EU AI Act High-Risk AI Testing & Validation Guide
The EU AI Act turns testing from good practice into a legal duty for providers of high-risk AI systems. Articles 9 to 15 require documented risk management, governed data, Annex IV technical documentation, automatic logs, human oversight and declared accuracy levels, all of which depend on repeatable, versioned evaluation runs.
- Instrument
- EU AI Act (Regulation (EU) 2024/1689)
- Primary citation
- Regulation (EU) 2024/1689, Articles 9 to 15, 17, 72 and Annex IV
- Authority
- European Commission (AI Office) and national market surveillance authorities
- Status
- As of November 2026: in force since 1 August 2024; prohibitions apply from 2 February 2025 and GPAI obligations from 2 August 2025. The Digital Omnibus on AI, adopted and in force since late July 2026, moved Annex III high-risk obligations to 2 December 2027 and Annex I product-embedded systems (for example medical devices) to 2 August 2028. Confirm dates against the Official Journal text before planning.
Statutory requirements
- 01
A risk management system that includes testing
Article 9Providers must run a continuous, iterative risk management process across the lifecycle: identify known and reasonably foreseeable risks, estimate risks under intended use and reasonably foreseeable misuse, and adopt targeted mitigation. Article 9 states that high-risk systems shall be tested to identify the most appropriate risk management measures, against prior defined metrics and probabilistic thresholds, and that testing can include real-world conditions. For an agent, foreseeable misuse includes prompt injection, out-of-scope requests and users who over-trust a recommendation.
- 02
Data and data governance
Article 10Training, validation and testing data sets must be relevant, sufficiently representative and, to the best extent possible, free of errors and complete in view of the intended purpose. Article 10 also requires examination for possible biases likely to affect health, safety or fundamental rights, and allows processing of special categories of personal data strictly for bias detection and correction under safeguards. For evaluation teams, this means the golden set itself is a governed artifact with provenance, coverage analysis and documented gaps.
- 03
Technical documentation per Annex IV
Article 11, Article 18 and Annex IVBefore placing a system on the market, the provider draws up technical documentation that demonstrates compliance. Annex IV lists the content: a general description, the development process, design specifications, validation and testing procedures, the metrics used to measure accuracy and resilience to errors, test logs and reports dated and signed by responsible persons, and the risk management description. Article 18 requires keeping the documentation for 10 years after the system is placed on the market.
- 04
Record-keeping and automatic logs
Articles 12 and 19High-risk systems must technically allow automatic recording of events over their lifetime, so that situations presenting risk and substantial modifications can be identified and post-market monitoring can work. Providers keep the logs under their control for at least six months under Article 19. For agents, the natural unit is the trajectory: every tool call, argument and intermediate state, tied to a model and prompt version.
- 05
Transparency, human oversight and declared accuracy
Articles 13, 14 and 15Article 13 requires instructions for use that state the level of accuracy, including its metrics, against which the system was tested and validated, plus known circumstances that may lead to risk. Article 14 requires design measures that let natural persons understand capacities and limitations, detect automation bias and override or interrupt the system. Article 15 requires an appropriate level of accuracy and cybersecurity, consistent performance across the lifecycle, resilience to errors and to attempts by third parties to alter use or performance, including adversarial inputs.
- 06
Quality management, post-market monitoring and penalties
Articles 17, 72, 73 and 99Article 17 requires a quality management system with written procedures for examination, test and validation before, during and after development. Article 72 requires a post-market monitoring plan, and Article 73 requires reporting of serious incidents. Under Article 99, non-compliance with provider and deployer obligations for high-risk systems can draw fines of up to EUR 15 million or 3% of worldwide annual turnover; the EUR 35 million or 7% tier applies to prohibited practices under Article 5, not to high-risk obligations.
Evaluation methodologies
Pre-defined metrics and probabilistic thresholds
Article 9(8) asks for testing against prior defined metrics and thresholds. Fix them in a versioned evaluation plan before the run: for example, zero tolerance on contraindication omissions, a pass^k floor on multi-step trajectories, and a calibrated judge score threshold per rubric criterion. Changing a threshold after seeing results should require a recorded rationale.
Representativeness and subgroup analysis
Slice results by the populations, languages, channels and settings named in the intended purpose. Report per-slice accuracy with confidence intervals and record which slices are thin. This is the practical evidence for Article 10 representativeness and for the Article 13 statement of known performance limits.
