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FreshBooks Integration Guide

Connect FreshBooks accounting, invoicing, expense, project, and time-tracking data with enterprise systems through REST APIs, OAuth 2.0, and selected webhook events.

FreshBooks integration options at a glance

FreshBooks primarily integrates through REST APIs secured with OAuth 2.0. Its APIs support common accounting and billing operations for Clients, Invoices, Payments, Expenses, Projects, and Time entries, with JSON responses and paginated collections. FreshBooks also provides webhook-style notifications for selected resources and events, although coverage should be verified for each object and event type. Selected resources support attachment or receipt operations. Martini can consume FreshBooks APIs, receive supported webhook notifications through an API endpoint or workflow, manage pagination and checkpoints, transform JSON, and apply business rules. For events without webhook coverage, scheduled polling provides a controlled synchronization alternative.

Integration pointSupported by FreshBooks?Common use casesHow Martini supports it
REST APIsYesFreshBooks REST APIs manage Clients, Invoices, Payments, Expenses, Projects, Time entries, and related accounting data. Common operations include listing, retrieving, creating, updating, and deleting supported resources.Martini can consume FreshBooks REST endpoints from workflows, handle JSON responses, paginate collection requests, transform fields, and expose reusable API-led integration services.
Webhooks / outbound callbacksLimitedFreshBooks provides webhook-style notifications for selected resources and events. Coverage, payload completeness, subscription scope, and delivery behavior must be verified for each integration.Martini can expose an inbound API or webhook workflow, validate incoming requests where required, deduplicate notifications, retrieve current FreshBooks state, and process events asynchronously.
File / attachment APIsLimitedSelected accounting resources support file or attachment operations, particularly expense receipts. The response may contain binary content, a download URL, or metadata requiring a separate request.Martini can retrieve supported attachment data, preserve file metadata, transform or route files, and apply retention and error-handling policies.
AuthenticationYesFreshBooks uses OAuth 2.0 with registered application credentials, authorization codes, bearer access tokens, refresh tokens, and resource permissions or scopes.Martini can store credentials and refresh tokens as protected configuration or secrets and use bearer access tokens when calling FreshBooks APIs.
Bulk / async / batch APIsNot confirmedA general-purpose FreshBooks bulk or asynchronous processing API was not confirmed. Large transfers should use paginated REST calls and incremental synchronization where supported.Martini can orchestrate paginated workflows, checkpoints, controlled concurrency, retries, and scheduled batches without assuming a FreshBooks bulk endpoint.
GraphQL APIsNot confirmedNo official FreshBooks GraphQL API was confirmed in the supplied research. FreshBooks integrations should be designed around REST APIs.Martini can consume GraphQL from other systems when needed, but the FreshBooks side should use its confirmed REST interfaces.
SOAP APIsNot confirmedNo official FreshBooks SOAP API was confirmed in the supplied research.Martini can consume SOAP services from other systems in a broader workflow, but should not assume SOAP access to FreshBooks.
Database accessNot confirmedFreshBooks does not provide direct customer database access as an integration mechanism. Reporting and persistence should use supported APIs or exports.Martini can write normalized FreshBooks data to supported databases for reporting, reconciliation, or downstream processing.

How FreshBooks exposes data and business events

FreshBooks REST APIs

FreshBooks REST APIs are the primary integration mechanism for accounting, invoicing, expense, project, and time-tracking data. The APIs expose JSON resources and commonly return paginated collections for list operations.

Martini implementation pattern

Martini implementation pattern: a workflow authenticates with an OAuth 2.0 access token, calls the appropriate FreshBooks resource endpoint, follows pagination, validates the response, maps the vendor object to a canonical model, and writes it to the target system or returns a controlled API response.

Implementation sequence

Obtain or refresh the FreshBooks OAuth access token
Call the required FreshBooks REST resource
Process each paginated collection response
Validate and map the JSON object
Apply business and ownership rules
Write the result to the target system and store the checkpoint

FreshBooks Webhooks

FreshBooks supports webhook-style notifications for selected resources and events. Coverage is not universal, so the integration must verify supported objects, event names, payload contents, subscription scope, and delivery behavior.

Martini implementation pattern

Martini implementation pattern: Martini exposes an inbound API or webhook workflow, accepts the notification quickly, validates the configured authentication or signature mechanism, records an event key, and retrieves the current FreshBooks resource when the notification is incomplete before processing it asynchronously.

