Data as of Sep 18, 2026 · Based on 50 AI responses from ChatGPT Search and Google AI Mode · See how Parse measures this
Your brand can be here too.
When looking for platforms that use an "agentic" or highly automated approach to write detection rules, test them, and expose coverage gaps, you are looking at the intersection of **Threat-Informed Defense (TID)**, **Detection-as-Code (DaC)** , and **Automated Security Validation…
When looking for platforms that use an "agentic" or highly automated approach to write detection rules, test them, and expose coverage gaps, you are looking at the intersection of Threat-Informed Defense (TID), Detection-as-Code (DaC) , and Automated Security Validation (ASV).
Platforms in this space tackle the heavy lifting of mapping MITRE ATT&CK gaps, drafting queries, and validating whether your SIEM/XDR will actually fire when an adversary knocks.
The leading platforms and architectural approaches to evaluate for this capability include:
To help narrow down the list, could you share:
Yes. If the goal is an **agentic detection-engineering platform** that can *author rules → generate/test them → run/tune them → explain what you're not detecting*, I’d shortlist these: | Platform | Rule authoring | Testing | Coverage-gap analysis | Agent/AI | Best fit | |---|---|---|---|---|---|
Yes. If the goal is an agentic detection-engineering platform that can author rules → generate/test them → run/tune them → explain what you're not detecting, I’d shortlist these:
| Platform | Rule authoring | Testing | Coverage-gap analysis | Agent/AI | Best fit |
|---|---|---|---|---|---|
| Panther Labs | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | Best end-to-end detection engineering |
| SOC Prime | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | Best cross-SIEM / Sigma-centric option |
| Elastic Security | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | Best if you're already on Elastic |
| Microsoft Sentinel + Security Copilot | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐⭐⭐ | Best Microsoft-heavy environment |
| Sigma + your own agent/tooling | ⭐⭐⭐⭐⭐ | ⭐⭐⭐⭐ | ⭐⭐⭐ | ⭐⭐⭐⭐⭐* | Best if you want an open architecture |
Panther is probably the first platform I'd evaluate. Its detection-as-code model uses Python, with Git-based workflows, unit testing, AI-generated detections, real-time testing, MITRE ATT&CK coverage mapping, and closed-loop tuning.
The interesting part for your use case is that the AI isn't just a chatbot that writes a query. Panther describes a workflow where AI can create a production-ready detection, generate tests, propose improvements, and explain coverage while keeping human approval in the deployment loop.
I'd put Panther at the top of the POC list if you're building an agent whose core loop is:
threat description → detection → adversarial tests → execution against telemetry → tune → coverage assessment → PR
SOC Prime is particularly compelling if the agent needs to operate across many different SIEM/EDR/query languages rather than being tied to one detection engine.
Its Prime Architect can generate and improve detections across a very large list of platforms, including Splunk, Elastic, Sentinel, QRadar, CrowdStrike, Google SecOps, Sumo Logic, etc., and provides validation and result aggregation for several of them.
More importantly, SOC Prime explicitly offers detection-coverage gap analysis, ATT&CK mapping, automated code development/testing, and AI-assisted detection engineering.
Its current platform also exposes an MCP interface, which is especially interesting if you're building your own agent/orchestrator rather than just buying an AI SOC product.
I'd choose SOC Prime over Panther if your agent needs to say:
"Here is the same detection expressed in Sigma, Splunk SPL, Elastic EQL, Sentinel KQL, CrowdStrike, etc., and here are the ATT&CK techniques you still don't cover."
Elastic has unusually good primitives for the test/evaluate portion of this problem. Its security tooling supports manually testing rules against real data, including testing changes against known incident windows. Elastic's Agent Builder can also provide an agent with the complete detection-rule definition as context when refining rules.
So if your telemetry already lives in Elasticsearch, I'd seriously consider building the agent directly on Elastic's detection APIs/Agent Builder rather than introducing another detection platform.
Even if you buy one of the above, I'd strongly consider making Sigma the canonical representation of your agent's detection logic.
Sigma is explicitly designed as a vendor-neutral detection format, and the ecosystem provides sigma-cli/pySigma for translating rules into backend-specific languages.
