Railway MCP Server

Instructions

Implementation Reference

• src/tools/variable.tool.ts:65-94 (registration)

  Registers the 'variable_delete' MCP tool using createTool, including Zod input schema, tool description, and thin handler delegating to variableService.deleteVariable

  createTool(
    "variable_delete",
    formatToolDescription({
      type: 'API',
      description: "Delete a variable for a service in a specific environment",
      bestFor: [
        "Removing unused configuration",
        "Security cleanup",
        "Configuration management"
      ],
      notFor: [
        "Temporary variable disabling",
        "Bulk variable removal"
      ],
      relations: {
        prerequisites: ["service_list"],
        nextSteps: ["deployment_trigger", "service_restart"],
        related: ["variable_list", "variable_set"]
      }
    }),
    {
      projectId: z.string().describe("ID of the project"),
      environmentId: z.string().describe("ID of the environment to delete the variable from (usually obtained from service_list)"),
      name: z.string().describe("Name of the variable to delete"),
      serviceId: z.string().optional().describe("ID of the service (optional, if omitted deletes a shared variable)")
    },
    async ({ projectId, environmentId, name, serviceId }) => {
      return variableService.deleteVariable(projectId, environmentId, name, serviceId);
    }
  ),

• src/services/variable.service.ts:56-72 (handler)

  Service layer handler that calls the repository to delete the variable and formats the response

  async deleteVariable(projectId: string, environmentId: string, name: string, serviceId?: string) {
    try {
      await this.client.variables.deleteVariable({
        projectId,
        environmentId,
        name,
        serviceId
      });
  
      const variableType = serviceId ? "service variable" : "shared environment variable";
      return createSuccessResponse({
        text: `Successfully deleted ${variableType} "${name}"`
      });
    } catch (error) {
      return createErrorResponse(`Error deleting variable: ${formatError(error)}`);
    }
  }

• src/api/repository/variable.repo.ts:49-68 (helper)

  Repository helper that executes the GraphQL mutation to delete the variable using the Railway API client

  async deleteVariable(input: VariableDeleteInput): Promise<void> {
    const { projectId, environmentId, serviceId, name } = input;
    await this.client.request<{ variableDelete: boolean }>(`
      mutation variableDelete(
        $projectId: String!,
        $environmentId: String!,
        $serviceId: String,
        $name: String!
      ) {
        variableDelete(
          input: {
            projectId: $projectId,
            environmentId: $environmentId,
            serviceId: $serviceId,
            name: $name
          }
        )
      }
    `, { projectId, environmentId, serviceId, name });
  }

• src/types.ts:202-207 (schema)

  TypeScript interface defining the input shape for variable deletion, used by the repository

  export interface VariableDeleteInput {
    projectId: string;
    environmentId: string;
    serviceId?: string;
    name: string;
  }