influxdata · jstirnaman · Oct 21, 2025
diff --git a/api-docs/influxdb3/core/v3/ref.yml b/api-docs/influxdb3/core/v3/ref.yml
@@ -204,7 +204,26 @@ tags:
   - name: Token
     description: Manage tokens for authentication and authorization
   - name: Write data
-    description: Write data to InfluxDB 3
+    description: |
+      Write data to InfluxDB 3 using line protocol format.
+
+      #### Timestamp precision across write APIs
+
+      InfluxDB 3 provides multiple write endpoints for compatibility with different InfluxDB versions.
+      The following table compares timestamp precision support across v1, v2, and v3 write APIs:
+
+      | Precision | v1 (`/write`) | v2 (`/api/v2/write`) | v3 (`/api/v3/write_lp`) |
+      |-----------|---------------|----------------------|-------------------------|
+      | **Auto detection** | ❌ No | ❌ No | ✅ `auto` (default) |
+      | **Seconds** | ✅ `s` | ✅ `s` | ✅ `s` or `second` |
+      | **Milliseconds** | ✅ `ms` | ✅ `ms` | ✅ `ms` or `millisecond` |
+      | **Microseconds** | ✅ `u` or `µ` | ✅ `us` | ✅ `us` or `microsecond` |
+      | **Nanoseconds** | ✅ `ns` | ✅ `ns` | ✅ `ns` or `nanosecond` |
+      | **Minutes** | ✅ `m` | ❌ No | ❌ No |
+      | **Hours** | ✅ `h` | ❌ No | ❌ No |
+      | **Default** | Nanosecond | Nanosecond | **Auto** (guessed) |
+
+      All timestamps are stored internally as nanoseconds.
 paths:
   /write:
     post:
@@ -430,11 +449,21 @@ paths:
         Use query parameters to specify options for writing data.
 
         #### Features
-        
+
         - **Partial writes**: Use `accept_partial=true` to allow partial success when some lines in a batch fail
-        - **Asynchronous writes**: Use `no_sync=true` to skip waiting for WAL synchronization, allowing faster response times but sacrificing durability guarantees  
+        - **Asynchronous writes**: Use `no_sync=true` to skip waiting for WAL synchronization, allowing faster response times but sacrificing durability guarantees
         - **Flexible precision**: Automatic timestamp precision detection with `precision=auto` (default)
 
+        #### Auto precision detection
+
+        When you use `precision=auto` or omit the precision parameter, InfluxDB 3 automatically detects
+        the timestamp precision based on the magnitude of the timestamp value:
+
+        - Timestamps < 5e9 → Second precision (multiplied by 1,000,000,000 to convert to nanoseconds)
+        - Timestamps < 5e12 → Millisecond precision (multiplied by 1,000,000)
+        - Timestamps < 5e15 → Microsecond precision (multiplied by 1,000)
+        - Larger timestamps → Nanosecond precision (no conversion needed)
+
         #### Related
 
         - [Use the InfluxDB v3 write_lp API to write data](/influxdb3/core/write-data/http-api/v3-write-lp/)
@@ -1911,13 +1940,24 @@ components:
     PrecisionWrite:
       enum:
         - auto
+        - ns
+        - nanosecond
+        - us
+        - microsecond
+        - ms
         - millisecond
+        - s
         - second
-        - microsecond
-        - nanosecond
       type: string
       description: |
         The precision for unix timestamps in the line protocol batch.
+
+        Supported values (both short and long forms are accepted):
+        - `auto` (default): Automatically detects precision based on timestamp magnitude
+        - `ns` or `nanosecond`: Nanoseconds
+        - `us` or `microsecond`: Microseconds
+        - `ms` or `millisecond`: Milliseconds
+        - `s` or `second`: Seconds
     QueryRequestObject:
       type: object
       properties:

