---
sidebar_position: 7
title: "Sessions"
description: "Session persistence, resume, search, management, and per-platform session tracking"
---

# Sessions

Mente automatically saves every conversation as a session. Sessions enable conversation resume, cross-session search, and full conversation history management.

## How Sessions Work

Every conversation — whether from the CLI, Telegram, Discord, Slack, WhatsApp, Signal, Matrix, or any other messaging platform — is stored as a session with full message history. Sessions are tracked in two complementary systems:

1. **SQLite database** (`~/.hermes/state.db`) — structured session metadata with FTS5 full-text search
2. **JSONL transcripts** (`~/.hermes/sessions/`) — raw conversation transcripts including tool calls (gateway)

The SQLite database stores:
- Session ID, source platform, user ID
- **Session title** (unique, human-readable name)
- Model name and configuration
- System prompt snapshot
- Full message history (role, content, tool calls, tool results)
- Token counts (input/output)
- Timestamps (started_at, ended_at)
- Parent session ID (for compression-triggered session splitting)

### Session Sources

Each session is tagged with its source platform:

| Source | Description |
|--------|-------------|
| `cli` | Interactive CLI (`hermes` or `hermes chat`) |
| `telegram` | Telegram messenger |
| `discord` | Discord server/DM |
| `slack` | Slack workspace |
| `whatsapp` | WhatsApp messenger |
| `signal` | Signal messenger |
| `matrix` | Matrix rooms and DMs |
| `mattermost` | Mattermost channels |
| `email` | Email (IMAP/SMTP) |
| `sms` | SMS via Twilio |
| `dingtalk` | DingTalk messenger |
| `feishu` | Feishu/Lark messenger |
| `wecom` | WeCom (WeChat Work) |
| `weixin` | Weixin (personal WeChat) |
| `bluebubbles` | Apple iMessage via BlueBubbles macOS server |
| `qqbot` | QQ Bot (Tencent QQ) via Official API v2 |
| `homeassistant` | Home Assistant conversation |
| `webhook` | Incoming webhooks |
| `api-server` | API server requests |
| `acp` | ACP editor integration |
| `cron` | Scheduled cron jobs |
| `batch` | Batch processing runs |

## CLI Session Resume

Resume previous conversations from the CLI using `--continue` or `--resume`:

### Continue Last Session

```bash
# Resume the most recent CLI session
hermes --continue
hermes -c

# Or with the chat subcommand
hermes chat --continue
hermes chat -c
```

This looks up the most recent `cli` session from the SQLite database and loads its full conversation history.

### Resume by Name

If you've given a session a title (see [Session Naming](#session-naming) below), you can resume it by name:

```bash
# Resume a named session
hermes -c "my project"

# If there are lineage variants (my project, my project #2, my project #3),
# this automatically resumes the most recent one
hermes -c "my project"   # → resumes "my project #3"
```

### Resume Specific Session

```bash
# Resume a specific session by ID
hermes --resume 20250305_091523_a1b2c3d4
hermes -r 20250305_091523_a1b2c3d4

# Resume by title
hermes --resume "refactoring auth"

# Or with the chat subcommand
hermes chat --resume 20250305_091523_a1b2c3d4
```

Session IDs are shown when you exit a CLI session, and can be found with `hermes sessions list`.

### Conversation Recap on Resume

When you resume a session, Hermes displays a compact recap of the previous conversation in a styled panel before the input prompt:

<img className="docs-terminal-figure" src="/img/docs/session-recap.svg" alt="Stylized preview of the Previous Conversation recap panel shown when resuming a Hermes session." />
<p className="docs-figure-caption">Resume mode shows a compact recap panel with recent user and assistant turns before returning you to the live prompt.</p>

The recap:
- Shows **user messages** (gold `●`) and **assistant responses** (green `◆`)
- **Truncates** long messages (300 chars for user, 200 chars / 3 lines for assistant)
- **Collapses tool calls** to a count with tool names (e.g., `[3 tool calls: terminal, web_search]`)
- **Hides** system messages, tool results, and internal reasoning
- **Caps** at the last 10 exchanges with a "... N earlier messages ..." indicator
- Uses **dim styling** to distinguish from the active conversation

To disable the recap and keep the minimal one-liner behavior, set in `~/.hermes/config.yaml`:

```yaml
display:
  resume_display: minimal   # default: full
```

:::tip
Session IDs follow the format `YYYYMMDD_HHMMSS_<8-char-hex>`, e.g. `20250305_091523_a1b2c3d4`. You can resume by ID or by title — both work with `-c` and `-r`.
:::

## Session Naming

Give sessions human-readable titles so you can find and resume them easily.

### Auto-Generated Titles

Hermes automatically generates a short descriptive title (3–7 words) for each session after the first exchange. This runs in a background thread using a fast auxiliary model, so it adds no latency. You'll see auto-generated titles when browsing sessions with `hermes sessions list` or `hermes sessions browse`.