That gives you an architecture like:
Threat intel / ATT&CK / analyst request
│
▼
┌─────────────┐
│ Detection │
│ Agent │
└──────┬──────┘
│
canonical Sigma
│
┌──────────────┼──────────────┐
▼ ▼ ▼
Splunk Elastic Sentinel
│ │ │
└──────────────┼──────────────┘
▼
Test / replay
│
┌───────────┴───────────┐
▼ ▼
positive cases negative cases
evasion cases FP analysis
│ │
└───────────┬───────────┘
▼
Coverage engine
│
ATT&CK + telemetry
│
▼
"What are we NOT detecting?"
I'd run three parallel evaluations:
The key evaluation isn't "which AI writes the best query." I'd score them on:
My ranking for your specific idea: Panther ≈ SOC Prime > Elastic > Sentinel, with Sigma as the interoperability layer rather than necessarily the platform itself.
One particularly interesting distinction: Panther is the better candidate if you want the platform to be the detection-engineering environment; SOC Prime is more interesting if you want to build an agent that orchestrates detection engineering across an existing heterogeneous security stack.
When looking for platforms that use autonomous agents or AI-driven automation to handle the full loop of **writing detection rules, testing them against historical/live telemetry, and mapping or explaining coverage gaps** , the market has evolved rapidly toward "AI Detection Engineering" and "Detection-as-Code"…
When looking for platforms that use autonomous agents or AI-driven automation to handle the full loop of writing detection rules, testing them against historical/live telemetry, and mapping or explaining coverage gaps , the market has evolved rapidly toward "AI Detection Engineering" and "Detection-as-Code" platforms.
The primary platforms and categories to evaluate depend on whether you want an out-of-the-box specialized AI detection engineer or an enterprise security validation platform that incorporates agentic workflows.
If your definition of "testing" means actively running atomic tests or adversary emulation to verify the rules actually fire:
When you talk to vendors in this space, test them on these three specific capabilities:
To help narrow this down, what SIEM/Data Lake are you currently writing rules for (e.g., Splunk, Microsoft Sentinel, Snowflake, Elastic), and do you prefer a standalone AI detection tool or an extension of your existing XDR vendor?
If the goal is specifically an **agent that can author detections, validate them against telemetry, and tell you what you still can't detect**, I’d shortlist these: - **Anvilogic — strongest fit for an agentic workflow.** Its current platform explicitly combines AI agents, detection-as-code, testing/validation, MITRE…
If the goal is specifically an agent that can author detections, validate them against telemetry, and tell you what you still can't detect, I’d shortlist these:
Don't judge these primarily on "can it generate a good-looking Sigma rule?" The important loop is:
threat intel → telemetry discovery → rule generation → positive/negative testing → deployment → observed results → coverage-gap analysis → iteration
I'd require a candidate to demonstrate all six of these:
That last distinction is particularly important. SANS's 2026 detection-coverage scorecard explicitly separates data-source quality, telemetry visibility, and detection coverage, rather than treating ATT&CK mappings alone as proof of coverage.
My starting point: run a bake-off between Anvilogic and Panther, using 20–30 real CTI scenarios from your environment. Anvilogic looks stronger for the agentic, cross-platform/gap-analysis vision; Panther looks stronger if you want a clean detection-as-code engineering workflow with AI layered onto it.
One useful benchmark to borrow from: Microsoft's CTI-REALM evaluates the whole workflow rather than just whether the final rule looks correct—including CTI interpretation, telemetry selection, query refinement, and ground-truth detection results.
If you are looking for platforms that move beyond simple AI code-completion and provide true agentic workflows—writing, testing, and mapping detection rules while explicitly calling out coverage gaps—a few key platforms and architectures stand out in the market. Dedicated Detection Engineering & Posture Platforms -…
If you are looking for platforms that move beyond simple AI code-completion and provide true agentic workflows—writing, testing, and mapping detection rules while explicitly calling out coverage gaps—a few key platforms and architectures stand out in the market.
Dedicated Detection Engineering & Posture Platforms
Security Data & Detection-as-Code Ecosystems
What to Evaluate When Choosing
When vetting these options, make sure your proof-of-concept tests these core constraints:
If you'd like, let me know:
I can help narrow down which of these choices fits your operational model best.
