{"schema_version":1,"experiment_id":"eoa_inverse_innovation_exp09_archetype_breadth150_20260804","cell_id":"decoupling_via_interface__computer_science","arm":"BREADTH_PROBE_ONE_SHOT","candidate_id":"decoupling_via_interface__computer_science__P1","proposal_index":1,"version":0,"title":"Versioned Runtime Introspection Contract for Language Tools","problem":"Debuggers, profilers, and heap analyzers read private virtual-machine layouts for objects, stack frames, threads, and garbage-collector metadata. A runtime team changing those internal representations can therefore break multiple tools even when the user-visible language behavior is unchanged.","actors":["Virtual-machine maintainers who change runtime representations","Debugger, profiler, and heap-analyzer maintainers who consume runtime state","Release engineers who qualify runtime-tool combinations","Developers who rely on trustworthy diagnostic output"],"observable_state":"Tool connectors contain offsets, private structure names, collector-specific cases, or other knowledge of runtime internals; after an internal-layout change, tool builds fail, attach operations fail, or the same program produces missing or differently interpreted diagnostic entities.","consequence":"Representation changes create coordinated repair work across otherwise independent tools, delay runtime evolution, and can yield diagnostic output whose semantic mismatch is not immediately visible.","affected_objective":"Allow runtime implementations and diagnostic tools to evolve independently while preserving accurate, usable introspection of supported semantic entities.","intervention":"Interpose a read-only, versioned runtime-introspection protocol between the virtual machine and its tools. The contract defines semantic operations such as enumerate threads, describe frames, identify objects, traverse references, and report capabilities without exposing private memory layouts. A runtime-specific adapter translates those operations to the current internal representation; tools consume only the protocol. Schema validation, capability negotiation, conformance fixtures, explicit error behavior, and managed deprecation govern contract evolution.","structural_mapping":[{"archetype_element":"Directly coupled components","domain_realization":"Diagnostic tools and the virtual machine are coupled through private runtime layouts and collector-specific metadata."},{"archetype_element":"Boundary separating internal structure from external interaction","domain_realization":"The protocol boundary separates VM representation details from the semantic runtime state tools are permitted to observe."},{"archetype_element":"Explicit interface contract","domain_realization":"A versioned schema specifies requests, responses, entity meanings, capability declarations, consistency guarantees, and error behavior."},{"archetype_element":"Indirection","domain_realization":"Tools request semantic entities through the protocol instead of dereferencing runtime structures directly."},{"archetype_element":"Translation layer","domain_realization":"Each runtime adapter maps its object, stack, thread, and collector representations into the contracted semantic model."},{"archetype_element":"Encapsulated implementation variation","domain_realization":"A runtime may change layouts or collectors without requiring tool changes when the contracted semantics remain satisfied."},{"archetype_element":"Managed interface evolution","domain_realization":"Capability negotiation, version identifiers, compatibility windows, and deprecation tests make protocol changes explicit."}],"mechanism_mapping":[{"mechanism_slug":"stable_interface_layer","role":"Provides one governed semantic surface on which all participating diagnostic tools can rely.","counterfactual_removal":"Without the stable layer, each tool must again depend on runtime-specific internal structures."},{"mechanism_slug":"adapter_layer","role":"Absorbs differences among runtime versions and internal representations while emitting the shared protocol.","counterfactual_removal":"Without adapters, the shared schema either exposes one runtime's internals or requires every tool to perform its own translation."},{"mechanism_slug":"interface_contract","role":"Defines observable meanings, consistency guarantees, supported failures, and version behavior that can be tested independently of implementation.","counterfactual_removal":"Without an explicit contract, apparent compatibility can conceal semantic drift and false decoupling."},{"mechanism_slug":"protocol_versioning_and_capability_negotiation","role":"Lets a tool discover which semantic operations a runtime supports and reject or degrade explicitly when requirements are unmet.","counterfactual_removal":"Without negotiation, incompatible runtime-tool combinations can silently misinterpret data or fragment into undocumented variants."