Offer configuration stays visible
Use Offers to decide what Custom API receives: product, price, buyer, checkout mode, invoice, and automation context.
Product surfaces
Where Custom API fits in the buying workflow
Integrations work best when the checkout surface, payment state, invoice record, and post-purchase automation all point at the same commercial object. These product screens show the Plandalf controls that should be configured before Custom API receives checkout, payment, tax, or workflow context.
Checkout layout and selling blocks stay editable
Before Custom API enters the stack, operators still need checkout templates, products, prices, coupons, order bumps, upsells, and branded offer content they can inspect.
Purchase events can start follow-up
Custom API should fit into the work after checkout: fulfilment, records, CRM updates, support context, webhooks, and sequences.
The buying surface can live where the buyer is
Custom API can start the sale through a hosted checkout, embedded checkout, modal, inline flow, or buy button depending on the stack.
Builder paths
Stack guides that use Custom API
Use these stack guides when a builder needs the whole path: sales surface, Plandalf offer, payment handoff, automation, fulfilment, records, and downstream integrations.
Custom API stack recipes
Find full stack guides that pair Custom API with checkout, payment, automation, fulfilment, records, and downstream integrations.
Offers overview
Use Offers to package products, prices, checkout pages, invoices, coupons, payment options, and follow-up context.
Hosted checkout
Use hosted checkout when Custom API should hand the buyer to a branded Plandalf checkout page.
SDK checkout
Use SDK checkout when Custom API belongs inside an app, custom site, or API-first stack.
Webhooks
Route checkout events, purchase events, payment state, invoices, and customer context into another tool.
Checkout completed fulfilment
Turn a completed checkout into access, receipts, CRM updates, support context, and records.
Overview
For teams that write their own code, Plandalf’s enrolment catch URL is a plain HTTP endpoint you can call from anywhere — your own backend, a serverless function, a scheduled job, a webhook receiver.
Not a third-party platform in the usual sense; it’s a catalog entry because the Emails tab renders “here’s how to enrol participants via your own code” the same way it renders Zapier or MailerLite instructions — one template, one code path, no special casing.
What Plandalf does here
- Direct enrolment API — the catch URL on each enrolment sequence
accepts a simple JSON body with
emailandref. No SDK required. - Stable
ref-keyed participants — repeat POSTs with the samerefre-resolve an existing participant rather than creating duplicates.
Setup templates
Drop-in implementations
Copy-paste setups for the most common ways to wire Custom API into Plandalf.
promo · automation
Enrol participants from your own code
If Zapier and your ESP's built-in automations don't cover the signal you want, POST directly to the promo's catch URL from anywhere — a server-side controller, a cron job, a form-submit handler, a Cloudflare Worker.
curl -X POST {{ promo.catch_url }} \
-H 'Content-Type: application/json' \
-d '{"email": "jane@example.com", "ref": "jane@example.com"}'
Notes:
- The
reffield is the participant's identifier — any stable string per person works (email, customer ID, UUID). Returning visitors with the samerefstay on the same deadline. emailis optional whenrefis not itself an address; it's used for email-tagged merge fields in timer URLs.
Automation graph
Connecting Custom API
How Custom API participates in Plandalf sequences: what events it exposes upward, and what actions Plandalf can perform on it.
Triggers from Custom API
Events Plandalf can subscribe to through webhooks, API work, checkout state, payment context, and connected integrations.
custom-api.webhook- Fires when Custom API POSTs to a Plandalf webhook URL — use for anything not covered by a native trigger.
Actions on Custom API
Things Plandalf sequences can do after checkout, payment, invoice, customer, or deadline events.
custom-api.custom_api_call- Hit any Custom API REST endpoint with a templated payload.
trigger: plandalf.checkout.completed
actions:
- custom-api.custom_api_call:
endpoint: /v1/event
payload:
email: ${customer.email}
plan: ${product_slug}Pair it with
Connect Custom API with…
Platforms whose roles complement Custom API inside a Plandalf sequence.
Custom API + ActiveCampaign
Compose Custom API and ActiveCampaign programmatically via the Plandalf SDK.
Custom API + beehiiv
Compose Custom API and beehiiv programmatically via the Plandalf SDK.
Custom API + Kit (ConvertKit)
Compose Custom API and Kit (ConvertKit) programmatically via the Plandalf SDK.
Custom API + Customer.io
Compose Custom API and Customer.io programmatically via the Plandalf SDK.
Custom API + Drip
Compose Custom API and Drip programmatically via the Plandalf SDK.
Custom API + Flodesk
Compose Custom API and Flodesk programmatically via the Plandalf SDK.
Integration methods
How Custom API connects to Plandalf
Each method below is the minimum viable setup. Pick the one closest to how you already use Custom API with checkout, payments, invoices, webhooks, API work, SDK checkout, and integrations.
- Method 1
REST API webhook
For anything not covered by a native trigger, configure a Custom API webhook to POST to Plandalf. The payload is forwarded into the sequence as `${event}`.
curl -X POST https://api.plandalf.com/v1/webhooks/custom-api \ -H "Authorization: Bearer $PLANDALF_API_KEY" \ -H "Content-Type: application/json" \ -d @event.json
FAQ
Common questions about the Custom API integration
Do I need a paid plan to use Custom API with Plandalf?
Plandalf itself is free to connect to Custom API. You only need a Custom API account that allows API access, which is almost every paid plan.
How long does setup take?
Under 10 minutes. OAuth (or paste an API key), pick the lists/segments you care about, and you're live. No code unless you want it.
Can I disconnect Custom API later without losing data?
Yes. Disconnecting only revokes the credentials — historical events Plandalf fired stay in your sequence logs, and Custom API's own records are untouched. You can reconnect any time and resume from the last seen event.
Does Plandalf store Custom API data?
Plandalf stores the minimum IDs needed to address a record in Custom API plus a log of events Plandalf fired. Source-of-truth data stays in Custom API.
What if my sdk need isn't covered by the actions or triggers listed here?
Use the generic `custom-api.custom_api_call` action or the inbound `custom-api.webhook` trigger. Anything Custom API's REST API can do, a Plandalf sequence can drive.
Is there a usage limit?
Plandalf respects Custom API's API rate limits and backs off on 429s. For very high-volume use cases, ask about a dedicated worker pool.
Where do I find Custom API's own documentation?
Custom API's homepage at https://plandalf.dev/docs/promos/api links to their developer docs. For Plandalf-side questions about the Custom API integration, see the Plandalf docs.