Verify Paystack Payments in Supabase Edge Functions

// supabase/functions/verify/index.ts
import { serve } from "https://deno.land/std@0.208.0/http/server.ts";
import { createClient } from "https://esm.sh/@supabase/supabase-js@2";

const corsHeaders = {
  "Access-Control-Allow-Origin": "*",
  "Access-Control-Allow-Headers": "authorization, x-client-info, apikey, content-type",
};

serve(async (req) => {
  if (req.method === "OPTIONS") {
    return new Response("ok", { headers: corsHeaders });
  }

  const url = new URL(req.url);
  const reference = url.searchParams.get("reference");

  if (!reference) {
    return new Response(
      JSON.stringify({ error: "Reference is required" }),
      { status: 400, headers: { ...corsHeaders, "Content-Type": "application/json" } }
    );
  }

  const secretKey = Deno.env.get("PAYSTACK_SECRET_KEY");

  // Call Paystack verify
  const paystackResponse = await fetch(
    "https://api.paystack.co/transaction/verify/" + encodeURIComponent(reference),
    { headers: { Authorization: "Bearer " + secretKey } }
  );

  const paystackData = await paystackResponse.json();

  if (!paystackData.status || paystackData.data.status !== "success") {
    return new Response(
      JSON.stringify({
        verified: false,
        status: paystackData.data?.status,
        message: paystackData.data?.gateway_response || "Payment not verified",
      }),
      { status: 400, headers: { ...corsHeaders, "Content-Type": "application/json" } }
    );
  }

  const txData = paystackData.data;

  // Update database using service role key (bypasses RLS)
  const supabase = createClient(
    Deno.env.get("SUPABASE_URL")!,
    Deno.env.get("SUPABASE_SERVICE_ROLE_KEY")!
  );

  const { error: dbError } = await supabase
    .from("orders")
    .update({
      status: "paid",
      paid_at: new Date().toISOString(),
      amount_paid: txData.amount / 100,
      currency: txData.currency,
    })
    .eq("reference", reference);

  if (dbError) {
    console.error("DB update failed:", dbError.message);
  }

  return new Response(
    JSON.stringify({
      verified: true,
      amount: txData.amount / 100,
      currency: txData.currency,
      reference: txData.reference,
      customer_email: txData.customer.email,
    }),
    { headers: { ...corsHeaders, "Content-Type": "application/json" } }
  );
});

supabase functions deploy verify

// Frontend call
const { data, error } = await supabase.functions.invoke('verify', {
  method: 'GET',
  // or pass as query param:
})

// Or direct fetch:
var response = await fetch(
  process.env.SUPABASE_URL + '/functions/v1/verify?reference=' + reference,
  {
    headers: { 'Authorization': 'Bearer ' + process.env.SUPABASE_ANON_KEY }
  }
)
var result = await response.json()

This guide is part of the Paystack integration guides by language and framework series.

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