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Lets the model make HTTP requests to external APIs during execution. Configure the endpoint and the model fills in the parameters at runtime.

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Configuration

  • URL – the endpoint to call. Supports environment variable substitution with ${VAR_NAME} syntax
  • Method – GET, POST, PUT, PATCH, DELETE
  • Headers – custom headers, also supporting ${VAR_NAME} substitution
  • Parameters – defined as a JSON Schema. For GET requests, parameters are serialised into the query string. For other methods, they travel as a JSON request body

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Environment variable substitution

Use ${VAR_NAME} in URLs and headers to inject values from your workspace’s environment variables at runtime. This keeps secrets out of your workflow definitions – store an API key as an environment variable, reference it in the header, and the actual value gets injected when the tool runs.

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Correlation headers

Every request the tool makes carries two headers identifying the run it came from, so your endpoint can correlate calls back to a PromptJuggler run:
  • PromptJuggler-RunId – the root run ID. It is shared across every prompt and workflow in the same run tree, so nested tool calls all report the same value.
  • PromptJuggler-Thread – the conversation thread ID.
PromptJuggler sets these after your custom headers, so they take precedence if you configure a header with the same name. HTTP header names are case-insensitive – match on the name, not its exact casing.