How to write line protocol to InfluxDB v2

Writing line protocol to InfluxDB OSS v2 sends a measurement, tags, fields, and an optional timestamp into a bucket without going through a client library. Operators and developers use this check to confirm that a bucket accepts a point before wiring an application, agent, or migration job to the same endpoint.

The v2 write endpoint is /api/v2/write. The request URL selects the organization, bucket, and timestamp precision, while the Authorization header carries an API token that can write to the destination bucket.

The sample point uses a Unix timestamp in seconds, so the request sets precision=s. Keep that precision aligned with the timestamp in the line protocol string or InfluxDB will store the point at the wrong time.

1. Choose the InfluxDB URL, organization, bucket, and timestamp precision for the write.

   InfluxDB URL: http://127.0.0.1:8086
   Organization: ops-team
   Bucket: factory_metrics
   Precision: seconds

   Use a scratch bucket or clearly disposable series when production data should not keep validation points.

2. Set the API token for the current terminal session.

   $ export INFLUX_TOKEN='API_TOKEN'

   Use a token with write permission on the target bucket. Do not paste a real token into shared transcripts, screenshots, or shell history.

3. Post one line protocol point to the v2 write endpoint.

   $ curl --request POST "http://127.0.0.1:8086/api/v2/write?org=ops-team&bucket=factory_metrics&precision=s" \
     --header "Authorization: Token $INFLUX_TOKEN" \
     --header "Content-Type: text/plain; charset=utf-8" \
     --data-binary 'temperature,site=plant-1,line=line-b value=23.1 1767225602' \
     --silent \
     --output /dev/null \
     --write-out 'HTTP %{http_code}\n'
   HTTP 204

   HTTP 204 means InfluxDB OSS v2 accepted the full batch. Failed writes return an error response for malformed line protocol, a missing bucket or organization, or a token that cannot write to the bucket.

4. Query the bucket for the inserted point.

   $ influx query --host http://127.0.0.1:8086 --org ops-team 'from(bucket: "factory_metrics") |> range(start: 2026-01-01T00:00:00Z, stop: 2026-01-01T00:01:00Z) |> filter(fn: (r) => r._measurement == "temperature") |> filter(fn: (r) => r.line == "line-b") |> keep(columns: ["_time", "_value", "site", "line"])'
   Result: _result
   Table: keys: [line, site]
              line:string             site:string                      _time:time                  _value:float
   ----------------------  ----------------------  ------------------------------  ----------------------------
                   line-b                 plant-1  2026-01-01T00:00:02.000000000Z                          23.1

   An empty result usually means the bucket, organization, token scope, tag predicate, or timestamp precision does not match the write.
   Related: How to run a Flux query in InfluxDB v2