initial commit

.drone.yml

@@ -0,0 +1,26 @@
+kind: pipeline
+name: default
+
+workspace:
+  base: /go
+  path: src/deadbeef.codes/steven/ynab-portfolio-monitor
+
+steps:
+
+- name: build server
+  image: golang
+  pull: always
+  environment:
+    GOOS: linux
+    GOARCH: amd64
+    CGO_ENABLED: 0
+  commands:
+  - go version
+  - go get
+  - go build -a -ldflags '-w'
+  - cp /etc/ssl/certs/ca-certificates.crt .
+
+- name: package in docker container
+  image: plugins/docker
+  settings:
+    repo: registry.deadbeef.codes/ynab-portfolio-monitor

.gitignore

@@ -0,0 +1,4 @@
+env.sh
+ynab-portfolio-monitor
+ynab-portfolio-monitor.exe
+data/persistentData.json

Dockerfile

@@ -0,0 +1,9 @@
+FROM scratch
+LABEL maintainer="himself@stevenpolley.net"
+COPY data data
+COPY ca-certificates.crt /etc/ssl/certs/
+COPY ynab-portfolio-monitor .
+
+EXPOSE 8080
+
+CMD [ "./ynab-portfolio-monitor" ]

README.md

@@ -1,3 +1,5 @@
 # ynab-portfolio-monitor
 
+[![Build Status](https://drone.deadbeef.codes/api/badges/steven/ynab-portfolio-monitor/status.svg)](https://drone.deadbeef.codes/steven/ynab-portfolio-monitor)
+
 Track your securities in YNAB for account types and update your balance automatically.

data/README.md

@@ -0,0 +1 @@
+data that's required to persist or cache will be written to this directory

go.mod

@@ -0,0 +1,3 @@
+module deadbeef.codes/steven/ynab-portfolio-monitor
+
+go 1.21.1

go.work

@@ -0,0 +1,6 @@
+go 1.21.1
+
+use (
+	.
+	./questrade
+)

