DevinMonitor

Token & cost monitor for the Devin CLI.

DevinMonitor reads Devin CLI's local session database and provides real-time monitoring, usage reports, and cost tracking — with Devin-specific metrics (TTFT, tokens/sec, finish-reason distribution, context growth, sub-agent usage) that other monitors don't offer.

中文文档

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Live dashboard

The live command renders a real-time bubbletea TUI that polls sessions.db every few seconds and shows a full at-a-glance view of the current session:

Panels:

• Tokens — input / output / cache-read / cache-write totals, live generation rate (tok/s, summed across concurrent requests over a 60-second rolling window), and averages.
• Context — current context size vs. model window, fill bar, average / peak / remaining tokens, cache-write indicator.
• Status — session cost, request count (with sub-agent count), duration, average request time, TTFT / total p50, total tool calls.
• Request stream — scrolling list of recent requests with TTFT, tok/s, elapsed, and finish reason, plus a TTFT sparkline with p50/p95.
• Context growth — full-session context size history with cache-hit ratio.
• Latency — TTFT / total / tok/s percentiles and finish-reason distribution bar.
• Tools — per-tool call counts with horizontal bars, including run_subagent and read_subagent calls.

Reports

All report commands render styled tables with consistent grey borders and a TOTALS row. Column widths adapt to the terminal; on wide terminals columns expand, on narrow terminals they truncate gracefully.

sessions — session list

session <id> — session detail

Shows metadata, token breakdown, sub-agent call list (with profile, task, background/foreground, completion status), and a per-tool call count breakdown.

daily / weekly / monthly — time-bucketed usage

Token, request, sub-agent, and cost totals per day / week / month, with the list of models used. Use --breakdown to add a per-model sub-table. weekly supports --start-day monday|sunday|....

models — per-model analytics

Requests, tokens (input / output / cache-read / cache-write), cost, cost share, and average generation speed per model.

model <name> — model detail

First/last used, days active, token totals, cost, average per day and per session, p50/p95 TTFT and total time, truncation rate, and a per-tool breakdown for that model.

projects — per-project usage

Sessions, requests, tokens, cost, and models used, grouped by working directory's project name.

agents — sub-agent usage statistics

Detailed sub-agent usage grouped by profile: total calls, sessions involved, background/foreground split, completion count, read_subagent waits, average/max duration, average/max task length, and average/max output length.

Install

go install github.com/garywhat/devinmonitor@latest

Or download a pre-built binary from Releases.

Or build from source:

git clone https://github.com/garywhat/devinmonitor.git
cd devinmonitor
go build -o devinmonitor .

Usage

# Real-time dashboard (needs a TTY)
devinmonitor live

# Session list
devinmonitor sessions

# Session detail
devinmonitor session fragrant-hunter

# Daily usage with per-model breakdown
devinmonitor daily --breakdown

# Weekly report starting on Monday
devinmonitor weekly --start-day monday --breakdown

# Monthly report
devinmonitor monthly

# Model analytics
devinmonitor models

# Model detail
devinmonitor model glm-5-2

# Per-project usage
devinmonitor projects

# Sub-agent usage statistics
devinmonitor agents

# Prometheus metrics endpoint
devinmonitor metrics --addr :9101

# Export normalized JSON
devinmonitor export --detailed > usage.json

Global flags

--data-dir string   Devin data directory (default: auto-detect)
--locale string     Language: en / zh (default: auto-detect from system)

Live dashboard controls

q          quit
r          switch to next session
1-4 / Tab  jump to section (compact mode)
L          toggle locale (en <-> zh)

Responsive TUI

The live dashboard adapts to terminal size with four breakpoints:

Breakpoint	Size	Layout
Full	>= 120 cols, >= 24 rows	complete 4-row dashboard
Compact	80-119 cols	2-column + tabbed views
Mini	< 80 cols	single-column flow for narrow windows / termux
Tiny	< 6 rows	single-line ticker for tmux splits

Window resize is handled instantly via bubbletea's WindowSizeMsg.

Data source

DevinMonitor reads sessions.db from Devin CLI's data directory:

• Linux: ~/.local/share/devin/cli/sessions.db
• macOS: ~/Library/Application Support/devin/cli/sessions.db
• Windows: %APPDATA%\devin\cli\sessions.db

Override with --data-dir or the DEVIN_DATA_DIR environment variable.

The connection is read-only + WAL + query_only, so it won't block Devin CLI's writes.

Schema adaptation

Devin CLI's SQLite schema is an internal implementation detail that may change between versions. The reader package isolates schema-specific SQL/JSON parsing behind a version-detected adapter. When Devin CLI changes its schema, only a new adapter (e.g. v2.go) is needed — reports and UI are unaffected.

Cost calculation

Layer	Source	When used
Authoritative	sessions.metadata.total_credit_cost / total_acu_cost	Non-zero (paid models)
Estimate	Built-in token x price table	Credit is zero (free models)
Future	External pricing API (openrouter etc.)	Planned

Free models (e.g. glm-5-2) show free in cost columns.

Prometheus metrics

The metrics command starts an HTTP server (default :9101) exposing Prometheus-format gauges:

• devinmonitor_sessions_total
• devinmonitor_requests_total
• devinmonitor_input_tokens_total / devinmonitor_output_tokens_total
• devinmonitor_cache_read_tokens_total / devinmonitor_cache_write_tokens_total
• devinmonitor_cost_total
• devinmonitor_model_* — per-model breakdown
• devinmonitor_project_* — per-project breakdown

Scrape it with Prometheus or curl:

devinmonitor metrics &
curl http://localhost:9101/metrics

Architecture

sessions.db -> Reader (schema adapter) -> Normalized model types
                                         |-- Report (sessions/daily/weekly/monthly/models/projects/agents)
                                         |-- Live (bubbletea dashboard)
                                         |-- Export (stable JSON for web upload)
                                         |-- Metrics (Prometheus endpoint)

The export format (export_schema: 1) is independent of Devin's internal schema, designed as a stable contract for future web-based sharing (token leaderboards, burn-rate comparisons, etc.).

Platform & locale

• Multi-arch: linux / darwin / windows x amd64 / arm64 (single binary, no CGO)
• i18n: English + 中文, auto-detected from system LANG / LC_ALL
• CJK rendering: correct character width via go-runewidth

Tech stack

• Go — single binary, no runtime dependencies
• bubbletea + lipgloss — responsive TUI framework
• modernc.org/sqlite — pure-Go SQLite (no CGO, cross-compile friendly)
• cobra — CLI command framework

License

MIT