Trusted AI Kernel (TAK)

Trusted AI Kernel (TAK)

Abstract

The Trusted AI Kernel (TAK) is a normative agent-harness and runtime-governance standard for trustworthy AI agent operation. It defines the minimum harness contract and control model needed when AI agents act on behalf of human principals inside enterprise, public-sector, or cross-organizational systems.

The problem TAK addresses is broader than runtime mediation alone: model capability does not create trustworthy agency, and ad hoc agent wrappers do not create a consistent basis for governed deployment. Trustworthy agency requires a standard harness that defines how authority, instructions, tool invocation, provider use, data sensitivity, memory, oversight, and evidence are assembled and enforced at runtime. TAK defines that harness contract.

TAK is intentionally concerned with runtime governance and harness consistency. It does not attempt to solve global agent naming or public badging. Those concerns belong to the companion GAID standard. TAK instead defines what a trustworthy agent harness and runtime MUST, SHOULD, and MAY do once an identified agent is allowed to operate.

1. Scope

This standard specifies requirements for:

This standard applies to:

This standard does not define:

Those concerns are addressed by GAID.

2. Conformance

An implementation conforms to this standard only if it satisfies all requirements identified as MUST for its claimed conformance profile.

This standard defines three conformance profiles:

An implementation:

2.1 Standard Versioning, Lifecycle, and Conformance Assertions

This standard SHOULD be versioned using a semantic-style scheme:

Implementations claiming conformance SHOULD declare:

Each normative MUST statement in this standard SHOULD map to one or more explicit conformance assertions in a companion test suite or implementation statement. This document does not require a single central test harness, but it does require that conformance claims be testable rather than rhetorical.

A suggested companion assertion rubric for this revision is published in tak-conformance-tests.md.

The intended lifecycle of TAK is open standards progression through multistakeholder implementation and liaison rather than indefinite treatment as an internal white paper.

The preferred near-term disposition is publication as an open industry specification with liaison into NIST, the Agentic AI Foundation, OASIS / CoSAI, and relevant IETF OAuth and GNAP work, with later venue-specific profiles or submissions preserving the same core runtime semantics.

3. Normative References

The following references are relevant to this standard and informed its design:

Reference Relevance
ISO/IEC 42001:2023 Organization-level AI management systems
NIST AI RMF 1.0 Risk management framing for AI systems
NIST AI Agent Standards Initiative Current U.S. public-sector standards activity for agents
NCCoE concept paper: software and AI agent identity and authorization Identity, authorization, auditing, and non-repudiation concerns for agents
NIST AI 800-2 benchmark evaluation draft Evaluation transparency and benchmark discipline
Model Context Protocol specification Tool and context interoperability
Model Context Protocol authorization specification HTTP transport authorization profile for MCP servers and clients
Anthropic: Introducing the Model Context Protocol Background on MCP as an open protocol
Linux Foundation: Agentic AI Foundation announcement Neutral governance venue for MCP and AGENTS.md stewardship
AGENTS.md Open declarative instruction format used across coding-agent ecosystems
RFC 9728 OAuth 2.0 Protected Resource Metadata Discovery and metadata for protected resource authorization surfaces
RFC 9635 Grant Negotiation and Authorization Protocol (GNAP) Negotiated delegated authorization model for dynamic access decisions
RFC 9767 GNAP Resource Server Connections Resource-server-side GNAP discovery and access-right connection model
RFC 9449 OAuth 2.0 Demonstrating Proof of Possession (DPoP) Sender-constrained token binding for high-assurance agent calls
OpenAI Preparedness Framework Frontier-model safety governance prior art, useful for scoping what TAK does and does not standardize
Anthropic Responsible Scaling Policy Frontier-model safety and deployment governance prior art, complementary rather than substitutive to runtime kernel controls
Google DeepMind Frontier Safety Framework Model-level severe-risk framework used to distinguish model governance from runtime governance
CoSAI: Agentic Identity and Access Management Agentic IAM control framing aligned to enterprise runtime operation
OWASP Top 10 for Agentic Applications Concrete agentic risk taxonomy and mitigation guidance
W3C Trace Context Cross-system trace propagation
RFC 9421 HTTP Message Signatures Message-level signatures for integrity and non-repudiation
in-toto Attestation Framework Specification Practical attestation statement and envelope model for signed evidence
Sigstore Documentation Operational signing, transparency, and verification substrate for attestations and release evidence
CSA MAESTRO Agentic AI threat-modeling framework
MITRE ATLAS Adversarial tactics and techniques knowledge base for AI systems
IMDA Model AI Governance Framework for Agentic AI National governance framework for agentic AI deployment
ISO/IEC 12792:2025 Transparency taxonomy for AI systems
ISO/IEC DIS 42102 Framework for characterizing AI system methods and capabilities