Implementation sequence

Receive the FreshBooks webhook notification
Validate the request and identify the resource event
Check the event or resource identifier for duplicates
Retrieve the current FreshBooks object when required
Map the object and apply synchronization rules
Acknowledge the notification and record the processing result

FreshBooks Attachments

Selected FreshBooks resources support attachment or receipt operations, particularly Expenses. The integration must determine whether content is returned inline, through a download URL, or as metadata requiring another request.

Martini implementation pattern

Martini implementation pattern: a workflow retrieves the FreshBooks resource and supported attachment representation, preserves file metadata, applies file-size and retention rules, and sends the document or reference to the target system without placing large content in ordinary logs.

Implementation sequence

Identify the FreshBooks resource and attachment reference
Request the supported attachment or receipt representation
Validate file metadata and content availability
Map the file to the target document model
Transfer or store the file using the target policy
Record the source identifier and transfer outcome

Scheduled FreshBooks Synchronization

Scheduled polling is the fallback for FreshBooks resources or events without suitable webhook coverage. Paginated REST requests and updated-time filters or other supported incremental mechanisms can limit each run.

Martini implementation pattern

Martini implementation pattern: a scheduled workflow loads the last successful watermark, retrieves changed FreshBooks objects page by page, processes records idempotently, and advances the checkpoint only after the relevant target writes succeed.

Implementation sequence

Start the workflow on a controlled schedule
Load the last successful synchronization watermark
Retrieve changed FreshBooks objects with pagination
Transform and validate each object
Write records and capture failures for retry
Advance the watermark after successful processing

Common FreshBooks integration patterns

Pattern 1: Create FreshBooks invoices from orders

When to use this pattern

Use this pattern when an approved order or subscription event must become a FreshBooks Client and Invoice. It is appropriate when the source system owns order approval while FreshBooks owns accounting document creation.

Integration direction
Shopify
Martini
FreshBooks
Example Mapping
FreshBooks FieldCanonical FieldTarget Field
order.customercustomer.externalIdClients.customerReference
order.lineItemsinvoice.linesInvoices.lines
order.currencybilling.currencyInvoices.currency
order.totalTaxbilling.taxAmountInvoices.taxes
Martini implementation pattern

Martini receives or retrieves the approved order, resolves or creates the FreshBooks Client, maps line items, tax, currency, and external references, and creates or updates the Invoice. A stored source order ID and FreshBooks Invoice ID prevent duplicates; validation failures are routed for correction while transient API failures use bounded retries.

Martini capabilities used
  • workflows
  • API consumption
  • OAuth 2.0 configuration
  • data mapping
  • business rules
  • error handling

Pattern 2: Reconcile invoices and payments

When to use this pattern

Use this pattern when CRM, payment, subscription, or customer-portal systems need current FreshBooks invoice and payment status. The design should distinguish invoice state from individual Payments and preserve partial-payment and currency information.

Integration direction
FreshBooks
Martini
Salesforce
Example Mapping
FreshBooks FieldCanonical FieldTarget Field
Invoices.invoiceidbilling.documentIdSalesforce.Invoice__c.externalId
Invoices.statusbilling.statusSalesforce.Invoice__c.status
Payments.amountpayment.amountSalesforce.Payment__c.amount
Payments.invoiceidpayment.invoiceIdSalesforce.Payment__c.invoiceExternalId
Martini implementation pattern

A FreshBooks webhook workflow or scheduled synchronization retrieves current Invoices and Payments, maps statuses and amounts, and updates the target system without overwriting locally managed fields. Martini records processed event or resource identifiers, retries transient failures, and uses reconciliation runs to detect missed or out-of-order notifications.

Martini capabilities used
  • webhooks
  • scheduled workflows
  • API consumption
  • data mapping
  • idempotency controls
  • error handling

Pattern 3: Synchronize expenses and receipts

When to use this pattern

Use this pattern when FreshBooks Expenses and associated receipts must be transferred to a financial platform, expense application, or reporting store. It is useful when category, tax, document, and duplicate controls are required.

Integration direction
FreshBooks
Martini
NetSuite
Example Mapping
FreshBooks FieldCanonical FieldTarget Field
Expenses.amountexpense.amountNetSuite.expense.amount
Expenses.categoryexpense.categoryNetSuite.expense.account
Expenses.vendorexpense.vendorNetSuite.expense.entity
Expenses.receiptexpense.attachmentNetSuite.expense.file
Martini implementation pattern

Martini retrieves paginated Expenses, maps categories, vendors, dates, tax, and amounts, and requests receipt data when the applicable FreshBooks attachment operation is available. The workflow stores cross-system identifiers, applies file retention and validation rules, and separates unsupported or malformed attachments from retryable API failures.