main.go

@@ -0,0 +1,145 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"time"
+
+	"deadbeef.codes/steven/ynab-portfolio-monitor/questrade"
+	"deadbeef.codes/steven/ynab-portfolio-monitor/ynab"
+)
+
+var (
+	persistentData      *PersistentData
+	questradeClient     *questrade.Client
+	ynabClient          *ynab.Client
+	questradeAccountIDs []int
+	ynabAccountIDs      []string
+)
+
+func init() {
+	log.Printf("ynab-portfolio-monitor init")
+
+	// Load application configuration from environment variables
+	envVars := make(map[string]string)
+	envVars["questrade_refresh_token"] = os.Getenv("questrade_refresh_token")
+	envVars["ynab_secret"] = os.Getenv("ynab_secret")
+	envVars["ynab_budget_id"] = os.Getenv("ynab_budget_id")
+
+	// Validate that all required environment variables are set
+	for key, value := range envVars {
+		if value == "" {
+			log.Fatalf("shell environment variable %s is not set", key)
+		}
+	}
+
+	for i := 0; true; i++ {
+		questradeAccountIDString := os.Getenv(fmt.Sprintf("questrade_account_%d", i))
+		ynabAccountID := os.Getenv(fmt.Sprintf("questrade_ynab_account_%d", i))
+		if questradeAccountIDString == "" || ynabAccountID == "" {
+			break
+		}
+
+		questradeAccountID, err := strconv.Atoi(questradeAccountIDString)
+		if err != nil {
+			log.Fatalf("failed to convert environment variable questrade_account_%d with value of '%s' to integer: %v", i, questradeAccountIDString, err)
+		}
+		questradeAccountIDs = append(questradeAccountIDs, questradeAccountID)
+		ynabAccountIDs = append(ynabAccountIDs, ynabAccountID)
+	}
+
+	// Load persistent data
+	var err error
+	persistentData, err = loadPersistentData()
+	if err != nil {
+		log.Fatalf("failed to load persistent data: %v", err)
+	}
+
+	// ynab client is static and has no persistent data so is initialized here and not in main program loop
+	ynabClient, err = ynab.NewClient(envVars["ynab_budget_id"], envVars["ynab_secret"])
+	if err != nil {
+		log.Fatalf("failed to create ynab client: %v", err)
+	}
+}
+
+func main() {
+	for {
+		var err error
+
+		// Questrade authentication needs to be refreshed and persistentData written to disk in case app restarts
+		questradeClient, err = questrade.NewClient(persistentData.QuestradeRefreshToken)
+		if err != nil {
+			log.Fatalf("failed to create questrade client: %v", err)
+		}
+
+		persistentData.QuestradeRefreshToken = questradeClient.Credentials.RefreshToken
+
+		err = savePersistentData(*persistentData)
+		if err != nil {
+			log.Fatalf("failed to save persistent data: %v", err)
+		}
+
+		// Update Questrade accounts
+		err = syncQuestrade()
+		if err != nil {
+			log.Fatalf("failed to sync questrade to ynab: %v", err)
+		}
+
+		// Update Bitcoin account
+
+		// Update ComputerShare account
+
+		log.Print("Sleeping for 6 hours...")
+		time.Sleep(time.Hour * 6)
+
+	}
+
+}
+
+func syncQuestrade() error {
+
+	for i, questradeAccountID := range questradeAccountIDs {
+		questradeBalance, err := questradeClient.GetQuestradeAccountBalance(questradeAccountID)
+		if err != nil {
+			return fmt.Errorf("failed to get questrade account balance for account ID '%d': %v", questradeAccountID, err)
+		}
+
+		ynabTransactionID, ynabTransactionAmount, err := ynabClient.GetTodayYnabCapitalGainsTransaction(ynabAccountIDs[i])
+		if err != nil {
+			return fmt.Errorf("failed to get ynab capital gains transaction ID: %v", err)
+		}
+
+		ynabAccount, err := ynabClient.GetAccount(ynabAccountIDs[i])
+		if err != nil {
+			return fmt.Errorf("failed to get ynab account with id '%s': %v", ynabAccountIDs[i], err)
+		}
+
+		balanceDelta := questradeBalance - ynabAccount.Data.Account.Balance
+		balanceDelta += ynabTransactionAmount // Take into account the existing transaction
+
+		if balanceDelta == 0 {
+			continue // If balanceDelta is 0 do not create a transaction i.e. market is closed today
+		}
+
+		if ynabTransactionID == "" {
+			// there is no transaction - so create a new one
+			err = ynabClient.CreateTodayYNABCapitalGainsTransaction(ynabAccountIDs[i], balanceDelta)
+			if err != nil {
+				return fmt.Errorf("failed to create YNAB capital gains transaction for account ID '%s': %v", ynabAccountIDs[i], err)
+			}
+			log.Printf("Creating new capital gains transaction for YNAB account '%s' for amount: %d", ynabAccountIDs[i], balanceDelta)
+
+		} else {
+			// there is an existing transaction - so update the existing one
+			err = ynabClient.UpdateTodayYNABCapitalGainsTransaction(ynabAccountIDs[i], ynabTransactionID, balanceDelta)
+			if err != nil {
+				return fmt.Errorf("failed to update YNAB capital gains transaction for account ID '%s': %v", ynabAccountIDs[i], err)
+			}
+			log.Printf("Updating existing capital gains transaction for YNAB account '%s' for amount: %d", ynabAccountIDs[i], balanceDelta)
+		}
+	}
+
+	return nil
+}

persistentData.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+)
+
+type PersistentData struct {
+	QuestradeRefreshToken string `json:"questradeRefreshToken"`
+}
+
+func loadPersistentData() (*PersistentData, error) {
+	persistentData := &PersistentData{}
+
+	f, err := os.Open("data/persistentData.json")
+	if errors.Is(err, os.ErrNotExist) {
+		// handle the case where the file doesn't exist
+		persistentData.QuestradeRefreshToken = os.Getenv("questrade_refresh_token")
+		return persistentData, nil
+	}
+
+	defer f.Close()
+
+	b, err := io.ReadAll(f)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read file data/persistentData.json: %v", err)
+	}
+
+	err = json.Unmarshal(b, persistentData)
+	if err != nil {
+		return nil, fmt.Errorf("failed to unmarshal data/persistentData.json to PersistentData struct: %v", err)
+	}
+
+	return persistentData, nil
+
+}
+
+func savePersistentData(PersistentData) error {
+	b, err := json.Marshal(persistentData)
+	if err != nil {
+		return fmt.Errorf("failed to marshal persistentData to bytes: %v", err)
+	}
+	err = os.WriteFile("data/persistentData.json", b, 0644)
+	if err != nil {
+		return fmt.Errorf("failed to write file data/persistentData.json: %v", err)
+	}
+	return nil
+}