Adversarial and perturbation testing
Article 15 names data poisoning, model poisoning, adversarial examples and confidentiality attacks. For agents, run prompt injection probes through retrieved documents and tool outputs, perturbation suites (typos, tone, code-mixed language, distracting context) and runaway-loop detection, and record the failure clusters with their mitigations.
Human oversight effectiveness tests
Test that the escalation path fires: cases where the agent must defer to a human, cases where confidence is low, and cases designed to provoke automation bias. Assert on the trajectory that the handoff tool was called before any irreversible action.
Testing artifacts to retain
The evidence folder an examiner, notified body or internal auditor will ask for. GONATURELLE compliance reports export most of it from signed runs.
- 01Versioned evaluation plan with pre-registered metrics, thresholds and acceptance criteria (Article 9(8))
- 02Golden dataset datasheet: provenance, labelling protocol, inter-annotator agreement, coverage and known gaps (Article 10)
- 03Annex IV section 2 validation and testing report, dated and signed, with per-slice results
- 04Trajectory logs for every evaluated case, retained under the Article 19 period at minimum
- 05Adversarial and perturbation test results with failure clusters and mitigation status (Article 15)
- 06Declared accuracy metrics as published in the instructions for use (Article 13(3)(b))
- 07SHA-256 signed run manifests linking model, prompt, tool schema and dataset versions
- 08Post-market monitoring plan with the regression suite that re-runs on every change (Article 72)
GONATURELLE assertion rules
Each assertion maps to a requirement above. Run them on every pull request with the fast path, and on the full suite before release.
from gonaturelle import EvalSuite, TrajectoryTester, assertions as A
# Article 9(8): thresholds fixed before the run, stored with the plan
PLAN = {'contraindication_omissions': 0, 'pass_k': 0.90, 'judge_min': 0.85}
suite = EvalSuite.load('healthcare/clinical-prior-auth-v2')
results = suite.evaluate(agent=my_clinical_agent, max_concurrency=10, repeats=4)
# Article 15: accuracy and consistency across repeated trials
results.assert_zero_contraindications()
results.assert_pass_k(k=4, min_rate=PLAN['pass_k'])
results.assert_all([
A.judge(rubric='medical-necessity-v3', threshold=PLAN['judge_min']),
A.no_pattern_in_tool_args(patterns=['ignore previous', 'system prompt']),
])
# Article 10: per-slice performance, flag thin slices
for slice_name in ['age_band', 'language', 'payer_type']:
results.slice_by(slice_name).assert_metric('accuracy', min=0.92, min_support=50)
# Article 14: human handoff precedes any irreversible action
TrajectoryTester(results).assert_order('escalate_to_reviewer', 'submit_determination', when='confidence < 0.7')
# Articles 11, 12 and 18: signed evidence for Annex IV section 2
results.export_manifest('annex_iv/run_manifest.json', sign=True)Audit checklist
EU AI Act testing questions
Does the Digital Omnibus remove the testing duties?
No. As of November 2026 it changes when high-risk obligations apply (2 December 2027 for Annex III systems and 2 August 2028 for Annex I product-embedded systems), not what Articles 9 to 15 require. Teams that build the evidence trail now avoid compressing a year of documentation into the months before the deadline.
Is an LLM-as-judge score acceptable evidence under Article 15?
Only if you can show the judge measures what you claim. Calibrate it against expert annotations, report agreement (Cohen's kappa or Gwet's AC1) and keep deterministic checks for anything safety-critical. An uncalibrated judge score is weak evidence of accuracy.
Does GONATURELLE make my system compliant or issue a conformity assessment?
No. GONATURELLE produces test evidence and Annex IV formatted reports. Conformity assessment under Article 43, the EU declaration of conformity and CE marking remain the provider's responsibility, and in some cases involve a notified body. This guide is not legal advice.
Are general-purpose model providers covered by the same testing rules?
GPAI model providers have separate obligations under Articles 53 and 55, including model evaluation and adversarial testing for models with systemic risk. If you build a high-risk agent on top of a GPAI model, the Articles 9 to 15 duties sit with you as the provider of the high-risk system.
Related guides
- 1NIST AI RMFNIST AI RMF & Generative AI Profile Testing Guide · United States (voluntary framework)
- 2ISO/IEC 42001ISO/IEC 42001 AI Management System Testing Guide · International (certifiable standard)
- 3GDPR Article 22GDPR Article 22 Automated Decision Testing Guide · European Union and EEA
- 4FDA SaMDFDA SaMD Clinical AI Testing & Validation Guide · United States (federal)
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