YC W25 · Zero-code backend observability

Every request,
crystal clear.

Subtrace gives backend teams full visibility into every API request — payload, headers, status code, latency, logs — in a Chrome DevTools-like interface. No instrumentation. No root. Just subtrace and see everything.

$ npx subtrace run --name my-api
2.5k GitHub stars · Used by YC companies · Runs on eBPF · Try live demo

subtrace — GET /api/users?page=2 200 OK 12ms
Headers Payload Response Logs
1"Authorization": "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
2"Content-Type": "application/json"
3"X-Request-ID": "req_4f8a2b1c3d9e"
4"User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7)..."
5"Accept": "application/json"
6"X-Rate-Limit-Remaining": "9841"
7"X-Response-Time": "12ms"
Latency12ms
Size2.4KB
Status200 OK
Timestamp14:02:31.847

The interface developers actually want. Not a dashboard full of noise.

What Subtrace does

Observability without
the ceremony

Most tools require you to instrument your code, install agents, or beg your DevOps team for access. Subtrace just needs a terminal.

Every request, indexed

Payload, headers, status codes, latency, logs — all stored and searchable. Not just errors. Not just sampled traces. Everything.

eBPF. Zero code changes.

Attach to any process without root privileges or code modifications. One command: subtrace run --name <process>. You're live.

Chrome DevTools interface

Familiar. Fast. Filter by path, method, status, header value, or payload content. Find the request that broke everything in seconds.

Team collaboration

Share request traces with teammates. Tag and annotate incidents. Query together — incident response becomes a shared session, not a solo scavenger hunt.

Replay & reproduce

Take any past request and replay it against your live service. Test fixes without faking the payload by hand. Reproduce the bug, verify the fix.

Local-first. Your data stays yours.

Run Subtrace entirely locally with no data leaving your infrastructure. For cloud sync, end-to-end encryption is available. Designed for regulated environments.

Getting started

Up in 30 seconds.

No agents. No configuration files. No DevOps ticket required.

01

Install

npm install -g @subtrace/cli
npx subtrace --version
02

Run

subtrace run --name my-backend-service
03

Debug

Open http://localhost:7777
Every request, live.
subtrace run --name api-server
Attaching to process: api-server (PID 4821)
eBPF probe active. Zero root required.
Dashboard running at http://localhost:7777
22 requests captured so far. 3 errors. 1 anomaly.
From the community

Engineers are catching on.

"Subtrace is what you get when someone builds Wireshark for modern backend stacks. The eBPF approach is genuinely clever — it just works without any setup."

Hacker News community HN front page, 500+ points

"We used to spend hours on production incidents. Now we open Subtrace and the request is right there — payload, headers, timing, everything. It's DevTools for the whole backend."

Backend engineer at a YC company Using Subtrace in production

"The TLS decryption without root is a brilliant hack. This is exactly what container debugging needed — something that understands pods and services natively."

The backend you deserve
starts with visibility.

Stop reconstructing incidents from scattered logs. Subtrace shows you exactly what happened, what was sent, and what came back — for every single request, in real time.

$ npx subtrace run --name your-backend

Free to start. No credit card required. Runs locally or in the cloud.