diff --git a/api-docs/influxdb3/enterprise/v3/ref.yml b/api-docs/influxdb3/enterprise/v3/ref.yml
@@ -204,7 +204,26 @@ tags:
   - name: Token
     description: Manage tokens for authentication and authorization
   - name: Write data
-    description: Write data to InfluxDB 3
+    description: |
+      Write data to InfluxDB 3 using line protocol format.
+
+      #### Timestamp precision across write APIs
+
+      InfluxDB 3 provides multiple write endpoints for compatibility with different InfluxDB versions.
+      The following table compares timestamp precision support across v1, v2, and v3 write APIs:
+
+      | Precision | v1 (`/write`) | v2 (`/api/v2/write`) | v3 (`/api/v3/write_lp`) |
+      |-----------|---------------|----------------------|-------------------------|
+      | **Auto detection** | ❌ No | ❌ No | ✅ `auto` (default) |
+      | **Seconds** | ✅ `s` | ✅ `s` | ✅ `s` or `second` |
+      | **Milliseconds** | ✅ `ms` | ✅ `ms` | ✅ `ms` or `millisecond` |
+      | **Microseconds** | ✅ `u` or `µ` | ✅ `us` | ✅ `us` or `microsecond` |
+      | **Nanoseconds** | ✅ `ns` | ✅ `ns` | ✅ `ns` or `nanosecond` |
+      | **Minutes** | ✅ `m` | ❌ No | ❌ No |
+      | **Hours** | ✅ `h` | ❌ No | ❌ No |
+      | **Default** | Nanosecond | Nanosecond | **Auto** (guessed) |
+
+      All timestamps are stored internally as nanoseconds.
 paths:
   /write:
     post:
@@ -430,11 +449,21 @@ paths:
         Use query parameters to specify options for writing data.
 
         #### Features
-        
+
         - **Partial writes**: Use `accept_partial=true` to allow partial success when some lines in a batch fail
-        - **Asynchronous writes**: Use `no_sync=true` to skip waiting for WAL synchronization, allowing faster response times but sacrificing durability guarantees  
+        - **Asynchronous writes**: Use `no_sync=true` to skip waiting for WAL synchronization, allowing faster response times but sacrificing durability guarantees
         - **Flexible precision**: Automatic timestamp precision detection with `precision=auto` (default)
 
+        #### Auto precision detection
+
+        When you use `precision=auto` or omit the precision parameter, InfluxDB 3 automatically detects
+        the timestamp precision based on the magnitude of the timestamp value:
+
+        - Timestamps < 5e9 → Second precision (multiplied by 1,000,000,000 to convert to nanoseconds)
+        - Timestamps < 5e12 → Millisecond precision (multiplied by 1,000,000)
+        - Timestamps < 5e15 → Microsecond precision (multiplied by 1,000)
+        - Larger timestamps → Nanosecond precision (no conversion needed)
+
         #### Related
 
         - [Use the InfluxDB v3 write_lp API to write data](/influxdb3/enterprise/write-data/http-api/v3-write-lp/)
@@ -2043,13 +2072,24 @@ components:
     PrecisionWrite:
       enum:
         - auto
+        - ns
+        - nanosecond
+        - us
+        - microsecond
+        - ms
         - millisecond
+        - s
         - second
-        - microsecond
-        - nanosecond
       type: string
       description: |
         The precision for unix timestamps in the line protocol batch.
+
+        Supported values (both short and long forms are accepted):
+        - `auto` (default): Automatically detects precision based on timestamp magnitude
+        - `ns` or `nanosecond`: Nanoseconds
+        - `us` or `microsecond`: Microseconds
+        - `ms` or `millisecond`: Milliseconds
+        - `s` or `second`: Seconds
     QueryRequestObject:
       type: object
       properties:

diff --git a/content/shared/influxdb3-write-guides/_index.md b/content/shared/influxdb3-write-guides/_index.md
@@ -1,29 +1,60 @@
 
-Use tools like the `influxctl` CLI, Telegraf, and InfluxDB client libraries to
-to write time series data to {{< product-name >}}. [Line protocol](#line-protocol)
-is the text-based format used to write data to InfluxDB. There are tools
-available to covert other formats (for example—[CSV](/influxdb3/version/write-data/use-telegraf/csv/))
-to line protocol.
+Use tools like the {{% show-in "cloud-dedicated,clustered" %}}`influxctl`{{% /show-in %}}{{% show-in "cloud-serverless" %}}`influx`{{% /show-in %}}{{% show-in "core,enterprise" %}}`influxdb3`{{% /show-in %}}
+ CLI, Telegraf, and InfluxDB client libraries
+to write time series data to {{< product-name >}}.
+[line protocol](#line-protocol)
+is the text-based format used to write data to InfluxDB.
 
