/compact to reduce size and /rewind to go back to earlier points.Session Commands
All session management commands start with/session.
/session save <name>
/session load <name>
/session attach <name>
/session detach
/session status
/session list
/session delete <name>
/session new (or /newsession)
/newsession: it also drops any session binding and rotates the shared hub thread, so no backlog from the old conversation leaks into the new one./session fork <new-name>
/rewind and undo stay per session) and keeps the attachments, the cost reference and the CCR archive keys. A session file written by a newer ChatCLI (higher schema version) is refused on load instead of being silently rewritten minus the fields this build does not know.Ideal for experimenting with different approaches without losing current progress, or branching a conversation in different directions./session export <md|jsonl> [path]
@trajectory uses). Falls back to the live history when the journal is off.chatcli-<session>-<timestamp>.<ext>, mode 0600./session transcript <search|show|export|stats>
search <query>ranks every journaled message with BM25 and prints the top hits with their position β#17 assistant β¦the deploy freeze ends on Fridayβ¦.show <from> [count]replays messages from a position (default 10), so a hit can be read in context.export <md|jsonl> [path]is the same as/session export.statsprints the message count, size, source (journal or live history) and journal id.
Automatic saving on exit
You donβt have to remember/session save: when the interactive REPL exits, the conversation is auto-saved under a reserved autosave-YYYYMMDD-HHMMSS name. Trivial sessions (fewer than 2 non-system messages) are skipped, and one-shot -p runs never autosave. Gated by CHATCLI_SESSION_AUTOSAVE (on by default, shown in /config session). Autosaved conversations are fully searchable and readable via @session.
MCP sessions autosave too: the MCP/ACP server mirrors each live conversation to a rolling mcp-<session> file after every turn (both the full-pipeline and plain paths), and manage_session clear saves one last time before discarding. An explicit CHATCLI_MCP_SESSION_AUTOSAVE always wins; unset, it follows the global CHATCLI_SESSION_AUTOSAVE gate β on by default. Retention for both surfaces is covered under Automatic Cleanup below.
Cross-surface continuity
A named session is ChatCLIβs durable continuity layer across surfaces: the interactive REPL, the MCP server (chatcli mcp-server), the ACP server (chatcli acp) and the Chat Gateway all read and write the same session file. Start on the terminal, continue in the IDE, finish on WhatsApp β same conversation.
While a named session is active (after /session save, /session load or /session attach), the binding works in both directions on every turn:
- Write-through β each completed turn is written to the session file immediately (atomic write: temp file + rename, so there are never torn files).
- Adoption β before each turn, writes made by other surfaces (MCP/ACP server, gateway daemon, another terminal) since the last sync are adopted: when the file is newer, it replaces the in-memory history wholesale (last-writer-wins).
autosave-, mcp- prefixes) are rolling mirrors owned by the autosave paths β they never become live bindings.Transcript journal
A saved session persists the conversation as it stands in memory β after a compaction the window holds a summary, and the original messages survive only as@recall keys in the CCR store (7-day TTL, size-capped). The transcript journal is the durable full record underneath that window:
~/.chatcli/transcripts/<id>.jsonl, one file per session, append-only, every line fsynced.- Every message is appended once, the first time it appears at the tail of the live history β at each chat turn end, at the start of every agent/coder turn (so the previous turnβs tool results are on disk before any rewrite can stub them) and when an agent run exits, however it exits. A hard kill mid-run loses at most the tool batch in flight.
- A history rewrite (auto-compact,
/compact, microcompact, skill aging, repeated-read dedup) is recorded as arewriteevent carrying the ordered hashes of the history it replaced; only genuinely new messages (the summary) are appended, nothing is duplicated. Those hashes are what/rewind compactand persisted/rewindcheckpoints resolve after a resume. - The journal is readable, not write-only:
/session exportand/session transcript search|show|statswork on it directly. - Every sync compares the whole history against the last journaled hashes, so a message changed in place (microcompact, read dedup, tool-result pairing repair, Level 1 trim) is recorded as a rewrite too β
/rewind compactand persisted checkpoints keep resolving in agent sessions. Hashes cover native tool calls (id, name, arguments) and images, and repeated tail messages (βokβ) are recorded as the separate messages they are. - The reader tolerates damage: a partial last line from a crash and any foreign line are skipped and counted, never fatal; the next append starts on a fresh line. A sealed line this process cannot open is still an error, because that is a key problem rather than corruption.
- Saved sessions carry their
transcript_id, so/session loadand/session attachkeep writing to the same journal across resumes. - Saved sessions also carry their
/context attachrecords (attachments: context id, priority, selected chunks, retrieval mode). Attach state used to be process-local β a restart or a load on another surface lost every attached context; loading a session now re-attaches the same contexts, skipping any that no longer exist. - With
CHATCLI_ENCRYPTION_KEYset, each line is sealed (same AES-256-GCM format as sessions) and the journal cannot be read without the key. - Journals follow the machine-session TTL (
CHATCLI_SESSION_TTL, 90 days by default).CHATCLI_SESSION_TRANSCRIPT=falsedisables the journal;/config sessionshows the active id.
Where Sessions Are Stored
Sessions are saved as JSON files in a per-user store β the same store every surface (REPL, MCP/ACP server, gateway daemon) reads and writes:/session save debug-api creates the file:
SessionManager is the internal component responsible for all session file I/O. It handles read/write errors (permissions, full disk, malformed JSON) and displays clear messages if something fails./compact.
