[taler-docs] branch master updated: add STEFAN support to exchange

[gnunet]

This is an automated email from the git hooks/post-receive script.

grothoff pushed a commit to branch master
in repository docs.

The following commit(s) were added to refs/heads/master by this push:
     new 3c808661 add STEFAN support to exchange
3c808661 is described below

commit 3c808661c6552fd2700cd25c42d5ff1e170f87c1
Author: Christian Grothoff <christian@grothoff.org>
AuthorDate: Fri Aug 11 16:30:40 2023 +0200

    add STEFAN support to exchange
---
 core/api-exchange.rst           | 25 +++++++++++++++++++++++++
 design-documents/047-stefan.rst |  5 ++++-
 manpages/taler.conf.5.rst       | 20 ++++++++++++++++++++
 3 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/core/api-exchange.rst b/core/api-exchange.rst
index fbc7184d..a21a3c14 100644
--- a/core/api-exchange.rst
+++ b/core/api-exchange.rst
@@ -116,6 +116,31 @@ possibly by using HTTPS.
       // The exchange's currency or asset unit.
       currency: string;
 
+      // How many digits should the amounts be rendered
+      // with by default. Small capitals should
+      // be used to render fractions beyond the number
+      // given here (like on gas stations).
+      currency_fraction_digits: integer;
+
+      // Absolute cost offset for the STEFAN curve used
+      // to (over) approximate fees payable by amount.
+      stefan_abs: Amount;
+
+      // Factor to multiply the logarithm of the amount
+      // with to (over) approximate fees payable by amount.
+      // Note that the total to be paid is first to be
+      // divided by the smallest denomination to obtain
+      // the value that the logarithm is to be taken of.
+      stefan_log: Amount;
+
+      // Linear cost factor for the STEFAN curve used
+      // to (over) approximate fees payable by amount.
+.
+      // Note that the total to be paid is first to be
+      // divided by the smallest denomination to obtain
+      // the value to be multiplied with.
+      stefan_lin: Amount;
+
       // Type of the asset. "fiat", "crypto", "regional"
       // or "stock".  Wallets should adjust their UI/UX
       // based on this value.
diff --git a/design-documents/047-stefan.rst b/design-documents/047-stefan.rst
index a37e7739..8ae3586e 100644
--- a/design-documents/047-stefan.rst
+++ b/design-documents/047-stefan.rst
@@ -38,7 +38,10 @@ Proposed Solution
 
 The proposal is for the exchange to advertise three STEFAN-parameters that
 encode a fee curve of the form ``stefan_abs + stefan_log * log P +
-stefan_lin * P`` where P is the price to be paid.  The fee curve will be the
+stefan_lin * P`` where P represents the price to be paid.
+Here, the numerical value for P is to be computed by
+dividing the actual price by the smallest denomination
+offered by the exchange. The fee curve will be the
 displayed fee, except in cases where the coin selection is exceptionally bad
 (which should happen in substantially less than 1% of all cases).  The fee
 curve will also be used as the maximum fee a merchant will cover unless the
diff --git a/manpages/taler.conf.5.rst b/manpages/taler.conf.5.rst
index 8c2bff10..5b75b249 100644
--- a/manpages/taler.conf.5.rst
+++ b/manpages/taler.conf.5.rst
@@ -113,6 +113,26 @@ ENABLE_REWARDS
   rewards is enabled or disabled, and protocol-compliant merchant
   backends will then enable or disable the feature accordingly.
 
+CURRENCY_FRACTION_DIGITS
+  How many digits should amounts be rendered
+  with by default. Small capitals should
+  be used to render fractions beyond the number
+  given here (like on gas stations).  Defaults to 0.
+  For EUR and USD, the value would be 2, while for
+  JPY it would be 0.
+
+STEFAN_ABS
+  Absolte amount to use in the STEFAN fee approximation
+  curve (see DD47).  Defaults to 0 if not specified.
+
+STEFAN_LOG
+  Logarithmic factor to use in the STEFAN fee approximation
+  curve (see DD47).  Defaults to 0 if not specified.
+
+STEFAN_LIN
+  Linear factor to use in the STEFAN fee approximation
+  curve (see DD47).  Defaults to 0 if not specified.
+
 BASE_URL
   The base URL under which the exchange can be reached.
   Added to wire transfers to enable tracking by merchants.

-- 
To stop receiving notification emails like this one, please contact
gnunet@gnunet.org.