feat(blocks): Implement Text Encode block (#11857)

## Summary
Implements a `TextEncoderBlock` that encodes plain text into escape
sequences (the reverse of `TextDecoderBlock`).

## Changes

### Block Implementation
- Added `encoder_block.py` with `TextEncoderBlock` in
`autogpt_platform/backend/backend/blocks/`
- Uses `codecs.encode(text, "unicode_escape").decode("utf-8")` for
encoding
- Mirrors the structure and patterns of the existing `TextDecoderBlock`
- Categorised as `BlockCategory.TEXT`

### Documentation
- Added Text Encoder section to
`docs/integrations/block-integrations/text.md` (the auto-generated docs
file for TEXT category blocks)
- Expanded "How it works" with technical details on the encoding method,
validation, and edge cases
- Added 3 structured use cases per docs guidelines: JSON payload
preparation, Config/ENV generation, Snapshot fixtures
- Added Text Encoder to the overview table in
`docs/integrations/README.md`
- Removed standalone `encoder_block.md` (TEXT category blocks belong in
`text.md` per `CATEGORY_FILE_MAP` in `generate_block_docs.py`)

### Documentation Formatting (CodeRabbit feedback)
- Added blank lines around markdown tables (MD058)
- Added `text` language tags to fenced code blocks (MD040)
- Restructured use case section with bold headings per coding guidelines

## How Docs Were Synced
The `check-docs-sync` CI job runs `poetry run python
scripts/generate_block_docs.py --check` which expects blocks to be
documented in category-grouped files. Since `TextEncoderBlock` uses
`BlockCategory.TEXT`, the `CATEGORY_FILE_MAP` maps it to `text.md` — not
a standalone file. The block entry was added to `text.md` following the
exact format used by the generator (with `<!-- MANUAL -->` markers for
hand-written sections).

## Related Issue
Fixes #11111

---------

Co-authored-by: Otto <otto@agpt.co>
Co-authored-by: lif <19658300+majiayu000@users.noreply.github.com>
Co-authored-by: Aryan Kaul <134673289+aryancodes1@users.noreply.github.com>
Co-authored-by: Nicholas Tindle <nicholas.tindle@agpt.co>
Co-authored-by: Nick Tindle <nick@ntindle.com>

autogpt_platform/backend/backend/blocks/encoder_block.py

@@ -0,0 +1,77 @@
+"""Text encoding block for converting special characters to escape sequences."""
+
+import codecs
+
+from backend.data.block import (
+    Block,
+    BlockCategory,
+    BlockOutput,
+    BlockSchemaInput,
+    BlockSchemaOutput,
+)
+from backend.data.model import SchemaField
+
+
+class TextEncoderBlock(Block):
+    """
+    Encodes a string by converting special characters into escape sequences.
+
+    This block is the inverse of TextDecoderBlock. It takes text containing
+    special characters (like newlines, tabs, etc.) and converts them into
+    their escape sequence representations (e.g., newline becomes \\n).
+    """
+
+    class Input(BlockSchemaInput):
+        """Input schema for TextEncoderBlock."""
+
+        text: str = SchemaField(
+            description="A string containing special characters to be encoded",
+            placeholder="Your text with newlines and quotes to encode",
+        )
+
+    class Output(BlockSchemaOutput):
+        """Output schema for TextEncoderBlock."""
+
+        encoded_text: str = SchemaField(
+            description="The encoded text with special characters converted to escape sequences"
+        )
+        error: str = SchemaField(description="Error message if encoding fails")
+
+    def __init__(self):
+        super().__init__(
+            id="5185f32e-4b65-4ecf-8fbb-873f003f09d6",
+            description="Encodes a string by converting special characters into escape sequences",
+            categories={BlockCategory.TEXT},
+            input_schema=TextEncoderBlock.Input,
+            output_schema=TextEncoderBlock.Output,
+            test_input={
+                "text": """Hello
+World!
+This is a "quoted" string."""
+            },
+            test_output=[
+                (
+                    "encoded_text",
+                    """Hello\\nWorld!\\nThis is a "quoted" string.""",
+                )
+            ],
+        )
+
+    async def run(self, input_data: Input, **kwargs) -> BlockOutput:
+        """
+        Encode the input text by converting special characters to escape sequences.
+
+        Args:
+            input_data: The input containing the text to encode.
+            **kwargs: Additional keyword arguments (unused).
+
+        Yields:
+            The encoded text with escape sequences, or an error message if encoding fails.
+        """
+        try:
+            encoded_text = codecs.encode(input_data.text, "unicode_escape").decode(
+                "utf-8"
+            )
+            yield "encoded_text", encoded_text
+        except Exception as e:
+            yield "error", f"Encoding error: {str(e)}"