questrade/account.go

@@ -0,0 +1,114 @@
+package questrade
+
+import (
+	"fmt"
+	"net/url"
+	"strconv"
+)
+
+// Account represents an account associated with the user on behalf
+// of which the API client is authorized.
+//
+// Ref: http://www.questrade.com/api/documentation/rest-operations/account-calls/accounts
+type Account struct {
+	// Type of the account (e.g., "Cash", "Margin").
+	Type string `json:"type"`
+
+	// Eight-digit account number (e.g., "26598145")
+	// Stored as a string, it's used for making account-related API calls
+	Number string `json:"number"`
+
+	// Status of the account (e.g., Active).
+	Status string `json:"status"`
+
+	// Whether this is a primary account for the holder.
+	IsPrimary bool `json:"isPrimary"`
+
+	// Whether this account is one that gets billed for various expenses such as inactivity fees, market data, etc.
+	IsBilling bool `json:"isBilling"`
+
+	// Type of client holding the account (e.g., "Individual").
+	ClientAccountType string `json:"clientAccountType"`
+}
+
+// Balance belonging to an Account
+//
+// Ref: http://www.questrade.com/api/documentation/rest-operations/account-calls/accounts-id-balances
+type Balance struct {
+
+	// Currency of the balance figure(e.g., "USD" or "CAD").
+	Currency string `json:"currency"`
+
+	// Balance amount.
+	Cash float32 `json:"cash"`
+
+	// Market value of all securities in the account in a given currency.
+	MarketValue float32 `json:"marketValue"`
+
+	// Equity as a difference between cash and marketValue properties.
+	TotalEquity float32 `json:"totalEquity"`
+
+	// Buying power for that particular currency side of the account.
+	BuyingPower float32 `json:"buyingPower"`
+
+	// Maintenance excess for that particular side of the account.
+	MaintenanceExcess float32 `json:"maintenanceExcess"`
+
+	// Whether real-time data was used to calculate the above values.
+	IsRealTime bool `json:"isRealTime"`
+}
+
+// AccountBalances represents per-currency and combined balances for a specified account.
+//
+// Ref: http://www.questrade.com/api/documentation/rest-operations/account-calls/accounts-id-balances
+type AccountBalances struct {
+	PerCurrencyBalances    []Balance `json:"perCurrencyBalances"`
+	CombinedBalances       []Balance `json:"combinedBalances"`
+	SODPerCurrencyBalances []Balance `json:"sodPerCurrencyBalances"`
+	SODCombinedBalances    []Balance `json:"sodCombinedBalances"`
+}
+
+// GetAccounts returns the logged-in User ID, and a list of accounts
+// belonging to that user.
+func (c *Client) GetAccounts() (int, []Account, error) {
+	list := struct {
+		UserID   int       `json:"userId"`
+		Accounts []Account `json:"accounts"`
+	}{}
+
+	err := c.get("v1/accounts", &list, url.Values{})
+	if err != nil {
+		return 0, []Account{}, err
+	}
+
+	return list.UserID, list.Accounts, nil
+}
+
+// GetBalances returns the balances for the account with the specified account number
+func (c *Client) GetBalances(number string) (AccountBalances, error) {
+	bal := AccountBalances{}
+
+	err := c.get("v1/accounts/"+number+"/balances", &bal, url.Values{})
+	if err != nil {
+		return AccountBalances{}, err
+	}
+
+	return bal, nil
+}
+
+func (c *Client) GetQuestradeAccountBalance(accountID int) (int, error) {
+	balances, err := c.GetBalances(strconv.Itoa(accountID))
+	if err != nil {
+		return 0, fmt.Errorf("failed to get balances for account ID '%d': %v", accountID, err)
+	}
+
+	for _, balance := range balances.CombinedBalances {
+		if balance.Currency != "CAD" {
+			continue
+		}
+
+		return int(balance.TotalEquity) * 1000, nil
+	}
+
+	return 0, fmt.Errorf("could not find a CAD balance for this account in questade response")
+}

