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.

API Rate Limits

The following is a table of the the most common API calls and their respective rate limits. These limits cannot be increased. Please take this into account when building out your application.

HTTP Verb	URL	Functionality	Rate Limits (per min/per user)
POST	/oauth/<user:id>	This API call allows you to get oauth_key for users.	30
POST	/oauth/<user:id>/login	Using basic auth to get refresh_token for users.	30
GET	/users	View all users created with your client keys (paginated).	100
POST	/users	Allows you to register a new user.	100
GET	/users/<user:id>	View user info and refresh_token.	30
PATCH	/users/<user:id>	Add/update KYC, log in credentials, profile, etc.	30
GET	/users/<user:id>/nodes	View all nodes linked to a user (paginated).	100
POST	/users/<user:id>/nodes	Allows you to create a deposit account or link an external bank account to a user.	100
GET	/users/<user:id>/nodes/<node:id>	View node info.	100
PATCH	/users/<user:id>/nodes/<node:id>	Update supp_id, verify micro-deposits, etc.	100
DELETE	/users/<user:id>/nodes/<node:id>	Unindex node from a user.	100
POST	/users/<user:id>/nodes/<node:id>/subnets	Allows you to issue a virtual account number on top of a node.	100
GET	/users/<user:id>/nodes/<node:id>/subnets	View all subnets linked to a node (paginated).	100
GET	/users/<user:id>/nodes/<node:id>/subnets/<subnet:id>	View subnet info.	100
PATCH	/users/<user:id>/nodes/<node:id>/subnets/<subnet:id>	Update subnet info.	100
GET	/users/<user:id>/trans	View all transactions of a user (paginated).	100
GET	/users/<user:id>/nodes/<node:id>/trans	View all transactions of a node (paginated).	100
POST	/users/<user:id>/nodes/<node:id>/trans	Allows you to create a transaction.	100
GET	/users/<user:id>/nodes/<node:id>/trans/<trans:id>	View transaction info.	100
PATCH	/users/<user:id>/nodes/<node:id>/trans/<trans:id>	Update notes on a transaction.	100
DELETE	/users/<user:id>/nodes/<node:id>/trans/<trans:id>	Only works if transaction has been created or queued.	100
GET	/subscriptions	View all subscriptions created with your client keys (paginated).	10
POST	/subscriptions	Create a subscription with webhook preferences.	10
GET	/subscriptions/<subscription:id>	View a subscription.	10
PATCH	/subscriptions/<subscription:id>	Update scope, url, is_active, etc.	10
GET	<:user_id>/statements	View a users statement	30
GET	<:node_id>/statements	View a node statements	30

Max HTTP Request Body Size

HTTP request body size is limited to 30 MB maximum.