lazaret/docs/schema.md

# Lazaret schemas

This document is a mutable coordination schema for Lazaret records and protocol
data shapes. The [specification](specification.md) defines their authoritative
physical use, while the TLA+ models define authoritative lifecycle and ordering
above the implementation abstraction. The diagrams coordinate logical fields,
variants, relationships, and serialization boundaries across implementation
work; they do not select a programming-language representation or override the
specification or models.

Every class carries exactly one serialization-category stereotype:
`<<serialized>>` identifies a record that may cross a configuration,
durable-storage, or protocol codec boundary, while `<<runtime>>` identifies an
in-memory authority or plan that must not implement Serde serialization or
deserialization. Shape stereotypes such as `<<enumeration>>` and `<<union>>` are
orthogonal and may coexist.

## Trusted host configuration

The trusted-host configuration dispatch identifier is exactly
`lazaret-trusted-host-config-v1`. The v1 TOML document has the following closed
shape; every table recursively rejects unknown fields, duplicate keys, duplicate
tables, field aliases, and unknown enumeration values.

| Table | Field | Presence and value |
| :--- | :--- | :--- |
| root | `schema` | required; exact dispatch identifier |
| root | `storage` | optional; defaults to an empty table |
| root | `network` | optional; defaults to an empty table |
| root | `profiles` | required; at least one dynamically named profile |
| `storage` | `data_root` | optional host path; defaults beneath the XDG data home |
| `network` | `default_allow` | optional list of IPv4 prefixes; defaults empty |
| `network` | `default_deny` | optional list of IPv4 prefixes; defaults empty |
| profile | `image` | required nonempty OCI image reference |
| profile | `isolate_gitignored` | optional Boolean; defaults `true` |
| profile | `persistent_dirs` | optional list of sandbox paths; defaults empty |
| profile | `allow_egress` | optional list of IPv4 prefixes; defaults empty |
| profile | `deny_egress` | optional list of IPv4 prefixes; defaults empty |
| profile | `env` | optional map from sandbox environment name to `env:` reference; defaults empty |
| profile | `volumes` | optional list of volume tables; defaults empty |
| profile | `escalation` | optional table; defaults to disabled with no rules |
| volume | `host` | required host path |
| volume | `container` | required sandbox path |
| volume | `kind` | required: `file` or `directory` |
| volume | `access` | optional: `read-only` or `read-write`; defaults `read-write` |
| volume | `create` | optional Boolean; defaults `false` |
| `escalation` | `enabled` | optional Boolean; defaults `false` |
| `escalation` | `auto_approve` | optional list of auto-approval rules; defaults empty |
| auto-approval rule | `executable` | required host executable path |
| auto-approval rule | `args` | optional ordered list of arguments; defaults empty |
| auto-approval rule | `allow_extra_args` | optional Boolean; defaults `false` |

Profile names are ASCII and match
`[A-Za-z0-9][A-Za-z0-9._-]{0,63}`, excluding `.` and `..`. The caller selects
one profile by its exact case-sensitive name; the document has no default
profile and declaration order never selects one. All configuration strings are
UTF-8 and NUL-free. Environment map keys and the names following `env:` match
`[A-Za-z_][A-Za-z0-9_]*`. An environment value is a reference only; literal
values and other reference schemes are invalid.

Host path declarations are absolute or begin with exactly `~/`; only a volume
`host` may instead begin with exactly `{profile_dir}/`. A declaration rejects an
empty suffix, an empty component, repeated or trailing separators, `.` or `..`,
and every other expansion, variable, glob, or shell form. In particular,
`~//etc` and `{profile_dir}//etc` are invalid. Sandbox paths are normalized
absolute UTF-8 paths with the same component restrictions; the root path is
invalid.

Persistent paths are pairwise distinct and neither equal nor ancestral in
either direction. Volume container paths are pairwise distinct and
non-ancestral. Each volume container path is a strict descendant of exactly one
persistent path; equality with that path is invalid. Resolution requires an
internal `SandboxLayoutV1`, whose closed protected-destination set contains
`/workspace` and every control, credential, mailbox, proc, sys, dev, runtime,
and other product-owned sandbox mount destination selected by the production
layout. Persistent and volume paths must not intersect any protected
destination in either ancestry direction. Configuration semantics do not assign
destinations other than the specification-fixed `/workspace`; the production
sandbox-layout constructor owns that complete set and cannot construct a layout
that omits `/workspace`. A volume source has the declared kind. `create=true` is
valid only for a directory source anchored strictly beneath `{profile_dir}`; a
file source is never created. Symlinks, magic links, mount crossings, sockets,
devices, FIFOs, and other special files cannot satisfy a source.

The v1 network language is IPv4-only. Each prefix is parsed, has host bits
cleared, and is deduplicated. Effective allow prefixes are the union of global
and selected-profile allows. Effective deny prefixes are the union of global,
selected-profile, and the three RFC 1918 prefixes. An exact normalized prefix
present in both sets is invalid; overlaps at different prefix lengths are valid
and use longest-prefix routing. The Agent Sandbox disables IPv6 for v1.

