Codex History Ingest — Conversation Mining

You are extracting knowledge from the user's past Codex sessions and distilling it into the Obsidian wiki. Session logs are rich but noisy: focus on durable knowledge, not operational telemetry.

This skill can be invoked directly or via the wiki-history-ingest router (/wiki-history-ingest codex).

Before You Start

Read .env to get OBSIDIAN_VAULT_PATH and CODEX_HISTORY_PATH (default to ~/.codex if unset)
Read .manifest.json at the vault root to check what has already been ingested
Read index.md at the vault root to understand what the wiki already contains

Ingest Modes

Append Mode (default)

Check .manifest.json for each source file. Only process:

Files not in the manifest (new session rollouts, new index files)
Files whose modification time is newer than ingested_at in the manifest

Use this mode for regular syncs.

Full Mode

Process everything regardless of manifest. Use after wiki-rebuild or if the user explicitly asks for a full re-ingest.

Codex Data Layout

Codex stores local artifacts under ~/.codex/.

~/.codex/
├── sessions/                          # Session rollout logs by date
│   └── YYYY/MM/DD/
│       └── rollout-<timestamp>-<id>.jsonl
├── archived_sessions/                 # Archived rollout logs
├── session_index.jsonl                # Lightweight index of thread id/name/updated_at
├── history.jsonl                      # Local transcript history (if persistence enabled)
├── config.toml                        # User config (contains history settings)
└── state_*.sqlite / logs_*.sqlite     # Runtime DBs (usually skip)

Key data sources ranked by value

session_index.jsonl — best inventory source for IDs, titles, and freshness
sessions/**/rollout-*.jsonl — rich structured transcript events
history.jsonl — useful fallback/timeline aid if enabled

Avoid ingesting SQLite internals unless the user explicitly asks.

Step 1: Survey and Compute Delta

Scan CODEX_HISTORY_PATH and compare against .manifest.json:

~/.codex/session_index.jsonl
~/.codex/sessions/**/rollout-*.jsonl
~/.codex/archived_sessions/** (optional; only if user asks for archived history)
~/.codex/history.jsonl (optional fallback)

Classify each file:

New — not in manifest
Modified — in manifest but file is newer than ingested_at
Unchanged — already ingested and unchanged

Report a concise delta summary before deep parsing.

Step 2: Parse Session Index First

session_index.jsonl typically has entries like:

{"id":"...","thread_name":"...","updated_at":"..."}

Use it to:

Build a canonical session inventory
Prioritize recent/high-signal sessions
Map rollout IDs to human-readable thread names

Step 3: Parse Rollout JSONL Safely

Each rollout-*.jsonl line is an event envelope with:

{
  "timestamp": "...",
  "type": "session_meta|turn_context|event_msg|response_item",
  "payload": { ... }
}

Extraction rules

Prioritize user intent and assistant-visible outputs
Favor response_item records with user/assistant message content
Use event_msg selectively for meaningful milestones; ignore pure telemetry
Treat session_meta as metadata (cwd, model, ids), not user knowledge

Skip/noise filters

Token accounting events
Tool plumbing with no semantic content
Raw command output unless it contains reusable decisions/patterns
Repeated plan snapshots unless they add novel decisions

Critical privacy filter

Rollout logs can include injected instructions, tool payloads, and sensitive text. Do not ingest verbatim system/developer prompts or secrets.

Remove API keys, tokens, passwords, credentials
Redact private identifiers unless relevant and approved
Summarize instead of quoting raw transcripts

Step 4: Cluster by Topic

Do not create one wiki page per session.

Group by stable topics across many sessions
Split mixed sessions into separate themes
Merge recurring concepts across dates/projects
Use cwd from metadata to infer project scope

Step 5: Distill into Wiki Pages

Route extracted knowledge using existing wiki conventions:

Project-specific architecture/process -> projects/<name>/...
General concepts -> concepts/
Recurring techniques/debug playbooks -> skills/
Tools/services -> entities/
Cross-session patterns -> synthesis/

For each impacted project, create/update projects/<name>/<name>.md (project name as filename, never _project.md).

Writing rules

Distill knowledge, not chronology
Avoid "on date X we discussed..." unless date context is essential
Add summary: frontmatter on each new/updated page (1-2 sentences, <= 200 chars)
Add provenance markers:
- ^[extracted] when directly grounded in explicit session content
- ^[inferred] when synthesizing patterns across events/sessions
- ^[ambiguous] when sessions conflict
Add/update provenance: frontmatter mix for each changed page

Step 6: Update Manifest, Log, and Index

Update `.manifest.json`

For each processed source file:

ingested_at, size_bytes, modified_at
source_type: codex_rollout | codex_index | codex_history
project: inferred project name (when applicable)
pages_created, pages_updated

Add/update a top-level project/session summary block:

{
  "project-name": {
    "source_path": "~/.codex/sessions/...",
    "last_ingested": "TIMESTAMP",
    "sessions_ingested": 12,
    "sessions_total": 40,
    "index_updated_at": "TIMESTAMP"
  }
}

Update special files

Update index.md and log.md:

- [TIMESTAMP] CODEX_HISTORY_INGEST sessions=N pages_updated=X pages_created=Y mode=append|full

Privacy and Compliance

Distill and synthesize; avoid raw transcript dumps
Default to redaction for anything that looks sensitive
Ask the user before storing personal/sensitive details
Keep references to other people minimal and purpose-bound

Reference

See references/codex-data-format.md for field-level parsing notes and extraction guidance.

codex-history-ingest