Summary generation fails: cannot unmarshal array from Claude Code 2.x JSON output

[bboutayeb]

What happened?

entire explain --checkpoint <id> --generate fails with a JSON parsing error. Entire expects a single JSON object from Claude CLI but Claude Code 2.x returns a JSON array when invoked with --output-format json.

$ entire explain --checkpoint 336b6c705d35 --generate
2026/03/22 00:32:21 INFO generating checkpoint summary
failed to generate summary: failed to generate summary: failed to parse claude CLI response: json: cannot unmarshal array into Go value of type summarize.claudeCLIResponse

The root cause: Claude Code 2.x --print --output-format json returns an array of objects ([{type:"system",...}, {type:"assistant",...}, {type:"result",...}]) instead of a single object. The Go struct summarize.claudeCLIResponse tries to unmarshal this array as a single object, which fails.

Auto-summarization on commit (strategy_options.summarize.enabled: true in .entire/settings.json) is also silently broken for the same reason — summaries are never generated.

Steps to reproduce

1. Have Claude Code 2.x installed
2. Enable summarize in .entire/settings.json:

   { "enabled": true, "strategy_options": { "summarize": { "enabled": true } } }

3. Make a commit (checkpoint is created without summary)
4. Run entire explain --checkpoint <id> --generate
5. Error: failed to parse claude CLI response: json: cannot unmarshal array into Go value of type summarize.claudeCLIResponse

You can verify the format change by running:

echo "hello" | claude --print --output-format json --max-turns 1
# Returns: [{...}, {...}, {...}]  ← array, not object

Entire CLI version

Entire CLI 0.5.1 (d46fdc2), Go version: go1.26.1, OS/Arch: linux/amd64

OS and architecture

Linux 6.6.87.2-microsoft-standard-WSL2 x86_64 (WSL2)

Agent

Claude Code 2.1.81

Terminal

Bash (WSL2)

Logs / debug output

$ entire explain --checkpoint 336b6c705d35 --generate
2026/03/22 00:32:21 INFO generating checkpoint summary
failed to generate summary: failed to generate summary: failed to parse claude CLI response: json: cannot unmarshal array into Go value of type summarize.claudeCLIResponse

Additional context

• Related to Explain command: failed to generate summary #334 (same explain --generate command, different error)
• The fix would likely involve parsing the JSON array and extracting the result object (last element with type: "result") instead of trying to unmarshal the entire response as a single object
• Git version: 2.47.2, shell: bash