An auto-approval rule is valid only while its profile escalation table is
enabled. Its executable resolves to a canonical regular executable outside the
Agent Workspace, every configured volume source, the profile directory, and
every Lazaret data, runtime, Domain, and control tree. At load and before every
execution, the object must have exactly one hard link, be owned by root or the
invoking user, grant no group or other write permission, and be executable by
the invoking user. Rule arguments are UTF-8, NUL-free strings.
`allow_extra_args=false` matches only the exact ordered argument list.
`allow_extra_args=true` requires at least one configured argument and matches
that nonempty ordered prefix followed by zero or more arguments. Exact duplicate
normalized rules are invalid.

`MailboxRequest.command_argv` is nonempty and every element is UTF-8 and
NUL-free. Element zero is an absolute path and must be byte-for-byte equal to
the rule's canonical executable path; elements one onward are the arguments
matched against `args`. Lazaret performs no `PATH` lookup. The structured v1
request language has no command-string or shell-expansion form; such an
unsupported input is `CommandRequiresShell` and cannot auto-approve. The host
launcher never inserts or interprets a shell. An explicitly configured exact
vector such as `/bin/sh`, `-c`, and a fixed command string remains a direct
vector and can match only that exact rule. A configured script remains eligible:
executing the same opened script object uses ordinary kernel shebang handling
without turning its arguments into a Lazaret-interpreted shell command.

```mermaid
classDiagram
    class TrustedHostConfigurationV1 {
        <<serialized>>
        schema_id
        profiles
    }

    class ResolvedDomainConfiguration {
        <<runtime>>
        selected_profile
        domain_id
        configuration_fingerprint
        effective_network_policy
        ephemeral_environment
        confined_authorities
    }

    class SandboxLayoutV1 {
        <<runtime>>
        protected_destinations
    }

    class ConfigurationFingerprintRecordV1 {
        <<serialized>>
        selected_profile
        storage_root
        runtime_root
        image
        isolate_gitignored
        persistent_dirs
        environment_references
        volumes
        effective_allow_prefixes
        effective_deny_prefixes
        escalation_enabled
        auto_approval_rules
    }

    class EnvironmentReference {
        <<serialized>>
        sandbox_name
        host_name
    }

    class ResolvedVolume {
        <<serialized>>
        canonical_host_source
        container_path
        kind
        access
        create
    }

    class ResolvedAutoApprovalRule {
        <<serialized>>
        canonical_executable
        args
        allow_extra_args
    }

    class ConfinedPathPlan {
        <<runtime>>
        retained_ancestor
        ancestor_device
        ancestor_inode
        ancestor_mount_id
        relative_suffix
        canonical_label
    }

    TrustedHostConfigurationV1 --> ResolvedDomainConfiguration : resolves selected profile
    SandboxLayoutV1 --> ResolvedDomainConfiguration : constrains sandbox destinations
    ResolvedDomainConfiguration --> ConfigurationFingerprintRecordV1
    ConfigurationFingerprintRecordV1 --> EnvironmentReference
    ConfigurationFingerprintRecordV1 --> ResolvedVolume
    ConfigurationFingerprintRecordV1 --> ResolvedAutoApprovalRule
    ResolvedDomainConfiguration --> ConfinedPathPlan
```

`ResolvedDomainConfiguration` is one move-owned, non-serializable value. It is
the only successful output of loading a selected profile and owns all retained
path descriptors, normalized selected-profile data, confined use plans, and
resolved environment values. Resolved environment values have no field in
`ConfigurationFingerprintRecordV1`; they are never serialized, hashed, logged,
or persisted. The parsed source and nonselected profiles do not become runtime
configuration authority.

`SandboxLayoutV1` is an internal, non-serializable product value with no public
unchecked constructor. Configuration resolution cannot succeed without it. Its
production constructor is owned by sandbox-layout construction and supplies the
complete normalized protected-destination set; configuration loading neither
guesses unnamed destinations nor permits a caller to remove `/workspace`. Every
member is a normalized, absolute, non-root sandbox path using the sandbox-path
grammar above; the finite set is nonempty and contains no duplicate member.

`ConfinedPathPlan` owns a retained ancestor directory descriptor and exposes to
consumers only its typed device, inode, and mount identity plus a normalized
relative suffix. `canonical_label` is diagnostic or fingerprint input, not open
authority. Consumers reopen relative to the retained descriptor and revalidate
the intended type and identity constraints. They do not receive an ambient
absolute path with which to repeat authorization.

