Moss

Moss

This connector uses the Moss Public API (https://public-api.getmoss.com/v1) of Moss, the spend management platform for companies in Germany and Europe: expenses (card transactions, invoices, reimbursements) with their line items and attached receipts, bank accounts (wallets) with balances and bank transactions, suppliers, expense accounts, VAT rates, payment terms, accounting dimensions and their items, users, teams and departments. It can also create suppliers, dimensions and dimension items. It cannot pay, approve, export or delete anything: the API offers no such call.

Setup (about 5 minutes, Moss admin)

1. Sign in to Moss as an admin and open Settings, Company Settings, API Keys (also shown as Settings, Platform, API Keys).
2. Click Generate API Key and confirm in the Moss mobile app.
3. Copy the Key ID (starts with kid_) into MOSS_KEY_ID and the Secret Key (starts with sk_) into MOSS_SECRET_KEY. The secret is shown once.
4. Install. The connector exchanges the key for a one-hour token at /oauth2/token (client credentials) and renews it by itself. It asks for the write scope, which includes read, because the create and update tools need it; switch those tools off if the AI should only read.

Workflow

• Expenses: moss_list_expenses with expense_date_from / expense_date_to, types (CARD_TRANSACTION, INVOICE, REIMBURSEMENT), statuses and export_statuses. Each expense carries its lines with net, VAT and gross amounts, expenseAccountId and taxRateId. Page with page while meta.pagination.hasMore is true (page_size up to 100).
• Receipts: moss_search_files with expense ids lists the attached files, moss_download_file returns one file.
• Look up ids: moss_get_supplier / moss_list_suppliers, moss_get_expense_account / moss_list_expense_accounts, moss_get_tax_rate / moss_list_tax_rates, moss_get_payment_term / moss_list_payment_terms, moss_get_user / moss_list_users, moss_get_team / moss_list_teams, moss_get_department / moss_list_departments.
• Dimensions (cost centres, cost carriers, projects): moss_list_dimensions, moss_get_dimension, then moss_list_dimension_items and moss_get_dimension_item.
• Money: moss_list_bank_accounts, moss_get_bank_account_balance (balance and availableBalance), moss_search_bank_transactions for a booking date range (required).

Writes: moss_create_supplier, moss_create_dimension, moss_update_dimension, moss_create_dimension_item and moss_update_dimension_item change master data used for booking; show the user what will be created or changed and wait for a yes. Pass external_user_id (the person who asked) so Moss can trace the change. moss_update_supplier is installed switched off because it can replace the IBAN that Moss pays the supplier's invoices to. Items and suppliers can be set ACTIVE or DEACTIVATED here; deleting is not offered. Records managed by an active accounting integration answer 409.

Formats: amounts are objects with a decimal string amount and a currency; homeAmount is in the company's home currency. Dates are YYYY-MM-DD, timestamps ISO 8601 in UTC. Ids are UUIDs.

Errors: 401 means the key was revoked or the token could not be issued (check MOSS_KEY_ID and MOSS_SECRET_KEY). 402 means a Moss module is not booked (e.g. Multiple Dimensions). 403 means the token lacks the scope. 422 means a referenced id (expense account, VAT rate, payment term, team) does not exist or is inactive. 429: Moss allows 180 reads and 20 writes per minute per organisation; wait for Retry-After.