TypeScript SDK - Elastly

The @elastly/sdk package is the supported way to call Elastly from Node.js. It is not a thin wrapper around HTTP. It solves the problems every integration hits: a price call that must never break your quote screen, typed errors you can branch on, webhooks you can trust, and a connector that pages, checkpoints, retries, and reports without you writing any of it.

npm install @elastly/sdk

Node 20.3 or later. Ships ESM and CommonJS, fully typed. Its only dependency is @elastly/api-contract, the same schema package our servers validate against, so the types in your editor cannot drift from the API.

Keys and scopes

Create API keys under Settings → API keys. Scopes are separate on purpose: a serving key can never write your catalog, and a connector key can never read prices.

Scope	Used for	SDK surface
ERP	Price serving	`elastly.prices`
Connector	Ingest and write-backs	`elastly.ingest`, `elastly.writebacks`, `defineConnector`

import { Elastly } from "@elastly/sdk"

const elastly = new Elastly({ apiKey: process.env.ELASTLY_API_KEY })

The one thing to get right: the decision id

Every priced line comes back with a pricingDecisionId. Store it in your own system, on the quote line it priced. When that quote later closes and you send it back to Elastly, the id ties what Elastly recommended to what your rep actually charged. That difference is what the model learns from. Skip it and everything still looks like it works: prices serve, quotes ingest, dashboards fill. But the model learns nothing from your quotes, and nothing tells you. So wire it first:

const result = await elastly.prices.get(line, { failOpen })

if (result.source === "elastly") {
  await erp.updateQuoteLine(quoteLineId, {
    elastlyPriceCents: result.priceCents,
    elastlyDecisionId: result.pricingDecisionId,
  })
}

Price a line, with a fallback

A price call usually runs inside a rep’s quote screen or a checkout render. If Elastly is slow or down, your system must keep working. The SDK makes that a policy you declare, not code you write:

import { staticFallback } from "@elastly/sdk"

const failOpen = staticFallback((line) => ({ priceCents: erp.listPrice(line.productSku) }), {
  deadlineMs: 800,
})

const result = await elastly.prices.get(
  { customerExternalId: "cust-1042", productSku: "VLV-200", quantity: 25 },
  { failOpen },
)

if (result.source === "elastly") {
  render(result.priceCents, result.reasonSummary, result.explanation)
} else if (result.source === "fallback") {
  render(result.priceCents) // result.cause.reason tells you why
}

Under this policy a timeout, a 5xx, a rate limit, a malformed body, or a network failure never throws. The SDK retries where it can, then calls your fallback and returns { source: "fallback" } with the cause attached. If your fallback returns null, you get { source: "unavailable" }, an explicit typed no-answer. Three things throw on purpose. A 4xx that means your request is wrong (invalid_request, feature_not_enabled) throws a typed error, because a bug in your integration is not an outage to paper over. An exception inside your own fallback surfaces. And the throwOnFailure() policy throws on everything, for batch jobs where a wrong price is worse than no price:

import { throwOnFailure } from "@elastly/sdk"

const results = await elastly.prices.getMany(lines, { failOpen: throwOnFailure() })

getMany prices up to 100 lines in one HTTP call. One unknown SKU fails that line alone, never the whole batch.

Typed errors

Every error is a typed class carrying the stable error code and the x-elastly-request-id of the call, so support can find the exact request. Branch on the class or on error.code:

import { ApiError, RateLimitError, UnknownProductError } from "@elastly/sdk"

try {
  await elastly.prices.get(line, { failOpen: throwOnFailure() })
} catch (error) {
  if (error instanceof RateLimitError) console.log(error.retryAfterMs)
  else if (error instanceof UnknownProductError) console.log(error.requestId)
  else if (error instanceof ApiError) console.log(error.code, error.status)
}

There is one class per API error code (UnknownProductError, NoCostBasisError, MonthlyVolumeExceededError, and the rest), all extending ApiError, which extends ElastlyError. Catch the base class to handle anything.

Verify a webhook

const event = elastly.webhooks.verify(rawBody, request.headers["elastly-signature"], secret)

if (event.event === "sync.completed") {
  console.log(event.data.connector, event.data.totals)
}

verify checks the signature in constant time, rejects anything older than five minutes, and returns a typed event. It throws SignatureVerificationError on a bad signature, a replay, or a malformed body. The four event types are sync.completed, recommendation.created, price.written_back, and test.ping.

What the SDK handles for you

Idempotency. Every mutating call carries a key that stays stable across retries, so a retried price call can never double-count against your plan.
Retries. Failed calls back off with full jitter and honor Retry-After and RateLimit-Reset.
A circuit breaker. After repeated failures it stops hammering Elastly and goes straight to your fallback, then probes once to recover.
Fail-open telemetry. Every call that falls open reports itself to Elastly (fire and forget, never on your latency path), so an outage that hit your quote screen shows up in your dashboard instead of staying invisible.

Build a connector

To push your own ERP or storefront into Elastly, the SDK ships a connector runtime: implement a few functions that read your data, and defineConnector runs the whole sync, with paging, checkpoints, retries, and write-back leases handled for you.

Build a connector

Feed your data in, apply approved prices back, in TypeScript or any other language.

Versioning

The SDK’s major version is bound to the API version in the URL. Every 0.x and 1.x release of @elastly/sdk talks to /api/v1. A major release of the SDK is the only thing that ever changes which API version an installed integration calls, so an upgrade within a major is always safe. The source is published to npm.

​Keys and scopes

​The one thing to get right: the decision id

​Price a line, with a fallback

​Typed errors

​Verify a webhook

​What the SDK handles for you

​Build a connector

Build a connector

​Versioning

Keys and scopes

The one thing to get right: the decision id

Price a line, with a fallback

Typed errors

Verify a webhook

What the SDK handles for you

Build a connector

Versioning