Cursor

← all harnesses · parser: crates/core/src/session/cursor.rs

Cursor’s native agent exports a transcript with the conversation in it and none of the accounting. The editor’s own database adds the title, folder, model and context; tokens and cost are recorded nowhere, and the parser’s module doc states the rule that keeps them blank: unavailable rather than estimated from incomplete evidence.

Where it lives

$CURSOR_HOME/projects/<project>/agent-transcripts/<id>/<id>.jsonl, defaulting to ~/.cursor (config::CURSOR_HOME). Only each project’s agent-transcripts directory is walked — the rest of a project is mcps/ and canvases/ with whole node_modules trees — and the file stem must be a full UUID.

A subagent is not a session. Its transcript sits at <id>/subagents/<sub>.jsonl and is folded into its parent (see below). Cursor sometimes keeps a top-level copy of a subagent too, as <sub>/<sub>.jsonl; any id seen under a subagents/ directory is never a row.

The same transcript can exist under two project slugs. Cursor retains a copy when a project is moved or reopened elsewhere. The UUID stays the stable identity, so list_sessions sorts by activity and keeps the first copy of each id — newest wins.

The format

JSONL of message records whose content is an array of blocks. cctop reads exactly one kind: blocks with type: "tool_use", for their name and input. Nothing else in the file is parsed.

There are no per-event timestamps, so tool details are pushed with an empty ts and the Tools panel cannot order or time them. The session’s own times come from the filesystem: created for the start (falling back to mtime, since not every platform records a creation time) and mtime for last activity.

The label is a project slug unless the database knows the folder. project_slug takes the directory name under the projects root, which turns / and _ alike into - and so is not a path. When the editor’s database records the chat’s workspace folder and that folder exists here, the row carries the real path instead (see below).

The editor’s database

Cursor’s global state.vscdb keeps, under the transcript’s own id, what the transcript leaves out. It lives in $CURSOR_USER_DIR/globalStorage/ (default ~/.config/Cursor/User) and, under WSL, in each /mnt/c/Users/*/AppData/Roaming/Cursor/User/ — Cursor runs on Windows and its agent writes transcripts on the Linux side. config::cursor_global_dbs finds them once per process.

• At list time, one query over composerHeaders gives each row its title, start time and workspace folder.
• At extraction, a point lookup of composerData:<id> in cursorDiskKV gives the model (Cursor’s Auto router, default, shows as auto and never reaches pricing), the reasoning effort, and each subagent’s type.
• For the context column, the same key’s promptTokenBreakdown: Cursor’s own count of the prompt it last sent against the window it allows.

On a Windows drive the database is opened immutable=1: a plain read-only open over 9P creates -shm/-wal files in Cursor’s directory and takes locks the Windows writer cannot see. Immutable writes nothing, but reads only what Cursor has checkpointed, so a live chat’s model or context can trail by a checkpoint. Every failure — no database, an older Cursor without composerHeaders, a read torn by a checkpoint — leaves the row as the transcript alone makes it.

Subagents

<id>/subagents/*.jsonl are the session’s subagents: their calls count toward the session’s tools and edits, each one is listed with its own tool count, and their writes keep the parent live. Their type comes from the database; their model and cost are not recorded, so they read ? and —.

What cannot be extracted

No tokens, no cost, and no per-call outcome — the database records none either: every message’s tokenCount is zero and every usageData empty. summarize sets cost_available = false and total_cost = None, so the money columns read as unavailable rather than as $0.00 — the two mean very different things, and a zero would be a claim. Provider::records_tool_outcomes is false, so ERR% is ─ rather than a reassuring 0%.

Tool counts are the transcript’s real signal, which is why the capability table’s Tools column is a ✓.

Liveness

Cursor runs one shared editor process, not one process per agent transcript, so there is nothing to attribute a PID to. loader::attach_processes infers liveness instead: a transcript whose mtime is within 90 seconds is running. That is why the README’s table says inferred rather than ✓, and why the CPU and memory columns stay blank — showing the editor’s own figures on a session row would attribute one agent’s cost to all of them.

What a row is doing comes from the transcript’s tail. Cursor ends every turn with {"type":"turn_ended","status":…}, so a finished turn reads as waiting for you; status: "error" is an API error unless its text says the user aborted or cancelled, which is how Cursor files a Stop. An AskQuestion call reads as a question waiting on you.

There is no resume command either: Session::resume_argv returns None, because the conversation lives inside the editor and no CLI invocation picks one back up. Callers show the transcript path instead of inventing a flag.

What cctop can still do

--install-hooks writes ~/.cursor/hooks.json (a flat shape, unlike Claude’s and Gemini’s nested one), so a live Cursor session can report the states its transcript cannot express. And access.rs lists the project’s own .cursorrules-style file with a note saying the rest — models, settings — lives in the editor UI where nothing can read it.