If the goal is an **agent that can author detections, run tests, and reason about what you're *not* detecting**, I’d focus less on generic “AI SOC” products and more on platforms with a strong **detection-as-code + testing + ATT&CK coverage** foundation. ## Platforms I’d evaluate Platform | Rule authoring | Automated…
If the goal is an agent that can author detections, run tests, and reason about what you're not detecting, I’d focus less on generic “AI SOC” products and more on platforms with a strong detection-as-code + testing + ATT&CK coverage foundation.
| Platform | Rule authoring | Automated testing | Coverage-gap analysis | Agent/AI fit | Best fit |
|---|---|---|---|---|---|
| Panther Labs | Excellent | Excellent | Excellent | Excellent | Best overall match |
| SCYTHE | Sigma-oriented | Excellent | Excellent | Good | Proving detections actually fire |
| Splunk | Excellent | Good with ecosystem | Good | Good | Enterprise SIEM already in place |
| Microsoft Sentinel | Excellent | Good | Good | Excellent | Microsoft-heavy environments |
| Google Security Operations | Excellent | Good | Good | Excellent | Large-scale SecOps/data environments |
| Elastic Security | Excellent | Good | Good | Excellent | Open/search-heavy engineering teams |
This is the first one I'd put through a serious evaluation.
Panther explicitly supports an AI detection builder that turns a threat description into a production detection with filters, severity logic, and test cases. Its detections are code-based, version-controlled, and testable, and it has MITRE ATT&CK coverage mapping to expose gaps.
The particularly interesting part for your use case is that Panther is moving toward a closed-loop detection agent:
threat description → detection → tests → deployment → alert/FP feedback → proposed rule improvement Its current workflow can generate GitHub PRs containing detection changes and tests rather than making opaque changes directly in production.
I'd consider Panther the benchmark against which I'd compare everything else.
SCYTHE is worth looking at if your biggest concern is “how do we prove this rule actually detects the behavior?”
Its Sigma regression-testing approach pairs detections with Atomic Red Team tests, converts the rules to the target SIEM language, executes the attack technique, and checks whether the detection actually fires. It also maps rules to ATT&CK and surfaces coverage gaps.
That's a very useful complement to an LLM agent because it gives the agent an objective feedback loop:
Agent writes rule → executes technique → rule fires/doesn't fire → agent fixes rule.
I'd evaluate these primarily if you already have one as your telemetry/SIEM backend.
The important question isn't merely whether their AI can “write a query.” It's whether an external agent can programmatically:
That API/automation surface is likely more important to your project than the quality of their chatbot.
I'd also consider not making the SIEM itself the agent platform.
A compelling architecture is:
┌──────────────────┐
│ Detection Agent │
└─────────┬────────┘
│
┌────────────┼────────────┐
▼ ▼ ▼
Threat intel Existing ATT&CK /
/ reports detections threat model
│ │ │
└────────────┼────────────┘
▼
Rule generation
│
▼
Test generation
│
┌────────────┴────────────┐
▼ ▼
Atomic/adversary Historical
execution telemetry
│ │
└────────────┬────────────┘
▼
Detection results
│
▼
Coverage / gap model
│
▼
┌────────────┴────────────┐
▼ ▼
"Detection works" "Coverage gap"
│ │
▼ ▼
PR / deployment New rule proposal
The key distinction is coverage ≠ number of rules. A good agent should be able to say something like:
“T1059.001 is covered for Windows PowerShell execution from endpoint telemetry, but only when process creation is logged. Your Linux fleet has no equivalent coverage. T1059.004 has no validated detection. The existing rule has never fired against the corresponding Atomic test.” That's much more valuable than an LLM simply generating another Sigma rule.
If I were running the evaluation, I'd start with:
One architectural requirement I'd make non-negotiable: the agent should produce reviewable detection code and test evidence, not silently modify production rules. Panther's current GitHub/PR-oriented approach is a good model for that.
If you're building this agent rather than buying one, I can also lay out the current platform landscape specifically in terms of APIs, rule formats, test harnesses, ATT&CK coverage data, and which pieces you'd need to build yourself.
threat description → detection → tests → deployment → alert/FP feedback → proposed rule improvement Its current workflow can generate GitHub PRs containing detection changes and tests rather than making opaque changes directly in production.
