Configure the TypeScript Client

createRepostClient() snapshots and validates its configuration. Fixed credentials and the API URL are resolved at construction; an apiKeyProvider is resolved once for each admitted send.

Client options

const repost = createRepostClient({
  apiKey: process.env.REPOST_SEND_API_KEY,
  apiUrl: process.env.REPOST_API_URL,
});

Option	Resolution when omitted
`apiKey`	`REPOST_SEND_API_KEY`, then `REPOST_TOKEN`, snapshotted at construction.
`apiUrl`	`REPOST_API_URL`, then `https://api.repost.sh`, snapshotted at construction.
`transport`	The one-attempt transport. Pass a custom transport or `stubTransport` for tests.
`generators`	Real clock and id generators. Override for determinism.
`token`	Deprecated alias for `apiKey`, checked after it and before the environment.

With no key available, a send throws RepostConfigurationError with error code CONFIGURATION and delivery state NOT_SENT. Every request goes to POST <apiUrl>/v1/messages with authorization: Bearer, content-type: application/json, and idempotency-key headers.

Transport tuning

Retries and operation deadlines belong to the client runtime. Network and connection-pool settings belong under httpTransportOptions:

import { createRepostClient } from "./generated/repost";

const repost = createRepostClient({
  maxAttempts: 4,
  retryBaseDelayMs: 250,
  attemptTimeoutMs: 30_000,
  operationTimeoutMs: 120_000,
  httpTransportOptions: { http2: true, maxConnectionsPerOrigin: 32 },
});

Option	Default	Meaning
`maxAttempts`	4	Total attempts, including the initial attempt.
`retryBaseDelayMs`	250	Exponential backoff base.
`attemptTimeoutMs`	30000	Maximum time for one attempt.
`operationTimeoutMs`	120000	Deadline shared by the entire send, including retries and backoff.
`maxInFlightOperations`	256	Admission limit; excess sends fail with `OVERLOADED`.
`maxBufferedBytes`	67108864	Shared request/response byte budget.

The deprecated maxRetries, baseDelayMs, and timeoutMs fields are still translated when they appear inside httpTransportOptions on the client. Passing them directly to createHttpTransport() or createNodeTransport() is rejected because a transport executes exactly one attempt.

Generators

The runtime asks three injectable functions for values it has to invent: now for the envelope timestamp and @default(now()), uuid for @default(uuid()) and minted idempotency keys, and cuid for @default(cuid()).

const repost = createRepostClient({
  generators: {
    now: () => "2026-01-01T00:00:00.000Z",
  },
});

Defaults are new Date().toISOString(), crypto.randomUUID(), and cuid2. Only the functions you set are overridden. now is called once per send and memoized, so the envelope timestamp and any now() default inside the same event always match.

Continue

Reliability

Retries, idempotency, and the error surface in detail.

Testing

The stub transport and deterministic generators in practice.

HTTP API

The endpoint these options point the client at.

Send

Schema

Publishing

Delivery

Customer experience

TypeScript

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Configure the TypeScript Client

Client options

Transport tuning

Generators

Continue

Reliability

Testing

HTTP API

​Client options

​Transport tuning

​Generators

​Continue

Reliability

Testing

HTTP API

Client options

Transport tuning

Generators

Continue