Xero API simulator

A hosted, read-only drop-in for the Xero Accounting API — an extra feature of x0 Professional. Point your OAuth and Accounting base URLs here instead of api.xero.com / identity.xero.com and exercise a real client against seeded orgs, nested JSON, pagination, attachments, and Xero-shaped errors — without a live Xero organisation or partner app review.

Not a Xero product and not affiliated with Xero Limited. Surface compatibility is intentional; data is synthetic. Available on Professional and Enterprise plans.

When to use it

CI / local dev for anything that talks to Xero Accounting (Excel connectors, ETL, agents)
Proving pagination, If-Modified-Since, 429 backoff, and attachment downloads
Onboarding a new engineer before they get Xero demo-company access

If you want flat Excel / OData tables rather than the raw Xero JSON, that is x0 — the product this simulator was built to test.

Base URL

Public host (x0-dev):

https://sim.dev.x0.co.nz

Health: GET https://sim.dev.x0.co.nz/_sim/health
OpenAPI: https://sim.dev.x0.co.nz/_sim/docs
Authorize: https://sim.dev.x0.co.nz/identity/connect/authorize
Token: https://sim.dev.x0.co.nz/connect/token
Connections: https://sim.dev.x0.co.nz/connections
Accounting: https://sim.dev.x0.co.nz/api.xro/2.0/…

Self-host is not required — Pro customers use this public host with provisioned credentials.

OAuth2

Authorization code + refresh token, Xero-style. Client auth is HTTP Basic (client_id:client_secret) or form fields. Authorize auto-approves seeded orgs (no consent UI) so CI can follow the redirect.

POST https://sim.dev.x0.co.nz/connect/token
Authorization: Basic base64(client_id:client_secret)
Content-Type: application/x-www-form-urlencoded

grant_type=authorization_code&code=…&redirect_uri=…
# or
grant_type=refresh_token&refresh_token=…

Then GET https://sim.dev.x0.co.nz/connections with the access token. Accounting calls need Authorization: Bearer … and xero-tenant-id: <tenant guid>.

Access ~30 minutes, refresh ~60 days. Register your redirect URI with us (or in Django admin if you run the sim yourself).

Accounting GETs

Nested Xero JSON under /api.xro/2.0/{Resource}. Writes return 403 (read-only v1).

x0 sync set (start here)

Resource	Pagination	Also
`Accounts`	none	attachments
`Organisation`	none	—
`Journals`	offset	—
`Contacts`	page / pageSize	attachments · history
`Invoices`	page / pageSize	attachments · history
`ManualJournals`	page / pageSize	attachments · history
`BankTransactions`	page / pageSize	attachments · history
`Payments`	page / pageSize	history

Remaining Accounting collections

BankTransfers, BatchPayments, BrandingThemes, Budgets, ContactGroups, CreditNotes, Currencies, Employees, ExpenseClaims, Items, LinkedTransactions, InvoiceReminders, Overpayments, Prepayments, PurchaseOrders, Quotes, Receipts, RepeatingInvoices, TaxRates, TrackingCategories, Users, PaymentServices

Reports (shells)

Reports/TenNinetyNine, Reports/AgedPayablesByContact, Reports/AgedReceivablesByContact, Reports/BalanceSheet, Reports/BankSummary, Reports/BudgetSummary, Reports/ExecutiveSummary, Reports/ProfitAndLoss, Reports/TrialBalance

Behaviour you can rely on

Pagination — page / pageSize (max 100). Journals use offset.
If-Modified-Since — supported on most collections.
Dates — Xero /Date(milliseconds)/ strings, not ISO.
Attachments — list + binary by id or filename on resources that have them.
History — /{Resource}/{id}/History where noted above.
Rate limits — 60 / minute and 5000 / day per tenant. Headers: X-DayLimit-Remaining, X-MinLimit-Remaining. Over limit → 429 + Retry-After.
Errors — Xero-shaped JSON (Type, Message, Detail, …).

Minimal curl

# after you have an access token + tenant id
SIM=https://sim.dev.x0.co.nz
curl -sS "$SIM/api.xro/2.0/Accounts" \
  -H "Authorization: Bearer $ACCESS" \
  -H "xero-tenant-id: $TENANT"

curl -sS "$SIM/api.xro/2.0/Contacts?page=1&pageSize=100" \
  -H "Authorization: Bearer $ACCESS" \
  -H "xero-tenant-id: $TENANT"

curl -sS "$SIM/api.xro/2.0/Journals?offset=0" \
  -H "Authorization: Bearer $ACCESS" \
  -H "xero-tenant-id: $TENANT"

Point an existing Xero client at the sim

Override the four Xero hosts (names vary by SDK):

XERO_API_BASE_URL=https://sim.dev.x0.co.nz/api.xro/2.0
XERO_CONNECTIONS_URL=https://sim.dev.x0.co.nz/connections
XERO_TOKEN_URL=https://sim.dev.x0.co.nz/connect/token
XERO_AUTHORIZE_URL=https://sim.dev.x0.co.nz/identity/connect/authorize

Same idea when x0 itself is pointed at the sim in development — see the simulator guide.

Get access

Hosted simulator credentials are a Professional feature (option xero_api_simulator). We provision an OAuth client_id / client_secret and a seeded tenant — those are not published on this page.

Request simulator credentials or email support@x0.co.nz with your redirect URI and what you are testing (include that you are on Professional, or ask about upgrading).

Guide: Xero API simulator · Pricing · x0 guides · About x0