+> [!Tip]
+> Tools are available to convert other formats (for example—[CSV](/influxdb3/version/write-data/use-telegraf/csv/)) to line protocol.
+
+{{% show-in "core,enterprise" %}}
+- [Choose the write endpoint for your workload](#choose-the-write-endpoint-for-your-workload)
+  - [Timestamp precision across write APIs](#timestamp-precision-across-write-apis)
+{{% /show-in %}}
 - [Line protocol](#line-protocol)
   - [Line protocol elements](#line-protocol-elements)
 - [Write data to InfluxDB](#write-data-to-influxdb)
   {{< children type="anchored-list" >}}
 
 {{% show-in "core,enterprise" %}}
-> [!Note]
-> 
+
+> [!Tip]
 > #### Choose the write endpoint for your workload
 > 
 > When creating new write workloads, use the
 > [InfluxDB HTTP API `/api/v3/write_lp` endpoint](influxdb3/version/write-data/http-api/v3-write-lp/)
 > and [client libraries](/influxdb3/version/write-data/client-libraries/).
 >
-> When bringing existing v1 write workloads, use the {{% product-name %}}
+> When bringing existing _v1_ write workloads, use the {{% product-name %}}
 > HTTP API [`/write` endpoint](/influxdb3/core/api/v3/#operation/PostV1Write).
 >
-> When bringing existing v2 write workloads, use the {{% product-name %}}
+> When bringing existing _v2_ write workloads, use the {{% product-name %}}
 > HTTP API [`/api/v2/write` endpoint]([/influxdb3/version/api/v3/#operation/PostV1Write](/influxdb3/version/api/v3/#operation/PostV2Write)).
+>
+> **For Telegraf**, use the InfluxDB v1.x [`outputs.influxdb`](https://github.com/influxdata/telegraf/blob/master/plugins/outputs/influxdb/README.md) or v2.x [`outputs.influxdb_v2`](https://github.com/influxdata/telegraf/blob/master/plugins/outputs/influxdb_v2/README.md) output plugins.
+> See how to [use Telegraf to write data](/influxdb3/version/write-data/use-telegraf/).
+
+## Timestamp precision across write APIs
+
+{{% product-name %}} provides multiple write endpoints for compatibility with different InfluxDB versions.
+The following table compares timestamp precision support across v1, v2, and v3 write APIs:
+
+| Precision | v1 (`/write`) | v2 (`/api/v2/write`) | v3 (`/api/v3/write_lp`) |
+|-----------|---------------|----------------------|-------------------------|
+| **Auto detection** | ❌ No | ❌ No | ✅ `auto` (default) |
+| **Seconds** | ✅ `s` | ✅ `s` | ✅ `s` or `second` |
+| **Milliseconds** | ✅ `ms` | ✅ `ms` | ✅ `ms` or `millisecond` |
+| **Microseconds** | ✅ `u` or `µ` | ✅ `us` | ✅ `us` or `microsecond` |
+| **Nanoseconds** | ✅ `ns` | ✅ `ns` | ✅ `ns` or `nanosecond` |
+| **Minutes** | ✅ `m` | ❌ No | ❌ No |
+| **Hours** | ✅ `h` | ❌ No | ❌ No |
+| **Default** | Nanosecond | Nanosecond | **Auto** (guessed) |
+
+- All write endpoints accept timestamps in line protocol format.
+- {{% product-name %}} multiplies timestamps by the appropriate precision value to convert them to nanoseconds for internal storage.
+- All timestamps are stored internally as nanoseconds regardless of the precision specified when writing.
+
 {{% /show-in %}}
 