3.1 Reuse and Profiling Rule

TAK is intended to compose adjacent standards, not replace them.

Accordingly:

In practice this means:

4. Terms and Definitions

For the purposes of this standard:

Term Definition
agent A software system that can reason, decide, and perform actions with or without tool use on behalf of a principal or workflow
principal The human or organizational authority under which an agent operates
runtime The execution environment that implements the agent harness and mediates prompts, tools, memory, policies, and outputs
agent harness The standard runtime structure that binds authority, instructions, model access, tools, memory, oversight, and evidence into one governed execution contract
immutable directive A runtime-enforced instruction that the agent cannot change through conversation
tool A callable capability that reads, writes, transforms, or acts on an internal or external system
execution mode The enforcement class governing how a tool call is handled at runtime
proposal A gated action that requires explicit human approval before execution
immediate An action the runtime may execute without per-action approval because policy allows it
delegation Transfer of a bounded task from one agent or orchestrator context to another
escalation Routing of a decision or blocker to a higher-authority human or agent context
memory Persisted or replayed context intended to influence subsequent agent behavior
context window governance Controls that determine what prior information is preserved, summarized, truncated, or excluded
provider budget The governed runtime view of rate, concurrency, token-throughput, quota, credit, funding-token, or contractual limits imposed by a model provider or inference service
backpressure Runtime behavior that slows, queues, defers, or rejects new inference work so provider and policy limits are not exceeded
inference queue A bounded, resumable runtime queue holding model invocations awaiting execution, retry, failover, or operator intervention
capability tier A policy classification that defines the minimum acceptable model capability and the allowed substitution set for a task or workflow
runtime transparency The ability for humans and auditors to inspect what the agent was allowed to do, attempted to do, and actually did
fabrication A model output that claims work, change, or completion not supported by tool or runtime evidence
operating profile The governed bundle of materially relevant runtime state for an identified agent, including model binding, instructions, tools, autonomy posture, and verification references
profile fingerprint A digest or equivalent marker derived from the materially relevant operating profile state
validation continuity Whether the currently running operating profile remains the same validated operational subject previously assessed or approved

5. Core Principle

The core principle of TAK is:

Humans hold authority. Agents hold capability. The kernel provides the standard harness on which trustworthy AI agents are built, operated, and evidenced.

The point is not merely to restrict the model or intercept model calls. The point is to establish a consistent and governable basis for how AI agents are built, invoked, supervised, and evidenced. Mediation is one function of that harness, but the larger purpose is to ensure that authority, capability, directives, execution, and evidence remain aligned throughout runtime operation.

6. Design Principles

An implementation of TAK:

7. Runtime Trust Model

7.1 Required Control Layers

A conforming implementation MUST apply runtime control in layers. At minimum, those layers MUST include:

  1. authentication of the human or calling system
  2. resolution of authority or role context
  3. evaluation of allowed capabilities
  4. agent-side grant or scope filtering
  5. execution gating for side-effecting operations

The runtime MUST NOT allow a lower layer to widen permissions restricted by a higher layer.

7.2 Effective Permission Rule

For any (principal, agent, tool) combination, the runtime MUST compute effective permission as the intersection of:

The runtime MUST NOT treat the model’s request as sufficient evidence of authorization.

7.3 Domain and Route Scoping

The runtime SHOULD expose only the domain-relevant subset of tools and context for a given route, task, or workflow stage.