I'd consider Panther the benchmark against which I'd compare everything else.
SCYTHE is worth looking at if your biggest concern is “how do we prove this rule actually detects the behavior?”
Its Sigma regression-testing approach pairs detections with Atomic Red Team tests, converts the rules to the target SIEM language, executes the attack technique, and checks whether the detection actually fires. It also maps rules to ATT&CK and surfaces coverage gaps.
That's a very useful complement to an LLM agent because it gives the agent an objective feedback loop:
Agent writes rule → executes technique → rule fires/doesn't fire → agent fixes rule.
I'd evaluate these primarily if you already have one as your telemetry/SIEM backend.
The important question isn't merely whether their AI can “write a query.” It's whether an external agent can programmatically:
That API/automation surface is likely more important to your project than the quality of their chatbot.
I'd also consider not making the SIEM itself the agent platform.
A compelling architecture is:
┌──────────────────┐
│ Detection Agent │
└─────────┬────────┘
│
┌────────────┼────────────┐
▼ ▼ ▼
Threat intel Existing ATT&CK /
/ reports detections threat model
│ │ │
└────────────┼────────────┘
▼
Rule generation
│
▼
Test generation
│
┌────────────┴────────────┐
▼ ▼
Atomic/adversary Historical
execution telemetry
│ │
└────────────┬────────────┘
▼
Detection results
│
▼
Coverage / gap model
│
▼
┌────────────┴────────────┐
▼ ▼
"Detection works" "Coverage gap"
│ │
▼ ▼
PR / deployment New rule proposal
The key distinction is coverage ≠ number of rules. A good agent should be able to say something like:
“T1059.001 is covered for Windows PowerShell execution from endpoint telemetry, but only when process creation is logged. Your Linux fleet has no equivalent coverage. T1059.004 has no validated detection. The existing rule has never fired against the corresponding Atomic test.” That's much more valuable than an LLM simply generating another Sigma rule.
If I were running the evaluation, I'd start with:
One architectural requirement I'd make non-negotiable: the agent should produce reviewable detection code and test evidence, not silently modify production rules. Panther's current GitHub/PR-oriented approach is a good model for that.
Building an autonomous or semi-autonomous detection engineering loop—where an agent writes rules (e.g., Sigma, KQL, SPL), tests them against telemetry or backtests, and maps coverage (like MITRE ATT&CK gaps)—typically requires combining **SecOps platforms with native AI reasoning** or **custom multi-agent…
Building an autonomous or semi-autonomous detection engineering loop—where an agent writes rules (e.g., Sigma, KQL, SPL), tests them against telemetry or backtests, and maps coverage (like MITRE ATT&CK gaps)—typically requires combining SecOps platforms with native AI reasoning or custom multi-agent orchestrators.
Instead of a single "off-the-shelf" agent that does everything natively out of the box, the ecosystem is divided into three categories of platforms to look at:
These platforms have deep telemetry access, making it easiest for their native AI assistants to write, contextually validate, and check rules against live data.
If your priority is the lifecycle management of rules (writing, translation, and repository syncing) rather than just querying a single vendor's data lake:
If you want an agent that custom-fetches threat intel, writes a Sigma rule, runs it through a test harness (like sigma-cli or a lab sandbox), and outputs a coverage gap report, you will likely need to build a specialized pipeline using agent frameworks integrated with your internal APIs:
To help narrow down the best fit, tell me:
Yes. If the goal is an **agentic detection engineer**—not merely an AI that generates SPL/KQL—the shortlist should emphasize four capabilities: 1. **Author** detections from CTI / ATT&CK / natural language. 2. **Test** them against replayed, simulated, or real telemetry.
