v2.1.0 — ephemeral runs & agent onboarding

Heimdall v2.1.0 — ephemeral runs & agent onboarding

Released: 2026-06-29 · Type: MINOR (additive) · Follows v2.0.0

A quality-of-life follow-up to the everything socket release. Nothing changes in
the transport or the security model — daemons still never listen, the hub is still
the sole listener. v2.1.0 adds two things: ephemeral runs that never rewrite
your config, and broader agent/CLI onboarding so any harness can talk to a
fleet out of the box.

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Highlights

--no-save / --ephemeral on every binary

Every binary persists resolved flags to its config file so the next run repeats
them. That is the right default for a daemon you set up once — but wrong for a
one-off. v2.1.0 adds two equivalent flags that run with the given options without
writing them back:

# spin up a hub on a throwaway port without making :19090 the new default
heimdall-hub --listen :19090 --no-save

# point a dashboard at another hub for one session, leave config untouched
heimdall-dashboard --hub other-hub:9090 --ephemeral

The flag itself is never persisted, and it is built in at the catalog layer so it
works uniformly across heimdall-hub, heimdall-daemon, heimdall-dashboard,
heimdall-helper, and heimdall-cli.

Agent onboarding for any harness

The heimdall-cli guide gained drop-in snippets beyond
the Claude Code trio:

• a .github/copilot-instructions.md block for GitHub Copilot,
• a portable CLI wrapper plus an OpenAI-style tool schema for Hermes,
  OpenAI-compatible, and custom harnesses,
• three real, unedited claude -p transcripts — a free-form "check my fleet",
  the /fleet slash command, and a targeted risk question — showing what fleet Q&A
  actually looks like, including hub discovery and capability-gap reporting.

Run-as-a-service guide

The Privileged Metrics guide now has a
complete, verified systemd setup: helper as root, daemon as your user, a
shared heimdall group, and a /run/heimdall socket matching the v2 0660 helper
socket. The fleet guide cross-links it.

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Upgrade guide

Drop-in. No config migration, no wire change — a v2.1.0 binary interoperates with a
v2.0.0 hub or daemon.

heimdall-dashboard update   # each binary self-updates
heimdall-<binary> --version # confirm v2.1.0

Or pull fresh binaries from the release page.

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Documentation map

• Guides: heimdall-cli ·
  Privileged metrics / run-as-a-service ·
  Monitor a fleet
• Reference: Configuration · Deployment ·
  CHANGELOG
• Previous release: v2.0.0 — the everything socket release