clog

A Claude Code hook that logs session events and conversation transcripts into a per-project DuckDB database, with semantic and text search.

Install

Nix flake

# bare binary
nix profile install .#clog

# wrapper with Ollama defaults (nomic-embed-text, localhost:11434)
nix profile install .#clog-ollama

From source

go build -o clog .

Usage

clog -i                          # ingest a hook event from stdin
clog -e [-n NUM]                 # embed unembedded messages
clog -s [-n NUM] "query"         # semantic search (requires embeddings)
clog -t [-n NUM] "pattern"       # case-insensitive text search
clog -c [-n NUM] "pattern"       # search tool call events ("*" for all)
clog -c "pattern" -v             # include tool responses in output

clog --ingest                    # long forms
clog --embed
clog --search "query"
clog --text-search "pattern"
clog --commands "bash"

Embedding providers

The first matching provider is used:

Variable	Provider	Model
OLLAMA_EMBED_MODEL	Ollama (local)	value of the variable (e.g. nomic-embed-text)
VOYAGE_API_KEY	Voyage AI	voyage-3-lite
OPENAI_API_KEY	OpenAI	text-embedding-3-small

When using Ollama, OLLAMA_HOST must also be set (usually http://localhost:11434). The clog-ollama wrapper sets both defaults.

Hook setup

Register in your Claude Code hooks config (~/.claude/settings.json):

{
  "hooks": {
    "SessionStart": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "clog -i"
          }
        ]
      }
    ],
    "SessionEnd": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "clog -i"
          }
        ]
      }
    ],
    "Stop": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "clog -i"
          }
        ]
      }
    ],
    "PostToolUse": [
      {
        "hooks": [
          {
            "type": "command",
            "command": "clog -i"
          }
        ]
      }
    ]
  }
}

Replace clog with clog-ollama if using the Ollama wrapper.

Teaching Claude Code to use clog

Add the following to your global ~/.claude/CLAUDE.md so Claude Code knows how to retrieve past conversations:

## Retrieving previous conversations (clog)

`clog-ollama` is installed as a Claude Code hook and logs all session transcripts to a DuckDB database. Use it to recall past conversations when context from previous sessions would be helpful.

- **Text search** (no embeddings needed):
  ```bash
  clog-ollama -t "search pattern" -n 10
  ```
  Case-insensitive substring match across all harvested messages. Returns messages with timestamps, roles (`[user]`/`[assistant]`), and session IDs.

- **Semantic search** (requires embeddings via `clog-ollama -e`):
  ```bash
  clog-ollama -s "natural language query" -n 5
  ```
  Embeds the query and finds similar messages via cosine similarity.

- **Tool call search** (requires PostToolUse hook):
  ```bash
  clog-ollama -c "bash" -n 10        # search by tool name
  clog-ollama -c "*" -n 10           # list all tool calls
  clog-ollama -c "bash" -v           # include tool responses
  ```
  Search past tool calls (Bash commands, file reads, edits, etc.) from the events table.

- Use `-n` to control how many results are returned (default varies by mode).

When to use:
- The user references something from a past session ("remember when we...", "like we did before")
- You need to find how a problem was previously solved
- The user asks to search their conversation history

Replace clog-ollama with clog if not using the Ollama wrapper.

Storage

Per-project DuckDB database at ~/.claude/logs/<project-slug>/events.duckdb, where the project slug is the working directory with / replaced by __.