### Domain and configuration digests

`DomainIdV1` is the 32-byte SHA-256 digest of the following preimage:

```text
"lazaret-domain-id-v1\0"
|| bytes(selected_profile_utf8)
|| bytes(canonical_workspace_path)
```

`ConfigurationFingerprintV1` is the 32-byte SHA-256 digest of the following
canonical record:

```text
"lazaret-configuration-fingerprint-v1\0"
|| bytes(selected_profile_utf8)
|| bytes(canonical_storage_root)
|| bytes(canonical_runtime_root)
|| bytes(image_utf8)
|| boolean(isolate_gitignored)
|| list(persistent_dirs)
|| list(environment_reference_records)
|| list(volume_records)
|| list(effective_allow_prefixes)
|| list(effective_deny_prefixes)
|| boolean(escalation_enabled)
|| list(auto_approval_rule_records)
```

The Domain-ID separator is the exact 20 ASCII bytes
`lazaret-domain-id-v1` followed by one NUL byte. Both variable fields use
`bytes`; concatenating their unframed bytes is not a valid v1 preimage.
`bytes(x)` is `u32be(length(x)) || x`; lengths and list counts must fit in
`u32`. A Boolean is one byte, `0x00` or `0x01`. Each list is
`u32be(item_count)` followed by `bytes(item_encoding)` for every item. Every
listed collection is order-independent and sorts complete item encodings by
unsigned bytewise order before framing, except that arguments inside one
auto-approval record retain their declared order. Strings use UTF-8 bytes and
canonical host paths use raw Linux pathname bytes.

An environment-reference record is `bytes(sandbox_name) || bytes(host_name)`.
A persistent-path item is `bytes(path)`, and an argument item is `bytes(arg)`.
A volume record is `bytes(canonical_host_source) || bytes(container_path) ||
kind || access || boolean(create)`, where file/directory are `0x00`/`0x01` and
read-only/read-write are `0x00`/`0x01`. An IPv4 prefix is its four network-order
address bytes followed by its one-byte prefix length. An auto-approval record is
`bytes(canonical_executable) || list_in_declared_order(args) ||
boolean(allow_extra_args)`. A declared-order argument list uses the same list
framing without sorting.

Source comments, TOML declaration order, defaults versus their explicit equal
values, nonselected profiles, configuration source pathname, host environment
values, retained descriptor numbers, filesystem inode metadata, and executable
contents are excluded. Every resolved selected-profile field above is included.
Neither digest is an authentication credential.

## Domain Store

```mermaid
classDiagram
    class DomainStore {
        <<serialized>>
    }

    class StoreMetadata {
        <<serialized>>
        schema_id
        schema_version
    }

    class Domain {
        <<serialized>>
        domain_id
        profile_name
        canonical_workspace
    }

    class Generation {
        <<serialized>>
        domain_id
        generation_id
        configuration_fingerprint
        coordinator_id
        network_sidecar_id
        sandbox_id
        durable_decision
    }

    class Participant {
        <<serialized>>
        generation_id
        role
        state
        ownership
    }

    class ParticipantState {
        <<serialized>>
        <<enumeration>>
        Intent
        LeaseHeld
        Prepared
        Committed
        ReleaseIntent
        Clean
    }

    class ParticipantOwnership {
        <<serialized>>
        <<union>>
        PreparedLower
        StateAnchor
        GitRouting
        Network
        Helper
        Sandbox
        Publication
    }

    class Session {
        <<serialized>>
        generation_id
        session_id
        cli_id
        session_anchor_id
        session_phase
    }

    class SessionTerminal {
        <<serialized>>
        generation_id
        session_id
        state
        container_id
    }

    class SessionTerminalState {
        <<serialized>>
        <<enumeration>>
        Intent
        Running
        ReleaseIntent
        Clean
    }

    class Mailbox {
        <<serialized>>
        generation_id
        identity_path
        inbox_path
        outbox_path
        state
    }

    DomainStore "1" *-- "1" StoreMetadata
    DomainStore "1" *-- "1" Domain
    Domain "1" --> "0..*" Generation
    Generation "1" --> "0..*" Participant
    Participant --> ParticipantState
    Participant --> "0..1" ParticipantOwnership
    Generation "1" --> "0..*" Session
    Session "1" --> "0..1" SessionTerminal
    SessionTerminal --> SessionTerminalState
    Generation "1" --> "0..1" Mailbox
    Mailbox --> ParticipantState
```

`durable_decision` and `session_phase` contain values defined by the application
protocol model. This schema records them without redefining either state machine.
Each store carries its own schema identity and version. The current Domain Store
identity is `lazaret-domain-store-v2` with version `2`. Domain Store v1 metadata
dispatches only to legacy migration handling; it is never decoded as v2. The
Storage Catalog remains `lazaret-storage-catalog-v1` with version `1`.

