Intro to APIs

We are RESTful

Synapse has built a RESTful JSON API for you. Which means, we use:

  • POST to create a document

  • PATCH to update it

  • GET to query one or more documents

  • DELETE to cancel or delete a document (Subtext: nothing gets deleted. It is either unindexed in case of a user or a bank account or it's canceled in case of a transaction)

To make things easier, all GET calls that get multiple documents support pagination and since our primary database is mongoDB (that's why we call everything documents), it also supports mongo filters. Example call for retrieving LOCKED users, page 2 with max 10 documents:

GET /users?page=2&limit=10&filter={"permission":"LOCKED"}

We use Headers

Mostly all requests (with some minor exceptions) require various kinds of headers. Here are some examples:

Header

Example Value

Description

X-SP-GATEWAY

your_client_id|your_client_key

Your client id and secret, separated by a pipe.

X-SP-USER

user_oauth_key|user_device_fingerprint

User's OAuth key and their device fingerprint, separated by a pipe.

X-SP-USER-IP

user_ip

User's IP Address.

X-SP-IDEMPOTENCY-KEY

idempotency_key

Idempotency key to go along with the POST API call.

Not all headers are needed for all API calls. Some require client-level authentication while some require user-level authentication. More on this later, but a good rule of thumb is any resource that requires actions performed by the user (open deposit account, create a transaction, etc.), require user credentials (X-SP-USER-IP) while others require client-level credentials (X-SP-GATEWAY).

Idempotent Requests

To prevent duplicate creation of users, nodes, transactions and subnets, it's important provide retry attempts with idempotency keys.

All POST calls support idempotency for safely retrying requests without accidentally performing the same operation twice. For example, if a request to create a transaction fails due to a network connectivity error, you can retry the request with the same idempotency key to guarantee that only a single charge is created.

Notes to keep in mind when making idempotent requests:

  • Idempotency keys expire after 24 hours.

  • It is best practice to wait for a failure response from the POST call before attempting to retry the call.

We are Easy

All Synapse functionality can be broken down into the following core resources:

  • Users: Individual or Business accounts you create in our System. User objects store all KYC and Authentication information for each user.

  • Nodes: Nodes are either deposit accounts, credit accounts that you open with us, or 3rd party accounts you link with us to be able to move funds on behalf of the user. Each user can link or create multiple nodes under them.

  • Transactions: Transactions resource enables you to send money between various nodes. Just supply addresses for from and to nodes, and we will move money between both accounts. This is handy because this gives you one unified way of creating all kinds of transactions: Internal Transfers, ACH Debit, ACH Credit, Interchange Pulls, Push to Card, Wires, BillPay, etc.

  • Statements: Each deposit or credit node (accounts we open for your users) automatically generates statements each month. This is to comply with regulations like Reg E and Z. The idea is that we will generate the statements and you will distribute them.

  • Subnets: With Transactions resource, you can create transactions between two nodes that exist in the Synapse system. But what if you wanted other networks and platforms to be able to interface with the Synapse system? That's where subnets come in handy. If a node is hosted by Synapse (deposit or credit), you can issue a Subnet on top of that node to interface with other platforms. That's the general idea. Currently, it supports two kinds of interfaces -- Account and Routing Numbers, and Card Numbers.

  • Shipments: If a Subnet is a card number, this resource enables you to ship a physical card to the user.

  • Subscriptions: Since it's not efficient to poll our entire system with API calls, Subscriptions enables you to set up webhook alerts with us so that whenever updates to objects happen, your system can automatically stay in sync.