diff --git a/docs/functions-cli.md b/docs/functions-cli.md
index 7617ad092572..c7160a85e687 100644
--- a/docs/functions-cli.md
+++ b/docs/functions-cli.md
@@ -91,8 +91,9 @@ The following table outlines the nested fields and related arguments under the `
| maxPendingMessagesAcrossPartitions | Int | N/A | The number of `maxPendingMessages` across all partitions. |
| useThreadLocalProducers | Boolean | N/A | N/A |
| cryptoConfig | [CryptoConfig](#cryptoconfig) | N/A | Refer to [code](https://github.com/apache/pulsar/blob/master/pulsar-client-admin-api/src/main/java/org/apache/pulsar/common/functions/CryptoConfig.java).|
-| batchBuilder | String | `--batch-builder` | The type of batch construction method. Available values: `DEFAULT` and `KEY_BASED`. The default value is `DEFAULT`. |
-| compressionType | String | N/A | Message data compression type used by a producer. The default value is [`LZ4`](https://github.com/lz4/lz4).
Available options:`NONE` (no compression)[`ZLIB`](https://zlib.net/)
[`ZSTD`](https://facebook.github.io/zstd/)[`SNAPPY`](https://google.github.io/snappy/)|
+| batchBuilder | String | `--batch-builder` | The type of batch construction method. Available values: `DEFAULT` and `KEY_BASED`. The default value is `DEFAULT`.
**Note:** If `batchingConfig.batchBuilder` is also set, that value takes precedence over this one. |
+| compressionType | String | N/A | Message data compression type used by a producer. The default value is [`LZ4`](https://github.com/lz4/lz4).
Available options:`NONE` (no compression)[`ZLIB`](https://zlib.net/)
[`ZSTD`](https://facebook.github.io/zstd/)[`SNAPPY`](https://google.github.io/snappy/)
**Note:** The Go client does not implement `SNAPPY`; a Go function configured with it falls back to `LZ4`. |
+| batchingConfig | [BatchingConfig](#batchingconfig) | N/A | The batching settings applied to the producer. When omitted, batching is enabled with a maximum publish delay of 10 ms. |
###### Resources
@@ -133,6 +134,33 @@ The following table outlines the nested fields and related arguments under the `
| consumerCryptoFailureAction | ConsumerCryptoFailureAction | N/A | N/A |
+###### BatchingConfig
+
+The following table outlines the nested fields under the `batchingConfig` field of `producerConfig`.
+These settings were introduced by [PIP-401](https://github.com/apache/pulsar/blob/master/pip/pip-401.md).
+
+:::note
+
+`batchingConfig` is currently applied by **Java** functions only. The Python and Go runtimes hard-code
+batching to enabled with a 10 ms maximum publish delay and ignore these settings
+([#26390](https://github.com/apache/pulsar/issues/26390),
+[#26391](https://github.com/apache/pulsar/issues/26391)).
+
+:::
+
+| Field Name | Type | Related Command Argument | Description |
+|---------------------------|---------|--------------------------|---------------|
+| enabled | Boolean | N/A | Whether the producer batches messages. The default value is `true`. |
+| batchingMaxPublishDelayMs | Int | N/A | The maximum time the producer waits before sending a batch, in milliseconds. The default value is `10`. |
+| batchingMaxMessages | Int | N/A | The maximum number of messages in a batch. When unset, the client default applies. |
+| batchingMaxBytes | Int | N/A | The maximum size of a batch, in bytes. When unset, the client default applies. |
+| batchBuilder | String | N/A | The type of batch construction method. Available values: `DEFAULT` and `KEY_BASED`. Takes precedence over `producerConfig.batchBuilder`. |
+| roundRobinRouterBatchingPartitionSwitchFrequency | Int | N/A | How often the round-robin router switches partitions for non-keyed messages, as a multiple of `batchingMaxPublishDelayMs`. The partition switch period is `frequency * batchingMaxPublishDelayMs`. |
+
+A function that sets no `producerConfig`, or a `producerConfig` with no `batchingConfig`, gets batching
+enabled with a maximum publish delay of 10 ms. This is the behaviour functions had before these settings
+became configurable, and it is the same across the Java, Python, and Go runtimes.
