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Portkey API accepts 4 kinds of headers for your requests:

Portkey Authentication

Portkey API Key

x-portkey-api-key / api_key / apiKey
string
required
Authenticate your requests with your Portkey API key. Obtain API key from the Portkey dashboard.
Environment variable: PORTKEY_API_KEY

Provider Authentication

In addition to the Portkey API key, you must provide information about the AI provider you’re using. There are 4 ways to do this:

1. Provider Slug + Auth

Useful if you do not want to save your API keys to Portkey vault and make direct requests.
x-portkey-provider / provider
string
Specifies the provider you’re using (e.g., openai, anthropic, vertex-ai).
List of Portkey supported providers here.
Authorization
string
Pass the auth details for the specified provider as a "Bearer $TOKEN".

If your provider expects their auth with headers such as x-api-key or api-key, you can pass the token with the Authorization header directly and Portkey will convert it into the provider-specific format.

2. AI Provider

x-portkey-provider / provider
string
Specify your AI Provider slug (from Model Catalog) to route requests through a managed provider. Use the @provider-slug format. (Docs)
The x-portkey-virtual-key / virtual_key / virtualKey parameter is the legacy equivalent and still works for backward compatibility.

3. Config

x-portkey-config / config
string or JSON
Pass your Portkey config with this header. Accepts a JSON object or a config ID that can also contain gateway configuration settings, and provider details.
  • Configs can be saved in the Portkey UI and referenced by their ID (Docs)
  • Configs also enable other optional features like Caching, Load Balancing, Fallback, Retries, and Timeouts.

4. Custom Host

x-portkey-custom-host / custom_host / customHost
string
Specifies the base URL where you want to send your request. Portkey validates custom host URLs and blocks private/reserved IP ranges by default. See Custom hosts for details.
x-portkey-provider / provider
string
Target provider that’s availabe on your base URL. If you are unsure of which target provider to set, you can set openai.
Authorization
string
Pass the auth details for the specified provider as a "Bearer $TOKEN".

If your provider expects their auth with headers such as x-api-key or api-key, you can pass the token with the Authorization header directly and Portkey will convert it into the provider-specific format.

Additional Portkey Headers

There are additional optional Portkey headers that enable various features and enhancements:

Trace ID

x-portkey-trace-id / trace_id / traceId
string
An ID you can pass to refer to one or more requests later on. If not provided, Portkey generates a trace ID automatically for each request. (Docs)

Metadata

x-portkey-metadata / metadata
JSON
Allows you to attach custom metadata to your requests, which can be filtered later in the analytics and log dashboards.
You can include the special metadata type _user to associate requests with specific users. (Docs)

Cache Force Refresh

x-portkey-cache-force-refresh / cache_force_refresh / cacheForceRefresh
boolean
Forces a cache refresh for your request by making a new API call and storing the updated value.
Expects true or false See the caching documentation for more information. (Docs)

Cache Namespace

x-portkey-cache-namespace / cache_namespace / cacheNamespace
string
Partition your cache store based on custom strings, ignoring metadata and other headers.

Request Timeout

x-portkey-request-timeout / request_timeout / requestTimeout
integer
Set timeout after which a request automatically terminates. The time is set in milliseconds.

Custom Headers

You can pass any other headers your API expects by directly forwarding them without any processing by Portkey.
This is especially useful if you want to pass send sensitive headers.

Forward Headers

x-portkey-forward-headers / forward_headers / forwardHeaders
array of strings
Pass all the headers you want to forward directly in this array. (Docs)

Python Usage

With the Python SDK, you need to transform your headers to Snake Case and then include them while initializing the Portkey client. Example: If you have a header of the format X-My-Custom-Header, it should be sent as X_My_Custom_Header in the SDK.Note: When using forward_headers, ensure the header names in the list are in their original format (e.g., X-My-Custom-Header), not the snake case format.

JavaScript Usage

With the JS SDK, you need to transform your headers to Camel Case and then include them while initializing the Portkey client. Example: If you have a header of the format X-My-Custom-Header, it should be sent as xMyCustomHeader in the SDK

Cloud-Specific Headers (Azure, Google, AWS)

Pass more configuration headers for Azure OpenAI, Google Vertex AI, or AWS Bedrock

Azure

  • x-portkey-azure-resource-name, x-portkey-azure-deployment-id, x-portkey-azure-api-version, Authorization, x-portkey-azure-model-name

Google Vertex AI

  • x-portkey-vertex-project-id, x-portkey-vertex-region, X-Vertex-AI-LLM-Request-Type

AWS Bedrock

  • x-portkey-aws-session-token, x-portkey-aws-secret-access-key, x-portkey-aws-region, x-portkey-aws-session-token

List of All Headers

The following is a comprehensive list of headers that can be used when initializing the Portkey client. Portkey adheres to language-specific naming conventions:
  • camelCase for JavaScript/Node.js parameters
  • snake_case for Python parameters
  • hyphenated-keys for HTTP headers

Using Headers

You can send these headers in multiple ways:
Last modified on April 8, 2026