Martini capabilities used
  • scheduled workflows
  • REST API consumption
  • file handling
  • data mapping
  • validation
  • error handling

Pattern 4: Synchronize projects and approved time

When to use this pattern

Use this pattern when project and workforce systems need to exchange FreshBooks Projects and Time entries or when approved time is used for billing reconciliation. Ownership of Clients, Projects, rates, approvals, and invoice creation should be defined before enabling bidirectional updates.

Integration direction
Project management platform
Martini
FreshBooks
Example Mapping
FreshBooks FieldCanonical FieldTarget Field
project.externalIdproject.idProjects.projectId
timeEntry.hourstime.durationTime entries.duration
timeEntry.clientIdtime.clientIdTime entries.clientId
timeEntry.approvedtime.approvalStatusTime entries.status
Martini implementation pattern

Martini retrieves or receives approved work data, resolves FreshBooks Clients and Projects, maps time and billing attributes, and writes only records that satisfy approval and ownership rules. Checkpoints, deterministic keys, and reconciliation reports make reruns safe and expose differences before invoice generation.

Martini capabilities used
  • workflows
  • scheduled synchronization
  • data mapping
  • business rules
  • checkpointing
  • error handling

Applications commonly integrated with FreshBooks

FreshBooks can be integrated with sales, commerce, payment, accounting, enterprise finance, and collaboration applications. These patterns typically use REST APIs on both sides, with Martini coordinating authentication, mapping, reconciliation, event handling, and operational controls.

Application Scenario Direction Martini Pattern
Salesforce Create FreshBooks Clients and Invoices from CRM opportunities or contracts and return invoice and payment status to Salesforce. Salesforce → Martini → FreshBooks Martini receives approved opportunity or contract data, maps customer and billing fields, creates or updates FreshBooks Clients and Invoices, and synchronizes status or payment results back to Salesforce with duplicate detection and retry handling.
HubSpot Synchronize customer, deal, invoice, and payment information between sales operations and billing processes. HubSpot → Martini → FreshBooks A Martini workflow consumes HubSpot deal events or scheduled changes, resolves the FreshBooks Client, creates or updates billing objects, and writes invoice status back to HubSpot while preserving system ownership for sales fields.
Shopify Create or reconcile FreshBooks Clients and Invoices from ecommerce orders, refunds, taxes, and payment outcomes. Shopify → Martini → FreshBooks Martini receives or retrieves Shopify order data, maps order lines and tax details to FreshBooks Invoices, stores the source order identifier, and processes later status or refund changes without creating duplicate invoices.
Stripe Reconcile payment events with FreshBooks Invoices and Payments and provide a consistent view of settlement status. Stripe → Martini → FreshBooks Martini receives payment notifications or polls payment status, matches the source transaction to a FreshBooks Invoice, maps amounts and currencies, and updates or reconciles Payments with idempotency controls.
QuickBooks Online Support accounting-platform migration or coexistence by moving or reconciling Clients, Invoices, Payments, and Expenses. QuickBooks Online → Martini → FreshBooks Martini extracts paginated objects from each platform, maps tax, currency, status, and identifiers to a canonical model, applies conflict rules, and records cross-system IDs for safe reruns.
Xero Synchronize accounting and invoicing information during migration or multi-system finance operations. Xero → Martini → FreshBooks Scheduled Martini workflows retrieve changed objects, normalize accounting fields and line items, apply ownership and tax rules, and write the result to FreshBooks or Xero with checkpointed reconciliation.
NetSuite Send FreshBooks invoice, expense, project, payment, or time data to an enterprise financial system or coordinate bidirectional finance processes. FreshBooks → Martini → NetSuite Martini polls FreshBooks or receives supported events, transforms objects into NetSuite-compatible structures, applies account and tax mappings, and routes validation failures for review rather than retrying unchanged requests.
Slack Notify finance and project teams about invoice failures, overdue invoices, payment changes, or synchronization errors. FreshBooks → Martini → Slack A Martini workflow consumes FreshBooks events or scheduled exception results, formats concise notifications with links or identifiers, and sends them to selected Slack channels while suppressing duplicate alerts.

How to build a FreshBooks integration in Martini

Objective

Establish FreshBooks access using a registered OAuth 2.0 application and protect tenant-specific identifiers and tokens.