+
### Example
The following example shows how to configure a function using YAML or JSON.
diff --git a/versioned_docs/version-4.2.x/functions-cli.md b/versioned_docs/version-4.2.x/functions-cli.md
index 7617ad092572..c7160a85e687 100644
--- a/versioned_docs/version-4.2.x/functions-cli.md
+++ b/versioned_docs/version-4.2.x/functions-cli.md
@@ -91,8 +91,9 @@ The following table outlines the nested fields and related arguments under the `
| maxPendingMessagesAcrossPartitions | Int | N/A | The number of `maxPendingMessages` across all partitions. |
| useThreadLocalProducers | Boolean | N/A | N/A |
| cryptoConfig | [CryptoConfig](#cryptoconfig) | N/A | Refer to [code](https://github.com/apache/pulsar/blob/master/pulsar-client-admin-api/src/main/java/org/apache/pulsar/common/functions/CryptoConfig.java).|
-| batchBuilder | String | `--batch-builder` | The type of batch construction method. Available values: `DEFAULT` and `KEY_BASED`. The default value is `DEFAULT`. |
-| compressionType | String | N/A | Message data compression type used by a producer. The default value is [`LZ4`](https://github.com/lz4/lz4).
Available options:`NONE` (no compression)[`ZLIB`](https://zlib.net/)
[`ZSTD`](https://facebook.github.io/zstd/)[`SNAPPY`](https://google.github.io/snappy/)|
+| batchBuilder | String | `--batch-builder` | The type of batch construction method. Available values: `DEFAULT` and `KEY_BASED`. The default value is `DEFAULT`.
**Note:** If `batchingConfig.batchBuilder` is also set, that value takes precedence over this one. |
+| compressionType | String | N/A | Message data compression type used by a producer. The default value is [`LZ4`](https://github.com/lz4/lz4).
Available options:`NONE` (no compression)[`ZLIB`](https://zlib.net/)
[`ZSTD`](https://facebook.github.io/zstd/)[`SNAPPY`](https://google.github.io/snappy/)
**Note:** The Go client does not implement `SNAPPY`; a Go function configured with it falls back to `LZ4`. |
+| batchingConfig | [BatchingConfig](#batchingconfig) | N/A | The batching settings applied to the producer. When omitted, batching is enabled with a maximum publish delay of 10 ms. |
###### Resources
@@ -133,6 +134,33 @@ The following table outlines the nested fields and related arguments under the `
| consumerCryptoFailureAction | ConsumerCryptoFailureAction | N/A | N/A |
+###### BatchingConfig
+
+The following table outlines the nested fields under the `batchingConfig` field of `producerConfig`.
+These settings were introduced by [PIP-401](https://github.com/apache/pulsar/blob/master/pip/pip-401.md).
+
+:::note
+
+`batchingConfig` is currently applied by **Java** functions only. The Python and Go runtimes hard-code
+batching to enabled with a 10 ms maximum publish delay and ignore these settings
+([#26390](https://github.com/apache/pulsar/issues/26390),
+[#26391](https://github.com/apache/pulsar/issues/26391)).
+
+:::
+
+| Field Name | Type | Related Command Argument | Description |
+|---------------------------|---------|--------------------------|---------------|
+| enabled | Boolean | N/A | Whether the producer batches messages. The default value is `true`. |
+| batchingMaxPublishDelayMs | Int | N/A | The maximum time the producer waits before sending a batch, in milliseconds. The default value is `10`. |
+| batchingMaxMessages | Int | N/A | The maximum number of messages in a batch. When unset, the client default applies. |
+| batchingMaxBytes | Int | N/A | The maximum size of a batch, in bytes. When unset, the client default applies. |
+| batchBuilder | String | N/A | The type of batch construction method. Available values: `DEFAULT` and `KEY_BASED`. Takes precedence over `producerConfig.batchBuilder`. |
+| roundRobinRouterBatchingPartitionSwitchFrequency | Int | N/A | How often the round-robin router switches partitions for non-keyed messages, as a multiple of `batchingMaxPublishDelayMs`. The partition switch period is `frequency * batchingMaxPublishDelayMs`. |
+
+A function that sets no `producerConfig`, or a `producerConfig` with no `batchingConfig`, gets batching
+enabled with a maximum publish delay of 10 ms. This is the behaviour functions had before these settings
+became configurable, and it is the same across the Java, Python, and Go runtimes.