### Host process identity and staged ownership

```mermaid
classDiagram
    class PidfsProcessAuthorityV1 {
        <<serialized>>
        boot_id
        pidfs_st_dev
        pidfs_st_ino
    }

    class PidfsProcessIdentityV1 {
        <<serialized>>
        host_pid
        start_time_ticks
    }

    class LegacyUnverifiedProcessIdentityV1 {
        <<serialized>>
        host_pid
        start_time_ticks
    }

    class HostProcessIdentity {
        <<serialized>>
        <<union>>
        PidfsV1
        LegacyUnverifiedV1
    }

    class PersistedHostProcessOwnership {
        <<serialized>>
        <<union>>
        Unassigned
        Staged
        Committed
    }

    class HostProcessOwnershipSlot {
        <<serialized>>
        <<enumeration>>
        SandboxHostCoordinator
        SandboxRuntimeSupervisor
        SandboxAttachedRunsc
        StateAnchorDaemon
        GitRoutingDaemon
        NetworkRuntimeSupervisor
        HelperConnectivityHelper
        HelperRuntimeSupervisor
        SessionTerminalHostCoordinator
        SessionTerminalExecClient
        EscalationHostProcess
    }

    class ProcessOwnershipMessageVersion {
        <<serialized>>
        <<enumeration>>
        V1
    }

    class StagedProcessOwnership {
        <<serialized>>
        version
        domain_id
        generation_id
        coordinator_id
        slot
        identity
    }

    class ProcessOwnershipCommitAck {
        <<serialized>>
        version
        committed
    }

    PidfsProcessIdentityV1 --> PidfsProcessAuthorityV1 : authority
    HostProcessIdentity --> PidfsProcessIdentityV1 : PidfsV1
    HostProcessIdentity --> LegacyUnverifiedProcessIdentityV1 : LegacyUnverifiedV1
    PersistedHostProcessOwnership --> PidfsProcessIdentityV1 : Staged
    PersistedHostProcessOwnership --> HostProcessIdentity : Committed
    StagedProcessOwnership --> ProcessOwnershipMessageVersion
    StagedProcessOwnership --> HostProcessOwnershipSlot
    StagedProcessOwnership --> PidfsProcessIdentityV1
    ProcessOwnershipCommitAck --> ProcessOwnershipMessageVersion
    ProcessOwnershipCommitAck --> StagedProcessOwnership : committed
```

`boot_id` is the canonical 16-byte UUID value from the current Linux boot ID;
`pidfs_st_dev` and `pidfs_st_ino` are distinct unsigned 64-bit pidfs types. Only
their typed `PidfsProcessAuthorityV1` tuple is positive durable authority.
`host_pid` is an unsigned 32-bit host-PID-namespace locator and
`start_time_ticks` is unsigned 64-bit negative evidence. Equality of the latter
two fields cannot produce or upgrade authority.

Every persisted host-process edge uses `PersistedHostProcessOwnership`.
`Unassigned` records that no process ownership has been acquired. `Staged`
contains only a current pidfs identity. It is positive authority for exact
same-handle cleanup and `PidfsRecoveryMatch`, including bootstrap recovery, but
cannot satisfy readiness, publication, dependent-resource creation, or
adoption. `Committed` may contain a current pidfs identity or a
legacy-unverified v1 PID/start-only value. Only committed current pidfs
ownership is serviceable; the legacy variant always refuses positive process
action. There is no observation-based conversion from legacy data to
`PidfsProcessIdentityV1`.

Participant `Intent` and `ReleaseIntent` may retain any process-slot phase.
Every active participant state and Session Terminal `Running` requires current
committed ownership in every role-required process slot. `Clean` requires every
process slot to be `Unassigned`.

`StagedProcessOwnership` binds one acquisition to its Domain, generation,
generation-scoped Session Coordinator ID, exact ownership slot, and complete
pidfs identity. `ProcessOwnershipCommitAck.committed` echoes that exact staged
value. The receiver accepts one matching v1 acknowledgment only while that
exact launch barrier is pending on the authenticated generation channel. A
mismatched, duplicated after release, unknown-version, lost, or unauthenticated
acknowledgment cannot release a barrier. These shapes define correlation and
the durable boundary; they do not select the authentication or transport codec.

### Session terminal ownership

```mermaid
classDiagram
    class SessionTerminal {
        <<serialized>>
        generation_id
        session_id
        state
        container_id
    }

    class PtyIdentity {
        <<serialized>>
        master_fd
        device
        inode
    }

    class GuestProcessIdentity {
        <<serialized>>
        leader_pid
        leader_start_time
        process_group_id
    }

    SessionTerminal --> PersistedHostProcessOwnership : host_coordinator
    SessionTerminal --> PtyIdentity : pty_master
    SessionTerminal --> PersistedHostProcessOwnership : exec_client
    SessionTerminal --> GuestProcessIdentity : guest_process
```

Host process ownership uses the phase-aware pidfs dispatch above. Guest
process identity uses the leader PID and start time observed inside the exact
generation-bound runsc container; its process-group ID is relative to that
container's root PID namespace and never converts to host process authority.
The PTY identity is exact only in combination with its Host Coordinator process
identity. `SessionTerminalState` is a physical recovery state below the
application protocol model; it does not redefine `session_phase`.

