Agent Session Format Check

Quickly verify whether a newer agent CLI version changes the local session format, usage/limits schema, or storage layout — and whether Agent Sessions can safely bump its verified support.

Evidence-first:

• Gather a report + sample paths first.
• Do not change parsers/fixtures/docs without explicit user approval.

Related skill: agent-support-matrix — maintains the matrix YAML, ledger, and update-checklist workflow. This skill focuses on detection and evidence collection; agent-support-matrix focuses on recording and gating version bumps.

Process doc: docs/agent-support/monitoring.md — defines the severity model, cadence (daily/weekly), and escalation workflow that feeds into this skill.

1 Quick Start (all agents)

1. Run weekly monitoring:

   Copy

   ./scripts/agent_watch.py --mode weekly
   

   Report path prints to stdout and is written under scripts/probe_scan_output/agent_watch/*/report.json.

2. In report.json, check each agent under results.<agent>:

   • verified_version, installed.parsed_version, upstream.parsed_version
   • weekly.local_schema (newest local session used for fingerprinting)
   • weekly.schema_diff and evidence.schema_matches_baseline
   • severity and recommendation

Interpretation:

• installed == verified and upstream == verified: no action.
• installed/upstream > verified and schema_matches_baseline == true: safe to bump (after approval).
• schema_matches_baseline == false: collect evidence and plan a parser/fixture update.

2 Usage / Limits Drift (Codex + Claude)

Usage and limits tracking can drift independently of session schema. Monitor both.

Codex

• Passive channel: session JSONL token_count / rate_limits event structure.
• Active channel (weekly): codex_status_capture.sh output schema — parsed as codex_status_json by agent_watch.py.
• Check: does report.json → results.codex.probes[codex_status_probe].ok return true? If not, investigate whether Codex changed its status output format.

Claude

• Active channel (weekly): claude_usage_capture.sh output schema — parsed as claude_usage_json.
• Context probe: ./scripts/claude-status --json records status.claude.com indicator/incidents (parsed as claude_status_json).
• Check: results.claude.probes[claude_usage_probe].ok — if false, the usage API response format may have changed, or authentication may be required.
• If probe health fails (parsing_failed, auth required, etc.), treat as high severity because the UI can break.

Known issue: Claude usage probe exit 16 (parsing_failed)

claude_usage_capture.sh can fail with exit 16 when Claude auth tokens are exhausted. The /usage TUI command itself stops working in this state. This is not a format change — resolution requires claude auth login. The failure is intermittent and clears after re-authentication. The Swift side silently retains the last known good snapshot.

What to look for in upstream release notes

• New or renamed fields in usage/billing/token responses.
• Auth changes (new scopes, cookie rotation, API key requirements).
• Rate-limit header changes or new quota enforcement mechanisms.

3 OpenCode Storage Changes

OpenCode uses a multi-file JSON tree (storage/session/, storage/message/, storage/part/) — not JSONL. The monitoring fingerprints this tree structure.

Current layout

~/.local/share/opencode/storage/
  session/<project>/ses_*.json
  message/<sessionId>/msg_*.json
  part/<messageId>/*.json

What to watch for

• New storage backends: OpenCode is a Go application. Watch upstream releases for introduction of SQLite, BoltDB/bbolt, Badger, or other embedded databases alongside or replacing the JSON file tree.
• Schema changes in any record type: session, message, or part records can evolve independently. The fingerprinter tracks keys per record kind.
• New record types or directories: a new sibling to session/message/part would indicate a storage expansion.
• Migration flags: look for version, migration, schema_version fields in session records or new migration files in the OpenCode repo.

Detection in agent_watch.py

• opencode_storage_latest_session kind scans the full tree (session + messages + parts).
• _opencode_storage_session_tree_schema_fingerprint() walks messages and parts for a session and reports keys per record kind.
• If a .db, .sqlite, or .bolt file appears under the storage root, the current scanner will not detect it. Risk keywords in agent-watch-config.json will flag release notes mentioning these backends, but a file-extension scan of the storage root is not yet implemented.
• TODO: add a file-extension probe to agent_watch.py that checks for *.db, *.sqlite, *.bolt files under the OpenCode storage root during weekly scans.

4 Discovery Path Contracts

Each agent has a discovery_path_contract in agent-watch-config.json defining the expected file layout Agent Sessions uses to discover sessions. If an upstream agent moves or renames its storage, discovery breaks even if the parser still works.

Weekly monitoring checks these contracts. When a contract fails:

• severity escalates to high.
• The session viewer will silently stop finding new sessions for that agent.
• Investigate whether the agent changed its storage location or naming convention.

Key contracts (simplified from regexes in agent-watch-config.json):

5 What to Collect as Evidence

From the weekly report (all agents):

• The path in results.<agent>.weekly.local_schema.file (newest session).
• The schema diff summary: unknown_types, unknown_keys (additive drift), missing_types, missing_keys (may mean "not observed in this sample").
• Probe results and ok status for usage probes.
• Discovery path contract pass/fail status.

Optional (recommended when a bump is needed):

• Copy the newest session file(s) into scripts/agent_captures/<timestamp>/<agent>/.
• Keep captures private (do not commit raw sessions; they can contain paths and prompts).

6 Verification Update Checklist (after approval)

1. Refresh fixtures for the affected agent under Resources/Fixtures/stage0/agents/<agent>/.
2. Ensure fixtures include the "important" event families when present:
   • Session metadata / session_meta payload keys.
   • Tool call / tool result events.
   • Usage/limits events (token_count, rate_limits, billing) when emitted.
   • Optional event wrappers (compaction, context, delta events) when present.
   • For OpenCode: representative session, message, and part JSON files.
3. Bump the verified version record:
   • docs/agent-support/agent-support-matrix.yml (agents.<key>.max_verified_version)
   • Append a new entry in docs/agent-support/agent-support-ledger.yml
   • Add a line to docs/agent-json-tracking.md under "Upstream Version Check Log"
4. Run tests locally:
   Copy

   xcodebuild -project AgentSessions.xcodeproj -scheme AgentSessions \
     -destination 'platform=macOS' test
   

5. Run discovery-contract tests:
   Copy

   ./scripts/xcode_test_stable.sh -only-testing:AgentSessionsTests/SessionParserTests
   

7 Redaction Guardrails (fixtures)

When turning a real session into a committed fixture:

• Replace long instruction bodies with a short placeholder string (keep structure).
• Remove or truncate large base64/data-url blobs if present.
• Prefer keeping only minimal, deterministic message text (e.g., "List the files").
• Keep the schema shape intact: do not delete keys just because values were redacted.
• For OpenCode multi-file fixtures: redact each file independently but preserve cross-file references (session ID in message paths, message ID in part paths).