/session list to see them all.Data Format (v2)
Session files use the v2 format, defined by theSessionData struct in the models package. The JSON structure is:
Message Fields
Format Evolution
- v1 (older versions): Maintained separate histories per mode β
chat_history,agent_history, andcoder_historyeach with their own messages. - v2 (current version): Uses a unified history. The
chat_historyfield contains all messages from all modes. Theagent_historyandcoder_historyfields exist for compatibility but are empty in new sessions.
Unified History and Sessions
ChatCLI uses a single message array for all interaction modes. This means:- When saving a session, the entire unified history is serialized β including messages from chat, agent, and coder mode.
- System messages, tool call results, and compacted summaries are all preserved in the file.
- When loading a session, the current history is completely replaced by the loaded sessionβs history.
Interaction with Other Systems
Sessions interact with several other ChatCLI subsystems. Here is how each one behaves:Compaction (/compact)
The /compact command reduces history size by creating summaries of older messages. If you save a session after compacting, the resulting file will be significantly smaller, as it contains summaries instead of the original messages.
Rewind (/rewind)
The checkpoints used by /rewind are saved with the session as ordered message-hash lists (checkpoints) and rebuilt from the transcript journal on /session load; a checkpoint whose messages the journal no longer holds is dropped. /rewind compact (undo the latest compaction) is also journal-backed after a resume. With the journal disabled, checkpoints are process-local as before.
Bootstrap (SOUL.md, etc.)
Bootstrap files are not part of the session. They are loaded automatically on every ChatCLI startup, regardless of which session is active. This ensures that the AIβs base behavior is always consistent.Memory (/memory)
Memory is global β it is not tied to any specific session. Data saved with /memory save is available across all sessions and survives ChatCLI restarts.
Context (/context attach)
Contexts attached via /context attach are not saved in the session file. When loading a session, you need to re-attach the necessary contexts manually.
Auto-Save and Persistence
Besides the explicit/session save, persistence has two automatic layers:
- Bound named session β after
/session save,/session loador/session attach, every turn is written through to the session file (see Cross-surface continuity; gated byCHATCLI_SESSION_WRITETHROUGH, on by default). - Exit autosave β an unbound conversation is still saved as
autosave-YYYYMMDD-HHMMSSwhen the interactive REPL exits (see Automatic saving on exit; gated byCHATCLI_SESSION_AUTOSAVE, on by default).
The .chatcli_history File (Donβt Confuse)
ChatCLI maintains a separate file called .chatcli_history that stores the command input history (similar to ~/.bash_history). This file:
- Contains only the text you typed at the prompt, not the AIβs responses
- Is controlled by the
HISTORY_FILEandHISTORY_MAX_SIZEenvironment variables - Has no relation to session files (
~/.chatcli/sessions/*.json)
Recommended Workflow
To get the most out of the session system, follow these practices:Name sessions after the task
fix-auth-bug, refactor-api, docs-v2, debug-memory-leak.Compact before saving
/compact before /session save to reduce file size and keep only the essential information.Start clean before switching sessions
/session new before loading another session. This ensures the previous context doesnβt interfere.Switch between tasks freely
Session Encryption
Session files can be encrypted at rest using AES-256-GCM to protect sensitive conversation data:Automatic Cleanup
ChatCLI applies a bounded lifecycle to machine-created sessions on startup (REPL and MCP/ACP server alike). The core rule: sessions you named are never deleted automatically β only theautosave- and mcp- prefixed files ChatCLI creates on its own are subject to retention.
Curating storage on demand
The startup pass is silent./storage makes the same policies visible: one line per local store with its file count, size, the rule that governs it and what would be removed right now, plus the stores that are never pruned (distilled memory, skills, plugins, contexts, agents, commands, scheduler, tokenizers, logs). /storage prune lists what the rules would remove, grouped by reason β past TTL, orphaned, test burst, stray temp file β and only /storage prune --apply removes it; /storage prune costs --apply scopes it to one store. Two rules exist only on demand because a boot pass must not guess: cost snapshots started in a burst (four or more sessions in one minute with at most two requests each), and the CCR and hub sweeps, which open their own stores. Coder checkpoints joined the startup pass: a shadow repository whose workspace is a temp directory or no longer exists is removed at boot, the rest follow the session TTL. chatcli storage prune --apply is the same thing without a REPL, for cron β or schedule it from inside with /schedule, which runs slash commands.
Name Validation
Session names are validated with a strict regex to prevent path traversal and problematic characters:- Allowed characters: letters (a-z, A-Z), numbers (0-9), hyphens (
-), underscores (_), and dots (.) - Length: 1 to 128 characters
- Forbidden: spaces, slashes, special characters,
..sequences
Frequently Asked Questions
Is there a size limit for sessions?
Is there a size limit for sessions?
HISTORY_MAX_SIZE variable (default: 100MB), but in practice sessions rarely exceed a few megabytes. If the history is too large, use /compact before saving to significantly reduce the size.Can I manually edit the session JSON file?
Can I manually edit the session JSON file?
version field).What happens if I load a session from an older version?
What happens if I load a session from an older version?
Can I have sessions with the same name in different directories?
Can I have sessions with the same name in different directories?
~/.chatcli/sessions, so the same names are visible from any directory and any surface (REPL, MCP/ACP server, gateway). That shared namespace is exactly what makes cross-surface continuity work; use task-specific names (projeto-a-debug, projeto-b-debug) to keep projects apart.