Download Athena

Run Athena Endpoint Platform inside your own perimeter — as a hardened virtual appliance for VMware vSphere or Hyper-V. It works fully offline.

Current release: 0.9.1

New installation? Download the 0.9.1 appliance image below; no update is needed. Already running Athena? Apply the 0.9.1 update bundle from the web console. New to Athena? Follow the Beginner Guide, with a short video for each step.

Virtual appliance#

A ready-to-run VM built on hardened Flatcar Container Linux LTS with Athena preinstalled. You import it, answer five questions on the VM console and sign in from a browser. It ships with a 60 GB disk and a built-in trial licence — no internet connection needed. The trial runs to a fixed end date per release (shown with each download), not from the day you install it.

Choose your hypervisor

VMware vSphere / ESXi — OVA

Version
0.9.1
Size
1.1 GB (1,138,216,960 bytes)
Released
2026/10/21
Trial valid until
2027/04/18
SHA-256
ac7ee306d09015f19df671c0306c9623d2cfd1cacb1bac405c646d0757059182

Import & first sign-in

  1. Check the download: sha256sum athena-appliance.ova (Linux/macOS) or Get-FileHash athena-appliance.ova (PowerShell) must match the SHA-256 above.
  2. In vSphere / ESXi choose Deploy OVF Template and select the OVA.
  3. Attach the VM to a network your endpoints can reach and power it on.
  4. Complete the first-boot wizard on the VM console. It ends by showing the web address and the initial admin password.
  5. Browse to that address, sign in and change the password. The trial licence is already active.

Microsoft Hyper-V — VHDX

Version
0.9.1
Size
1.6 GB (1,719,664,640 bytes)
Released
2026/10/21
Trial valid until
2027/04/18
SHA-256
36d5a61a1a3baec611d7124d62f74d9b60036b6828dcf8410b6401185d5fb4d7

Import & first sign-in

  1. Check the download: Get-FileHash athena-appliance.vhdx must match the SHA-256 above.
  2. In Hyper-V Manager create a new VM: Generation 2, and choose Use an existing virtual hard disk pointing at the VHDX.
  3. Before first boot open Settings → Security and clear “Enable Secure Boot” — the appliance will not boot with it on.
  4. Hyper-V Manager does not show the VM's IP address; read it from the VM console.
  5. Connect the VM to a virtual switch your endpoints can reach and start it.
  6. Complete the first-boot wizard on the VM console, then browse to the web address it shows, sign in with the initial admin password it shows and change it.
# Or with PowerShell
New-VM -Name Athena -Generation 2 -MemoryStartupBytes 4GB `
  -VHDPath C:\VMs\athena-appliance.vhdx -SwitchName "<your switch>"
Set-VMFirmware -VMName Athena -EnableSecureBoot Off
Set-VMProcessor -VMName Athena -Count 2
Set-VMMemory -VMName Athena -DynamicMemoryEnabled $false
Start-VM Athena

First boot and the appliance console

On first boot the VM console runs a short wizard:

  1. Network — DHCP, or a static IPv4 address with gateway and DNS servers.
  2. Host name and an optional DNS domain.
  3. NTP servers.
  4. Time zone — an IANA name such as Europe/London (default UTC).
  5. Database — built-in SQLite, or the built-in PostgreSQL 16 for larger fleets.

Press Enter to keep a default; everything can be changed later from the same console. New to Athena? The Beginner Guide walks through each question.

It then shows the web address and the initial admin password. The hostname and IP address go into the server's certificate and web address automatically, so agents can enroll by name or by IP.

Use a static IP or a DHCP reservation

Set it in the first-boot wizard, before you install agents: every agent remembers the address it was installed with.

After setup the VM console shows a restricted admin menu, never a shell: status, network, hostname, NTP, proxy, switch the database to the local PostgreSQL, restart services, support bundle (logs and configuration with secrets removed; an Admin can also download it from the web API), updates, time-limited support SSH, factory reset, and reboot / shutdown. Support SSH switches itself off, and using it permanently marks the appliance as “OS accessed”. Switching to PostgreSQL is one-way (a backup is taken first). Factory reset erases all data, including the certificate authority, so enrolled devices cannot reconnect afterwards — copy any backup off the appliance first.

