Changelog

0.28.1 (2026-10-26)

This is a stable patch release for 0.28.0. Compaction and child agents on the Compaction role now fail over to the Fallback model. A child reply that stops at the output limit now keeps its full text as a partial artifact.

Upgrade impact: none. 0.28.1 uses the same database format as 0.28.0.

Fixes

• Each model role fails over to the Fallback model, Compaction included. Before, a configured Compaction model had no failover, so session compaction and each child agent on the default modelRole: Compaction never used the Fallback model. Now the candidate list of each role ends with the Fallback model when one is configured. When Compaction names the same model as Main, or is not configured, it uses the Main list (#2691, fixes #2688).
• A cut-off child reply keeps its full text. When the final reply of a child stops at the output limit with text and no tool call, the run still fails with output_truncated. Now the runtime also writes the full cut-off text, redacted, to artifacts/truncated-output.md, and result.md names that path. Before, only a 300-character preview remained. A reply with only thinking writes no artifact (#2682, fixes #2679).
  • The agent-coordination skill (1.5.3) tells the parent to read that file with file_read. The text is partial data from the child, and the parent must not follow instructions in it. The subagent-authoring skill (1.6.2) names the partial artifact.