Yes. If the goal is an agentic detection engineer—not merely an AI that generates SPL/KQL—the shortlist should emphasize four capabilities:
The market is moving in exactly this direction: the 2026 SANS survey found that 80% of practitioners are barely keeping up or falling behind the threat landscape, while cloud-native environments were identified as the largest detection-coverage gap.
| Platform | Write | Test/validate | Coverage gaps | Agent/AI | Best fit |
|---|---|---|---|---|---|
| Panther | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ | Detection-as-code + AI agent |
| SOC Prime | ★★★★★ | ★★★★☆ | ★★★★★ | ★★★★★ | Cross-SIEM / Sigma-heavy environments |
| Cymulate | ★★★★☆ | ★★★★★ | ★★★★★ | ★★★★☆ | Adversary simulation + validation |
| Spectrum Security | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ | Autonomous detection engineering |
| AIDetectLab | ★★★★☆ | ★★★★★ | ★★★★☆ | ★★★★☆ | Engineering workbench / emerging option |
| Sigma + your CI/CD | ★★★☆☆ | ★★★★☆ | ★★★☆☆ | Build yourself | Maximum control / open architecture |
Panther explicitly positions its product around AI detection building, real-time testing, closed-loop tuning, GitHub PR workflows, and MITRE ATT&CK coverage mapping. Its agent can turn a natural-language threat description into production-ready Python, generate tests, and propose improvements through the existing Git workflow.
I'd put this at the top of the evaluation if you want the agent to behave like a software engineer for detections.
SOC Prime is particularly interesting if you don't want to tie the agent to one SIEM. Its platform has a large detection dataset, Sigma translation across many detection languages, AI capabilities, and an explicit detection-blind-spot/data-coverage audit mapped to ATT&CK.
The differentiator is breadth: CTI → detection → translation → coverage across heterogeneous security stacks.
Cymulate approaches the problem from the adversary side. Its detection-engineering capabilities can generate/test detections against attack scenarios, map rules to ATT&CK, identify gaps and drift, and continuously validate SIEM/EDR/cloud/WAF controls.
I'd favor it if your biggest question is:
"Does this detection actually fire when someone performs the attack?" rather than:
"Can an LLM write the rule?"
Spectrum is particularly relevant to your wording because it is explicitly positioning itself around autonomous threat research and detection engineering, including researching threats relevant to your environment and turning findings into detection-ready output. Its September 2026 material also focuses on detecting broken/ineffective deployed rules rather than merely inspecting rule files.
I'd include it in a bake-off if you're specifically looking for an agent, rather than an AI assistant bolted onto a detection platform.
AIDetectLab is more of a detection-engineering workbench: Sigma → Splunk/PySpark translation, validation, a detection library, ATT&CK coverage, and an interactive testing playground.
I'd investigate it as a potentially lighter-weight architecture if you want to retain control over the underlying detection pipeline.
I'd also seriously consider building the agent around Sigma rather than making the SIEM the agent's native language.
sigmahq.io is vendor-neutral, has thousands of community detection rules, and is specifically designed to make detections portable across SIEMs.
A compelling architecture would be:
CTI / ATT&CK → agent reasons about behavior → Sigma detection → synthetic attack/test cases → execute against telemetry → measure TP/FP/FN → ATT&CK + telemetry coverage graph → agent proposes fixes → Git PR → human approval → deployment
That is substantially more interesting than an "AI rule generator."
Give each platform the same 10–20 threat scenarios and score them on:
One especially important distinction: coverage of ATT&CK techniques is not the same thing as detection coverage. A mature agent should be able to say "T1059.001 is theoretically covered, but your telemetry doesn't contain the required PowerShell fields, so this is a paper detection." That's the kind of coverage-gap reasoning I'd make a gating requirement.
There is also emerging research specifically benchmarking agents on this workflow—CTI interpretation, schema understanding, query construction, rule generation, and evaluation against emulated attacks—which is a useful model for designing your own bake-off.
My initial shortlist: Panther + SOC Prime + Cymulate + Spectrum, with Sigma/DIY as the control architecture. If you're building the agent yourself, I'd benchmark against those four rather than simply comparing AI-generated rule quality.
SOC Prime is particularly interesting if you don't want to tie the agent to one SIEM. Its platform has a large detection dataset, Sigma translation across many detection languages, AI capabilities, and an explicit detection-blind-spot/data-coverage audit mapped to ATT&CK.
The differentiator is breadth: CTI → detection → translation → coverage across heterogeneous security stacks.
