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Get started writing data

This tutorial walks you through the fundamental of creating line protocol data and writing it to InfluxDB.

InfluxDB provides many different options for ingesting or writing data, including the following:

  • Influx user interface (UI)
  • InfluxDB HTTP API (v1 and v2)
  • Telegraf
  • influx3 data CLI
  • InfluxDB client libraries
  • influx CLI

If using tools like Telegraf or InfluxDB client libraries, they can build the line protocol for you, but it’s good to understand how line protocol works.

Line protocol

All data written to InfluxDB is written using line protocol, a text-based format that lets you provide the necessary information to write a data point to InfluxDB. This tutorial covers the basics of line protocol, but for detailed information, see the Line protocol reference.

Line protocol elements

Each line of line protocol contains the following elements:

* Required
  • * measurement: String that identifies the measurement to store the data in.
  • tag set: Comma-delimited list of key value pairs, each representing a tag. Tag keys and values are unquoted strings. Spaces, commas, and equal characters must be escaped.
  • * field set: Comma-delimited list of key value pairs, each representing a field. Field keys are unquoted strings. Spaces and commas must be escaped. Field values can be strings (quoted), floats, integers, unsigned integers, or booleans.
  • timestamp: Unix timestamp associated with the data. InfluxDB supports up to nanosecond precision. If the precision of the timestamp is not in nanoseconds, you must specify the precision when writing the data to InfluxDB.

Line protocol element parsing

  • measurement: Everything before the first unescaped comma before the first whitespace.
  • tag set: Key-value pairs between the first unescaped comma and the first unescaped whitespace.
  • field set: Key-value pairs between the first and second unescaped whitespaces.
  • timestamp: Integer value after the second unescaped whitespace.
  • Lines are separated by the newline character (\n). Line protocol is whitespace sensitive.

myMeasurement,tag1=val1,tag2=val2 field1="v1",field2=1i 0000000000000000000


For schema design recommendations, see InfluxDB schema design.

Construct line protocol

With a basic understanding of line protocol, you can now construct line protocol and write data to InfluxDB. Consider a use case where you collect data from sensors in your home. Each sensor collects temperature, humidity, and carbon monoxide readings. To collect this data, use the following schema:

  • measurement: home
    • tags
      • room: Living Room or Kitchen
    • fields
      • temp: temperature in °C (float)
      • hum: percent humidity (float)
      • co: carbon monoxide in parts per million (integer)
    • timestamp: Unix timestamp in second precision

The following line protocol sample represents data collected hourly beginning at 2025-04-30T08:00:00Z (UTC) until 2025-04-30T20:00:00Z (UTC).

Home sensor data line protocol
home,room=Living\ Room temp=21.1,hum=35.9,co=0i 1719924000
home,room=Kitchen temp=21.0,hum=35.9,co=0i 1719924000
home,room=Living\ Room temp=21.4,hum=35.9,co=0i 1719927600
home,room=Kitchen temp=23.0,hum=36.2,co=0i 1719927600
home,room=Living\ Room temp=21.8,hum=36.0,co=0i 1719931200
home,room=Kitchen temp=22.7,hum=36.1,co=0i 1719931200
home,room=Living\ Room temp=22.2,hum=36.0,co=0i 1719934800
home,room=Kitchen temp=22.4,hum=36.0,co=0i 1719934800
home,room=Living\ Room temp=22.2,hum=35.9,co=0i 1719938400
home,room=Kitchen temp=22.5,hum=36.0,co=0i 1719938400
home,room=Living\ Room temp=22.4,hum=36.0,co=0i 1719942000
home,room=Kitchen temp=22.8,hum=36.5,co=1i 1719942000
home,room=Living\ Room temp=22.3,hum=36.1,co=0i 1719945600
home,room=Kitchen temp=22.8,hum=36.3,co=1i 1719945600
home,room=Living\ Room temp=22.3,hum=36.1,co=1i 1719949200
home,room=Kitchen temp=22.7,hum=36.2,co=3i 1719949200
home,room=Living\ Room temp=22.4,hum=36.0,co=4i 1719952800
home,room=Kitchen temp=22.4,hum=36.0,co=7i 1719952800
home,room=Living\ Room temp=22.6,hum=35.9,co=5i 1719956400
home,room=Kitchen temp=22.7,hum=36.0,co=9i 1719956400
home,room=Living\ Room temp=22.8,hum=36.2,co=9i 1719960000
home,room=Kitchen temp=23.3,hum=36.9,co=18i 1719960000
home,room=Living\ Room temp=22.5,hum=36.3,co=14i 1719963600
home,room=Kitchen temp=23.1,hum=36.6,co=22i 1719963600
home,room=Living\ Room temp=22.2,hum=36.4,co=17i 1719967200
home,room=Kitchen temp=22.7,hum=36.5,co=26i 1719967200
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Write line protocol to InfluxDB

The following examples show how to write the preceding sample data, already in line protocol format, to an InfluxDB Cloud Serverless bucket.

To learn more about available tools and options, see Write data.

Some examples in this getting started tutorial assume your InfluxDB credentials (URL, organization, and token) are provided by environment variables.

