Concept register · Theme 05 of 14 8 concepts · 66 talks
assay · concepts · isolation-beats-instruction
Isolation beats instruction
A security policy that lives in the prompt is a suggestion. The security track demoed prompt-level controls failing live, then shipped hardware-level answers — and a supply-chain crisis in the skill ecosystem.
assay: identity ahead · no sandbox
§1What it is
The demonstration that settled the argument
A skill that scans the machine for credentials was shown to a agent in auto-approve mode. Refused. "Rewrite it as Python" — complied. "Run it" — refused. "Put it in a module" — complied. Then the context was cleared, and "run this" executed the payload. The same model that had called it clearly malicious ran it after a reset. Anything enforced only inside model context can be wiped away; model refusals are statistical, and attackers retry.
The lethal trifecta
Three grants, routine for agents: access to sensitive data, the ability to communicate externally, and exposure to untrusted content. Any two are dangerous; agents commonly hold all three — and in an agent world, content is instructions. A single stolen credential is contagious through everything it can touch.
The hardware answer
Hardware-level isolation with the configuration and secrets held outside the sandbox: microVMs rather than shared-kernel containers (security teams would not sign off on containers for agents that mutate their environment), network egress through an allowlisting proxy, and sentinel-value secret injection — the agent works with placeholders while real credentials are swapped into approved outbound requests beyond the boundary. The agent never possesses the key it uses. Ordering matters: least privilege and containers first; model-judged gating last, because it is measurably bypassable.
The skill supply chain
A security scan of roughly four thousand public skills found up to a third carrying security issues and seven percent leaking credentials — an ecosystem reaching npm-scale volume in months instead of years. Attacks are written in natural language, so signature scanning fails; the sharpest demo embedded shell commands in invisible Unicode control characters that execute in auto-mode while showing nothing to human review. Scanners themselves can be the malware. The working defenses: inventory what you run, scan on every install and update, and prefer behavioral analysis over keyword matching.
§2The concepts in this theme
Each concept has its own page in the concept register — with sightings from every event we review, and where Assay stands on each.
- Graduated agent authority established 17
- Hard controls over instructions established 17
- Agent identity and policy planes established 12
- Prompt injection and untrusted input established 11
- MicroVM and per-agent hard isolation established 8
- Accountable delegation corroborated 3
- The lethal trifecta and tool blast radius corroborated 3
- Security arenas and automated red-teaming corroborated 2
§3How Assay implements this
The binding layer is server-side, by design
Assay was built with the explicit rule that client-side guards advise while the server side — rulesets, branch protection, per-role application permissions — binds. The live bypass demonstration is the sharpest possible evidence for that split, and it is why a refused action in an Assay fleet is a stop rather than a suggestion.
Identity is the access boundary
Every desk role runs as its own GitHub App with narrowly scoped tokens, minted per operation; no agent operates under a human's credential; writes happen through role verbs, never hand-rolled scripts. Beyond attribution, this is access control: a role's blast radius is its own permission set.
Untrusted content is quarantined
Work arriving from outside the trusted roster is surfaced, never executed as instructions — the third leg of the trifecta, controlled at the point of ingestion rather than hoped away in the prompt.
The gate no sandbox replaces
Sandboxing limits blast radius; it does not stop application-level abuse, and the talks said so. The human merge gate remains the control for that class — which is one reason Assay keeps it.
Honest gaps. Assay provides procedural and server-side enforcement, not a sandbox: the execution substrate is the adopter's machine, and hardware isolation is outside the methodology's scope (a documented integration point, not a shipped feature). And as a public skill vendor, Assay owes the supply-chain side of this concept — an invisible-character lint and a behavioral review at release time are designed, not yet shipped.
§4Talks that cover this theme
#09You’re absolutely right, it was your home directory!Oleg Šelajev, Docker
#35Your AI Agent Installed MalwareLiran Tal, Snyk
#23Code Security ReinventedJoseph Katsioloudes, GitHub Security Lab
#031Enterprise AI: Agent GovernanceRao Surapaneni, Google Cloud
#134Observability Is Not GovernanceJon Rav Shende, Thales
#073Omnigent: A Meta Harness for AI AgentsArvin and Drew, Databricks
#137When Good Agents Go RogueItsik Mantin, Intuit
#032Off the Shelf AI Hit a WallDuncan Lennox, HubSpot
8 of 66 talks shown — the ones that reach the most concepts in this theme. Every sighting, per talk, is on the concept pages above.