Skip to content

Action parsers

Action parsers interpret the output of the LM and return actions (tool calls/commands to execute) and thoughts (any other output of the LM, e.g., justifying the tool calls).

sweagent.tools.parsing

Our parsers parse output from the LM into thoughts and actions.

For example, our most basic parser is the ThoughtActionParser. It expects the model response to be a discussion followed by a command wrapped in backticks like so:

Let's look at the files in the current directory.

Action:
 ```
ls -l
 ```

For models that support function calling, we instead recommend using the FunctionCallingParser.

To use a specific parser, set the parse_function key in your tool config to the type field of the parser.

agent:
    tools:
        ...
        parse_function:
            type: "thought_action"

Or from the command line: --agent.tools.parse_function.type=thought_action.

Describing available tools

If you do not use the FunctionCallingParser, you need to include documentation about the available tools in your system prompt. You can use the {{command_docs}} variable to include the automatically generated documentation or explicitly describe the available tools. Also see #1130.

FN_REGEX_PATTERN module-attribute 

FN_REGEX_PATTERN = '<function=([^>]+)>\\n(.*?)</function>'

FN_PARAM_REGEX_PATTERN module-attribute 

FN_PARAM_REGEX_PATTERN = '<parameter=([^>]+)>(.*?)</parameter>'

ParseFunction module-attribute 

ParseFunction = ActionParser | ThoughtActionParser | ActionOnlyParser | XMLThoughtActionParser | XMLFunctionCallingParser | FunctionCallingParser | EditFormat | Identity | JsonParser | BashCodeBlockParser | SingleBashCodeBlockParser

AbstractParseFunction

Bases: ABC

Abstract class for parsing functions. We use get to generate the right parser based on the name of the parser.

error_message instance-attribute 

error_message: str

format_error_template property 

format_error_template

ActionParser pydantic-model

Bases: AbstractParseFunction, BaseModel

Expects the model response to be a single command. Example: "ls -l"

Fields:

error_message pydantic-field 

error_message: str = '    The command you provided was not recognized. Please specify one of the commands (+ any necessary arguments) from the following list in your response. Do not include any other text.\n\n    COMMANDS:\n    {command_docs}\n    '

type pydantic-field 

type: Literal['action'] = 'action'

Type for (de)serialization. Do not change.

ActionOnlyParser pydantic-model

Bases: AbstractParseFunction, BaseModel

Expects the model response to be a single command.

Fields:

error_message pydantic-field 

error_message: str = 'No message found in model response.'

type pydantic-field 

type: Literal['action_only'] = 'action_only'

Type for (de)serialization. Do not change.

ThoughtActionParser pydantic-model

Bases: AbstractParseFunction, BaseModel

Expects the model response to be a discussion followed by a command wrapped in backticks. Example: Let's look at the files in the current directory. 

ls -l

Fields:

error_message pydantic-field 

error_message: str

type pydantic-field 

type: Literal['thought_action'] = 'thought_action'

Type for (de)serialization. Do not change.

XMLThoughtActionParser pydantic-model

Bases: AbstractParseFunction, BaseModel

Expects the model response to be a discussion followed by a command wrapped in XML tags. Example: Let's look at the files in the current directory. ls -l

Fields:

error_message pydantic-field 

error_message: str

type pydantic-field 

type: Literal['xml_thought_action'] = 'xml_thought_action'

Type for (de)serialization. Do not change.

XMLFunctionCallingParser pydantic-model

Bases: AbstractParseFunction, BaseModel

Expects the model response to be a tool calling format, where the command and parameters are specified in XML tags. Example: Let's look at the files in the current directory. find /testbed -type f -name "_discovery.py"

Fields:

error_message pydantic-field 

error_message: str

type pydantic-field 

type: Literal['xml_function_calling'] = 'xml_function_calling'

EditFormat pydantic-model

Bases: ThoughtActionParser, BaseModel

Expects the model response to be a discussion followed by a command wrapped in backticks. Example: We'll replace the contents of the current window with the following: 

import os
os.listdir()

Fields:

error_message pydantic-field 

error_message: str

type pydantic-field 

type: Literal['edit_format'] = 'edit_format'

Type for (de)serialization. Do not change.

Identity pydantic-model

Bases: AbstractParseFunction, BaseModel

This parser does not do any parsing. It just returns the model response as both the thought and action.

Fields:

error_message pydantic-field 

error_message: str = '    It seems like something went wrong with your output. Please try again.\n    '

type pydantic-field 

type: Literal['identity'] = 'identity'

Type for (de)serialization. Do not change.

FunctionCallingParser pydantic-model

Bases: AbstractParseFunction, BaseModel

Expects the model response to be a LiteLLM tool call.

Fields:

error_message pydantic-field 

error_message: str

type pydantic-field 

type: Literal['function_calling'] = 'function_calling'

Type for (de)serialization. Do not change.

JsonParser pydantic-model

Bases: AbstractParseFunction, BaseModel

Expects the model response to be a JSON object.

Fields:

error_message pydantic-field 

error_message: str

type pydantic-field 

type: Literal['json'] = 'json'

Type for (de)serialization. Do not change.

BashCodeBlockParser pydantic-model

Bases: AbstractParseFunction, BaseModel

Executes all commands in ```bash code blocks.

Fields:

error_message pydantic-field 

error_message: str

type pydantic-field 

type: Literal['all_bash_code_blocks'] = 'all_bash_code_blocks'

SingleBashCodeBlockParser pydantic-model

Bases: AbstractParseFunction, BaseModel

Executes all commands in ```bash code blocks.

Fields:

error_message pydantic-field 

error_message: str

type pydantic-field 

type: Literal['single_bash_code_block'] = 'single_bash_code_block'
Our projects
Mini-SWE-Agent Mini-SWE-Agent SWE-rex SWE-ReX SWE-smith SWE-smith SWE-bench SWE-bench sb-cli sb-cli