Invariants

agentic-proteins is trustworthy only while it preserves established callers without creating an independent owner for Runtime behavior. These invariants apply to imports, transports, orchestration aliases, providers, state, and artifacts.

Compatibility invariants

Invariant	Observable violation	Protecting evidence
canonical ownership	a bridge module defines new run, state, tool, provider, or artifact policy	forwarding contracts and import-boundary tests
top-level identity	a promised export is copied or wrapped when object identity is part of compatibility	Runtime forwarding identity tests
behavioral parity	identical supported requests produce unexplained state, artifact, error, or transport differences	bridge-to-Runtime comparison tests
failure fidelity	Runtime refusal, failure, warning, or unavailable-provider state becomes fallback success	negative CLI, HTTP, provider, and run tests
artifact fidelity	bridge output drops provenance, terminal state, warnings, or stable identifiers	artifact-first and run-invariant tests
optional isolation	importing the base package activates or requires optional local or remote providers	provider isolation and disabled-dependency tests
migration visibility	a legacy path lacks a named canonical destination or measurable removal condition	bridge contract and retirement-budget tests
no new dependency direction	Runtime or another canonical package begins depending on the bridge	package import-boundary tests

flowchart LR
    L["legacy caller"] --> B["compatibility boundary"]
    B --> R["Runtime owner"]
    R --> O["state, artifact, or transport result"]
    O --> P["parity evidence"]
    B -. must not own .-> N["new Runtime policy"]

Interpretation

Identity and behavioral parity are different guarantees. Identity is relevant for forwarded Python objects. Behavioral parity is relevant for CLI, HTTP, provider, execution, and serialization paths. Neither guarantee establishes scientific validity of the returned result.

Historical breadth is not itself an invariant. Agents, tools, providers, execution, orchestration, and transport paths may be narrowed when caller and retirement evidence permits. The invariant is that narrowing is deliberate and that remaining callers retain the declared contract.

When an invariant fails

Treat divergence as a compatibility defect or an ownership defect. Record the exact path, Runtime comparison, affected caller, and retained output. Do not normalize the difference away in the bridge or document it as a second valid policy without changing canonical ownership.