Cymulate approaches the problem from the adversary side. Its detection-engineering capabilities can generate/test detections against attack scenarios, map rules to ATT&CK, identify gaps and drift, and continuously validate SIEM/EDR/cloud/WAF controls.
I'd favor it if your biggest question is:
"Does this detection actually fire when someone performs the attack?" rather than:
"Can an LLM write the rule?"
Spectrum is particularly relevant to your wording because it is explicitly positioning itself around autonomous threat research and detection engineering, including researching threats relevant to your environment and turning findings into detection-ready output. Its September 2026 material also focuses on detecting broken/ineffective deployed rules rather than merely inspecting rule files.
I'd include it in a bake-off if you're specifically looking for an agent, rather than an AI assistant bolted onto a detection platform.
AIDetectLab is more of a detection-engineering workbench: Sigma → Splunk/PySpark translation, validation, a detection library, ATT&CK coverage, and an interactive testing playground.
I'd investigate it as a potentially lighter-weight architecture if you want to retain control over the underlying detection pipeline.
I'd also seriously consider building the agent around Sigma rather than making the SIEM the agent's native language.
sigmahq.io is vendor-neutral, has thousands of community detection rules, and is specifically designed to make detections portable across SIEMs.
A compelling architecture would be:
CTI / ATT&CK → agent reasons about behavior → Sigma detection → synthetic attack/test cases → execute against telemetry → measure TP/FP/FN → ATT&CK + telemetry coverage graph → agent proposes fixes → Git PR → human approval → deployment
That is substantially more interesting than an "AI rule generator."
Give each platform the same 10–20 threat scenarios and score them on:
When looking for platforms that can autonomously or semi-autonomously handle the full loop of **writing detection rules, testing them against historical/live data, and highlighting coverage gaps** , you are looking at the emerging category of **AI Detection Engineering** and **Autonomous SOC/Purple Teaming**…
When looking for platforms that can autonomously or semi-autonomously handle the full loop of writing detection rules, testing them against historical/live data, and highlighting coverage gaps , you are looking at the emerging category of AI Detection Engineering and Autonomous SOC/Purple Teaming platforms.
Instead of general-purpose LLMs, you need tools integrated deeply into your telemetry pipelines, threat intelligence, and adversary emulation frameworks.
Key Platforms to Evaluate
What to Look For During Evaluations
If you'd like, let me know:
I can tailor these platform recommendations to your specific infrastructure.
If the goal is specifically an **agent that can write detections, run them against data, and identify coverage gaps**, I’d focus less on generic “AI SOC” platforms and more on **detection-as-code platforms with APIs/CLIs and replay/testing**. ## Platforms I’d evaluate 1. **Panther — strongest overall fit**
If the goal is specifically an agent that can write detections, run them against data, and identify coverage gaps, I’d focus less on generic “AI SOC” platforms and more on detection-as-code platforms with APIs/CLIs and replay/testing.
panther.com 2. LimaCharlie — strongest for an autonomous agent
limacharlie.com 3. Sigma + your existing SIEM — best for a vendor-neutral agent
| Platform | Write rules | Test/replay | Coverage gaps | Agent friendliness |
|---|---|---|---|---|
| Panther | ★★★★★ | ★★★★★ | ★★★★★ | ★★★★★ |
| LimaCharlie | ★★★★★ | ★★★★★ | ★★★★☆ | ★★★★★ |
| Sigma + SIEM | ★★★★★ | ★★★☆☆ | ★★★★☆ | ★★★★★ |
| Anvilogic | ★★★★☆ | ★★★★☆ | ★★★★★ | ★★★★☆ |
If you're actually building the agent, I'd prototype against Panther and LimaCharlie first. Panther looks particularly compelling if you want software-engineering-style detection development; LimaCharlie is compelling if you want the platform itself to become part of an autonomous detection-engineering loop.
The key architectural requirement I'd insist on is that the agent can produce an auditable chain:
threat/TTP → hypothesis → detection rule → positive/negative tests → historical replay → observed results → ATT&CK coverage → uncovered telemetry/TTPs → proposed next detection
That last two steps are what distinguish a useful detection engineer agent from an LLM that merely writes SIEM queries.