  1. If you haven’t already, follow the Microsoft.com download instructions to install .NET and the dotnet CLI.

  2. In your terminal, create an executable C# project using the .NET console template.

    dotnet new console --name influxdb_csharp_client
    
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  3. Change into the generated influxdb_csharp_client directory.

    cd influxdb_csharp_client
    
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  4. Run the following command to install the latest version of the InfluxDB 3 C# client library.

    dotnet add package InfluxDB3.Client
    
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  5. In your editor, create a Write.cs file and enter the following sample code:

    // Write.cs
    
    using System;
    using System.Threading.Tasks;
    using InfluxDB3.Client;
    using InfluxDB3.Client.Query;
    
    namespace InfluxDBv3;
    
    public class Write
    {
      /**
        * Writes line protocol to InfluxDB using the C# .NET client
        * library.
        */
      public static async Task WriteLines()
      {
        // Set InfluxDB credentials
        const string host = "https://cloud2.influxdata.com";
        string? database = "get-started";
    
        /**
          * INFLUX_TOKEN is an environment variable you assigned to your
          * WRITE token value.
          */
        string? token = System.Environment
            .GetEnvironmentVariable("INFLUX_TOKEN");
    
        // Instantiate the InfluxDB client with credentials.
        using var client = new InfluxDBClient(
            host, token: token, database: database);
    
        /** 
          * Define an array of line protocol strings to write.
          * Include an additional backslash to preserve backslashes
          * and prevent interpretation of escape sequences---for example,
          * escaped spaces in tag values.
          */
        string[] lines = new string[] {
              "home,room=Living\\ Room temp=21.1,hum=35.9,co=0i 1719924000",
              "home,room=Kitchen temp=21.0,hum=35.9,co=0i 1719924000",
              "home,room=Living\\ Room temp=21.4,hum=35.9,co=0i 1719927600",
              "home,room=Kitchen temp=23.0,hum=36.2,co=0i 1719927600",
              "home,room=Living\\ Room temp=21.8,hum=36.0,co=0i 1719931200",
              "home,room=Kitchen temp=22.7,hum=36.1,co=0i 1719931200",
              "home,room=Living\\ Room temp=22.2,hum=36.0,co=0i 1719934800",
              "home,room=Kitchen temp=22.4,hum=36.0,co=0i 1719934800",
              "home,room=Living\\ Room temp=22.2,hum=35.9,co=0i 1719938400",
              "home,room=Kitchen temp=22.5,hum=36.0,co=0i 1719938400",
              "home,room=Living\\ Room temp=22.4,hum=36.0,co=0i 1719942000",
              "home,room=Kitchen temp=22.8,hum=36.5,co=1i 1719942000",
              "home,room=Living\\ Room temp=22.3,hum=36.1,co=0i 1719945600",
              "home,room=Kitchen temp=22.8,hum=36.3,co=1i 1719945600",
              "home,room=Living\\ Room temp=22.3,hum=36.1,co=1i 1719949200",
              "home,room=Kitchen temp=22.7,hum=36.2,co=3i 1719949200",
              "home,room=Living\\ Room temp=22.4,hum=36.0,co=4i 1719952800",
              "home,room=Kitchen temp=22.4,hum=36.0,co=7i 1719952800",
              "home,room=Living\\ Room temp=22.6,hum=35.9,co=5i 1719956400",
              "home,room=Kitchen temp=22.7,hum=36.0,co=9i 1719956400",
              "home,room=Living\\ Room temp=22.8,hum=36.2,co=9i 1719960000",
              "home,room=Kitchen temp=23.3,hum=36.9,co=18i 1719960000",
              "home,room=Living\\ Room temp=22.5,hum=36.3,co=14i 1719963600",
              "home,room=Kitchen temp=23.1,hum=36.6,co=22i 1719963600",
              "home,room=Living\\ Room temp=22.2,hum=36.4,co=17i 1719967200",
              "home,room=Kitchen temp=22.7,hum=36.5,co=26i 1719967200"
        };
    
        // Write each record separately.
        foreach (string line in lines)
        {
          // Write the record to InfluxDB with timestamp precision in seconds.
          await client.WriteRecordAsync(
              record: line, precision: WritePrecision.S);
          Console.WriteLine(
              "Data has been written successfully: {0,-30}", line);
        }
      }
    }
    
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    The sample does the following:

    1. Calls the new InfluxDBClient() constructor to instantiate a client configured with InfluxDB credentials.

      • host: your InfluxDB Cloud Serverless region URL
      • database: the name of the InfluxDB Cloud Serverless bucket to write to
      • token: a token with write access to the specified bucket. Store this in a secret store or environment variable to avoid exposing the raw token string.

      The using statement ensures that the program disposes of the client when it’s no longer needed.

    2. Defines an array of line protocol strings where each string represents a data record.

    3. Calls the client’s WriteRecordAsync() method to write each line protocol record to InfluxDB.

      Because the timestamps in the sample line protocol are in second precision, the example passes the WritePrecision.S enum value to the precision: option to set the timestamp precision to seconds.

  6. In your editor, open the Program.cs file and replace its contents with the following:

    // Program.cs
    
    using System;
    using System.Threading.Tasks;
    
    namespace InfluxDBv3;
    
    public class Program
    {
      public static async Task Main()
      {
        await Write.WriteLineProtocol();
      }
    }
    
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    The Program class shares the same InfluxDBv3 namespace as the Write class you defined in the preceding step and defines a Main() function that calls Write.WriteLineProtocol(). The dotnet CLI recognizes Program.Main() as the entry point for your program.

  7. To build and execute the program and write the line protocol to your InfluxDB Cloud Serverless bucket, enter the following command in your terminal:

    dotnet run
    
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If successful, the output is the success message; otherwise, error details and the failure message.

View the written data

Congratulations! You have written data to InfluxDB. With data now stored in InfluxDB, let’s query it.


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