Trust Posture Schema

This page is the normative reference for the JSONB body stored in trust_posture_revisions.body. It covers the v1.0 schema, every field’s type and semantics, validation rules, and the per-axis composition rules the composer applies when folding Platform → Org → Team. The conceptual overview is at Trust Posture; this page is the spec.

Top-level shape

{
  "posture_schema_version": "v1.0",
  "sideband": {
    "coherence": { /* see below */ },
    "fault_line": { /* see below */ },
    "fleet": { /* see below */ }
  },
  "fleet_identification": { "by": "team_membership" },
  "fan_out": { "rule": "per_named_affected_agent" }
}

Field	Type	Required	Notes
`posture_schema_version`	string (literal `"v1.0"`)	✓	Strict — future schema versions bump this and the validator rejects unknown values.
`sideband`	object	✓	Container for the three sideband axes.
`fleet_identification`	object	✓	How the observer enumerates the fleet for sweep.
`fan_out`	object	✓	How findings produce per-agent advisories.

Strict-unknown-field rejection. Top-level and nested objects reject unknown keys. Adding a field requires a schema-version bump.

`sideband` axes

`sideband.coherence`

Drives computeTeamCoherence (@mnemom/team-coherence). Detector takes no internal config; the posture body is the firing policy.

{
  "enabled": true,
  "cadence_seconds": 600,
  "fire_on": {
    "pairwise_governance_floor_below": 0.5,
    "conflict_edge_count_exceeds": 3,
    "outlier_agents_count_exceeds": 0
  },
  "severity_on_fire": "medium"
}

Field	Type	Required	Range	Notes
`enabled`	boolean	✓	—	Master switch.
`cadence_seconds`	positive integer	✓	≥ 1	Sweep interval floor.
`fire_on.pairwise_governance_floor_below`	number or null	✓	[0, 1] or null	Pairwise governance below this fires. null disables this condition.
`fire_on.conflict_edge_count_exceeds`	integer or null	✓	≥ 0 or null	Conflict-edge count strictly above this fires. null disables.
`fire_on.outlier_agents_count_exceeds`	integer or null	✓	≥ 0 or null	Outlier-agent count strictly above this fires. null disables.
`severity_on_fire`	enum	✓	`low \| medium \| high \| critical`	Stamped onto the advisory.

Detector fires when any of the fire_on conditions is satisfied. To disable a condition entirely, set it to null. To disable the entire axis, set enabled: false.

`sideband.fault_line`

Drives analyzeFaultLines (@mnemom/agent-alignment-protocol).

{
  "enabled": true,
  "cadence_seconds": 600,
  "severity_floor": "high",
  "use_reputation_scores": true,
  "severity_on_fire": "high"
}

Field	Type	Required	Range	Notes
`enabled`	boolean	✓	—	Master switch.
`cadence_seconds`	positive integer	✓	≥ 1	Sweep interval floor.
`severity_floor`	enum	✓	`low \| medium \| high \| critical`	Findings below this severity are dropped.
`use_reputation_scores`	boolean	✓	—	Whether to weight `impact_score` by reputation.
`severity_on_fire`	enum	✓	`low \| medium \| high \| critical`	Stamped onto the advisory.

The fault-line detector emits findings at four severity tiers (low / medium / high / critical, derived from impact_score thresholds in the SDK). severity_floor is the cutoff — findings below that severity don’t fire. severity_on_fire is what the resulting pending_advisories row carries.

`sideband.fleet`

Drives checkFleetCoherence / checkFleetFaultLines (@mnemom/agent-alignment-protocol).

{
  "enabled": true,
  "cadence_seconds": 600,
  "patterns": {
    "outliers": true,
    "min_pair_score_below": 0.5,
    "cluster_partition": true
  },
  "severity_on_fire": "medium"
}

Field	Type	Required	Range	Notes
`enabled`	boolean	✓	—	Master switch.
`cadence_seconds`	positive integer	✓	≥ 1	Sweep interval floor.
`patterns.outliers`	boolean	✓	—	Fire when at least one outlier (>1σ below fleet mean) is detected.
`patterns.min_pair_score_below`	number or null	✓	[0, 1] or null	Fire when min_pair_score is strictly below this. null disables.
`patterns.cluster_partition`	boolean	✓	—	Fire when the fleet partitions into incompatible clusters (compatibility ≥ 0.7 in the SDK).
`severity_on_fire`	enum	✓	`low \| medium \| high \| critical`	Stamped onto the advisory.

A finding is emitted when any enabled pattern fires.