 {{% hide-in "core,enterprise" %}}

diff --git a/content/shared/influxdb3-write-guides/http-api/_index.md b/content/shared/influxdb3-write-guides/http-api/_index.md
@@ -1,4 +1,22 @@
 Use the InfluxDB HTTP API to write data to {{< product-name >}}.
-There are different APIs you can use depending on your integration method.
+Different APIs are available depending on your integration method.
+
+{{% show-in "core,enterprise" %}}
+> [!Tip]
+> #### Choose the write endpoint for your workload
+> 
+> When creating new write workloads, use the
+> [InfluxDB HTTP API `/api/v3/write_lp` endpoint](influxdb3/version/write-data/http-api/v3-write-lp/)
+> and [client libraries](/influxdb3/version/write-data/client-libraries/).
+>
+> When bringing existing _v1_ write workloads, use the {{% product-name %}}
+> HTTP API [`/write` endpoint](/influxdb3/core/api/v3/#operation/PostV1Write).
+>
+> When bringing existing _v2_ write workloads, use the {{% product-name %}}
+> HTTP API [`/api/v2/write` endpoint]([/influxdb3/version/api/v3/#operation/PostV1Write](/influxdb3/version/api/v3/#operation/PostV2Write)).
+>
+> **For Telegraf**, use the InfluxDB v1.x [`outputs.influxdb`](https://github.com/influxdata/telegraf/blob/master/plugins/outputs/influxdb/README.md) or v2.x [`outputs.influxdb_v2`](https://github.com/influxdata/telegraf/blob/master/plugins/outputs/influxdb_v2/README.md) output plugins.
+> See how to [use Telegraf to write data](/influxdb3/version/write-data/use-telegraf/).
+{{% /show-in %}}
 
 {{< children >}}
diff --git a/content/shared/influxdb3-write-guides/http-api/compatibility-apis.md b/content/shared/influxdb3-write-guides/http-api/compatibility-apis.md
@@ -5,6 +5,22 @@ The `/api/v2/write` (v2-compatible) and `/write` (v1-compatible) HTTP API
 endpoints work with InfluxDB [client libraries](/influxdb3/version/reference/client-libraries/), [Telegraf](/telegraf/v1/), and third-party integrations 
 to write points as line protocol data to {{% product-name %}}.
 
+> [!Tip]
+> #### Choose the write endpoint for your workload
+> 
+> When creating new write workloads, use the
+> [InfluxDB HTTP API `/api/v3/write_lp` endpoint](influxdb3/version/write-data/http-api/v3-write-lp/)
+> and [client libraries](/influxdb3/version/write-data/client-libraries/).
+>
+> When bringing existing v1 write workloads, use the {{% product-name %}}
+> HTTP API [`/write` endpoint](/influxdb3/core/api/v3/#operation/PostV1Write).
+>
+> When bringing existing v2 write workloads, use the {{% product-name %}}
+> HTTP API [`/api/v2/write` endpoint]([/influxdb3/version/api/v3/#operation/PostV1Write](/influxdb3/version/api/v3/#operation/PostV2Write)).
+>
+> **For Telegraf**, use the InfluxDB v1.x [`outputs.influxdb`](https://github.com/influxdata/telegraf/blob/master/plugins/outputs/influxdb/README.md) or v2.x [`outputs.influxdb_v2`](https://github.com/influxdata/telegraf/blob/master/plugins/outputs/influxdb_v2/README.md) output plugins.
+> See how to [use Telegraf to write data](/influxdb3/version/write-data/use-telegraf/).
+
 > [!Note]
 > #### Compatibility APIs differ from native APIs
 > 

diff --git a/content/shared/influxdb3-write-guides/http-api/v3-write-lp.md b/content/shared/influxdb3-write-guides/http-api/v3-write-lp.md
@@ -3,24 +3,81 @@ Use the `/api/v3/write_lp` endpoint to write data to {{% product-name %}}.
 This endpoint accepts the same [line protocol](/influxdb3/version/reference/line-protocol/)
 syntax as previous versions of InfluxDB, and supports the following:
 