This is not only a usability optimization. It is a control. Smaller, better-bounded tool surfaces reduce:

TAK authority layers

Figure 1. Layered authority mediation is a required kernel behavior inside the broader TAK harness, not only a UI convenience.

7.4 Approved Operating Profiles

A conforming runtime MUST treat an agent’s approved operating profile as a governed runtime artifact.

At minimum, the operating profile SHOULD include:

For governed agents, the runtime MUST NOT execute against undeclared or unapproved materially relevant profile state.

7.5 Runtime Identity Proof Posture

For an identified governed agent, the runtime SHOULD be able to support a stronger claim than:

The stronger claim is:

TAK does not define the external identity namespace itself. That belongs to companion identity work such as GAID. TAK does, however, define the runtime conditions under which such identity claims can be trusted in operation.

7.6 Core Runtime Semantics Versus Protocol Carriers

TAK implementations SHOULD follow a stable-core and profile pattern similar to mature identity and directory standards.

In that pattern:

TAK therefore MUST NOT be treated as a replacement for LDAP, SCIM, HTTP, or message protocols. It defines what those carriers need to say about trusted runtime state, not the transport itself.

7.7 Material Change and Validation Continuity

The runtime MUST treat material change as a trust-relevant event.

Material change includes:

The same enduring subject identity MAY remain valid while validation continuity is broken.

Therefore, the runtime SHOULD distinguish:

and MUST NOT silently assume they are equivalent.

7.8 Profile Fingerprints and Attestation

For governed agents, the runtime SHOULD support:

Acceptable higher-assurance attestation substrates MAY include hardware-rooted measurements such as TPM, TDX, or SEV-SNP, as well as software evidence stacks such as DSSE, in-toto, Sigstore, or SCITT-style statement publication, provided they let a verifier bind profile state to the governed runtime instance that actually executed the work.

This allows relying parties and auditors to distinguish between:

7.9 Attestation and Projection Profiles

When TAK state is projected into external systems, the projection SHOULD preserve the distinction between:

For example:

An implementation SHOULD document those profile mappings explicitly so external systems know which parts of TAK they can rely on and which parts remain internal kernel evidence.

7.10 Vendor-Neutral Reference Model

The following reference model is intentionally independent from any one product platform.

It shows the stable TAK control relationship between:

TAK reference model

Figure 2. TAK defines a vendor-neutral harness control plane that sits between authority, agents, tools, and evidence.

8. Tool Execution and Action Gating

8.1 Tool Definitions

A conforming implementation MUST define tools with machine-readable metadata sufficient to enforce policy. At minimum, each tool definition MUST declare:

The runtime MUST NOT rely solely on natural-language tool descriptions for governance decisions.

Declarative instruction artifacts such as AGENTS.md MAY provide human- and agent-readable operating guidance for coding or workflow agents, but the runtime MUST still maintain machine-readable tool and control metadata independently of those documents.

8.2 Execution Modes

At minimum, the runtime MUST support two execution modes:

Mode Meaning
immediate Runtime may execute without per-action approval, subject to policy
proposal Runtime must pause and request human approval before execution

The runtime MAY define more granular subclasses, but it MUST NOT weaken the semantics of proposal.

8.3 Proposal Requirements

For proposal actions, the runtime MUST present:

The runtime MUST record whether the proposal was:

8.4 Default Safety Rule

If a tool:

then the runtime MUST default that tool to proposal unless a higher-assurance policy explicitly permits immediate execution.

8.5 Provider Budgets and Backpressure

A conforming runtime MUST implement provider-aware rate budgeting and backpressure for any provider, model, or upstream inference service that can impose:

These limits are runtime-governance signals, not merely application exceptions.

Predictive backpressure is often inferred rather than explicitly published by providers. A conforming runtime MAY derive predictive state from recent 429 behavior, Retry-After hints, token-usage headers, contract ceilings, or observed admission patterns where direct provider telemetry is incomplete.

The runtime MUST:

8.6 Dependency Drift and Revalidation

The runtime MUST recognize that material drift can originate from dependencies as well as from deliberate local configuration edits.