questrade/client.go

@@ -0,0 +1,137 @@
+package questrade
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strconv"
+	"time"
+)
+
+const loginServerURL = "https://login.questrade.com/oauth2/"
+
+type LoginCredentials struct {
+	AccessToken  string `json:"access_token"`
+	TokenType    string `json:"token_type"`
+	ExpiresIn    int    `json:"expires_in"`
+	RefreshToken string `json:"refresh_token"`
+	ApiServer    string `json:"api_server"`
+}
+
+// A client is the structure that will be used to consume the API
+// endpoints. It holds the login credentials, http client/transport,
+// rate limit information, and the login session timer.
+type Client struct {
+	Credentials        LoginCredentials
+	SessionTimer       *time.Timer
+	RateLimitRemaining int
+	RateLimitReset     time.Time
+	httpClient         *http.Client
+	transport          *http.Transport
+}
+
+// authHeader is a shortcut that returns a string to be placed
+// in the authorization header of API calls
+func (l LoginCredentials) authHeader() string {
+	return l.TokenType + " " + l.AccessToken
+}
+
+// Send an HTTP GET request, and return the processed response
+func (c *Client) get(endpoint string, out interface{}, query url.Values) error {
+	req, err := http.NewRequest("GET", c.Credentials.ApiServer+endpoint+query.Encode(), nil)
+	if err != nil {
+		return err
+	}
+	req.Header.Add("Authorization", c.Credentials.authHeader())
+
+	res, err := c.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("http get request failed: %v", err)
+	}
+
+	err = c.processResponse(res, out)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// processResponse takes the body of an HTTP response, and either returns
+// the error code, or unmarshalls the JSON response, extracts
+// rate limit info, and places it into the object
+// output parameter. This function closes the response body after reading it.
+func (c *Client) processResponse(res *http.Response, out interface{}) error {
+	body, err := io.ReadAll(res.Body)
+	res.Body.Close()
+	if err != nil {
+		return err
+	}
+
+	if res.StatusCode != 200 {
+		return newQuestradeError(res, body)
+	}
+
+	err = json.Unmarshal(body, out)
+	if err != nil {
+		return err
+	}
+
+	reset, _ := strconv.Atoi(res.Header.Get("X-RateLimit-Reset"))
+	c.RateLimitReset = time.Unix(int64(reset), 0)
+	c.RateLimitRemaining, _ = strconv.Atoi(res.Header.Get("X-RateLimit-Remaining"))
+
+	return nil
+}
+
+// Login takes the refresh token from the client login credentials
+// and exchanges it for an access token. Returns a timer that
+// expires when the login session is over.
+// TODO - Return a proper error when login fails with HTTP 400 - Bad Request
+func (c *Client) Login() error {
+	login := loginServerURL
+
+	vars := url.Values{"grant_type": {"refresh_token"}, "refresh_token": {c.Credentials.RefreshToken}}
+	res, err := c.httpClient.PostForm(login+"token", vars)
+
+	if err != nil {
+		return err
+	}
+
+	err = c.processResponse(res, &c.Credentials)
+	if err != nil {
+		return err
+	}
+
+	c.SessionTimer = time.NewTimer(time.Duration(c.Credentials.ExpiresIn) * time.Second)
+
+	return nil
+}
+
+// NewClient is the factory function for clients - takes a refresh token and logs in
+func NewClient(refreshToken string) (*Client, error) {
+	transport := &http.Transport{
+		ResponseHeaderTimeout: 5 * time.Second,
+	}
+
+	client := &http.Client{
+		Transport: transport,
+	}
+
+	// Create a new client
+	c := &Client{
+		Credentials: LoginCredentials{
+			RefreshToken: refreshToken,
+		},
+		httpClient: client,
+		transport:  transport,
+	}
+
+	err := c.Login()
+	if err != nil {
+		return nil, err
+	}
+
+	return c, nil
+}

