|author||Florian Dold <firstname.lastname@example.org>||2016-01-12 15:37:11 +0100|
|committer||Florian Dold <email@example.com>||2016-01-12 15:37:11 +0100|
Diffstat (limited to 'api-merchant.rst')
1 files changed, 18 insertions, 90 deletions
diff --git a/api-merchant.rst b/api-merchant.rst
index 752b167..c61a6df 100644
@@ -1,12 +1,13 @@
-The Merchant API
+The Merchant HTTP API
-This Merchant API defines the
-interactions between a browser-based wallet and an HTTP-based RESTful merchant.
-The protocol allows the customer and the merchant to agree upon a
-contract and for the customer to spend coins according to the contract
-proposed by the merchant.
+The merchant API defines
+This Merchant API defines the interactions between a browser-based wallet and
+an HTTP-based RESTful merchant. The protocol allows the customer and the
+merchant to agree upon a contract and for the customer to spend coins according
+to the contract proposed by the merchant.
It is assumed that the browser has a secure and possibly
customer-anonymizing channel to the merchant, typically by using the
@@ -23,28 +24,9 @@ is expected to check that the time of his machine is approximately
-In our settlement, the "merchant" is divided in two independent
-compontents, the `frontend` and the `backend`.
-The `frontend` is the existing shopping portal of the merchant.
-The architecture tries to minimize the amount of modifications necessary
-to the `frontend` as well as the trust that needs to be placed into the
-`frontend` logic. Taler requires the frontend to facilitate two
-JSON-based interactions between the wallet and the `backend`, and
-one of those is trivial.
-The `backend` is a standalone C application intended to implement all
-the cryptographic routines required to interact with the Taler wallet
-and a Taler mint.
Taler's wallet is designed to notify the user when a certain webpage
is offering Taler as a payment option. It does so by simply changing the color of
@@ -87,9 +69,9 @@ A precise specification and sample code for implementing the signalling
is provided in the dedicated :ref:`section <message-passing-ref>`.
To create a contract, the `frontend` needs to generate the body of a
`contract` in JSON format. This `proposition` is then signed by the
@@ -106,16 +88,16 @@ responsible for generating the fullfillment page.
The contract format is specified in the `contract`_ section.
Data such as dates, binary blobs, and other useful formats, are encoded as described in :ref:`encodings-ref`.
A `contract` is a JSON object having the following structure, which is returned as a
successful response to the following two calls:
@@ -222,9 +204,9 @@ Wallet-Frontend
In order to reach mutual acknowledgement, and to avoid signaling loops,
we define two interactions. One is initiated by the HTML page inquiring
@@ -427,58 +409,4 @@ cookies to identify the shopping session.
The error codes and data sent to the wallet are a mere copy of those gotten from the mint when attempting to pay. The section about :ref:`deposit <deposit>` explains them in detail.
-The RESTful API
-The following API are made available by the merchant's `backend` to the merchant's `frontend`.
-.. http:post:: /contract
- Ask the backend to add some missing (mostly related to cryptography) information to the contract.
- :reqheader Content-Type: application/json
- The `proposition` that is to be sent from the frontend is a `contract` object without the fields
- * `merchant_pub`
- * `mints`
- * `H_wire`
- The `backend` then completes this information based on its configuration.
- **Success Response**
- :status 200 OK: The backend has successfully created the contract.
- :resheader Content-Type: application/json
- The `frontend` should pass this response verbatim to the wallet.
- **Failure Responses: Bad contract**
- :status 400 Bad Request: Request not understood. The JSON was invalid. Possibly due to some error in formatting the JSON by the `frontend`.
-.. http:post:: /pay
- Asks the `backend` to execute the transaction with the mint and deposit the coins.
- :reqheader Content-Type: application/json
- The `frontend` passes the :ref:`deposit permission <deposit-permission>` received from the wallet, by adding the fields `max_fee`, `amount` (see :ref:`contract`) and optionally adding a field named `edate`, indicating a deadline by which he would expect to receive the bank transfer for this deal
- **Success Response: OK**
- :status 200 OK: The mint accepted all of the coins. The `frontend` should now fullfill the contract. This response has no meaningful body, the frontend needs to generate the fullfillment page.
- **Failure Responses: Bad mint**
- :status 400 Precondition failed: The given mint is not acceptable for this merchant, as it is not in the list of accepted mints and not audited by an approved auditor.
- **Failure Responses: Mint trouble**
- The `backend` will return verbatim the error codes received from the mint's :ref:`deposit <deposit>` API. If the wallet made a mistake, like by double-spending for example, the `frontend` should pass the reply verbatim to the browser/wallet. This should be the expected case, as the `frontend` cannot really make mistakes; the only reasonable exception is if the `backend` is unavailable, in which case the customer might appreciate some reassurance that the merchant is working on getting his systems back online.