Examples include:

Where such drift materially affects capability or risk posture, the runtime SHOULD trigger revalidation requirements or equivalent policy review rather than continuing to treat prior approval state as unquestionably current.

At minimum, the human-consumable runtime state SHOULD distinguish conditions such as:

8.7 Bounded and Resumable Inference Queues

A conforming runtime MUST support bounded, resumable inference queues rather than assuming every user request maps directly to an immediate model call.

The inference queue MUST:

For consequential or side-effecting workflows, the runtime MUST ensure that queue resumption does not silently duplicate already-completed actions.

Queue entries SHOULD carry, at minimum:

8.8 Policy-Based Failover and Scheduled Retry

A conforming runtime SHOULD support policy-based fallback to another approved model or provider when the originally selected path is unavailable, rate-limited, misconfigured, or otherwise unsuitable.

If failover is supported, the runtime:

When failover is not allowed or not useful, the runtime MAY schedule retry after a known reset window or budget-replenishment event.

If scheduled retry is used, the runtime MUST:

8.9 Illustrative Queue and Provider Pseudocode

The following pseudocode is informative, but it expresses the minimum runtime behavior the standard expects.

function processInferenceRequest(request):
  prior = findCompletedInferenceByIdempotencyKey(request.idempotency_key)
  if prior is not null:
    emit("tak.inference.reused", request, prior)
    return prior

  profile = resolveApprovedOperatingProfile(request.agent_id)
  tier = resolveCapabilityTier(request.task_class, request.sensitivity_class)
  budget = getProviderBudget(profile.primary_provider, profile.model_binding)

  if not budget.canAdmit(request):
    emit("tak.provider.backpressure", request, budget)
    queue.defer(
      request,
      reason = "provider_budget",
      next_eligible_time = budget.nextResetWindow()
    )
    emit("tak.queue.deferred", request, budget)
    return deferredToUser(request, budget)

  queue.admit(request)
  emit("tak.queue.admitted", request, budget)

  result = tryPrimaryExecution(request, profile)
  lastResult = result
  if result.success:
    emit("tak.inference.completed", request, result)
    return result

  if policyAllowsFailover(request, profile, tier, result.failure_reason):
    alternate = selectApprovedAlternateProvider(request, profile, tier)
    emit("tak.provider.failover_selected", request, alternate)
    retry = executeWithProvider(request, alternate)
    lastResult = retry
    if retry.success:
      emit("tak.inference.completed", request, retry)
      return retry

  if lastResult.retry_after_window is not null:
    queue.defer(
      request,
      reason = "retry_after_window",
      next_eligible_time = lastResult.retry_after_window
    )
    emit("tak.queue.deferred", request, lastResult)
    return deferredToUser(request, lastResult)

  escalateToHuman(
    request,
    incident_class = classifyProviderIncident(lastResult),
    evidence = lastResult
  )
  emit("tak.hitl.escalated", request, lastResult)
  return escalationNotice(request, lastResult)

At minimum, this behavior demonstrates:

8.10 Example Runtime Event Shapes

TAK implementations SHOULD make runtime state machine-readable even when the user-facing UI remains conversational.

Illustrative examples:

{
  "event_type": "tak.queue.admitted",
  "agent_id": "AGT-ORCH-200",
  "principal_id": "HR-200",
  "request_id": "req-7d1a",
  "task_class": "architecture-review",
  "capability_tier": "reasoning-high",
  "provider": "anthropic",
  "model": "claude-opus-4-6",
  "queue_depth": 3,
  "created_at": "2026-05-11T14:06:12Z"
}
{
  "event_type": "tak.provider.backpressure",
  "agent_id": "AGT-ORCH-200",
  "request_id": "req-7d1a",
  "provider": "anthropic",
  "reason": "token_throughput_limit",
  "retry_after_seconds": 45,
  "budget_state": {
    "daily_remaining": 142000,
    "burst_state": "exhausted"
  },
  "created_at": "2026-05-11T14:06:14Z"
}
{
  "event_type": "tak.provider.failover_selected",
  "agent_id": "AGT-ORCH-200",
  "request_id": "req-7d1a",
  "primary_provider": "anthropic",
  "primary_model": "claude-opus-4-6",
  "alternate_provider": "openai",
  "alternate_model": "gpt-5.4",
  "policy_basis": [
    "capability_tier_match",
    "approved_for_internal_confidential"
  ],
  "created_at": "2026-05-11T14:06:16Z"
}
{
  "event_type": "tak.hitl.escalated",
  "agent_id": "AGT-ORCH-200",
  "request_id": "req-7d1a",
  "incident_class": "provider_auth_or_contract_failure",
  "needs_human_action": true,
  "gaid_scope_violation_detected": false,
  "created_at": "2026-05-11T14:06:20Z"
}