}],"causal_chain":["Tools currently encode private runtime representations because those representations are their interaction surface.","Private representation changes therefore propagate into tool connectors even when externally meaningful runtime semantics remain constant.","The introspection contract narrows the dependency surface to named semantic entities, operations, guarantees, and errors.","Runtime-specific adapters translate changing internal representations into that stable surface.","Contract fixtures and schema validation detect translation loss or semantic drift at the boundary.","Tools that depend only on the contract need not change when an internal change remains behaviorally conformant.","Versioning and capability negotiation expose nonconformant semantic changes as managed interface events rather than accidental breakage."],"baseline":"Each diagnostic tool maintains a direct, runtime-specific connector that reads private layouts, with compatibility established through paired releases, manual fixes, and end-to-end testing after runtime changes.","nearest_rivals":["Freeze or slowly change runtime layouts: reduces immediate breakage by constraining the runtime rather than containing representation variation behind an interface.","Coordinate atomic runtime-and-tool migrations: manages each propagated change but leaves every tool exposed to future internal changes.","Maintain a separate compatibility shim inside each tool: absorbs some variation locally but duplicates translation logic and does not establish a shared semantic contract.","Publish private layout documentation: makes direct coupling more legible but still requires consumers to change when documented internals change."],"remaining_contrastive_claim":"Unlike layout freezing, coordinated migrations, documentation, or per-tool shims, the proposed protocol relocates dependency from mutable VM representation to one testable semantic contract and concentrates representation translation on the runtime side; it succeeds only if tools cease relying on hidden layouts and the contract preserves the state they actually require.","authority_safety":{"decision_authority":"The runtime observability maintainer may authorize an experimental, feature-flagged adapter and test protocol on a non-production branch; runtime and tool release owners retain authority over adoption, compatibility policy, and production rollout.","authorized_first_step":"Build a read-only prototype covering thread enumeration, frame description, and object identity for two test runtime builds, then connect one debugger and one profiler in an isolated harness.","excluded_actions":["Attaching the prototype to production processes","Writing to runtime memory or changing program execution","Removing existing tool connectors","Declaring the experimental schema a supported public contract","Changing release compatibility or deprecation policy","Exporting application payloads, secrets, or unrestricted object contents"],"halt_rollback":"Stop if the adapter changes runtime behavior, exposes excluded payloads, produces ambiguous entity mappings, or exceeds the test harness's preset resource limits. Disable the feature flag and return the test tools to their existing connectors; no production interface is replaced."},"negative_tests":{"strongest_counterevidence":"Existing failures may arise mainly from genuine semantic changes, timing requirements, or consistency guarantees that cannot be represented without exposing VM internals; alternatively, the tools may already use a stable supported interface and the suspected direct coupling may be incidental.","problem_falsifier":"A bounded review of recent runtime changes and the selected tool connectors finds no private-layout dependencies, or finds that internal representation changes do not require connector changes or cause diagnostic mismatches.","intervention_falsifier":"After substituting the second runtime build behind the adapter, either tool still requires runtime-specific code changes, the same protocol response denotes different semantic state, required diagnostic information is lost, or measured pause time, memory use, or response latency exceeds thresholds fixed before the trial.","risks":["The semantic model may be too weak for advanced diagnostics or so broad that it recreates VM internals.","Snapshot consistency may differ across runtimes and cause semantically misleading results.","The adapter may become a latency, memory, or failure bottleneck.","Capability negotiation may proliferate into version fragmentation.","Tools may retain hidden direct-memory dependencies, creating false decoupling.","Sensitive application data may cross the interface unless exposure is narrowly controlled.","A widely adopted but poorly designed contract may ossify and constrain later runtime improvements.","Runtime-specific adapters may accumulate into maintenance-heavy adapter sprawl."]},"next_evidence_step":"In an isolated repository fixture, select two runtime builds that differ in object or stack representation and one debugger plus one profiler. Implement only the three authorized read-only operations, define golden semantic fixtures and preset resource limits, run both tools against both builds, and record semantic mismatches, residual private-layout references, adapter-only versus tool-side changes, and protocol overhead. This test does not authorize production deployment or broader schema expansion.","prior_art_status":"UNSEARCHED","diversity_from_prior_proposals":"Not assessed against other candidates because the one-shot isolation forbids inspecting prior proposals; this candidate was derived only from the supplied archetype and domain card.","revision_record":{"parent_version":null,"progress_targets_addressed":[],"conceptual_changes":[],"operational_changes":[],"evidence_changes":[],"claim_changes":[]}}