n8n-io/n8n · error · NodeOperationError

Misconfigured placeholder

Error message

Misconfigured placeholder '${placeholder.name}'

What it means

Consistency check between the tool's parameter list and its placeholder definitions: a placeholder definition has no matching parameter that the model could fill at call time, so the definition is dead/misconfigured and the request built from it would be incomplete.

Solutions

1. Add a tool parameter with the same name as the placeholder
2. Or remove the orphaned placeholder definition

When it happens

Trigger: Thrown at packages/@n8n/nodes-langchain/nodes/tools/ToolHttpRequest/ToolHttpRequest.node.ts:387 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of n8n-io/n8n@5ac6606e81 (2026-08-12). Data as JSON: /api/errors/3bb39581b738fb29. Report an issue: GitHub.

Appendix: source

Thrown at packages/@n8n/nodes-langchain/nodes/tools/ToolHttpRequest/ToolHttpRequest.node.ts:387

		if (sendBody) {
			updateParametersAndOptions({
				ctx: this,
				itemIndex,
				toolParameters,
				placeholdersDefinitions,
				requestOptions,
				rawRequestOptions,
				requestOptionsProperty: 'body',
				inputTypePropertyName: 'specifyBody',
				jsonPropertyName: 'jsonBody',
				parametersPropertyName: 'parametersBody.values',
			});
		}

		for (const placeholder of placeholdersDefinitions) {
			if (!toolParameters.find((parameter) => parameter.name === placeholder.name)) {
				throw new NodeOperationError(
					this.getNode(),
					`Misconfigured placeholder '${placeholder.name}'`,
					{
						itemIndex,
						description:
							"This placeholder is defined in the 'Placeholder Definitions' but isn't used anywhere. Either remove the definition, or add the placeholder to a part of the request.",
					},
				);
			}
		}

		const func = configureToolFunction(
			this,
			itemIndex,
			toolParameters,
			requestOptions,
			rawRequestOptions,
			httpRequest,

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