# Software Verification > Design or execute risk-proportionate software verification by binding engineering claims to fixed methods, oracles, environments, and inspectable evidence. Use for architecture testing, undefined coverage, stale or missing evidence, named claims that must run, or an independent final check. Keep inner-loop feedback, fresh-context verification, design decisions, and release authority distinct. - Skill: `zhuochun/software-verification` (Agent Skill, multi-file: 4 files) - Install (CLI): `npx skillmds@latest add zhuochun/software-verification` - Raw SKILL.md: https://api.skillmd.com/api/skills/zhuochun/software-verification/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: zhuochun (https://skillmd.com/u/zhuochun) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/zhuochun/software-verification --- # Software Verification Own the claim-to-evidence lifecycle without changing acceptance criteria after results are visible. Verification can guide execution or challenge a completed candidate; it does not approve release, cutover, risk, or support policy. ## Select the mode and independence - Use **strategy mode** when claims, methods, oracles, environments, or renewal rules are missing or stale. Produce a verification contract, not proof. - Use **execution mode** when the contract is fixed. Reuse matching evidence and execute missing, stale, invalidated, suspicious, or explicitly fresh claims. - Use **independent mode** when consequence, irreversibility, uncertainty, or builder bias warrants a fresh context, separately authored oracle, consumer evidence, different owner, or another control with permission to reject. - A builder may run fast inner-loop feedback repeatedly. Do not call it an independent final verdict merely because the result is recorded clearly. - One task may move from strategy to execution only after freezing the claim, method, oracle, tolerance, inputs, environment, evidence owner, and validity limit. Record any later correction as a contract revision and rerun affected evidence; never repair the oracle to fit an observed result. ## Preserve authority and safety - Preserve upstream claim keys, labels, meaning, scope, and accountable owners. Add `VER-*` evidence obligations instead of relabeling product contracts. - Distinguish intended, specified, implemented, executed, observed, verified, released, and accepted states. A passing method proves only its named claim under the exercised conditions. - Respect security, privacy, data handling, environment, and change-management requirements. Production traffic, fault injection, destructive tests, mutation, external writes, expensive load, and user-affecting experiments require authorization, isolation, stop controls, and cleanup. - Preserve raw output and diagnostic artifacts proportionately. The agent's summary supplements evidence; it does not replace it. ## Reuse evidence and identify the target Invalidate evidence only for changed claims or their exercised code, configuration, data, method, oracle, or material environment. Prose-only edits normally need document checks; executable examples, changed requirements, suspect evidence, required repository gates, and explicitly fresh verification can require runtime checks. Preserve known failures and omissions when reusing evidence; a skill transition is not itself a reason to rerun an unaffected suite. When completion includes a running or installed system, identify the actual serving process or deployment, revision, configuration, and relevant contract versions. Exercise the requested consumer path on that target. A clean checkout, test server, or healthy stale process does not establish the running outcome. Use the owned restart or deployment path only within existing authority; if unavailable, report the narrower tested result and unverified runtime claim. ## Design the verification contract 1. **Inventory claims.** Preserve accepted behavior and invariants. Rewrite vague confidence goals as falsifiable claims about behavior, contracts, data, security, performance, failure, recovery, rollout, or diagnosis. 2. **Classify risk.** Record consequence, uncertainty, exposure, reversibility, affected population, and detection or recovery difficulty. 3. **Expose assumptions.** Name material environment, traffic, timing, ordering, dependency, identity, clock, failure, operator, and data assumptions. 4. **Choose falsifying evidence.** Select the cheapest credible method that can disprove each claim. Add layers only for distinct uncertainty or justified defense in depth. When runtime evidence is selected, consume named `observability-design` signal contracts and define falsification and limits without recreating their population, window, missing-data, navigation, or routing semantics. 5. **Fix method boundaries and oracles.** State exercised and omitted regions, representativeness, pass or fail properties, tolerances, comparison rules, invalidation, and renewal. For new or changed checks, select proportionate controls that expose false acceptance and false rejection. Calibrate consequential semantic judges against coherent human labels and held-out cases while preserving genuine unknowns. 6. **Sequence and own the portfolio.** Put fast deterministic feedback early; reserve expensive, risky, or production-like evidence for claims that need it. Name execution point, evidence owner, location, and remaining gaps. Read the relevant section of [references/evidence-portfolio.md](references/evidence-portfolio.md) when method, oracle, coverage, fidelity, or independence is missing or suspect, or a durable strategy matrix is needed. A fixed sufficient contract proceeds to execution without a new method survey merely because it crosses a boundary. Preserve required calibration, negative controls, and fresh evidence obligations. For agent or tool-system evaluation, use the reference's **Agent and tool-using systems** section to frame or check the contract. In particular, retention decisions require trigger negatives and a with-or-without ablation. A fixed contract is not sufficient merely because its positive output cases pass. ## Execute fixed claims 1. **Ingest and preflight.** Validate claim labels, strategy version, snapshot, method, oracle, tools, permissions, fidelity, isolation, duration, stops, cleanup, and artifact locations. Mark an incomplete contract for strategy repair before observing the candidate. 2. **Establish comparison state.** Capture relevant baseline, candidate, configuration, workload, dependency state, time window, and prior evidence. 3. **Execute in feedback order.** Preserve invocation, inputs, environment, material times, exit status, and raw results. Check discovery, exclusions, and planned controls; when enforcement is claimed, verify the required path executes the check and propagates its failure. 4. **Apply the fixed oracle.** Classify each attempt **pass**, **fail**, **inconclusive**, or **not run**. A flaky pass, partial environment, invalid oracle, missing assertion, clean dynamic run, or absent signal is not success. 5. **Preserve counterexamples and boundaries.** Minimize only while failure reproduces. Separate product, harness, environment, and oracle failures; state which populations, schedules, faults, and runtime modes were absent. 6. **Stop and clean up safely.** Stop on a predefined threshold, unexpected blast radius, lost isolation, corrupted baseline, or failed control path. Restore temporary state and report cleanup evidence. 7. **Synthesize per claim.** Preserve contradictions, stale or unexecuted regions, decisive failures, and validity limits. Green majorities do not cancel a failed critical invariant. 8. **Route the owning defect.** Send implementation defects to `$scoped-change-implementation`, unexplained causes to `$software-failure-diagnosis`, weak contracts back to strategy mode, missing runtime signals to `$observability-design`, and missing or unsafe security assumptions to `$software-security-design` or their narrower design owner. Read [references/evidence-execution.md](references/evidence-execution.md) when execution needs a durable ledger, attempt or counterexample record, non-obvious method-boundary prompts, or independence calibration. ## Quality gates - Every material claim traces by key and label to a frozen oracle or explicit gap; results retain matching snapshot and environment identity. - Methods exercise the uncertainty they own and state what they cannot prove. - Failures, inconclusive results, omitted evidence, flaky attempts, and counterexamples remain visible. - Risky execution respects authorization, isolation, stops, and cleanup. - Independent claims identify the distinct context, criteria, evidence, owner, or rejection right that makes the verdict independent. - Evidence remains distinct from release, cutover, risk, and support decisions. ## Reject verification theater - Do not count tests, coverage, dashboards, model reviews, or formal artifacts as universal confidence. - Do not infer dynamic behavior that the workload, population, schedule, failure, or instrumentation did not exercise. - Do not let the same agent's narrative certify that required work occurred.