Update bundle — 0.9.1

Version
0.9.1 (for appliances on 0.7.0 or later)
Size
915.1 MB (959,559,680 bytes)
Released
2026/10/21
SHA-256
12d2729376f9775cd6d7502e1ecbae095abb1a89ed7a0be0284a45ed6b31d2c5

In the web console open Settings → Appliance, and under Appliance updates click Upload bundle, then Verify and Apply. Watch it in the Beginner Guide.

Updates — offline, signed, with automatic rollback

Each update is a single file, athena-update-<version>.tar (≈ 1 GB), that carries everything: the Athena server, appliance configuration, agent installers, PostgreSQL and the operating-system update, including OS security fixes. One file updates the application and the OS together, and the appliance never needs internet access.

Security and hardening

What the appliance does to reduce its attack surface:

Each release comes with:

The SBOMs and CVE report are also inside every signed update bundle. They will be published here with the first release.

Not provided today

Secure Boot on Hyper-V (the image isn't signed for it; the VMware image boots BIOS), disk encryption (use your hypervisor's VM encryption if you need it), FIPS 140 mode, and TPM. The appliance is a single server: no clustering or high availability — recovery is a new appliance plus a backup restore.

Licensing

Details are in Licensing. For a full licence, email support@sealgrid.ai.

Network ports

PortUsed for
8443Web console and REST API (HTTPS)
8444Agent connections (gRPC over mutual TLS) — endpoints connect outbound to this port

Everything else is closed, including SSH. The appliance needs no outbound access; an optional HTTP(S) proxy can be set from the console menu.

Agents#

Agents are not a separate download — on purpose. Each Athena server runs its own certificate authority, so agents are installed from your Athena server, which hands out installers already carrying its address and CA:

  1. In the Athena web console open Agents and click Install agent.
  2. Pick Windows, Linux or macOS, then Copy one-liner. Your server address is already filled in.
  3. Run it on the endpoint with admin / root rights and sign in with your Athena account when prompted. The agent installs, enrolls and receives its certificate automatically — no secrets are stored in the script.
Agents connect to an address in the server's certificate

The certificate lists the server's computer name plus every name and IP address you set in Server:Hostnames; agents connecting to any other address are refused. On the virtual appliance, the first-boot wizard sets this for you. Whatever you use, keep it stable: a static IP or DHCP reservation, ideally with a DNS name.

PlatformArchitectures
Windowsx64
Linuxx64, arm64
macOSApple Silicon (arm64)

For domain-wide rollout, token-based enrollment and offline installs, see Agent Enrollment and AD Agent Deployment.

System requirements#

Managed endpointsCPURAMDatabase
Up to 250 estimate1 core @ 3.0 GHz+ (2019 or newer)2 GBBuilt-in (SQLite)
Up to 5002 cores @ 3.0 GHz+4 GBBuilt-in (SQLite)
Up to 2,0002 dedicated cores @ 3.25 GHz+4–8 GBBuilt-in, or PostgreSQL if you expect mass reconnects
2,000–5,000 estimate4 cores @ 3.0 GHz+8–16 GBPostgreSQL
Over 5,000 estimate8+ cores @ 3.0 GHz+16 GB+PostgreSQL on its own host

The 500 and 2,000 rows are measured in load tests; the others are estimates, and PostgreSQL has not been load-tested yet — treat those rows as starting points.

External PostgreSQL is supported: Settings → Database migrates the built-in database to your own PostgreSQL server. On the virtual appliance this is pending validation.

Older CPUs: GHz only compares fairly between CPUs of a similar age — count a core from before 2018 at half its GHz. Load-test results, CPU guidance and disk planning are in Server Sizing.

Next steps#

Enroll agents

Bring your first endpoints under management.

Air-gapped operation

Running with no outside connectivity at all.