Zephr
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Platform / Fleet

The platform ledger for profiles, devices, and servers.

Fleet is the shipped installation-scoped ledger behind every governed client connection. Profiles define which servers a client connects to, devices identify the enrolled and revoked client instances, and servers are the MCP entries governed by the profile — all bound to one installation’s scope, with SCPE scope controls in fleet-domain.

Shipped - profiles, devices, servers

Profile - billing-service.default

v1
Profile identity
billing-service - default
Installation binding
installation fp_01HQ9C4M7T2XKD
Server membership
zephr - issue-tracker - runbooks
SCPE scope controls
toolsAllow - toolsDeny - write - network
Integrity / version
sha256:41a7e0d9c8b25f36 - v1

example profile ledger - illustrative, from fleet-domain

The mesh

One profile. Many devices. One installation.

Each device holds a device key and sends a secret reference to the profile. The profile names the servers. The mesh is installation-scoped - revoke a device and the mesh rewrites itself without the others.

Devices around one shared storeEach device keeps its own key and sends only a reference to the store. A secret value never leaves the machine that owns it.profilerefs onlylaptopdevice keydesktopdevice keyci runnerscoped tokendashed = a reference, never a value

  • laptop

    holds device key

    sends key id + signature

  • desktop

    holds device key

    sends key id + signature

  • ci runner

    holds scoped token

    sends secret ref

A secret value never leaves the machine that owns it.

Illustrative mesh — references travel, secret values do not.

Profiles

Profiles surface is shipped.

Versioned, canonically-serialized connection profiles. Content-hashed, bound to an admitted installation scope, and content-addressed so the ledger can verify the ledger.

Profile identitybilling-service - defaultInstallation bindinginstallation fp_01HQ9C4M7T2XKDServer membershipzephr - issue-tracker - runbooksSCPE scope controlstoolsAllow - toolsDeny - write - networkIntegrity / versionsha256:41a7e0d9c8b25f36 - v1Profile identitybilling-service - defaultInstallation bindinginstallation fp_01HQ9C4M7T2XKDServer membershipzephr - issue-tracker - runbooksSCPE scope controlstoolsAllow - toolsDeny - write - networkIntegrity / versionsha256:41a7e0d9c8b25f36 - v1
Profile identitybilling-service - defaultInstallation bindinginstallation fp_01HQ9C4M7T2XKDServer membershipzephr - issue-tracker - runbooksSCPE scope controlstoolsAllow - toolsDeny - write - networkIntegrity / versionsha256:41a7e0d9c8b25f36 - v1Profile identitybilling-service - defaultInstallation bindinginstallation fp_01HQ9C4M7T2XKDServer membershipzephr - issue-tracker - runbooksSCPE scope controlstoolsAllow - toolsDeny - write - networkIntegrity / versionsha256:41a7e0d9c8b25f36 - v1
Profile identitybilling-service - defaultInstallation bindinginstallation fp_01HQ9C4M7T2XKDServer membershipzephr - issue-tracker - runbooksSCPE scope controlstoolsAllow - toolsDeny - write - networkIntegrity / versionsha256:41a7e0d9c8b25f36 - v1Profile identitybilling-service - defaultInstallation bindinginstallation fp_01HQ9C4M7T2XKDServer membershipzephr - issue-tracker - runbooksSCPE scope controlstoolsAllow - toolsDeny - write - networkIntegrity / versionsha256:41a7e0d9c8b25f36 - v1
Profile identitybilling-service - defaultInstallation bindinginstallation fp_01HQ9C4M7T2XKDServer membershipzephr - issue-tracker - runbooksSCPE scope controlstoolsAllow - toolsDeny - write - networkIntegrity / versionsha256:41a7e0d9c8b25f36 - v1Profile identitybilling-service - defaultInstallation bindinginstallation fp_01HQ9C4M7T2XKDServer membershipzephr - issue-tracker - runbooksSCPE scope controlstoolsAllow - toolsDeny - write - networkIntegrity / versionsha256:41a7e0d9c8b25f36 - v1

illustrative example - not live data

Devices

Device ledger and device surface are shipped.

