Priority Level

Medium (Nice to have)

Is your feature request related to a problem? Please describe.

The existing AgentRolloutSeedSource supports two vendor-specific formats (Claude Code and Codex). ATIF is designed as a portable interchange format that any agent system can emit, making it a natural addition. With ATIF support, users can seed dataset generation from agent traces regardless of which agent framework produced them, without writing a custom handler.

Describe the solution you'd like

Each agent trace is represented as a JSON object. We could either support a directory where each file is a JSON object, or support reading from a .jsonl file where each line is a full agent trace.

High level changes

1. Add ATIF to AgentRolloutFormat enum
2. Implement AtifAgentRolloutFormatHandler
3. Register the handler with BUILTIN_AGENT_ROLLOUT_FORMAT_HANDLERS

Example

from data_designer import DataDesigner, AgentRolloutSeedSource, AgentRolloutFormat

dd = DataDesigner()
config = dd.config_builder()
config.with_seed_dataset(
    AgentRolloutSeedSource(
        format=AgentRolloutFormat.ATIF,
        path="/path/to/traces",
    )
)

Describe alternatives you've considered

No response

Additional context

No response