questrade/errors.go

@@ -0,0 +1,41 @@
+package questrade
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+type QuestradeError struct {
+	Code       int `json:"code"`
+	StatusCode int
+	Message    string `json:"message"`
+	Endpoint   string
+}
+
+func newQuestradeError(res *http.Response, body []byte) QuestradeError {
+	// Unmarshall the error text
+	var e QuestradeError
+	err := json.Unmarshal(body, &e)
+	if err != nil {
+		e.Code = -999
+		e.Message = string(body)
+	}
+
+	e.StatusCode = res.StatusCode
+	e.Endpoint = res.Request.URL.String()
+
+	return e
+}
+
+func (q QuestradeError) Error() string {
+	return fmt.Sprintf("\nQuestradeError:\n"+
+		"\tStatus code: HTTP %d\n"+
+		"\tEndpoint: %s\n"+
+		"\tError code: %d\n"+
+		"\tMessage: %s\n",
+		q.StatusCode,
+		q.Endpoint,
+		q.Code,
+		q.Message)
+}

questrade/go.mod

@@ -0,0 +1,3 @@
+module deadbeef.codes/steven/ynab-portfolio-monitor/questrade
+
+go 1.21.1

ynab/accounts.go

@@ -0,0 +1,40 @@
+package ynab
+
+import (
+	"fmt"
+	"net/url"
+)
+
+// Reference: https://api.ynab.com/v1#/Accounts/
+
+type Accounts struct {
+	Data struct {
+		Account struct {
+			ID                  string      `json:"id"`
+			Name                string      `json:"name"`
+			Type                string      `json:"type"`
+			OnBudget            bool        `json:"on_budget"`
+			Closed              bool        `json:"closed"`
+			Note                interface{} `json:"note"`
+			Balance             int         `json:"balance"`
+			ClearedBalance      int         `json:"cleared_balance"`
+			UnclearedBalance    int         `json:"uncleared_balance"`
+			TransferPayeeID     string      `json:"transfer_payee_id"`
+			DirectImportLinked  bool        `json:"direct_import_linked"`
+			DirectImportInError bool        `json:"direct_import_in_error"`
+			Deleted             bool        `json:"deleted"`
+		} `json:"account"`
+		ServerKnowledge int `json:"server_knowledge"`
+	} `json:"data"`
+}
+
+func (c *Client) GetAccount(accountID string) (*Accounts, error) {
+	response := Accounts{}
+
+	err := c.get(fmt.Sprintf("/accounts/%s", accountID), &response, url.Values{})
+	if err != nil {
+		return nil, fmt.Errorf("failed to get accounts: %v", err)
+	}
+
+	return &response, nil
+}

