chimera.types

chimera.types defines the dataclasses that flow across the provider / loop / tool boundary. Importing from a single module avoids circular imports between layers.

Tool I/O

Type	Fields	Purpose
ToolCall	id, name, arguments (dict)	One LLM-emitted tool invocation.
ToolResult	output (str), error (str | None)	Return value of BaseTool.execute(). success property is error is None.
CommandResult	stdout, stderr, returncode	Result of a shell command.
TestResult	passed, failed, skipped, output	Test-runner result.

Messages

Type	Fields
Message	role ("system" | "user" | "assistant" | "tool"), content, tool_calls, tool_call_id
ContentBlock	base class for typed content
TextContent	text
ImageContent	media_type, data

Step / agent results

Type	Fields
StepResult	tool_calls, tool_results, text, usage, cost
AgentResult	output, success, steps, tool_calls, cost, error, messages

File diffs

Type	Fields
ChangeType	enum: CREATE, MODIFY, DELETE
FileChange	path, change_type, before, after

Approvals

PendingApproval (chimera.types.PendingApproval) wraps a tool call that needs human confirmation. Carries the tool_name, args, and a callable to resolve the decision.

Import shortcut

Most user code does not import chimera.types directly — common types are re-exported from the top-level chimera:

from chimera import Agent, ToolResult, AgentResult

See also

• chimera.core for the loop that produces StepResult.
• chimera.events for the event types emitted alongside the dataclasses above.