9. Human-in-the-Loop and Oversight Tiers

9.1 HITL Tiers

A conforming implementation SHOULD classify agents and actions by oversight tier. At minimum, the following conceptual levels SHOULD exist:

Tier Meaning
0 blocked; no autonomous action permitted
1 approve-before-execution
2 review-after-execution
3 autonomous with mandatory logging

9.2 Enforcement

The runtime MUST enforce the effective oversight tier at execution time. It is not sufficient to store a tier as metadata without affecting behavior.

The runtime MUST NOT allow the model to self-upgrade its oversight tier.

9.3 Supervisor Visibility

For TAK-Managed and above, the runtime MUST provide a human-supervisor-visible view of:

10. Immutable Directives and Hidden Instruction Governance

10.1 Directive Sources

A conforming implementation MUST distinguish between:

10.2 Immutability

If a directive is marked immutable, the runtime MUST ensure that:

10.3 Governance of Hidden Instructions

Because hidden instructions are a material governance surface, a TAK-Managed or TAK-Assured implementation MUST maintain a reviewable record of:

The runtime SHOULD NOT expose raw hidden prompts to end users by default, but it MUST preserve enough metadata for authorized audit and governance review.

TAK directive flow

Figure 3. Directives are not merely prompt text. They are a governed runtime control surface.

11. Delegation, Coordination, and Specialist Topology

11.1 Delegation Narrowing

When an agent delegates to another agent, the delegated agent:

11.2 Specialist and Coordinator Patterns

An implementation SHOULD distinguish:

This distinction matters because the same agent shape should not be assumed to fit all work equally well.

11.3 Escalation

A conforming runtime MUST support escalation to a human or higher-authority control point when:

11.4 Provider and Governance Incident Escalation

A conforming runtime MUST support HITL and human escalation for operational incidents that cannot be safely resolved through autonomous retry or failover alone.

At minimum, the escalation path MUST cover:

The runtime SHOULD treat these conditions similarly to an employee reporting an observed security or data-handling incident: safe continuation pauses, the issue is surfaced clearly, and a human owner is brought into the loop.

When such an incident is detected, the runtime MUST:

TAK delegation chain

Figure 4. Delegation is valid only when authority narrows, not widens.

12. Memory and Context-Window Governance

12.1 Memory Is a Governed Surface

Persistent memory, retrieved memory, and prior conversation context MUST be treated as governed runtime inputs.

Memory is not a neutral convenience. It changes future behavior. Therefore, TAK requires explicit control over:

12.2 Retention Rules

A TAK-Managed or higher implementation MUST define policies for:

The runtime MUST NOT expose memory derived from one principal, tenant, or authorization boundary to another principal, tenant, or authorization boundary without explicit policy permission.

12.3 Context Truncation and Summarization

When context windows are limited, the runtime MUST favor:

The runtime SHOULD document summarization and truncation behavior so operators understand what information may have been omitted.

12.4 Memory Validation

For TAK-Assured, memory that materially affects consequential action SHOULD be treated as advisory until revalidated against a current source of truth.

13. Audit, Evidence, and Non-Repudiation

13.1 Minimum Audit Events

A conforming implementation MUST record, at minimum:

13.2 Evidence Fields

Audit records SHOULD include:

13.3 Non-Repudiation

For TAK-Assured, the runtime SHOULD support cryptographic binding or message-level evidence sufficient to prove:

GAID provides the companion identity and receipt model for this purpose.