`SessionTerminal=Intent` permits partial acquisition: `container_id`,
`pty_master`, and `guest_process` are optional, while both process slots use the
three-phase ownership union. `Running` requires all three non-process identities
and current committed HC and exec-client ownership. `ReleaseIntent` retains all
recorded evidence, including staged current pidfs authority. `Clean` requires
all three optional identities absent and both process slots unassigned. A bare
Intent may become this explicit cleared snapshot only after runtime absence is
proven.

## Session terminal protocol

```mermaid
classDiagram
    class SessionTerminalEvent {
        <<serialized>>
        <<union>>
    }

    class TerminalInput {
        <<serialized>>
        session_id
        bytes
    }

    class TerminalResize {
        <<serialized>>
        session_id
        rows
        columns
        pixel_width
        pixel_height
    }

    class TerminalSignal {
        <<serialized>>
        session_id
        signal
    }

    class TerminalSignalKind {
        <<serialized>>
        <<enumeration>>
        Interrupt
        Quit
        Suspend
    }

    class SessionClose {
        <<serialized>>
        session_id
    }

    class SessionTerminalMessage {
        <<serialized>>
        <<union>>
    }

    class TerminalOutput {
        <<serialized>>
        session_id
        bytes
    }

    class SessionExit {
        <<serialized>>
        session_id
        outcome
        exit_code
    }

    class SessionExitOutcome {
        <<serialized>>
        <<enumeration>>
        Exited
        Terminated
        RuntimeLost
    }

    SessionTerminalEvent --> TerminalInput
    SessionTerminalEvent --> TerminalResize
    SessionTerminalEvent --> TerminalSignal
    SessionTerminalEvent --> SessionClose
    TerminalSignal --> TerminalSignalKind
    SessionTerminalMessage --> TerminalOutput
    SessionTerminalMessage --> SessionExit
    SessionExit --> SessionExitOutcome
```

`exit_code` is present only for `Exited` and is the status collected from the
non-detached runsc exec client. Interactive PTY output is one merged byte stream;
it does not preserve stdout and stderr as separate channels.

## Protocol cryptography

```mermaid
classDiagram
    class GenerationIdentity {
        <<serialized>>
        agent_profile
        domain_id
        generation_id
        configuration_fingerprint
        coordinator_id
        sandbox_id
    }

    class TrustManifest {
        <<serialized>>
        protocol_version
        generation_identity
        tls_ca_sha256
        protocol_issuer_public_key
        issuer_signature
    }

    class TlsCredential {
        <<serialized>>
        generation_identity
        role
        subject_id
        certificate_der
        certificate_sha256
    }

    class ProtocolPublicationIdentity {
        <<serialized>>
        protocol_version
        generation_identity
        tls_ca_certificate_der
        trust_manifest_sha256
        coordinator_tls_certificate_sha256
    }

    class SandboxCredentialBundle {
        <<serialized>>
        protocol_version
        generation_identity
        trust_manifest
        coordinator_protocol_credential
        sandbox_protocol_credential
        sandbox_private_key
    }

    class TlsRole {
        <<serialized>>
        <<enumeration>>
        SessionCoordinator
        ClientCLI
    }

    class ProtocolCredential {
        <<serialized>>
        protocol_version
        credential_id
        generation_identity
        role
        subject_id
        public_key
        issuer_signature
    }

    class ProtocolCredentialRole {
        <<serialized>>
        <<enumeration>>
        SessionCoordinator
        AgentSandbox
    }

    class SessionBinding {
        <<serialized>>
        generation_identity
        cli_id
        session_id
        session_anchor_public_key
    }

    class SessionRequestCapability {
        <<serialized>>
        protocol_version
        capability_id
        session_binding
        coordinator_credential_id
        sandbox_credential_id
        coordinator_signature
    }

    TrustManifest --> GenerationIdentity
    TlsCredential --> TlsRole
    TlsCredential --> GenerationIdentity
    ProtocolPublicationIdentity --> GenerationIdentity
    ProtocolPublicationIdentity --> TrustManifest
    ProtocolPublicationIdentity --> TlsCredential : coordinator TLS leaf
    SandboxCredentialBundle --> GenerationIdentity
    SandboxCredentialBundle --> TrustManifest
    SandboxCredentialBundle --> ProtocolCredential : coordinator verifier
    SandboxCredentialBundle --> ProtocolCredential : sandbox signer
    ProtocolCredential --> GenerationIdentity
    ProtocolCredential --> ProtocolCredentialRole
    SessionBinding --> GenerationIdentity
    SessionRequestCapability --> SessionBinding
    SessionRequestCapability --> ProtocolCredential : coordinator signer
    SessionRequestCapability --> ProtocolCredential : sandbox subject
```

