TPipe executes PCP Kotlin requests with the versioned pcp-kotlin-v1 dialect. The dialect is an internal compatibility boundary around Kotlin’s experimental custom-scripting APIs; applications continue to use the existing PCP models and KotlinExecutor API.

Fixed contract

• Language version: Kotlin 2.0
• API version: Kotlin 2.0
• JVM target: 24
• Execution model: one-shot
• Dependencies: host application classpath only
• Compiler warnings: version warnings suppressed for this fixed dialect

Each request gets a fresh scripting host. Declarations and script state do not survive between requests, and TPipe does not resolve Maven dependencies or process @DependsOn annotations.

Bindings

registerBinding() keeps the original live host object. A script can use the object only when host application access is enabled and the binding name is explicitly present in KotlinContext.exposedBindings. Registered but unexposed objects are absent. Named classes are supported through Kotlin provided properties; local and anonymous binding types retain their compatibility behavior rather than being widened to Any.

When introspection is enabled, PcpRegistry and the live PcpContext are provided. Explicit custom bindings are applied afterward, preserving the existing collision behavior.

Results and safety

The final non-null, non-Unit expression is rendered as Result: <value>. null and Unit do not add a result line. Standard output and error retain the existing channel and trimming behavior. Security validation runs before the backend compiles or evaluates a script.

The timeout is an outward wait bound. It returns a timeout result but does not terminate arbitrary JVM bytecode still running in the daemon thread. The K2 host is not a JVM security sandbox; PCP policy validation remains the security boundary.

Versioning

Upgrading the repository compiler must not silently change pcp-kotlin-v1. Any incompatible scripting behavior requires a new dialect identifier and a compatibility review.