RFC 8628 device-flow for MCP session tokens is shipped. Hosted-tool provider-credential enrollment on that flow is not (provider_binding_not_available). The device ledger and surface are shipped.

> zephr fleet device list
1 laptop       enrolled 2026-03-09  ok
2 workstation  enrolled 2026-03-12  ok
3 ci runner    enrolled 2026-03-14  mcp device-flow shipped
zephr fleet device list

What is shipped

  • ledgerenrollment + revocation records
  • surfacelist, get, revoke - all governed by SCPE
  • auth flowMCP device-flow shipped; provider binding not available

Device-flow

RFC 8628 device-flow — shipped steps, one gap.

The device-flow for MCP session tokens is shipped. Hosted-tool provider-credential enrollment on that flow is not. The timeline below shows the shipped rail and the gap step.

Device-flow authentication timelineRFC 8628 device-flow steps in order: Enrollment, Device key, Session token, Provider binding. The shipped steps form a solid rail; the gap step is drawn dashed. RFC 8628 device-flow for MCP session tokens is shipped. Provider binding is not available.EnrollmentDevice registers with the installation scope.Device keyEach device holds its own key.Session tokenRFC 8628 device-flow for MCP session tokens.—Provider bindingHosted-tool provider-credential enrollment.provider_binding_not_available
  1. 01

    Enrollment

    Device registers with the installation scope.

    shipped

  2. 02

    Device key

    Each device holds its own key.

    shipped

  3. 03

    Session token

    RFC 8628 device-flow for MCP session tokens.

    shipped

  4. 04

    Provider binding

    Hosted-tool provider-credential enrollment.

    provider_binding_not_available

    not available

RFC 8628 device-flow for MCP session tokens is shipped. Provider binding is not available.

illustrative device-flow — not live data

Servers

Server inventory and detail surfaces are shipped.

MCP/server entries named by a profile, represented inside installation-scoped Fleet state with governed scope and integrity information.

Total servers in this installation

0

3 named by the profile

  • zephrCore MCP server - the platform surface itself●shipped
  • issue-trackerMCP server named by the profile●shipped
  • runbooksMCP server bound to the same installation●shipped

Tenancy

One installation. SCPE. fleet-domain.

Every Fleet object is bound to one installation. SCPE scope controls in fleet-domain govern what a profile or server may expose - toolsAllow, toolsDeny, write, network. Widening scope is not a retry; it is a new admission.

installation

prof
devi
serv

What Fleet ships

Profiles, devices, and servers - each with its real state.

Three ledger surfaces are shipped. Device-flow authentication that enrols devices is not yet a finished runtime, and is badged accordingly rather than mocked up as shipped.

  • Profiles ledger

    Shipped

    Versioned, canonically-serialized connection profiles, content-hashed and bound to an admitted installation scope.

    fleet-domain profile schema - shipped

  • Devices ledger

    Shipped

    Enrollment and revocation records that identify which client instances may act on a profile, with installation-scoped reads and revocation.

    fleet_device table + revocation - shipped

  • Servers inventory

    Shipped

    MCP/server entries named by a profile, represented inside installation-scoped Fleet state with governed scope and integrity information.

    installation-scoped server reads - shipped

  • SCPE scope controls

    Shipped

    Scope and policy data in fleet-domain that govern what a profile or server may expose: tool allow/deny, write, network, and tool budgets.

    fleet-domain ScopeBinding - shipped

  • Device-flow authentication

    Evolving - MCP device-flow shipped; provider binding not

    RFC 8628 device-flow for MCP session tokens is shipped. Hosted-tool provider-credential enrollment on that flow is not (provider_binding_not_available). The device ledger and surface are shipped.

    fleet_device schema contract - runtime gated

Close

Governed profiles, devices, and servers - shipped.

Fleet is easiest to trust once you connect a client and see the ledger state for yourself. Start the Connect journey, or read the platform architecture.

Connect a clientThe platform