ynab/client.go

@@ -0,0 +1,143 @@
+package ynab
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"time"
+)
+
+// Reference: https://api.ynab.com/
+
+const apiBaseURL = "https://api.ynab.com/v1/budgets/"
+
+// A client is the structure that will be used to consume the API
+// endpoints. It holds the login credentials, http client/transport,
+// rate limit information, and the login session timer.
+type Client struct {
+	BearerToken string
+	BudgetID    string
+	httpClient  *http.Client
+	transport   *http.Transport
+}
+
+// Send an HTTP GET request, and return the processed response
+func (c *Client) get(endpoint string, out interface{}, query url.Values) error {
+	req, err := http.NewRequest("GET", apiBaseURL+c.BudgetID+endpoint+"?"+query.Encode(), nil)
+	if err != nil {
+		return fmt.Errorf("failed to create new GET request: %v", err)
+	}
+	req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", c.BearerToken))
+
+	res, err := c.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("http GET request failed: %v", err)
+	}
+
+	err = c.processResponse(res, out)
+	if err != nil {
+		return fmt.Errorf("failed to process response: %v", err)
+	}
+	return nil
+}
+
+// Format the message body, send an HTTP POST request, and return the processed response
+func (c *Client) post(endpoint string, out interface{}, body interface{}) error {
+	// Attempt to marshall the body as JSON
+	json, err := json.Marshal(body)
+	if err != nil {
+		return fmt.Errorf("failed to marshal body to json: %v", err)
+	}
+
+	req, err := http.NewRequest("POST", apiBaseURL+c.BudgetID+endpoint, bytes.NewBuffer(json))
+	if err != nil {
+		return fmt.Errorf("failed to create new POST request: %v", err)
+	}
+	req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", c.BearerToken))
+	req.Header.Add("Content-Type", "application/json")
+
+	res, err := c.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("http POST request failed: %v", err)
+	}
+
+	err = c.processResponse(res, out)
+	if err != nil {
+		return fmt.Errorf("failed to process response: %v", err)
+	}
+	return nil
+}
+
+// Format the message body, send an HTTP POST request, and return the processed response
+func (c *Client) put(endpoint string, out interface{}, body interface{}) error {
+	// Attempt to marshall the body as JSON
+	json, err := json.Marshal(body)
+	if err != nil {
+		return fmt.Errorf("failed to marshal body to json: %v", err)
+	}
+
+	req, err := http.NewRequest("PUT", apiBaseURL+c.BudgetID+endpoint, bytes.NewBuffer(json))
+	if err != nil {
+		return fmt.Errorf("failed to create new POST request: %v", err)
+	}
+	req.Header.Add("Authorization", fmt.Sprintf("Bearer %s", c.BearerToken))
+	req.Header.Add("Content-Type", "application/json")
+
+	res, err := c.httpClient.Do(req)
+	if err != nil {
+		return fmt.Errorf("http POST request failed: %v", err)
+	}
+
+	err = c.processResponse(res, out)
+	if err != nil {
+		return fmt.Errorf("failed to process response: %v", err)
+	}
+	return nil
+}
+
+// processResponse takes the body of an HTTP response, and either returns
+// the error code, or unmarshalls the JSON response, extracts
+// rate limit info, and places it into the object
+// output parameter. This function closes the response body after reading it.
+func (c *Client) processResponse(res *http.Response, out interface{}) error {
+	body, err := io.ReadAll(res.Body)
+	res.Body.Close()
+	if err != nil {
+		return fmt.Errorf("failed to read response body: %v", err)
+	}
+
+	if res.StatusCode != 200 && res.StatusCode != 201 {
+		return fmt.Errorf("unexpected http status code '%d': %v", res.StatusCode, err)
+	}
+
+	err = json.Unmarshal(body, out)
+	if err != nil {
+		return fmt.Errorf("failed to unmarshal response body: %v", err)
+	}
+
+	return nil
+}
+
+// NewClient is the factory function for clients - takes a bearer token
+func NewClient(budgetID, bearerToken string) (*Client, error) {
+	transport := &http.Transport{
+		ResponseHeaderTimeout: 5 * time.Second,
+	}
+
+	client := &http.Client{
+		Transport: transport,
+	}
+
+	// Create a new client
+	c := &Client{
+		BudgetID:    budgetID,
+		BearerToken: bearerToken,
+		httpClient:  client,
+		transport:   transport,
+	}
+
+	return c, nil
+}

