How do I mock the Avalara AvaTax REST API locally?

Install stunt, add a one-service block to stunt.yaml (adapter: embedded:avalara-style), and run stunt up. You get a local, stateful stand-in for Avalara AvaTax REST API 2 — 8 routes over rest — with no remote account, no network, and no bills.

Is the Avalara AvaTax REST API mock data synthetic?

Yes — entirely. The adapter returns generated data only; stunt's adapter lint rejects real-looking secrets and PII at build time. It simulates the shape and behavior of Avalara AvaTax REST API (routes, status codes, pagination, webhooks), never real records.

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avalara-style

simulates Avalara AvaTax REST API 2

restadapter v0.1.08 routes

verification

VMVM tier — no SDK suite yet· surface 8 · not implemented 5 · differs 3

use it

# add to stunt.yaml
services:
  avalara:
    adapter: embedded:avalara-style

# then
$ stunt up

The embedded: source extracts this adapter from the binary — no git clone, fully offline.

how to mock the Avalara AvaTax REST API locally

Install stunt, paste the service block above into stunt.yaml, run stunt up — then point your client at localhost instead of Avalara AvaTax REST API. It works offline, keeps state across requests and restarts, and every response is synthetic: the route shapes, status codes, pagination, and webhook delivery follow the real Avalara AvaTax REST API 2 surface — the data is fake, the behavior is real.

backing stores

transactionscompanies

api surface (8)

generated from the adapter manifest — exactly what boots, nothing more

8 routes

POST/v2/tax/calculate

POST/v2/transactions/create

GET/v2/transactions

GET/v2/transactions/{id}

POST/v2/transactions/{id}/void

GET/v2/companies

GET/v2/definitions/nexuses

GET/v2/definitions/taxcodes

VM-verified behaviors (19)

✓every v2 endpoint demands a credential: a bare call is a 401 AuthenticationRequired envelope
✓any Bearer or any HTTP Basic credential opens the gate
✓a non-Basic/Non-Bearer scheme does not count as a credential
✓the effective rate keys off the address state (CA 0.095) with a State/County/City/Special breakdown
✓the summary aggregates the taxable base per jurisdiction
✓per-line tax rounds to cents: two lines aggregate, line 2 keeps its own tax
✓SDK decimal strings ("100.00") price identically to JSON numbers
✓the shipFrom/shipTo form keys off shipTo (NY 0.0875)
✓unknown or missing addresses fall back to the synthetic 0.0825 default
✓create prices the document, mints id/code/companyId and applies AvaTax defaults
✓an omitted date defaults to the clock's today, and advances with it
✓read round-trips by id; unknown ids are 404 NotFound
✓the list supports OData $filter and $orderBy with @recordsetCount
✓$top/$skip pages through an @odata.nextLink that round-trips
✓void flips status to Cancelled and the record reads back cancelled
✓re-void is idempotent
✓the companies catalog lists DEFAULT and STORE1 with default locations
✓nexus $filter literals are typed: id eq 1001 matches ints, hasNexus eq true matches bools
✓the taxcode catalog is filterable by taxCode

Not implemented (5)

No company CRUD — GET /v2/companies list only
No address validation (/v2/addresses/resolve)
No createoradjust, settle, or per-line transaction operations
No customers, certificates, or exemption endpoints
No jurisdiction lookups — definitions serve nexuses and taxcodes only

Differs from the real API (3)

Tax is a deterministic split — State 50%, County 25%, City 20%, Special 5% of the rate
Void returns a minimal {id, status} envelope; real AvaTax returns the full TransactionModel
Re-void is idempotent 200; real AvaTax rejects voiding a Cancelled document

full scorecard →

want more of the Avalara AvaTax REST API surface? adapters are YAML + Starlark — the authoring guide covers adding routes, fixtures, and state machines. Open an issue for anything big first, or just file a PR — merged routes ship in the next release.