Auto-titling only fires once per session and is skipped if you've already set a title manually.

### Setting a Title Manually

Use the `/title` slash command inside any chat session (CLI or gateway):

```
/title my research project
```

The title is applied immediately. If the session hasn't been created in the database yet (e.g., you run `/title` before sending your first message), it's queued and applied once the session starts.

You can also rename existing sessions from the command line:

```bash
hermes sessions rename 20250305_091523_a1b2c3d4 "refactoring auth module"
```

### Title Rules

- **Unique** — no two sessions can share the same title
- **Max 100 characters** — keeps listing output clean
- **Sanitized** — control characters, zero-width chars, and RTL overrides are stripped automatically
- **Normal Unicode is fine** — emoji, CJK, accented characters all work

### Auto-Lineage on Compression

When a session's context is compressed (manually via `/compress` or automatically), Hermes creates a new continuation session. If the original had a title, the new session automatically gets a numbered title:

```
"my project" → "my project #2" → "my project #3"
```

When you resume by name (`hermes -c "my project"`), it automatically picks the most recent session in the lineage.

### /title in Messaging Platforms

The `/title` command works in all gateway platforms (Telegram, Discord, Slack, WhatsApp):

- `/title My Research` — set the session title
- `/title` — show the current title

## Session Management Commands

Hermes provides a full set of session management commands via `hermes sessions`:

### List Sessions

```bash
# List recent sessions (default: last 20)
hermes sessions list

# Filter by platform
hermes sessions list --source telegram

# Show more sessions
hermes sessions list --limit 50
```

When sessions have titles, the output shows titles, previews, and relative timestamps:

```
Title                  Preview                                  Last Active   ID
────────────────────────────────────────────────────────────────────────────────────────────────
refactoring auth       Help me refactor the auth module please   2h ago        20250305_091523_a
my project #3          Can you check the test failures?          yesterday     20250304_143022_e
—                      What's the weather in Las Vegas?          3d ago        20250303_101500_f
```

When no sessions have titles, a simpler format is used:

```
Preview                                            Last Active   Src    ID
──────────────────────────────────────────────────────────────────────────────────────
Help me refactor the auth module please             2h ago        cli    20250305_091523_a
What's the weather in Las Vegas?                    3d ago        tele   20250303_101500_f
```

### Export Sessions

```bash
# Export all sessions to a JSONL file
hermes sessions export backup.jsonl

# Export sessions from a specific platform
hermes sessions export telegram-history.jsonl --source telegram

# Export a single session
hermes sessions export session.jsonl --session-id 20250305_091523_a1b2c3d4
```

Exported files contain one JSON object per line with full session metadata and all messages.

### Delete a Session

```bash
# Delete a specific session (with confirmation)
hermes sessions delete 20250305_091523_a1b2c3d4

# Delete without confirmation
hermes sessions delete 20250305_091523_a1b2c3d4 --yes
```

### Rename a Session

```bash
# Set or change a session's title
hermes sessions rename 20250305_091523_a1b2c3d4 "debugging auth flow"

# Multi-word titles don't need quotes in the CLI
hermes sessions rename 20250305_091523_a1b2c3d4 debugging auth flow
```

If the title is already in use by another session, an error is shown.

### Prune Old Sessions

```bash
# Delete ended sessions older than 90 days (default)
hermes sessions prune

# Custom age threshold
hermes sessions prune --older-than 30

# Only prune sessions from a specific platform
hermes sessions prune --source telegram --older-than 60

# Skip confirmation
hermes sessions prune --older-than 30 --yes
```

:::info
Pruning only deletes **ended** sessions (sessions that have been explicitly ended or auto-reset). Active sessions are never pruned.
:::

### Session Statistics

```bash
hermes sessions stats
```

Output:

```
Total sessions: 142
Total messages: 3847
  cli: 89 sessions
  telegram: 38 sessions
  discord: 15 sessions
Database size: 12.4 MB
```

For deeper analytics — token usage, cost estimates, tool breakdown, and activity patterns — use [`hermes insights`](/reference/cli-commands#hermes-insights).

## Session Search Tool

The agent has a built-in `session_search` tool that performs full-text search across all past conversations using SQLite's FTS5 engine.