Trust Manifests, credentials, capabilities, and private keys are ephemeral
protocol material, not Domain Store records.

```mermaid
classDiagram
    class SignedProtocolRecord {
        <<serialized>>
        <<union>>
        payload_bytes
        signature
    }

    class MailboxRequest {
        <<serialized>>
        protocol_version
        session_binding
        request_id
        session_capability
        sandbox_credential_id
        command_argv
        justification
    }

    class MailboxCancellation {
        <<serialized>>
        protocol_version
        session_binding
        request_id
        session_capability
        sandbox_credential_id
    }

    class MailboxResultAck {
        <<serialized>>
        protocol_version
        session_binding
        request_id
        request_sha256
        session_capability
        sandbox_credential_id
        highest_contiguous_sequence
    }

    class DeveloperDecision {
        <<serialized>>
        protocol_version
        session_binding
        request_id
        request_sha256
        decision
        approved_command_argv
    }

    class DeveloperDecisionKind {
        <<serialized>>
        <<enumeration>>
        Approve
        Deny
    }

    class MailboxResult {
        <<serialized>>
        protocol_version
        session_binding
        request_id
        request_sha256
        coordinator_credential_id
        outcome
        exit_code
        chunk_count
        stdout_sha256
        stderr_sha256
    }

    class MailboxResultChunk {
        <<serialized>>
        protocol_version
        session_binding
        request_id
        request_sha256
        coordinator_credential_id
        sequence
        stream
        bytes
    }

    class ResultStream {
        <<serialized>>
        <<enumeration>>
        Stdout
        Stderr
    }

    class EscalationOutcome {
        <<serialized>>
        <<enumeration>>
        Completed
        Denied
        TimedOut
        Cancelled
        Failed
    }

    SignedProtocolRecord --> MailboxRequest
    SignedProtocolRecord --> MailboxCancellation
    SignedProtocolRecord --> MailboxResultAck
    SignedProtocolRecord --> DeveloperDecision
    SignedProtocolRecord --> MailboxResult
    SignedProtocolRecord --> MailboxResultChunk
    MailboxRequest --> SessionBinding
    MailboxRequest --> SessionRequestCapability
    MailboxCancellation --> SessionBinding
    MailboxCancellation --> SessionRequestCapability
    MailboxResultAck --> SessionBinding
    MailboxResultAck --> SessionRequestCapability
    DeveloperDecision --> SessionBinding
    DeveloperDecision --> DeveloperDecisionKind
    MailboxResult --> SessionBinding
    MailboxResult --> EscalationOutcome
    MailboxResultChunk --> SessionBinding
    MailboxResultChunk --> ResultStream
```

`SessionCoordinator` is the logical protocol identity served physically by the
Host Coordinator. It is not a distinct Host Coordinator principal. Physical
encoding, signing, size, and validation rules are defined by the specification.

### Participant ownership

```mermaid
classDiagram
    class ParticipantOwnership {
        <<serialized>>
        <<union>>
    }

    class NamespaceIdentity {
        <<serialized>>
        device
        inode
    }

    class MountIdentity {
        <<serialized>>
        mount_id
        device
        inode
    }

    class PreparedLowerOwnership {
        <<serialized>>
        optional prepared_artifact_id
        optional source_identity
        optional lease_state
        optional path
        optional device
        optional inode
    }

    class StateAnchorOwnership {
        <<serialized>>
        optional lower_artifact_id
        optional upper_path
        optional work_path
        optional merged_path
        daemon
        optional mount
    }

    class GitRoutingOwnership {
        <<serialized>>
        optional mountpoint
        optional host_root
        optional isolated_root
        daemon
        optional mount
    }

    class NetworkOwnership {
        <<serialized>>
        optional derived_policy_digest
        optional readiness_fingerprint
        optional readiness_evidence
        optional namespace
        runtime_supervisor
    }

    class HelperOwnership {
        <<serialized>>
        optional network_sidecar_id
        connectivity_helper
        runtime_supervisor
    }

    class SandboxOwnership {
        <<serialized>>
        optional container_id
        optional runtime_root
        optional bundle_digest
        host_coordinator
        runtime_supervisor
        attached_runsc
    }

    class PublicationOwnership {
        <<serialized>>
        optional socket_path
        optional identity_path
    }

    ParticipantOwnership --> PreparedLowerOwnership
    ParticipantOwnership --> StateAnchorOwnership
    ParticipantOwnership --> GitRoutingOwnership
    ParticipantOwnership --> NetworkOwnership
    ParticipantOwnership --> HelperOwnership
    ParticipantOwnership --> SandboxOwnership
    ParticipantOwnership --> PublicationOwnership
    StateAnchorOwnership --> PersistedHostProcessOwnership : daemon
    StateAnchorOwnership --> MountIdentity : mount
    GitRoutingOwnership --> PersistedHostProcessOwnership : daemon
    GitRoutingOwnership --> MountIdentity : mount
    NetworkOwnership --> NamespaceIdentity : namespace
    NetworkOwnership --> PersistedHostProcessOwnership : runtime_supervisor
    NetworkOwnership --> NetworkReadinessEvidence : readiness_evidence
    HelperOwnership --> PersistedHostProcessOwnership : connectivity_helper
    HelperOwnership --> PersistedHostProcessOwnership : runtime_supervisor
    SandboxOwnership --> PersistedHostProcessOwnership : host_coordinator
    SandboxOwnership --> PersistedHostProcessOwnership : runtime_supervisor
    SandboxOwnership --> PersistedHostProcessOwnership : attached_runsc
```

