Filter by Address and Asset

The event filter first selects input.transaction. The Cardano filter then requires both the configured address and asset fingerprint to match. Edit WithAddresses and WithAssetFingerprints for your targets; remove the asset option to watch all matching address transactions.

Follow the bundle setup, then run from its root:

export CARDANO_NODE_SOCKET_PATH=/path/to/node.socket
go run ./event-address-filter

Download main.go as part of the complete bundle.

Source

// Copyright 2026 Blink Labs Software
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
  "context"
  "errors"
  "fmt"
  "log/slog"
  "os"
  "os/signal"
  "syscall"

  "github.com/blinklabs-io/adder/event"
  filter_chainsync "github.com/blinklabs-io/adder/filter/cardano"
  filter_event "github.com/blinklabs-io/adder/filter/event"
  input_chainsync "github.com/blinklabs-io/adder/input/chainsync"
  output_embedded "github.com/blinklabs-io/adder/output/embedded"
  "github.com/blinklabs-io/adder/pipeline"
  "github.com/kelseyhightower/envconfig"
)

// Config holds the Cardano node connection settings.
type Config struct {
  SocketPath string `split_words:"true"`
  Magic      uint32
}

func main() {
  if err := run(); err != nil {
    slog.Error("adder example failed", "error", err)
    os.Exit(1)
  }
}

func run() (err error) {
  cfg := Config{
    Magic:      764824073,
    SocketPath: "/ipc/node.socket",
  }
  if err := envconfig.Process("cardano_node", &cfg); err != nil {
    panic(err)
  }

  p := pipeline.New()

  inputOpts := []input_chainsync.ChainSyncOptionFunc{
    input_chainsync.WithAutoReconnect(true),
    input_chainsync.WithIntersectTip(true),
    input_chainsync.WithStatusUpdateFunc(updateStatus),
    input_chainsync.WithNetworkMagic(cfg.Magic),
    input_chainsync.WithSocketPath(cfg.SocketPath),
  }
  input := input_chainsync.New(
    inputOpts...,
  )
  p.AddInput(input)

  filterEvent := filter_event.New(
    filter_event.WithTypes([]string{event.TypeTransaction}),
  )
  p.AddFilter(filterEvent)

  filterChainsync := filter_chainsync.New(
    filter_chainsync.WithAddresses(
      []string{
        "addr1q93l79hdpvaeqnnmdkshmr4mpjvxnacqxs967keht465tt2dn0z9uhgereqgjsw33ka6c8tu5um7hqsnf5fd50fge9gq4lu2ql",
      },
    ),
    // Remove the entire WithAssetFingerprints call to disable asset filtering.
    // Filter on DJED asset https://cexplorer.io/asset/asset15f3ymkjafxxeunv5gtdl54g5qs8ty9k84tq94x
    filter_chainsync.WithAssetFingerprints(
      []string{"asset15f3ymkjafxxeunv5gtdl54g5qs8ty9k84tq94x"},
    ),
  )

  p.AddFilter(filterChainsync)

  output := output_embedded.New(
    output_embedded.WithCallbackFunc(handleEvent),
  )

  p.AddOutput(output)

  ctx, cancel := signal.NotifyContext(
    context.Background(), os.Interrupt, syscall.SIGTERM,
  )
  defer cancel()
  if err := p.StartContext(ctx); err != nil {
    if ctx.Err() != nil {
      return nil
    }
    return fmt.Errorf("failed to start pipeline: %w", err)
  }
  defer func() {
    err = errors.Join(err, p.Stop())
  }()

  for {
    select {
    case <-ctx.Done():
      return nil
    case <-p.Failed():
      return fmt.Errorf("pipeline failed: %w", p.Failure())
    case err, ok := <-p.ErrorChan():
      if !ok {
        return p.Failure()
      }
      slog.Error("pipeline diagnostic", "error", err)
    }
  }
}

func handleEvent(evt event.Event) error {
  slog.Info("received event", "type", evt.Type)
  return nil
}

func updateStatus(status input_chainsync.ChainSyncStatus) {
  slog.Info("chainsync status update", "status", status)
}