### How It Works

1. FTS5 searches matching messages ranked by relevance
2. Groups results by session, takes the top N unique sessions (default 3)
3. Loads each session's conversation, truncates to ~100K chars centered on matches
4. Sends to a fast summarization model for focused summaries
5. Returns per-session summaries with metadata and surrounding context

### FTS5 Query Syntax

The search supports standard FTS5 query syntax:

- Simple keywords: `docker deployment`
- Phrases: `"exact phrase"`
- Boolean: `docker OR kubernetes`, `python NOT java`
- Prefix: `deploy*`

### When It's Used

The agent is prompted to use session search automatically:

> *"When the user references something from a past conversation or you suspect relevant prior context exists, use session_search to recall it before asking them to repeat themselves."*

## Per-Platform Session Tracking

### Gateway Sessions

On messaging platforms, sessions are keyed by a deterministic session key built from the message source:

| Chat Type | Default Key Format | Behavior |
|-----------|--------------------|----------|
| Telegram DM | `agent:main:telegram:dm:<chat_id>` | One session per DM chat |
| Discord DM | `agent:main:discord:dm:<chat_id>` | One session per DM chat |
| WhatsApp DM | `agent:main:whatsapp:dm:<canonical_identifier>` | One session per DM user (LID/phone aliases collapse to one identity when mapping exists) |
| Group chat | `agent:main:<platform>:group:<chat_id>:<user_id>` | Per-user inside the group when the platform exposes a user ID |
| Group thread/topic | `agent:main:<platform>:group:<chat_id>:<thread_id>` | Shared session for all thread participants (default). Per-user with `thread_sessions_per_user: true`. |
| Channel | `agent:main:<platform>:channel:<chat_id>:<user_id>` | Per-user inside the channel when the platform exposes a user ID |

When Hermes cannot get a participant identifier for a shared chat, it falls back to one shared session for that room.

### Shared vs Isolated Group Sessions

By default, Hermes uses `group_sessions_per_user: true` in `config.yaml`. That means:

- Alice and Bob can both talk to Hermes in the same Discord channel without sharing transcript history
- one user's long tool-heavy task does not pollute another user's context window
- interrupt handling also stays per-user because the running-agent key matches the isolated session key

If you want one shared "room brain" instead, set:

```yaml
group_sessions_per_user: false
```

That reverts groups/channels to a single shared session per room, which preserves shared conversational context but also shares token costs, interrupt state, and context growth.

### Session Reset Policies

Gateway sessions are automatically reset based on configurable policies:

- **idle** — reset after N minutes of inactivity
- **daily** — reset at a specific hour each day
- **both** — reset on whichever comes first (idle or daily)
- **none** — never auto-reset

Before a session is auto-reset, the agent is given a turn to save any important memories or skills from the conversation.

Sessions with **active background processes** are never auto-reset, regardless of policy.

## Storage Locations

| What | Path | Description |
|------|------|-------------|
| SQLite database | `~/.hermes/state.db` | All session metadata + messages with FTS5 |
| Gateway transcripts | `~/.hermes/sessions/` | JSONL transcripts per session + sessions.json index |
| Gateway index | `~/.hermes/sessions/sessions.json` | Maps session keys to active session IDs |

The SQLite database uses WAL mode for concurrent readers and a single writer, which suits the gateway's multi-platform architecture well.

### Database Schema

Key tables in `state.db`:

- **sessions** — session metadata (id, source, user_id, model, title, timestamps, token counts). Titles have a unique index (NULL titles allowed, only non-NULL must be unique).
- **messages** — full message history (role, content, tool_calls, tool_name, token_count)
- **messages_fts** — FTS5 virtual table for full-text search across message content

## Session Expiry and Cleanup

### Automatic Cleanup

- Gateway sessions auto-reset based on the configured reset policy
- Before reset, the agent saves memories and skills from the expiring session
- Opt-in auto-pruning: when `sessions.auto_prune` is `true`, ended sessions older than `sessions.retention_days` (default 90) are pruned at CLI/gateway startup
- After a prune that actually removed rows, `state.db` is `VACUUM`ed to reclaim disk space (SQLite does not shrink the file on plain DELETE)
- Pruning runs at most once per `sessions.min_interval_hours` (default 24); the last-run timestamp is tracked inside `state.db` itself so it's shared across every Hermes process in the same `HERMES_HOME`

Default is **off** — session history is valuable for `session_search` recall, and silently deleting it could surprise users. Enable in `~/.hermes/config.yaml`:

```yaml
sessions:
  auto_prune: true          # opt in — default is false
  retention_days: 90        # keep ended sessions this many days
  vacuum_after_prune: true  # reclaim disk space after a pruning sweep
  min_interval_hours: 24    # don't re-run the sweep more often than this
```

Active sessions are never auto-pruned, regardless of age.

### Manual Cleanup

```bash
# Prune sessions older than 90 days
hermes sessions prune

# Delete a specific session
hermes sessions delete <session_id>

# Export before pruning (backup)
hermes sessions export backup.jsonl
hermes sessions prune --older-than 30 --yes
```

:::tip
The database grows slowly (typical: 10-15 MB for hundreds of sessions) and session history powers `session_search` recall across past conversations, so auto-prune ships disabled. Enable it if you're running a heavy gateway/cron workload where `state.db` is meaningfully affecting performance (observed failure mode: 384 MB state.db with ~1000 sessions slowing down FTS5 inserts and `/resume` listing). Use `hermes sessions prune` for one-off cleanup without turning on the automatic sweep.
:::