+
### Example
The following example shows how to configure a function using YAML or JSON.
diff --git a/versioned_docs/version-5.0.x/functions-cli.md b/versioned_docs/version-5.0.x/functions-cli.md
index 7617ad092572..c7160a85e687 100644
--- a/versioned_docs/version-5.0.x/functions-cli.md
+++ b/versioned_docs/version-5.0.x/functions-cli.md
@@ -91,8 +91,9 @@ The following table outlines the nested fields and related arguments under the `
| maxPendingMessagesAcrossPartitions | Int | N/A | The number of `maxPendingMessages` across all partitions. |
| useThreadLocalProducers | Boolean | N/A | N/A |
| cryptoConfig | [CryptoConfig](#cryptoconfig) | N/A | Refer to [code](https://github.com/apache/pulsar/blob/master/pulsar-client-admin-api/src/main/java/org/apache/pulsar/common/functions/CryptoConfig.java).|
-| batchBuilder | String | `--batch-builder` | The type of batch construction method. Available values: `DEFAULT` and `KEY_BASED`. The default value is `DEFAULT`. |
-| compressionType | String | N/A | Message data compression type used by a producer. The default value is [`LZ4`](https://github.com/lz4/lz4).
Available options:`NONE` (no compression)[`ZLIB`](https://zlib.net/)
[`ZSTD`](https://facebook.github.io/zstd/)[`SNAPPY`](https://google.github.io/snappy/)|
+| batchBuilder | String | `--batch-builder` | The type of batch construction method. Available values: `DEFAULT` and `KEY_BASED`. The default value is `DEFAULT`.
**Note:** If `batchingConfig.batchBuilder` is also set, that value takes precedence over this one. |
+| compressionType | String | N/A | Message data compression type used by a producer. The default value is [`LZ4`](https://github.com/lz4/lz4).
Available options:`NONE` (no compression)[`ZLIB`](https://zlib.net/)
[`ZSTD`](https://facebook.github.io/zstd/)[`SNAPPY`](https://google.github.io/snappy/)
**Note:** The Go client does not implement `SNAPPY`; a Go function configured with it falls back to `LZ4`. |
+| batchingConfig | [BatchingConfig](#batchingconfig) | N/A | The batching settings applied to the producer. When omitted, batching is enabled with a maximum publish delay of 10 ms. |
###### Resources
@@ -133,6 +134,33 @@ The following table outlines the nested fields and related arguments under the `
| consumerCryptoFailureAction | ConsumerCryptoFailureAction | N/A | N/A |
+###### BatchingConfig
+
+The following table outlines the nested fields under the `batchingConfig` field of `producerConfig`.
+These settings were introduced by [PIP-401](https://github.com/apache/pulsar/blob/master/pip/pip-401.md).
+
+:::note
+
+`batchingConfig` is currently applied by **Java** functions only. The Python and Go runtimes hard-code
+batching to enabled with a 10 ms maximum publish delay and ignore these settings
+([#26390](https://github.com/apache/pulsar/issues/26390),
+[#26391](https://github.com/apache/pulsar/issues/26391)).
+
+:::
+
+| Field Name | Type | Related Command Argument | Description |
+|---------------------------|---------|--------------------------|---------------|
+| enabled | Boolean | N/A | Whether the producer batches messages. The default value is `true`. |
+| batchingMaxPublishDelayMs | Int | N/A | The maximum time the producer waits before sending a batch, in milliseconds. The default value is `10`. |
+| batchingMaxMessages | Int | N/A | The maximum number of messages in a batch. When unset, the client default applies. |
+| batchingMaxBytes | Int | N/A | The maximum size of a batch, in bytes. When unset, the client default applies. |
+| batchBuilder | String | N/A | The type of batch construction method. Available values: `DEFAULT` and `KEY_BASED`. Takes precedence over `producerConfig.batchBuilder`. |
+| roundRobinRouterBatchingPartitionSwitchFrequency | Int | N/A | How often the round-robin router switches partitions for non-keyed messages, as a multiple of `batchingMaxPublishDelayMs`. The partition switch period is `frequency * batchingMaxPublishDelayMs`. |
+
+A function that sets no `producerConfig`, or a `producerConfig` with no `batchingConfig`, gets batching
+enabled with a maximum publish delay of 10 ms. This is the behaviour functions had before these settings
+became configurable, and it is the same across the Java, Python, and Go runtimes.
+
### Example
The following example shows how to configure a function using YAML or JSON.