Welcome to GNU Taler
--------------------

What is Taler?
==============

Taler is an electronic payment system providing the ability to pay
anonymously using digital cash.  Taler consists of a network protocol
definition (using a RESTful API over HTTP), a Exchange (which creates
digital coins), a Wallet (which allows customers to manage, store and
spend digital coins), and a Merchant website which allows customers to
spend their digital coins.  Naturally, each Merchant is different, but
Taler includes code examples to help Merchants integrate Taler as a
payment system.

Taler is currently developed by a worldwide group of independent free software
developers and Taler Systems SA.  Taler is free software and an official GNU
package (https://www.gnu.org/).

This is an alpha release with a few known bugs, lacking a few important
features, documentation, testing, performance tuning and an external security
audit.  However, you can run the code and it largely works fine.  This package
also only includes the Taler exchange, not the other components of the system.

Documentation about Taler can be found at https://taler.net/.
Our bug tracker is at https://bugs.taler.net/.


Joining GNU
===========

This is a GNU program, developed by the GNU Project and part of the
GNU Operating System. If you are the author of an awesome program and
want to join us in writing Free Software, please consider making it an
official GNU program and become a GNU maintainer.  You can find
instructions on how to do so at http://www.gnu.org/help/evaluation.
We are looking forward to hacking with you!


Dependencies:
=============

Build tools for compiling Taler exchange from source:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

- gcc or clang
- autoconf           >= 2.69        (building from git)
- automake           >= 1.11.1      (building from git)
- recutils           >= 1.0         (building from git)
- libtool            >= 2.2
- makeinfo           >= 4.8
- make[*3]
- pkgconf or pkg-config
- sphinx
- sphinx-rtd-theme
- sphinx-multiversion

Direct dependencies
~~~~~~~~~~~~~~~~~~~

These are the direct dependencies for running a Taler exchange:

- GNUnet            >= 0.23.3
- GNU libmicrohttpd >= 0.9.71
- PostgreSQL        >= 15.0


Project structure
=================

The project structure is currently as follows:

src/include/
  -- installed headers for public APIs

src/util/
  -- common utility functions (currency representation,
     Taler-specific cryptography, Taler-specific json
     support)

src/pq/
  -- Postgres-specific utility functions

src/exchangedb/
  -- Exchange database backend (with database-specific plugins)

src/exchange/
  -- taler exchange server

src/exchange-tools/
  -- taler exchange helper programs

src/lib/
  -- libtalerexchange: C API to issue HTTP requests to exchange.
     Note that this library is not thread safe.

src/auditor/
  -- tools to generate reports about financial performance and
     to validate that the exchange has been operating correctly

src/auditordb/
  -- database logic for the auditor component (with database-specific
     plugins)

src/benchmark/
  -- tool to run performance measurements

src/templating/
  -- logic to generate HTML pages from templates at runtime

src/kyclogic/
  -- core logic and plugins to trigger and manage KYC processes
     as required by banking regulation

src/bank-lib/
  -- bank REST client logic and implementation of an in-memory
     RTGS emulator ("fakebank") for testing.

src/extensions/
  -- extensions to the core logic of an exchange

src/json/
  -- helper functions for generating and parsing JSON

src/mhd/
  -- helper functions for interacting with GNU libmicrohttpd

src/curl/
  -- helper functions for interacting with libcurl


Getting Started
===============

Please follow the exchange manual you can view after
installing using

$ info taler-exchange

or by visiting https://docs.taler.net/.
