Tool parser

Gemini

Gemini CLI session discovery, JSON/JSONL chat parsing, token and thought tracking.

Gemini

Gemini CLI writes project-scoped chat session files under ~/.gemini/tmp/<project_hash>/chats/. Recent builds use JSONL session files; older or exported sessions can appear as single JSON documents with the same top-level session metadata and messages array.

Status: implemented (src/tools/gemini/).

Where the data lives

Path	Notes
`~/.gemini/tmp/<project_hash>/chats/session-*.jsonl`	Current JSONL session format
`~/.gemini/tmp/<project_hash>/chats/session-*.json`	Older/exported JSON session format

Env var override: GEMINI_DIR replaces ~/.gemini. The adapter still expects sessions below that root’s tmp/<project>/chats/ tree.

Discovery rules (src/tools/gemini/discovery.rs):

Read direct child project directories under ~/.gemini/tmp/.
Scan each <project_hash>/chats/ directory.
Match files whose name starts with session- and whose extension is .json or .jsonl.
Use <project_hash> as the fallback project label.

flowchart TD A[gemini tmp root] --> B[project hash dirs] B --> C[chats session files] C --> D{JSON or JSONL} D --> E[session metadata] E --> F[user messages update prompt preview] E --> G[gemini messages with tokens and model] G --> H[emit ParsedCall per message]

Record format

The JSON format is a session object:

{
  "sessionId": "90a6c51d-c8dd-480c-a6a4-30b0265bb001",
  "projectHash": "project-hash",
  "startTime": "2026-05-01T18:34:30.869Z",
  "messages": [
    { "id": "u1", "type": "user", "content": "run tests" },
    {
      "id": "g1",
      "type": "gemini",
      "timestamp": "2026-05-01T18:34:40.000Z",
      "model": "gemini-2.5-pro",
      "tokens": { "input": 120, "output": 30, "cached": 20, "thoughts": 5 },
      "toolCalls": [
        { "name": "run_command", "args": { "command": "cargo test" } }
      ]
    }
  ]
}

The JSONL format stores the metadata as one line, followed by message lines. Lines with $set are ignored.

Token & cost mapping

One ParsedCall is emitted for each Gemini/model message with both tokens and model.

`ParsedCall` field	Source
`input_tokens`	`tokens.input` - `tokens.cached`
`output_tokens`	`tokens.output` + `tokens.tool` + any unallocated `tokens.total` remainder + `tokens.thoughts`
`cached_input_tokens`	`tokens.cached`
`cache_read_input_tokens`	`tokens.cached`
`cache_creation_input_tokens`	always `0`
`reasoning_tokens`	`tokens.thoughts`
`model`	message `model`
`timestamp`	message `timestamp`, falling back to session `startTime`

Gemini reports cached tokens inside the input total, so the parser subtracts cached input before pricing while still preserving the cache-read bucket.

Tools / bash extraction

Gemini toolCalls names map to canonical tool labels:

Gemini tool	Normalized
`read_file`, `ReadFile`	`Read`
`write_file`, `create_file`, `WriteFile`	`Write`
`edit_file`, `EditFile`, `replace`	`Edit`
`delete_file`	`Delete`
`list_dir`, `ListDir`	`LS`
`grep_search`, `search_files`, `SearchText`	`Grep`
`find_files`	`Glob`
`run_command`, `Shell`	`Bash`
`web_search`	`WebSearch`
anything else	passed through unchanged

For Bash, the parser reads args.command or args.cmd, including JSON-encoded string arguments, and splits shell pipelines/separators with tools::jsonl::split_bash_commands.

Deduplication

dedup_key = format!("gemini:{session_id}:{message_id}") when a message id exists.

If a message id is missing, the parser falls back to session id, timestamp, model, and token counts. Message-level keys let the archive import newly appended messages from an updated session file without duplicating earlier calls.

Known limitations

Gemini project names are project hashes unless future session files expose a real working directory.
Gemini limit snapshots are not imported because the local session format does not expose plan windows in the same shape as Codex.
Unknown future model names are displayed as their raw model string and priced through the normal pricing table fallback path.