An open standard from Agentic Thinking Limited
⚠ EU AI Act Article 12 · 2 August 2026 · record-keeping enforceable for high-risk AI systems

The open hook standard for EU AI Act compliance.

AgentHook is the specification for the lifecycle hooks every AI agent runtime should expose, so operators, auditors, and regulators can record what an agent did, when, why, and with what reasoning.

Apache-2.0 in perpetuity. Stewarded by Agentic Thinking Limited under a binding charter with a no-relicence pledge, an irrevocable patent grant, and a written stewardship-transfer trigger to a neutral foundation.

v0.1 draft · Apache License 2.0 · perpetual no-relicence pledge

Article 12 needs hooks. Vendors don't agree on what they look like.

EU AI Act Article 12 requires automatic event logging for high-risk AI systems. Every enterprise deploying agentic AI in regulated jurisdictions needs auditable, transcript-grade records of every action an agent takes. Agent runtimes today expose hooks inconsistently. Coverage varies between vendors and over time. There is no shared definition of what a complete hook surface looks like, what events must be emitted, or what metadata each event must carry.

100%
Compliance burden lands on the deployer
Article 12 places record-keeping obligations on whoever puts the system into service. Vendors are not required to make this easy.
N×M
Bespoke integrations per provider, per tool
Without a standard, every enterprise rebuilds the same compliance plumbing for every agent runtime. Costs scale with vendor count multiplied by tool count.
14 wks
To enforcement, as of today
Article 12 becomes enforceable on 2 August 2026. The window for vendor-side hook coverage to mature on its own has closed.

Standardised hook envelopes, every runtime, every compliance tool.

Today, compliance tools have to be rebuilt per agent provider because each runtime exposes a different hook surface. With AgentHook, every conforming runtime emits the same envelope, and a single audit, policy, or memory subscriber connects to all of them.

TODAY Inconsistent hooks. N×M integration burden. Agent Runtime A PreTool only Agent Runtime B PreTool + PostTool Agent Runtime C No hooks Audit Policy Memory Bespoke integration per pair WITH AGENTHOOK Standard envelope. Every runtime, every tool. Agent Runtime A AgentHook conformant Agent Runtime B AgentHook conformant Agent Runtime C AgentHook conformant AGENTHOOK envelope Apache 2.0 Audit Policy Memory One envelope. One integration per side.
Today

Each compliance tool has to know each runtime's hook surface, fail-mode behaviour, and metadata shape. Every new vendor adds another integration. Every change to a vendor's hooks breaks the audit trail.

With AgentHook

Runtimes emit a standard envelope. Compliance tools subscribe once and work across every conforming runtime. Vendor changes are absorbed by the envelope contract, not by every downstream subscriber.

Ten canonical event types. One envelope. Apache 2.0.

AgentHook defines the wire-format envelope every event must carry, the canonical set of event types every conforming runtime emits, the standard metadata keys per event type, and the hook delivery semantics (sync versus async, fail-mode behaviour). It is implementation-neutral: any transport, any host language, provided the envelope and semantics are honoured.

Event
Phase
Description
PreToolUse
before
The agent is about to execute a tool call.
PostToolUse
after
The tool call returned, or threw.
UserPromptSubmit
before
The user submitted a prompt to the agent.
PreLLMCall
before
The agent is about to call its LLM.
PostLLMCall
after
The LLM call returned. Carries reasoning and response content for transcript-grade Article 12 records.
ModelResponse
after
The model has finished generating its response.
SessionStart
state
A new agent session began.
SessionEnd
state
An agent session ended.
AgentHandoff
during
The agent is delegating to another agent.
ErrorOccurred
after
An error was raised that did not terminate the session.

Implementations may emit additional event types using PascalCase names. Subscribers may ignore unknown types. Buses must not reject events on unrecognised event_type.

Read the full specification →

Three tiers. One open self-test rig. One signed report path.

A publisher claims a tier. A test rig verifies the claim. The self-test harness is open source and free for any implementer. A hosted Conformance-as-a-Service is operated by the steward for procurement-grade signed reports, on a cost-recovery basis. Conformance certification is never used to gate participation in the working group or in the specification.

Bronze

Lifecycle correctness

Publisher emits the canonical event types with the envelope format. Required fields populated, valid JSON, valid event_id, valid timestamp.

Threshold: 80% pass on Bronze test set
Silver

LLM transcript

Bronze plus matched Pre and Post LLM call pairs carrying model, provider, token counts, and response content.

Threshold: 80% pass on Silver test set
Gold

Reasoning and correlation

Silver plus reasoning content capture when the provider exposes it, and correlation IDs on Pre events that initiate sub-agent calls or retries.

Threshold: 80% pass on Gold test set

Six binding licensing commitments. Stewardship that transfers when adoption justifies it.

The specification is published and stewarded by Agentic Thinking Limited (UK), a private company limited by shares (company number 17152930). Stewardship is provisional. The intent is to transfer to a neutral foundation when adoption justifies the legal and operational cost. The following commitments are binding on the steward and any successor.

01
Apache License 2.0 in perpetuity

The licence shall not be replaced, restricted, or supplemented with additional terms by the steward or any successor.

02
No royalty fees

No fee may be charged for the right to implement the specification, claim conformance, or use the AgentHook name in describing an implementation.

03
No participation gating

Any individual or organisation may submit Proposals and contribute to working-group discussion. Vote-eligible seats are limited to founding and elected members; this does not restrict contribution.

04
Patent grant

Royalty-free, irrevocable patent licence to any party implementing the specification. Survives any change of stewardship.

05
Right to fork

The specification may be forked at any time under Apache 2.0. The steward may not assert trademark rights against forks (provided the forks do not represent themselves as the official specification).

06
Twelve-month notice on changes

Any amendment to the Charter or to these commitments requires twelve months' public notice and unanimous Working Group approval.

Read the Charter → Working Group rules →

The specification is pre-v1.0. Contributions, implementations, and conformance trials are welcomed.

Working group composition is being finalised ahead of the public draft. Any individual or organisation may contribute to discussion in GitHub Issues. Substantive specification changes follow the AgentHook Proposal (AHP) process.