On-Chain Purchase Follow-Up - Onchain Suite Docs

Goal. When a wallet completes a purchase on-chain, a mint, a swap, a deposit, follow up automatically: confirm in-app, suggest the next step, and email where you have an address. Who it’s for. Web3 teams. This is the wallet-native parallel of the Web2 Purchase confirmation: the purchase happens on-chain, so there’s often nothing to send from your backend, the platform sees it for you, and the first touch is in-app rather than email. Outcome to move. Repeat on-chain activity and the share of buyers who take the next step.

Prerequisites

Your contract configured in project settings, so the platform can watch it.
The in-app SDK installed, so the follow-up can land in your dApp.

Build it

Trigger on the on-chain purchase (no code)

For EVM contracts, the platform watches the chain for you. In the automation builder, pick the preset that matches the purchase, Swap completed, Token acquired (a mint), or Liquidity added (a deposit), and give it your contract. That’s the whole setup. See Contract-based flows.trigger (Swap completed) → send in-app (Thanks for your swap)

Follow up in-app, and by email where you have one

Add a Send in-app block, then branch so wallets with an email also get one:trigger → send in-app → branch (has email → send email | else → in-app only)The in-app message reaches the wallet in your dApp; the email reaches the ones who’ve shared an address through a capture form.

Purchases your backend knows about (optional)

Some purchases aren’t a plain on-chain event, a fiat on-ramp, a Solana contract, or an off-chain store tied to a wallet. Send those in yourself as a custom event keyed by the wallet:

curl -X POST https://api.onchainsuite.com/api/v1/events \
  -H "Authorization: Bearer sk_live_…" \
  -H "Content-Type: application/json" \
  -d '{
    "event": "purchase_completed",
    "contact": { "walletAddress": "0xabc..." },
    "payload": { "sku": "pass-gold", "total_usd": 49.0 },
    "idempotencyKey": "purchase:0xabc:9184"
  }'

import os, requests

requests.post(
    "https://api.onchainsuite.com/api/v1/events",
    headers={"Authorization": f"Bearer {os.environ['ONCHAIN_SECRET_KEY']}"},
    json={
        "event": "purchase_completed",
        "contact": {"walletAddress": "0xabc..."},
        "payload": {"sku": "pass-gold", "total_usd": 49.0},
        "idempotencyKey": "purchase:0xabc:9184",
    },
).raise_for_status()

await fetch("https://api.onchainsuite.com/api/v1/events", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.ONCHAIN_SECRET_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    event: "purchase_completed",
    contact: { walletAddress: "0xabc..." },
    payload: { sku: "pass-gold", total_usd: 49.0 },
    idempotencyKey: "purchase:0xabc:9184",
  }),
});

$ch = curl_init("https://api.onchainsuite.com/api/v1/events");
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        "Authorization: Bearer " . getenv("ONCHAIN_SECRET_KEY"),
        "Content-Type: application/json",
    ],
    CURLOPT_POSTFIELDS => json_encode([
        "event" => "purchase_completed",
        "contact" => ["walletAddress" => "0xabc..."],
        "payload" => ["sku" => "pass-gold", "total_usd" => 49.0],
        "idempotencyKey" => "purchase:0xabc:9184",
    ]),
]);
curl_exec($ch);
curl_close($ch);

body, _ := json.Marshal(map[string]any{
    "event":          "purchase_completed",
    "contact":        map[string]string{"walletAddress": "0xabc..."},
    "payload":        map[string]any{"sku": "pass-gold", "total_usd": 49.0},
    "idempotencyKey": "purchase:0xabc:9184",
})
req, _ := http.NewRequest("POST",
    "https://api.onchainsuite.com/api/v1/events", bytes.NewReader(body))
req.Header.Set("Authorization", "Bearer "+os.Getenv("ONCHAIN_SECRET_KEY"))
req.Header.Set("Content-Type", "application/json")
http.DefaultClient.Do(req)

Activate and publish.

As with any automation, both are required.

Test

Do the on-chain action with a wallet you control and wait out the short finality delay, then confirm the automation registered an entry and the in-app message arrived. See Testing a flow.

Measure

In-app delivered and viewed, and email open and click where you sent one.
Repeat purchases from wallets that entered the follow-up.
Email capture rate among buyers who had no address.

Variations

Upsell the holders. Trigger on Token acquired and point minters at your next drop.
Win-back. Pair with an on-chain trigger like Exchange outflow to catch a wallet heading for the door.
Web2 parallel. A regular, off-chain checkout? Use Purchase confirmation.

​Prerequisites

​Build it

​Test

​Measure

​Variations

Prerequisites

Build it

Test

Measure

Variations