Pier

Stellar testnet and mainnet

Stellar events,
delivered.

Subscribe to contract events and payments once. Pier watches every ledger and delivers each match to webhooks, live streams, the pull API, message queues, chat apps, your laptop or an AI agent, with retries, replay and a dashboard. No poller to write.

npx pier-cli login
Open the dashboard Quickstart →

Sign in with GitHub. Testnet, and mainnet with a daily cap. The console is live: switch a stream off, then back on.

Try the exchange deposit demo → A real testnet payment with a memo, delivered by Pier to RabbitMQ and credited by the exchange.

Live on Stellar testnet Three Pier subscriptions, streamed to this page
Ledger … Connecting to Pier…
Streams
    Real testnet events, delivered by Pier as they happen. Open one to see everything Pier delivers for it. Switch a stream off: Pier keeps its events. Switch it back on: they arrive first, then it goes live again.

    Delivers to

    From zero to events in three commands.

    Get a key on the dashboard (GitHub sign-in), then pick your tool. Needs Node.js 20.19 or newer.

    # 1. log in with the key from the dashboard
npx pier-cli login --key pier_… --api https://136-112-187-130.sslip.io
# 2. subscribe: XLM transfers on testnet (add --network mainnet for mainnet)
npx pier-cli subscribe --contract CDLZFC3SYJYDZT7K67VZ75HPJVIEUVNIXF47ZG2FB2RMQQVU2HHGCYSC --topic sym:transfer,**
# 3. forward every match to a local server, resuming where you stopped
npx pier-cli listen <subscription-id> --forward http://localhost:3000/webhook

    Send events where your code already is.

    Up to five destinations per subscription, added from the dashboard or the API. Credentials are stored encrypted and never shown again.

    Your code

    • WebhooksSigned with Standard Webhooks; each event retried on its own with backoff.
    • Server-Sent EventsA live stream that resumes from the last event you handled.
    • Pull APIEvery match after a cursor, page by page, for 7 days.
    • Your laptoppier-cli listen --forward posts to localhost. No public URL, no tunnel.

    Queues and streams

    • Apache KafkaKeyed by subscription; TLS and SASL (PLAIN, SCRAM).
    • RabbitMQPersistent messages with publisher confirms.
    • NATS JetStreamMessage ids let the stream drop a re-sent event.
    • Amazon SQSStandard or FIFO; FIFO also drops a re-send within 5 minutes.
    • Google Pub/SubAttributes carry the position and event id.
    • Azure Service BusQueues and topics; the event id as message id drops a re-send.
    • Azure Event HubsPartitioned by subscription.
    • Azure Event GridEvent Grid schema or CloudEvents, on topics and namespaces.

    People and agents

    • Discord, Slack, TelegramOne readable line per event in a channel.
    • AI agentsAn MCP server, a Pier skill and llms.txt: agents subscribe instead of writing a poller.
    • DashboardFilter builder with a preview, live events, delivery health and usage.

    The parts you would otherwise build.

    Filters, previewed

    Contract events by contract and topic, or payments to and from an account. The dashboard shows what a filter would have matched on recent ledgers before you save it.

    Testnet and mainnet

    One API for both networks. On mainnet, filters name their contracts or account and each team matches up to 10,000 events a day.

    Retries and resume

    Each failed delivery is retried with exponential backoff, up to 200 attempts. A destination that keeps failing stops and can be resumed with one click.

    Replay from any position

    Every event has a position. Pull or stream from any position in the last 7 days, and resume from the last position you handled.

    Delivery health

    Per destination: delivered, waiting, last error and daily counts, in the dashboard and the API.

    Decoded, and raw

    Each event comes with its raw XDR and a decoded JSON view, plus ledger, transaction and contract.

    Limits and guarantees.

    What Pier does today, plainly.

    DeliveryAt least once. Pushed destinations don't preserve order: order by position and de-duplicate by event id. Pull and streams return events by position.
    RetriesExponential backoff from 5 seconds to 10 minutes, up to 200 attempts per event; up to 4 deliveries in flight per destination.
    Retention7 days of events, for replay and pull.
    NetworksTestnet; mainnet with filters that name contracts or an account, and 10,000 matched events per team per day.
    Per team20 subscriptions, 5 destinations each, 10 open streams, 120 API requests a minute.
    If Pier is downYour cursor waits for you, and you can always read Stellar RPC getEvents directly.

    Questions.

    What is a position?

    Every event Pier stores gets a position: a number that only grows. It is the cursor for pull and streams, the SSE event id, and part of each webhook's id, so you can order and de-duplicate what you receive.

    Do I need my own RPC node?

    No. Pier reads Stellar RPC for you and matches every event against your filters; you only receive what matches.

    What happens when my endpoint is down?

    Each event is retried with backoff while other events keep flowing. After 200 failed attempts the destination stops; resume it from the dashboard or the API when you're ready.

    Can I keep my API key in a browser app?

    No. Keep it on a server. For browser apps, read the stream on your server and pass events on.

    Where are the docs?

    llms.txt covers the API, filters and destination bodies; the Pier skill walks through wiring events into an app. The npm packages each have a README.

    Coming later

    Coming later: backfill from the ledger archive and Terraform.

    Start on testnet now.

    npx pier-cli login
    Open the dashboard