-##### Query parameters
+## Query parameters
 
 - `?accept_partial=<BOOLEAN>`: Accept or reject partial writes (default is `true`).
 - `?no_sync=<BOOLEAN>`: Control when writes are acknowledged:
   - `no_sync=true`: Acknowledges writes before WAL persistence completes.
   - `no_sync=false`: Acknowledges writes after WAL persistence completes (default).
 - `?precision=<PRECISION>`: Specify the precision of the timestamp.
-  By default, {{% product-name %}} uses the timestamp magnitude to auto-detect the precision.
+  By default, {{% product-name %}} uses the timestamp magnitude to auto-detect the precision (`auto`).
   To avoid any ambiguity, you can specify the precision of timestamps in your data.
-  
+
   The {{< product-name >}} `/api/v3/write_lp` API endpoint supports the following timestamp precisions:
-
-  - `ns` (nanoseconds)
-  - `us` (microseconds)
-  - `ms` (milliseconds)
-  - `s` (seconds)
 
-##### Request body
+  - `auto` (automatic detection, default)
+  - `ns` or `nanosecond` (nanoseconds)
+  - `us` or `microsecond` (microseconds)
+  - `ms` or `millisecond` (milliseconds)
+  - `s` or `second` (seconds)
+
+### Auto precision detection
+
+When you use `precision=auto` (or omit the parameter), {{% product-name %}} automatically detects the timestamp precision based on the magnitude of the timestamp value:
+
+- Timestamps < 5e9 → Second precision (multiplied by 1,000,000,000 to convert to nanoseconds)
+- Timestamps < 5e12 → Millisecond precision (multiplied by 1,000,000)
+- Timestamps < 5e15 → Microsecond precision (multiplied by 1,000)
+- Larger timestamps → Nanosecond precision (no conversion needed)
+
+### Precision examples
+
+The following examples show how to write data with different timestamp precisions:
+
+{{< code-tabs-wrapper >}}
+{{% code-tabs %}}
+[Auto (default)](#)
+[Nanoseconds](#)
+[Milliseconds](#)
+[Seconds](#)
+{{% /code-tabs %}}
+{{% code-tab-content %}}
+```bash
+# Auto precision (default) - timestamp magnitude determines precision
+curl "http://{{< influxdb/host >}}/api/v3/write_lp?db=sensors" \
+  --header "Authorization: Bearer DATABASE_TOKEN" \
+  --data-raw "cpu,host=server1 usage=50.0 1708976567"
+```
+
+The timestamp `1708976567` is automatically detected as seconds.
+{{% /code-tab-content %}}
+{{% code-tab-content %}}
+```bash
+# Explicit nanosecond precision
+curl "http://{{< influxdb/host >}}/api/v3/write_lp?db=sensors&precision=ns" \
+  --header "Authorization: Bearer DATABASE_TOKEN" \
+  --data-raw "cpu,host=server1 usage=50.0 1708976567000000000"
+```
+{{% /code-tab-content %}}
+{{% code-tab-content %}}
+```bash
+# Millisecond precision
+curl "http://{{< influxdb/host >}}/api/v3/write_lp?db=sensors&precision=ms" \
+  --header "Authorization: Bearer DATABASE_TOKEN" \
+  --data-raw "cpu,host=server1 usage=50.0 1708976567000"
+```
+{{% /code-tab-content %}}
+{{% code-tab-content %}}
+```bash
+# Second precision
+curl "http://{{< influxdb/host >}}/api/v3/write_lp?db=sensors&precision=s" \
+  --header "Authorization: Bearer DATABASE_TOKEN" \
+  --data-raw "cpu,host=server1 usage=50.0 1708976567"
+```
+{{% /code-tab-content %}}
+{{< /code-tabs-wrapper >}}
+
+## Request body
 
 - Line protocol