generated: '2026-09-06'
method: searched
source: https://docs.acornfinance.com/api-postback
api: Acorn Finance Partner Postback API
note: >-
  Acorn Finance publishes no AsyncAPI document and no event-streaming surface. It does
  publish a real webhook: the Partner Postback API, in which Acorn POSTs loan
  application status changes to a URL the partner hosts. This artifact captures that
  webhook catalog. No AsyncAPI pointer is emitted because no AsyncAPI specification
  exists; the `Webhooks` pointer is emitted because the surface is genuinely
  documented and published.
transport: https
direction: provider-to-partner
subscription:
  self_service: false
  mechanism: out-of-band
  detail: >-
    There is no subscription or webhook-management API. The partner shares its
    postback URL and API key with the Acorn team, who enter them into the dealer
    portal.
  evidence: https://docs.acornfinance.com/api-postback
endpoint_requirements:
- field: postback-url
  required: true
  validation: >-
    Must be https. Must not contain the characters != & % ^ $ # @ *. Must not begin
    or end with a hyphen.
- field: postback-api-key
  required: true
  validation: Must be a string and must not contain a comma.
authentication:
  scheme: shared secret in a request header
  header: X-Authorization
  value: the partner-supplied postback API key
  signature: none
  detail: >-
    Acorn presents the partner's own API key back to the partner on each call. There
    is no HMAC signature, no timestamp, and no replay-prevention nonce documented, so
    a partner cannot cryptographically verify that a postback originated with Acorn
    beyond the shared secret.
  evidence: https://docs.acornfinance.com/api-postback
events:
- id: application.offered
  process_status: OFFERED
  description: The applicant received one or more loan offers.
- id: application.no-offer
  process_status: NO OFFER
  description: No lender in the network extended an offer.
- id: application.funded
  process_status: FUNDED
  description: A selected loan was funded.
note_on_states: >-
  The postback documentation names offered, no-offers and funded as the triggering
  events. The full application state set surfaced on GET /company_applications also
  includes SELECTED and EXPIRED; the documentation additionally says emails are sent
  for "offered, selected and funded applications", so whether SELECTED triggers a
  postback is ambiguous in the published material and is not asserted here.
request:
  method: POST
  content_type: application/json
  target: partner-hosted URL
  fields:
  - name: partnerId
    description: >-
      The utm_content value carried on the Payment Amount Widget; represents the
      partner's own estimate or document id.
  - name: dealerId
    description: The Acorn dealer id for the company user on the application.
  - name: processStatus
    description: OFFERED | NO OFFER | FUNDED
  - name: loanAmount
  - name: applicationId
  - name: applicationDate
  - name: firstName
  - name: lastName
  - name: phoneNumber
  - name: email
  pii_note: >-
    The postback body carries applicant name, phone number and email address. Partners
    receiving it are receiving consumer PII from a licensed lender-broker.
response:
  description: >-
    Unusually, this webhook expects a data-bearing response. Acorn uses the partner's
    reply to compose the borrower-facing Offered / No Offers / Funded emails, so the
    partner's endpoint is effectively an inbound lookup API as well as an event sink.
  fields:
  - name: sendEmail
    type: boolean
    description: >-
      Master switch. When false, Acorn sends no emails to the users on the
      application and the remaining fields are ignored.
  - name: overRideRepInfo
    type: boolean
    description: >-
      When true, Acorn uses the rep identity from this response instead of the saved
      dealer record when generating the email.
  - name: displayName
  - name: repFirstName
  - name: repLastName
  - name: repEmail
  - name: companyName
  - name: projectName
  - name: projectUrl
  - name: projectAddress
retry_policy:
  published: false
  note: No retry, backoff, timeout or delivery-guarantee behaviour is documented.
delivery_guarantee:
  published: false
ip_allowlist:
  published: false
asyncapi_spec: false