Sharing Traces is Now 15x Faster

Sharing a trace is now up to 15x faster while sending 98% less data. The longer the session you're sharing the more you'll notice this improvement.

Why longer sessions used to share slowly

Previously, each share re-uploaded the full trace. We now share incrementally. Events record server acceptance, and the CLI sends only new or failed events when sharing via traces share, the TUI, or an agent hook.

Measuring the difference

We replayed a real 10,391-event Claude Code session one turn at a time, sharing after each turn, with the old CLI (v0.6.33) and the current one (v0.6.38).

• Each share dropped from 17.2 seconds to 1.1 second, and from about 20 MB to under 100 KB.
• Over the last 55 turns, the old CLI uploaded 1,110 MB and sent each message 52 times. The new one uploaded 22.7 MB and sent each message once.
• Total time spent sharing over those 55 turns fell from 16 minutes to under a minute and a half.

No slowdown as sessions grow

With the old CLI, every 1,000 events in a session added about 47 seconds and 4 MB to each share. Now they add under 0.1 seconds, and the upload size depends only on the newest turn.

Complete traces even with concurrent shares

When several sessions share at once, a hook that finds an upload running already skips its turn. The old CLI was slow enough that skipping happened often, which means some trace shares were incomplete. In our tests with the old CLI, 40% of sessions ended without their final turn on the server. With incremental sharing, none did. The skip still exists, but shares now finish fast enough that it rarely happens.

Also in this release

• Visibility stays as you set it. Changes you make on the web, or that an org policy sets, now survive later shares. The CLI only sends a visibility when you pass --visibility.
• Subagents stay with their parents. A subagent that starts mid-session is picked up on the next share and linked under its parent. This works for every agent Traces supports.
• Clearer errors. A failed share now says what went wrong, like authentication, rate limits, or a rejected payload.

Try it

Incremental sharing is on by default from v0.6.34. Upgrade to the latest:

brew upgrade traces

traces share

And if anything looks off, traces share --force re-uploads everything.