Instructions in Martini

  • Register or identify the FreshBooks application and required scopes
  • Store client credentials, refresh tokens, and account identifiers as protected Martini configuration or secrets
  • Configure bearer-token authentication and token refresh behavior
  • Keep credentials out of workflow payloads, URLs, and logs

Objective

Select an event-driven or scheduled entry point based on the FreshBooks resource and its confirmed notification coverage.

Instructions in Martini

  • Use a FreshBooks webhook endpoint for supported events
  • Use a scheduler for resources without suitable webhook coverage
  • Define the resource, event, account, and tenant scope
  • Set a polling watermark or event deduplication key

Objective

Obtain the current FreshBooks object or collection and make the workflow resilient to pagination and incomplete notifications.

Instructions in Martini

  • Call the relevant FreshBooks REST endpoint
  • Retrieve the current object when a webhook contains only an identifier
  • Follow pagination links or response metadata
  • Persist page progress and synchronization checkpoints

Objective

Coordinate validation, enrichment, target calls, and exception paths in a maintainable Martini workflow.

Instructions in Martini

  • Separate authentication, retrieval, transformation, and target-write stages
  • Apply account and business ownership rules
  • Route validation failures separately from transient API failures
  • Use reusable workflow logic for common FreshBooks resource handling

Objective

Convert FreshBooks JSON objects into a canonical model and target-specific payloads without coupling downstream systems to vendor fields.

Instructions in Martini

  • Map Clients, Invoices, Payments, Expenses, Projects, and Time entries explicitly
  • Normalize dates, currencies, taxes, statuses, identifiers, and line items
  • Handle optional fields and resource-specific attachment behavior
  • Preserve FreshBooks and source-system identifiers for reconciliation

Objective

Control creation, update, reconciliation, and duplicate behavior before writing to downstream systems.

Instructions in Martini

  • Check for existing Clients or Invoices before creation
  • Define ownership for customer, project, tax, currency, and payment fields
  • Use deterministic synchronization keys and processed-event identifiers
  • Reject or quarantine records that fail required business validation

Common FreshBooks data objects used in integrations

ObjectTypical UseCommon target systemsMartini handling
ClientsRepresent customers or organizations billed by a FreshBooks business and provide the customer context for invoices and projects.Salesforce, HubSpot, Shopify, NetSuite, XeroMartini maps source customer identifiers, contact details, billing attributes, and account relationships; it stores cross-system IDs and checks for existing Clients before creation.
InvoicesRepresent issued billing documents with line items, taxes, totals, status, and payment information.Salesforce, Shopify, Stripe, NetSuite, XeroMartini transforms line items, tax, currency, totals, and external references, applies duplicate-prevention rules, and routes validation or reconciliation exceptions separately from transient failures.
PaymentsRepresent payments recorded against Invoices or client balances and support settlement reconciliation.Stripe, Salesforce, NetSuite, Xero, customer portalsMartini matches Payments to source transactions and Invoices, preserves partial-payment information where supported, and applies idempotency using transaction or resource identifiers.
ExpensesRepresent business expenses with amounts, categories, vendors, dates, and associated receipts where available.NetSuite, Xero, QuickBooks Online, data warehouses, expense platformsMartini maps categories, tax treatment, dates, amounts, and vendor data, retrieves supported receipt information, and prevents duplicate expense imports.
ProjectsOrganize billable work for clients and provide context for time tracking and project billing.NetSuite, project management platforms, workforce systems, reporting storesMartini synchronizes project identifiers, client relationships, status, and ownership while applying rules for which system controls project creation and updates.
Time entriesCapture billable or non-billable work recorded against Projects and Clients.workforce platforms, project management systems, NetSuite, reporting storesMartini converts time, project, client, approval, and billing attributes into the target model and can use approved entries for billing or reconciliation workflows.

Authentication and security considerations

OAuth 2.0 access

FreshBooks uses OAuth 2.0 for third-party application access. Applications are registered to obtain client credentials, exchange an authorization code for tokens, and send access tokens as bearer tokens.

Protect integration credentials

  • Store client secrets, access tokens, refresh tokens, scopes, and FreshBooks account identifiers in protected Martini environment configuration or secrets.
  • Request only the permissions required by the integration.
  • Plan for token refresh, revocation, reauthorization, and account or business changes.
  • Do not place credentials in workflow payloads, URLs, or ordinary logs.

Secure inbound notifications

For FreshBooks webhook workflows, validate the authentication or signature mechanism required by the configured FreshBooks subscription, record event identifiers, and avoid treating an unverified notification as trusted business data.

