Crate fts_server

Flow Trading Service (FTS)

This crate is part of a collection of crates that together implement flow trading as proposed by Budish, Cramton, et al, in which trade occurs continuously over time via regularly-scheduled batch auctions.

The different crates in this workspace are as follows:

• fts_core: Defines a set of data primitives and operations but defers the implementations of these operations, consistent with a so-called “hexagonal architecture” approach to separating responsibilities.
• fts_solver: Provides a reference solver for the flow trading quadratic program.
• fts_server: A REST API HTTP server for interacting with the solver and persisting state across auctions.
• fts_demo: An implementation of the core data operations using SQLite, suitable for exploration of flow trading-based marketplaces such as a forward market.

FTS Server

This crate provides a REST API for the core flow trading operations. Building the sibling crate fts-demo will generate an OpenAPI schema. A running server will host this schema at http://localhost:8080/rapidoc.

On the use of JSON and HTTP

It is true that JSON is a significantly flawed choice for (de)serialization of bid data. It is also true that a RESTful API over HTTP is questionable, at best, with respect to building a trading platform. On the other hand, these choices allow for virtually any programming environment to easily interface with the server, as well as open the door to rich, web-based clients.

Given that this project is primarily intended to motivate the use of flow trading, especially in the context of forward markets, these trade-offs are more than reasonable. With that said, the design of flow trading specifically discourages high-frequency execution, so the performance overhead of these trade-offs are also largely irrelevant.

Authorization

In the interest of simplicity, endpoints that process bid data (or execute administrative actions) expect HTTP requests to contain the Authorization header with a JWT bearer token. The sub: claim of this token must be the bidder’s UUID. To authorize an administrative action, this token must contain the custom claim admin: true. It is left to the operator to securely authenticate and generate these tokens.

API Endpoints and Data Types

Please refer to the automatically generated OpenAPI schema for up-to-date documentation of the endpoints. Note that any endpoint expecting a datetime type expects an RFC3339-compliant string.

Structs

AppState

Application state shared across all request handlers.

CustomJWTClaims

Custom claims structure for JWT tokens.

Now

A wrapper for the current time in UTC.

Update

Represents an update to be sent via server-sent events.

Functions

generate_jwt

Generate a JWT token and account string

router

Creates the application router with all routes configured.

start

Starts the HTTP server with the configured application.

state

Creates the application state and solver background task.