TAK audit surfaces

Figure 5. Audit is not a side effect of the runtime. It is part of the runtime.

14. Runtime Transparency

14.1 Required Transparency

A TAK-Managed implementation MUST provide operators with a way to inspect:

14.2 Human-Facing Honesty

The runtime MUST prevent or correct outputs that falsely claim:

This control is fundamental to trust.

15. Safety and Security Controls

15.1 Fabrication and Unsafe Narration

A conforming runtime MUST detect and mitigate situations where the model:

15.2 Injection Resistance

The runtime SHOULD implement layered defenses against:

15.3 Sensitivity Handling

The runtime MUST allow policy to vary by data sensitivity. At minimum, the implementation SHOULD distinguish sensitivity classes such as:

The runtime MUST NOT silently route restricted data into lower-trust tools, providers, or delegated contexts that are not cleared for it.

15.4 Open-World Tooling

External network or cross-boundary tools SHOULD be treated as higher-risk surfaces. A TAK-Managed implementation SHOULD explicitly classify such tools rather than treating them as ordinary local operations.

15.5 Threat-Model Alignment

An implementation SHOULD maintain an explicit threat model for the agent runtime.

At minimum, that threat model SHOULD identify:

Threat enumeration SHOULD align where useful to emerging public catalogs such as the OWASP Top 10 for Agentic Applications, CSA MAESTRO, and MITRE ATLAS.

A shared starter artifact for this work MAY be published as agent-standards-threat-model.md, provided implementations still adapt it to their real deployment boundaries.

16. Evaluation and Red Teaming

16.1 Minimum Evaluation Expectations

A conforming implementation MUST test the runtime, not only the model. At minimum, it MUST evaluate:

Fabrication resistance and related trust claims MUST be backed by a published evaluation methodology and baseline rates, either by profiling a recognized benchmark suite or by documenting an organization-specific evaluation pack with reproducible pass criteria.

16.2 Advanced Evaluation

A TAK-Assured implementation SHOULD additionally evaluate:

16.3 External Signals

The growing public focus on agent security, identity, evaluation, and interoperability is relevant here. NIST’s current work on agent standards and benchmark evaluation confirms that trustworthy agency is not only a model-quality problem, but a runtime governance problem as well.

16.4 Evaluation Cadence and Threat Catalog Coverage

Evaluation MUST NOT be treated as a one-time launch ritual.

At minimum, a conforming implementation MUST re-run the applicable evaluation set:

TAK-Assured implementations SHOULD additionally map at least the most relevant scenarios to external threat catalogs such as OWASP Top 10 for Agentic Applications, CSA MAESTRO, and MITRE ATLAS, so evaluation coverage is legible outside one vendor stack.

17. Conformance Profiles

17.1 TAK-Basic

TAK-Basic requires:

17.2 TAK-Managed

TAK-Managed requires everything in TAK-Basic, plus:

17.3 TAK-Assured

TAK-Assured requires everything in TAK-Managed, plus:

Implementations claiming any TAK profile SHOULD publish an assertion mapping, evidence pack, or equivalent rubric such as the companion tak-conformance-tests.md document.

18. Security Considerations

This standard assumes:

The consequence is that a trustworthy agent runtime cannot be reduced to prompt design alone.

19. Informative Annex A: Relationship to GAID

TAK and GAID are designed to work together.

In practical terms:

20. Informative Annex B: Relationship to DPF

DPF already demonstrates a number of TAK patterns in practice, including:

That makes DPF a useful proving ground for the first conformance assessment of this standard.

For the purposes of this standards family, DPF should be understood as an initial implementation prototype rather than as a claim of full conformance.

The prototype value is that DPF can concretely demonstrate:

The most useful near-term DPF outcomes under this standard include:

21. Summary

The key message of this standard is simple:

AI agents become trustworthy and repeatable in practice only when they run inside a standard kernel harness that governs authority, tools, memory, provider use, oversight, and evidence with discipline.

TAK provides that discipline. It is not a substitute for broader organizational governance. It is the runtime harness standard and control model that makes operational governance real.