[xgtcode]

Summary

• Update AIO sandbox image defaults and related Studio environment handling.
• Make /run_sse SSE payload event IDs unique for streaming partial events by appending :veid:<n> at the interface layer.
• Keep final non-partial ADK event IDs unchanged when possible so feedback/session lookup continues to use the original ADK event ID.

Details

ADK 2.6+ may reuse the same Event.id across streaming partial: true chunks. Studio currently deduplicates streamed events by payload id, so repeated partial IDs can cause later streamed content to be dropped.

This PR fixes the compatibility issue at the SSE output boundary:

• partial: true events are emitted with derived IDs like original-id:veid:0.
• first non-partial/final events keep their original ADK ID.
• duplicate IDs within the same SSE response are rewritten with :veid:<n>.
• ADK session event IDs are not modified.

Covered paths:

• AgentKit dynamic /run_sse
• generated runtime dynamic /run_sse
• harness /run_sse override
• matching /invoke SSE output paths

Compatibility

This does not change ADK runner/session internals. Final event IDs remain compatible with feedback and session-based lookup in the normal path.

Native A2A protocol fields are not changed; only ADK-like SSE payloads emitted to Studio are adapted.

Verification

• uv run --extra dev pre-commit run --all-files passed
• uv run --extra dev pytest tests/integrations/agentkit/test_app.py tests/cloud/test_harness_app_http.py tests/cli/test_generated_agent_backend_codegen_extended.py -q passed
  • 121 passed