Configure idempotency headers

For endpoints you’ve configured as idempotent, Fern’s SDKs allow you to specify idempotency headers. Typically the headers include Idempotency-Key, but you can also specify additional headers.

How it works for SDK users

Your SDK users can specify an idempotency header like this:

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const response = await client.transactions.send({
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  amount: 100,
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  currency: "usd",
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}, {
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  idempotencyKey: "64099353-b48b-4dcd-98b7-74df1cc57933"
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});

Setting up idempotency headers

To set up idempotency headers in your API, configure the idempotency headers and mark individual endpoints as idempotent.

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# Configure the idempotency headers
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x-fern-idempotency-headers:
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  - header: IDEMPOTENCY-KEY
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    name: idempotency_key
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# Mark an individual endpoint as idempotent
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paths:
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  /foo:
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    post:
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      x-fern-idempotent: true