Live prices over SSE

GET /v1/prices/stream opens a long-lived text/event-stream connection. We push a price event every time a new swap touches one of your subscribed mints, plus a comment-only heartbeat every ~15 seconds so intermediaries don't reap the connection as idle.

Specify mints with the tokens query param — comma-separated:

curl -N \
  -H "X-API-Key: $REALFLOW_API_KEY" \
  "https://api.realflow.so/v1/prices/stream?tokens=So111...,EPjFW..."

// Browser EventSource can't set headers, so pass api_key= in the query.
const es = new EventSource(
  "https://api.realflow.so/v1/prices/stream?tokens=So111...,EPjFW...&api_key=" + KEY
);

es.addEventListener("price", (ev) => {
  const { mint, price_usd, ts } = JSON.parse(ev.data);
  console.log(mint, price_usd, ts);
});

import { EventSource } from "eventsource";

const es = new EventSource(
  "https://api.realflow.so/v1/prices/stream?tokens=So111...,EPjFW...",
  { fetch: (u, init) => fetch(u, { ...init, headers: { ...init.headers, "X-API-Key": process.env.REALFLOW_API_KEY } }) }
);

es.addEventListener("price", (ev) => {
  const { mint, price_usd, ts } = JSON.parse(ev.data);
  console.log(mint, price_usd, ts);
});

Wire format

Each price event:

event: price
id: 1730500000000
data: {"mint":"EPjFW...","price_usd":"1.0001","ts":1730500000000}

mint — SPL mint address.
price_usd — decimal string; parse with Decimal if you care about sub-cent precision.
ts — epoch milliseconds at which the price was derived.
id — same epoch-ms; clients should track the most recent one and pass it back as Last-Event-ID on reconnect.

Heartbeats

A comment-only line (: keepalive\n\n) is emitted every ~15s. EventSource clients ignore comments — they exist purely to keep proxies and load balancers from closing the connection.

Plan limits

Concurrent SSE connections per key — enforced via the key's sse_connections_max. Excess attempts → 429 rate_limited.
Mints per connection — enforced via max_tokens_per_sse_conn. Exceeding → 400 validation_failed.

Reconnect handling

SSE clients reconnect automatically (per the spec). When they do, they include Last-Event-ID; we use that to resume from the last event you saw, so you don't miss prices during transient drops or our blue/green deploys.

Pricing