`Participant.ownership=None` is the single encoding of a bare role-bound
Intent. Once a role snapshot exists it never returns to `None`. `Intent` admits
a non-empty partial matching snapshot. `ReleaseIntent` admits a non-empty
partial or complete matching snapshot and retains every exact acquired value.
`Clean` requires a matching explicit empty snapshot: all optional physical
fields are absent and all process slots are unassigned. This distinguishes
"nothing acquired yet" from "absence was proved and cleanup committed."

The only serviceable role/state pairs are:

| Role | Active state | Required physical evidence |
|---|---|---|
| `PreparedLower` | `LeaseHeld` | artifact ID, source, `lease_state=LeaseHeld`, path, device, inode |
| `StateAnchor` | `Prepared` | lower artifact, three paths, mount, current committed daemon |
| `GitRouting` | `Prepared` | three paths, mount, current committed daemon |
| `Network` | `Committed` | policy digest, fingerprint, readiness evidence, namespace, current committed RS |
| `Helper` | `Committed` | sidecar ID, current committed helper and RS |
| `Sandbox` | `Committed` | container, runtime root, bundle digest, current committed HC, RS, and runsc |
| `Publication` | `Committed` | socket and identity paths |

Network readiness evidence must name the enclosing Participant generation and
match its policy digest, fingerprint, namespace, and committed RS identity.

Intent acquisition is monotonic: optional fields move only absent-to-present,
and newly acquired child slots move only `Unassigned` to `Staged` to exact
matching current `Committed`. A current committed owner or supervisor may
enter a newly created dependent-role snapshot directly and is then immutable;
legacy ownership cannot use this rule. Recorded evidence cannot be replaced or
cleared. A transition to ReleaseIntent preserves all evidence; PreparedLower
changes only its lease phase to `ReleaseIntent`. ReleaseIntent becomes Clean
only after independent absence proof and atomically clears every physical
field. A bare Intent may become Clean only after the same sealed runtime-absence
check.

The direct existing-process edges are Network RS, Helper RS, Sandbox HC, and
Session Terminal HC. State Anchor daemon, Git-routing daemon, Helper process,
Sandbox RS, attached runsc, and Session Terminal exec client are acquired child
edges and require staging.
No bare Intent moves directly to an active state. PreparedLower must also move
from recorded `lease_state=Intent` to `LeaseHeld`; it cannot acquire the catalog
lease from an absent lease phase.

## Storage Catalog

```mermaid
classDiagram
    class StorageCatalog {
        <<serialized>>
    }

    class StoreMetadata {
        <<serialized>>
        schema_id
        schema_version
    }

    class PreparedArtifact {
        <<serialized>>
        prepared_artifact_id
        source_identity
        selected_manifest_digest
        policy_id
        id_map_digest
        path
        device
        inode
        state
    }

    class ArtifactState {
        <<serialized>>
        <<enumeration>>
        Available
        Reclaiming
    }

    class ArtifactLease {
        <<serialized>>
        prepared_artifact_id
        domain_id
        generation_id
    }

    class PrepareOperation {
        <<serialized>>
        operation_id
        expected_artifact_id
        source_identity
        stage_path
        device
        inode
    }

    StorageCatalog "1" *-- "1" StoreMetadata
    StorageCatalog "1" *-- "0..*" PreparedArtifact
    StorageCatalog "1" *-- "0..*" ArtifactLease
    StorageCatalog "1" *-- "0..*" PrepareOperation
    PreparedArtifact --> ArtifactState
    PreparedArtifact "1" --> "0..*" ArtifactLease
    PrepareOperation "0..*" --> "0..1" PreparedArtifact : publishes
```

An artifact lease identifies one prepared artifact, Domain, and generation. Its
Domain and generation fields correspond to a Domain Store generation; the stores
do not form one transactional database.

`ReleaseIntent` is a physical recovery state. It does not redefine the modeled
lease lifecycle: the specification defines how Domain Store release intent,
physical unmount, and Storage Catalog lease removal refine model unmount and
release actions. After Host Coordinator loss, the exact Runtime Supervisor may
unmount under the retained Prepared ownership record, but the Artifact Lease
remains until bootstrap Host Coordinator recovery records release intent.

