. prefer items closer to the point (linear, curves...) or equally anywhere within sphere 



## Changes

* Version number increments for every change, no matter frequency


### Mutability

* Delta can contain only changes (add, delete)


### Overides

* time overrides, like "open now"
* availability overrides, like "sold out"
* price overrides, like "everything 50% off"


### Pubsub

* rapidly changing data
* entity that is moving around (taxi)
* prices that rapidly change (auctions)


## vocabulary:

* how does a vocabulary of "bare necessities" look like? (wood, maize, chicken, coal, single bed, car seat)
* should not require map through language hub (english)