Banker API

Banker is a GraphQL banking API for fetching bank account and transaction data and statistics. Uses OFX transaction files to upload data from common banks like Chase.

Libraries

• gin-gonic > HTTP web framework (https://github.com/gin-gonic/gin)
• gqlgen > GraphQL code generation (https://github.com/99designs/gqlgen)
• dataloaden > GraphQL dataloader code generation (https://github.com/vektah/dataloaden)
• sqlc > SQL model/query code generation (https://github.com/sqlc-dev/sqlc)

Setup

Prereqs

• Brew (mac only) (https://mac.install.guide/homebrew/3)
• Go (https://go.dev/doc/install)
• Air (https://github.com/air-verse/air)

How to run (development server)

To start the server, run Air (May depend upon where you have air installed)

~/.air

Latest Updates

• Added dataloaders to efficiently query and cache data for nested subqueries in large queries
• Query cursor pagination via GraphQL edges and nodes
• File upload that supports OFX transaction files to retrieve transaction and account data
• Merchant matching by using a Natural Language Model (NLM) by parsing merchant data from transaction descriptions

Example Queries

Accounts data query

query accounts {
  accounts(page:{
    first: 2
    after: "Y3Vyc29yOm9mZnNldDox"
  }) {
    edges {
      node {
        id
        uploadSource
        type
        name
        routingNumber
        transactions(page: {
          first: 4
          after: "Y3Vyc29yOm9mZnNldDox"
        }) {
          edges {
            node {
              description
              amount
              date
            }
            cursor
          }
        }
      }
      cursor
    }
    pageInfo {
      hasNextPage
      hasPreviousPage
      totalCount
    }
  }
}

Transaction data query

query transactions {
  transactions(page: {
    after: "Y3Vyc29yOm9mZnNldDo2"
    first: 10
  }) {
    edges {
      node {
        id
        description
        amount
        payee
        date
        updated
        merchant {
          name
          sourceId
        }
      }
      cursor
    }
    pageInfo {
      hasNextPage
      hasPreviousPage
      totalCount
    }
  }
}

Merchants data query

query merchants {
  merchants(page:{
    first: 10
  }) {
    edges {
      node {
        id
        name
        sourceId
        ownerId
        transactions(page:{
          first: 2
        }) {
          edges {
            node {
              description
              payee
              amount
              date
            }
          }
        }
      }
      cursor
    }
    pageInfo {
      hasNextPage
      hasPreviousPage
      totalCount
    }
  }
}

Development

To generate sqlc models, graphql models, and graphql dataloaders, run:

./scripts/generate.sh

This command runs sqlc generate, gqlgen generate, go generate ./internal/dataloaders/... to compile sql and graphql schema files into go