`fleet_identification`

{ "by": "team_membership" }

Field	Type	Required	Allowed values
`by`	string	✓	`team_membership`

In v1.0, team_membership is the only valid value. The field is present so future identification modes (by capability, by tag, by metadata predicate) can be added additively without breaking existing rows. Validators reject unknown values.

`fan_out`

{ "rule": "per_named_affected_agent" }

Field	Type	Required	Allowed values
`rule`	string	✓	`per_named_affected_agent`

In v1.0, per_named_affected_agent is the only valid value — every named affected agent in a finding receives one pending_advisories row. Future modes (deduplicated, aggregated, throttled) extend this enum additively.

Composition rules

The composer (composeTrustPosture in mnemom-api) folds Platform → Org → Team with strictest-wins per axis. Mirrors the cards composition idiom.

Field shape	Rule	Stricter direction
`*.enabled` (bool)	OR-true	Any layer enabling fires the detector
`cadence_seconds` (number)	min	Shorter = more frequent = stricter
`fire_on.pairwise_governance_floor_below` etc. (number or null)	min-among-defined; null contributes nothing	Lower threshold = fires earlier = stricter
`fire_on.conflict_edge_count_exceeds` etc. (number or null)	min-among-defined	Lower count threshold = fires earlier
`severity_floor` (enum)	min	Lower floor = more advisories = stricter
`severity_on_fire` (enum)	max	Higher = louder advisory = stricter
`patterns.outliers`, `patterns.cluster_partition` (bool)	OR-true	Any layer enabling that pattern fires it
`patterns.min_pair_score_below` (number or null)	min-among-defined	Lower = fires later vs. higher = fires earlier — see note
`use_reputation_scores` (bool)	OR-true	Any layer wanting reputation modulation gets it
`fleet_identification.by` (enum)	precedence: highest layer wins	Single value in v1; deterministic for forward-compat
`fan_out.rule` (enum)	precedence: highest layer wins	Single value in v1; deterministic for forward-compat

On min_pair_score_below direction: the field expresses “fire when the worst pair is below this.” A higher threshold fires more often (stricter); a lower threshold fires less often (looser). The composer uses min here — meaning the lower (looser) value wins. If you want stricter behavior, set the value higher at your layer. This is a deliberate exception to “lower = stricter” because the field’s semantic is the upper bound at which firing starts. The composer documents it explicitly.

Cascade closure

The platform guarantees: every team has an effective posture. The platform default (tp-platform-standard) is the floor — every team’s effective body composes at least the platform layer. If the gather RPC returns a degraded envelope (e.g., the platform seed somehow missing), the in-process composer synthesizes a fallback floor matching tp-platform-standard’s body. Production should never see this path; it’s defensive belt-and-suspenders, with a sentinel posture_id: tp-synthetic-fallback in the output’s scopes_applied for telemetry.

Validation rules summary

Rule	Behavior
Unknown top-level keys	400
Unknown nested keys (in any object)	400
`posture_schema_version != "v1.0"`	400
Non-boolean `enabled`	400
Non-positive-integer `cadence_seconds`	400
`severity_on_fire` / `severity_floor` not in	400
Numeric out of range (e.g., `pairwise_governance_floor_below > 1.0`)	400
Non-integer `conflict_edge_count_exceeds` / `outlier_agents_count_exceeds`	400
Missing required field	400
`fleet_identification.by` not in allowed values	400
`fan_out.rule` not in allowed values	400

Validation failures return a structured { ok: false, errors: [{ field, rule, message }, …] } body so client tooling can surface specific field errors.

Body size

Server-side limit: 256 KiB per posture body. Cards’ equivalents are 128 KiB (alignment) and 64 KiB (protection); postures are larger by design because of the multi-axis schema and future-axis headroom (Trust-Rating gating, attestation flags, control-tag mappings). A 413 response means your body is over the limit. Postures rarely approach 256 KiB in practice — the canonical Mnemom defaults are <2 KiB each.

Overview

Identity & Cards

Posture & Policy

Detection & Safe House

AEGIS

Reputation & Risk

Lifecycle

Gateway

Pricing

Migrations

Policy

Specifications

Changelog

Top-level shape

`sideband` axes

`sideband.coherence`

`sideband.fault_line`

`sideband.fleet`

`fleet_identification`

`fan_out`

Composition rules

Cascade closure

Validation rules summary

Body size

See also

​Top-level shape

​sideband axes

​sideband.coherence

​sideband.fault_line

​sideband.fleet

​fleet_identification

​fan_out

​Composition rules

​Cascade closure

​Validation rules summary

​Body size

​See also

Top-level shape

`sideband` axes

`sideband.coherence`

`sideband.fault_line`

`sideband.fleet`

`fleet_identification`

`fan_out`

Composition rules

Cascade closure

Validation rules summary

Body size

See also