Operational considerations for FreshBooks integrations

Pagination and checkpoints

FreshBooks collection responses are commonly paginated. Store page progress and a last-successful watermark, and allow for records modified during a synchronization window.

Rate limits and retries

Respect FreshBooks rate limits and response headers where provided. Use bounded exponential backoff for throttling and transient failures, but do not repeatedly retry malformed requests or business validation errors.

Idempotency and reconciliation

Store source and FreshBooks identifiers, use deterministic synchronization keys, and record processed webhook events. Reconciliation workflows should detect missed, delayed, duplicated, or out-of-order notifications.

Accounting data quality

Define ownership for invoice status, taxes, discounts, credits, refunds, currencies, rounding, and partial payments. Keep vendor-specific mappings isolated from canonical and target models.

Attachments and schema changes

Confirm whether expense receipts are returned as binary content, a download URL, or metadata. Use tolerant mappings for optional fields, monitor FreshBooks API changes, and test representative invoice, payment, tax, currency, and line-item variations.

Why use Martini instead of scripts or point-to-point integrations?

Centralized orchestration

Martini coordinates FreshBooks API calls, webhook intake, scheduled synchronization, target-system writes, validation, and reconciliation in maintainable workflows rather than scattering logic across scripts.

Reusable integration assets

Common authentication, pagination, mapping, error, and checkpoint logic can be reused across Clients, Invoices, Payments, Expenses, Projects, and Time entries while keeping vendor-specific behavior isolated.

Controlled transformation

Martini maps FreshBooks JSON into canonical and target-specific models, applies tax, currency, ownership, and duplicate rules, and can expose controlled APIs for other systems.

Operational reliability

Workflow-level error handling, retries, logging, monitoring, and reconciliation provide a more consistent operating model than individual point-to-point scripts.

Frequently asked questions

How can FreshBooks be integrated with enterprise systems?

FreshBooks can be integrated through its REST APIs secured with OAuth 2.0, selected webhook-style event notifications, and resource-specific attachment or receipt operations. REST APIs support Clients, Invoices, Payments, Expenses, Projects, and Time entries. Systems can use webhooks for supported events and scheduled, paginated API synchronization for resources without suitable event coverage.

Can Martini integrate with FreshBooks?

Yes. Martini can integrate with FreshBooks by consuming its REST APIs, managing OAuth 2.0 authentication, receiving supported FreshBooks webhook notifications, processing selected attachments, and orchestrating mappings, business rules, synchronization, retries, and reconciliation workflows.

Do I need a connector to integrate FreshBooks with Martini?

No. A dedicated FreshBooks connector is not required. Martini can use FreshBooks' confirmed native integration mechanisms, including REST APIs, OAuth 2.0, selected webhook notifications, and supported attachment operations.

Is there any extra Lonti cost to integrate FreshBooks with Martini?

Lonti does not charge an additional per-connector or per-vendor fee to integrate FreshBooks with Martini. Integration usage is subject to the provisioned capacity of the Martini environment. Separate costs may apply from FreshBooks, cloud infrastructure, or other third-party systems depending on subscriptions, usage, and deployment choices.

Which FreshBooks integration methods should be used?

REST APIs secured with OAuth 2.0 are the primary and recommended method. Selected FreshBooks resources also support webhook-style notifications, while attachment or receipt operations are available for certain resources. No official FreshBooks GraphQL or SOAP API, general-purpose bulk API, or direct database access was confirmed.

Can Martini receive FreshBooks webhooks?

Yes, Martini can expose an inbound API or webhook workflow for FreshBooks notifications. FreshBooks webhook coverage is resource- and event-specific, so the integration should verify supported events, validate requests as required, deduplicate notifications, retrieve current state when necessary, and use polling reconciliation for missed events.

How are FreshBooks data synchronization and mapping handled?

Martini can use webhook-triggered workflows or scheduled REST API polling with pagination and stored watermarks. JSON mappings transform FreshBooks Clients, Invoices, Payments, Expenses, Projects, and Time entries into canonical and target-specific models, while business rules control ownership, tax, currency, status, and identifier reconciliation.

How does Martini handle FreshBooks errors, retries, and duplicates?

Martini workflows can separate authentication, rate-limit, transient, validation, and business errors. Transient failures can use bounded retries and backoff, while validation failures are routed for correction. Cross-system IDs, deterministic references, processed event identifiers, checkpoints, and reconciliation runs help prevent duplicate Clients, Invoices, Payments, and other objects.