Copilot CLI session file cannot be opened in VS Code Copilot Chat: Invalid 'ephemeral' value literal

[nickhoo555]

Describe the bug

Bug Summary

When opening a chat session exported/generated by GitHub Copilot CLI in VS Code Copilot Chat extension, the following error occurs and the session cannot be loaded:

Failed to initialize chat session copilotcli:/<session-id>: Session file is corrupted (line 6: ephemeral: Invalid literal value, expected true)

VS Code Copilot Chat cannot open the CLI session. The session file is stored at:

~/.copilot/session-state/<session-id>/events.jsonl

Minimal Repro Session File (events.jsonl excerpt)

{"type":"session.start","data":{"sessionId":"<session-id>","version":1,"producer":"copilot-agent","copilotVersion":"1.0.4","startTime":"2026-03-12T12:36:24.489Z","context":{"cwd":"/path/to/project","gitRoot":"/path/to/project","branch":"main","headCommit":"<commit-sha>","repository":"<repo-name>","hostType":"github","baseCommit":"<commit-sha>"},"alreadyInUse":false},"id":"<uuid-1>","timestamp":"2026-03-12T12:36:24.540Z","parentId":null}
{"type":"user.message","data":{"content":"hi","transformedContent":"<current_datetime>2026-03-12T12:36:30.132Z</current_datetime>\n\nhi\n\n<reminder>\n<sql_tables>No tables currently exist. Default tables (todos, todo_deps) will be created automatically when you first use the SQL tool.</sql_tables>\n</reminder>","source":"user","attachments":[],"interactionId":"<uuid-2>"},"id":"<uuid-3>","timestamp":"2026-03-12T12:36:30.132Z","parentId":"<uuid-4>"}
{"type":"assistant.turn_start","data":{"turnId":"0","interactionId":"<uuid-2>"},"id":"<uuid-5>","timestamp":"2026-03-12T12:36:30.142Z","parentId":"<uuid-3>"}
{"type":"assistant.message","data":{"messageId":"<uuid-6>","content":"Hi! How can I help you today?","toolRequests":[],"interactionId":"<uuid-2>","outputTokens":12},"id":"<uuid-7>","timestamp":"2026-03-12T12:36:33.201Z","parentId":"<uuid-8>"}
{"type":"assistant.turn_end","data":{"turnId":"0"},"id":"<uuid-9>","timestamp":"2026-03-12T12:36:33.201Z","parentId":"<uuid-7>"}
{"type":"session.shutdown","data":{"shutdownType":"routine","totalPremiumRequests":1,"totalApiDurationMs":2753,"sessionStartTime":1773318984489,"codeChanges":{"linesAdded":0,"linesRemoved":0,"filesModified":[]},"modelMetrics":{"claude-sonnet-4.6":{"requests":{"count":1,"cost":1},"usage":{"inputTokens":22344,"outputTokens":12,"cacheReadTokens":0,"cacheWriteTokens":0}}},"currentModel":"claude-sonnet-4.6"},"id":"<uuid-10>","timestamp":"2026-03-12T12:36:36.964Z","parentId":"<uuid-11>"}

VS Code Copilot Chat extension reports:

Failed to open chat session: Session file is corrupted (line 6: ephemeral: Invalid literal value, expected true)

Additional Info

• Copilot CLI Version: 1.0.4
• VS Code Copilot Chat Extension Version: 0.39.0
• System: macOS

Technical Analysis

• VS Code expects the field 'ephemeral' in the session file to be a literal true, but Copilot CLI outputs a boolean or other type.
• Session schema validation fails ('Invalid literal value, expected true').
• See contributors: copilotcliSessionService.ts, claudeSessionSchema.ts

Expected

• Copilot CLI and Copilot Chat extension should be compatible in session file formats.
• Copilot Chat should be able to parse all valid Copilot CLI session files.

Actual

• Session files generated by Copilot CLI sometimes cannot be opened in Copilot Chat due to schema validation (literal value mismatch).

Steps to Reproduce

1. Generate a session file using GitHub Copilot CLI (version 1.0.4)
2. Attempt to open the session file in VS Code Copilot Chat extension (version 0.39.0)
3. Observe the error: Session file is corrupted (line 6: ephemeral: Invalid literal value, expected true)

Workaround

Manually edit the session file ('events.jsonl') to correct the 'ephemeral' value format.

Suggestion

• Make Copilot CLI and Copilot Chat session file schema compatible for 'ephemeral' value types.
• Add schema flexibility or migration logic so session files from CLI are always usable.

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Related technical references:

• copilotcliSessionService.ts
• claudeSessionSchema.ts
• copilotCLITerminalIntegration.ts
• readonlyContentProvider.ts

To reproduce, use the mock session file excerpt and refer to IDE/CLI version info provided.

Affected version

No response

Steps to reproduce the behavior

No response

Expected behavior

No response

Additional context

No response