autogpt_platform/backend/backend/blocks/test/test_text_encoder.py

@@ -0,0 +1,77 @@
+import pytest
+
+from backend.blocks.encoder_block import TextEncoderBlock
+
+
+@pytest.mark.asyncio
+async def test_text_encoder_basic():
+    """Test basic encoding of newlines and special characters."""
+    block = TextEncoderBlock()
+    result = []
+    async for output in block.run(TextEncoderBlock.Input(text="Hello\nWorld")):
+        result.append(output)
+
+    assert len(result) == 1
+    assert result[0][0] == "encoded_text"
+    assert result[0][1] == "Hello\\nWorld"
+
+
+@pytest.mark.asyncio
+async def test_text_encoder_multiple_escapes():
+    """Test encoding of multiple escape sequences."""
+    block = TextEncoderBlock()
+    result = []
+    async for output in block.run(
+        TextEncoderBlock.Input(text="Line1\nLine2\tTabbed\rCarriage")
+    ):
+        result.append(output)
+
+    assert len(result) == 1
+    assert result[0][0] == "encoded_text"
+    assert "\\n" in result[0][1]
+    assert "\\t" in result[0][1]
+    assert "\\r" in result[0][1]
+
+
+@pytest.mark.asyncio
+async def test_text_encoder_unicode():
+    """Test that unicode characters are handled correctly."""
+    block = TextEncoderBlock()
+    result = []
+    async for output in block.run(TextEncoderBlock.Input(text="Hello 世界\n")):
+        result.append(output)
+
+    assert len(result) == 1
+    assert result[0][0] == "encoded_text"
+    # Unicode characters should be escaped as \uXXXX sequences
+    assert "\\n" in result[0][1]
+
+
+@pytest.mark.asyncio
+async def test_text_encoder_empty_string():
+    """Test encoding of an empty string."""
+    block = TextEncoderBlock()
+    result = []
+    async for output in block.run(TextEncoderBlock.Input(text="")):
+        result.append(output)
+
+    assert len(result) == 1
+    assert result[0][0] == "encoded_text"
+    assert result[0][1] == ""
+
+
+@pytest.mark.asyncio
+async def test_text_encoder_error_handling():
+    """Test that encoding errors are handled gracefully."""
+    from unittest.mock import patch
+
+    block = TextEncoderBlock()
+    result = []
+
+    with patch("codecs.encode", side_effect=Exception("Mocked encoding error")):
+        async for output in block.run(TextEncoderBlock.Input(text="test")):
+            result.append(output)
+
+    assert len(result) == 1
+    assert result[0][0] == "error"
+    assert "Mocked encoding error" in result[0][1]

docs/integrations/README.md

@@ -192,6 +192,7 @@ Below is a comprehensive list of all available blocks, categorized by their prim
 | [Get Current Time](block-integrations/text.md#get-current-time) | This block outputs the current time |
 | [Match Text Pattern](block-integrations/text.md#match-text-pattern) | Matches text against a regex pattern and forwards data to positive or negative output based on the match |
 | [Text Decoder](block-integrations/text.md#text-decoder) | Decodes a string containing escape sequences into actual text |
+| [Text Encoder](block-integrations/text.md#text-encoder) | Encodes a string by converting special characters into escape sequences |
 | [Text Replace](block-integrations/text.md#text-replace) | This block is used to replace a text with a new text |
 | [Text Split](block-integrations/text.md#text-split) | This block is used to split a text into a list of strings |
 | [Word Character Count](block-integrations/text.md#word-character-count) | Counts the number of words and characters in a given text |

docs/integrations/block-integrations/text.md

@@ -380,6 +380,42 @@ This is useful when working with data from APIs or files where escape sequences
 
 ---
 
+## Text Encoder
+
+### What it is
+Encodes a string by converting special characters into escape sequences
+
+### How it works
+<!-- MANUAL: how_it_works -->
+The Text Encoder takes the input string and applies Python's `unicode_escape` encoding (equivalent to `codecs.encode(text, "unicode_escape").decode("utf-8")`) to transform special characters like newlines, tabs, and backslashes into their escaped forms.
+
+The block relies on the input schema to ensure the value is a string; non-string inputs are rejected by validation, and any encoding failures surface as block errors. Non-ASCII characters are emitted as `\uXXXX` sequences, which is useful for ASCII-only payloads.
+<!-- END MANUAL -->
+
+### Inputs
+
+| Input | Description | Type | Required |
+|-------|-------------|------|----------|
+| text | A string containing special characters to be encoded | str | Yes |
+
+### Outputs
+
+| Output | Description | Type |
+|--------|-------------|------|
+| error | Error message if encoding fails | str |
+| encoded_text | The encoded text with special characters converted to escape sequences | str |
+
+### Possible use case
+<!-- MANUAL: use_case -->
+**JSON Payload Preparation**: Encode multiline or quoted text before embedding it in JSON string fields to ensure proper escaping.
+
+**Config/ENV Generation**: Convert template text into escaped strings for `.env` or YAML values that require special character handling.
+
+**Snapshot Fixtures**: Produce stable escaped strings for golden files or API tests where consistent text representation is needed.
+<!-- END MANUAL -->
+
+---
+
 ## Text Replace
 
 ### What it is