## Derived network policy

```mermaid
classDiagram
    class DerivedNetworkPolicy {
        <<serialized>>
        schema_id
        address_families
        default_actions
        prefix_rules
        resolvers
    }

    class AddressFamilyDisposition {
        <<serialized>>
        family
        disposition
    }

    class DefaultAction {
        <<serialized>>
        family
        action
    }

    class PrefixRule {
        <<serialized>>
        family
        network
        action
    }

    class Resolver {
        <<serialized>>
        family
        address
    }

    class AddressFamily {
        <<serialized>>
        <<enumeration>>
        IPv4
        IPv6
    }

    class PolicyAction {
        <<serialized>>
        <<enumeration>>
        Allow
        Deny
    }

    DerivedNetworkPolicy "1" *-- "2" AddressFamilyDisposition
    DerivedNetworkPolicy "1" *-- "1..2" DefaultAction
    DerivedNetworkPolicy "1" *-- "0..*" PrefixRule
    DerivedNetworkPolicy "1" *-- "1..*" Resolver
    AddressFamilyDisposition --> AddressFamily
    DefaultAction --> AddressFamily
    DefaultAction --> PolicyAction
    PrefixRule --> AddressFamily
    PrefixRule --> PolicyAction
    Resolver --> AddressFamily
```

The policy has exactly one disposition for each address family. Each enabled
family has exactly one default action. Prefixes and addresses are canonical, and
equal-prefix action conflicts are invalid. Policy identity is the SHA-256 digest
of its canonical form with a schema-specific domain separator.

## Network readiness

```mermaid
classDiagram
    class NetworkReadinessEvidence {
        <<serialized>>
        domain_id
        generation_id
        network_sidecar_id
        readiness_fingerprint
    }

    class NetworkReadinessAttestation {
        <<serialized>>
        schema_id
        domain_id
        generation_id
        configuration_fingerprint
        network_sidecar_id
        derived_policy_digest
        enforcement_namespace
        runtime_supervisor
        connectivity_helper
        observation
    }

    class NetworkObservation {
        <<serialized>>
        policy_delivery
        helper_ready
        observed_routes
        routes_attested
    }

    class PolicyDelivery {
        <<serialized>>
        <<enumeration>>
        SealedMemfd
    }

    class NetworkReadinessIdentity {
        <<serialized>>
        schema_id
        domain_id
        generation_id
        configuration_fingerprint
        network_sidecar_id
        derived_policy_digest
        enforcement_namespace
    }

    class NamespaceIdentity {
        <<serialized>>
        device
        inode
    }

    class NetworkReachabilityProbe {
        <<serialized>>
        domain_id
        generation_id
        enforcement_namespace
    }

    class DeniedDestinationObservation {
        <<serialized>>
        destination
        unreachable
    }

    class PermittedDestinationObservation {
        <<serialized>>
        destination
        reachable
    }

    class DnsObservation {
        <<serialized>>
        resolver
        query_name
        resolved_addresses
    }

    NetworkReadinessEvidence --> NetworkReadinessAttestation : accepts
    NetworkReadinessEvidence --> NetworkReadinessIdentity : fingerprints
    NetworkReadinessEvidence --> NetworkReachabilityProbe : includes
    NetworkReadinessAttestation --> NamespaceIdentity : enforcement_namespace
    NetworkReadinessAttestation --> PidfsProcessIdentityV1 : runtime_supervisor
    NetworkReadinessAttestation --> PidfsProcessIdentityV1 : connectivity_helper
    NetworkReadinessAttestation --> NetworkObservation
    NetworkObservation --> PolicyDelivery
    NetworkReadinessIdentity --> NamespaceIdentity : enforcement_namespace
    NetworkReadinessAttestation ..> NetworkReadinessIdentity : projects
    NetworkReachabilityProbe --> NamespaceIdentity : enforcement_namespace
    NetworkReachabilityProbe "1" *-- "1..*" DeniedDestinationObservation
    NetworkReachabilityProbe "1" *-- "1..*" PermittedDestinationObservation
    NetworkReachabilityProbe "1" *-- "1..*" DnsObservation
```

The readiness fingerprint is the SHA-256 digest of the canonical readiness
identity with a schema-specific domain separator. Process identities and network
observations are attestation evidence but are not part of that fingerprint. The
Host Coordinator binds the accepted attestation and generation-bound reachability
probe into Network Readiness Evidence before publication.

`NetworkReadinessAttestation.schema_id` is exactly
`lazaret-network-attestation-v1`.
`NetworkReadinessIdentity.schema_id` is exactly
`lazaret-network-readiness-identity-v1`. They are independent version-dispatch
domains: the v1 attestation projects only to the v1 readiness identity, and any
other identifier or version is refused without fallback or cross-domain
interpretation.

The readiness-fingerprint domain separator is the UTF-8 bytes of
`lazaret-network-readiness-identity-v1` followed by exactly one zero byte. This
fixes the domain-separation context only; it does not select the byte encoding of
the canonical readiness-identity fields.