ynab/transactions.go

@@ -0,0 +1,125 @@
+package ynab
+
+import (
+	"fmt"
+	"net/url"
+	"time"
+)
+
+// Reference: https://api.ynab.com/v1#/Transactions/
+
+type BaseTransaction struct {
+	Type                  string      `json:"type,omitempty"`
+	ParentTransactionID   interface{} `json:"parent_transaction_id,omitempty"`
+	ID                    string      `json:"id,omitempty"`
+	Date                  string      `json:"date,omitempty"`
+	Amount                int         `json:"amount,omitempty"`
+	Memo                  string      `json:"memo,omitempty"`
+	Cleared               string      `json:"cleared,omitempty"`
+	Approved              bool        `json:"approved,omitempty"`
+	FlagColor             interface{} `json:"flag_color,omitempty"`
+	AccountID             string      `json:"account_id,omitempty"`
+	AccountName           string      `json:"account_name,omitempty"`
+	PayeeID               string      `json:"payee_id,omitempty"`
+	PayeeName             string      `json:"payee_name,omitempty"`
+	CategoryID            string      `json:"category_id,omitempty"`
+	CategoryName          string      `json:"category_name,omitempty"`
+	TransferAccountID     interface{} `json:"transfer_account_id,omitempty"`
+	TransferTransactionID interface{} `json:"transfer_transaction_id,omitempty"`
+	MatchedTransactionID  interface{} `json:"matched_transaction_id,omitempty"`
+	ImportID              string      `json:"import_id,omitempty"`
+	Deleted               bool        `json:"deleted,omitempty"`
+}
+
+// Used for single transaction requests / responses
+type Transaction struct {
+	Data struct {
+		TransactionIDs  []string        `json:"transaction_ids,omitempty"`
+		Transaction     BaseTransaction `json:"transaction"`
+		ServerKnowledge int             `json:"server_knowledge,omitempty"`
+	}
+}
+
+type TransactionRequest struct {
+	Transaction BaseTransaction `json:"transaction,omitempty"`
+}
+
+// Used for multiple transaction requests / responses
+type Transactions struct {
+	Data struct {
+		Transactions    []BaseTransaction `json:"transactions"`
+		ServerKnowledge int               `json:"server_knowledge"`
+	} `json:"data"`
+}
+
+// Accepts a YNAB account ID and timestamp and returns all transactions in that account
+// since the date provided
+func (c *Client) GetAccountTransactions(accountID string, sinceDate time.Time) (*Transactions, error) {
+	response := Transactions{}
+	urlQuery := url.Values{}
+	urlQuery.Add("since_date", sinceDate.Format("2006-01-02"))
+
+	err := c.get(fmt.Sprintf("/accounts/%s/transactions", accountID), &response, urlQuery)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get account transactions: %v", err)
+	}
+
+	return &response, nil
+}
+
+// Accepts a YNAB account ID and returns the transaction ID, amount and an error for the
+// the first transaction found with Payee Name "Capital Gains or Losses"
+func (c *Client) GetTodayYnabCapitalGainsTransaction(accountID string) (string, int, error) {
+	ynabTransactions, err := c.GetAccountTransactions(accountID, time.Now())
+	if err != nil {
+		return "", 0, fmt.Errorf("failed to get ynab transactions: %v", err)
+	}
+
+	for _, transaction := range ynabTransactions.Data.Transactions {
+		if transaction.PayeeName != "Capital Gains or Losses" {
+			continue
+		}
+		return transaction.ID, transaction.Amount, nil
+	}
+
+	return "", 0, nil
+}
+
+// Accepts a YNAB account ID and transaction amount and creates a new YNAB transaction
+func (c *Client) CreateTodayYNABCapitalGainsTransaction(accountID string, amount int) error {
+	transaction := TransactionRequest{}
+	transaction.Transaction.AccountID = accountID
+	transaction.Transaction.Amount = amount
+	transaction.Transaction.Date = time.Now().Format("2006-01-02")
+	transaction.Transaction.Cleared = "cleared"
+	transaction.Transaction.Approved = true
+	transaction.Transaction.PayeeName = "Capital Gains or Losses"
+
+	response := &Transaction{}
+
+	err := c.post("/transactions", response, transaction)
+	if err != nil {
+		return fmt.Errorf("failed to post transaction: %v", err)
+	}
+	return nil
+}
+
+// Accepts a YNAB account ID and transaction amount and creates a new YNAB transaction
+func (c *Client) UpdateTodayYNABCapitalGainsTransaction(accountID string, transactionID string, amount int) error {
+	transaction := TransactionRequest{}
+	transaction.Transaction.AccountID = accountID
+	transaction.Transaction.ID = transactionID
+	transaction.Transaction.Amount = amount
+	transaction.Transaction.Date = time.Now().Format("2006-01-02")
+	transaction.Transaction.Cleared = "cleared"
+	transaction.Transaction.Approved = true
+	transaction.Transaction.PayeeName = "Capital Gains or Losses"
+
+	response := &Transaction{}
+
+	err := c.put(fmt.Sprintf("/transactions/%s", transactionID), response, transaction)
+	if err != nil {
+		return fmt.Errorf("failed to put transaction: %v", err)
+	}
+	return nil
+}