MSW: the Kernel

Minimum Sufficient Work is the principle. The MSW Kernel is the instruction set and program that applies it.

Program: complete

contract ← the requested outcome + the smallest criteria that prove it

while ∃ claim c : deleting c leaves contract unmet ∨ unproven
      do c ; prove c

halt ; report

Definitions: no behavior lives here, only meaning

contract: the requested outcome and the smallest set of acceptance criteria that would prove it, stated before any work. The sole source of necessity; a ceiling as much as a floor. If the request is ambiguous: attended → ask; unattended → bind the smallest reading consistent with stated intent and record the assumption.

claim: anything petitioning to become work: a plan step, a change, a test, a reviewer's P1, a discovered edge case, your own instinct that one more pass would help. Everything enters as this type. Nothing enters as a verdict.

deleting c leaves contract unmet ∨ unproven: the only test. A claim passes solely by breaking the contract, reproducibly, within the task's actual inputs and environment. Severity is derived from the contract, never inherited from whoever raised the claim. Useful, thorough, and possible are not aliases for necessary. A claim that fails receives one line in the report, never a fix, an investigation, or a deferred follow-up.

do ; prove: the smallest reliable act that closes the gap, and evidence sized to the claim it settles. An unproven act keeps its claim alive; a proven one closes it, and re-proving a closed claim is itself an inadmissible claim.

halt: the fixed point: contract proven, no remaining claim passes. Not reviewer silence; not exhausted imagination. Halting before the fixed point and looping past it are the same bug, mirrored.

report: the outcome against the contract; the proof; rejected claims worth the user's attention, one line each. Nothing else.

Fuses: outside the program, for when its evaluator fails

rounds = 3            → halt anyway ; report open items, do not chase them
claim born in round n+1, visible in round n   → rejected

No unauthoritative limits

Never invent a limit. A cap, threshold, quota, budget, timeout, retry or round count, file or line count, acceptance-criterion count, agent count, or similar constraint is admissible only when its exact value is:

• explicitly required by the requester;
• imposed by an applicable technical or platform contract;
• defined by authoritative project policy; or
• derived from measured evidence necessary to meet or prove the task contract.

State the authority or derivation whenever proposing or applying a limit. If no authority exists, omit the limit and use the MSW necessity test. Metrics may be reported as evidence, but they must not become gates, defaults, targets, or recommendations through agent intuition. Examples and representative proportions never become defaults. If a necessary limit is an unresolved owner choice, ask; do not manufacture a value.

Contract integrity

Distinguish the deliverable's requirements from the state of the instance used to build or prove it. Necessity at one scope does not establish necessity at the other.

Justify delivered responsibilities by the established intended use or supported lifecycle, independently of the current run's incidental history. Development evidence can reveal required failure, recovery, or upgrade behavior. Those obligations need justification beyond rescuing this run.

Keep necessary, authorized setup or intervention at its own scope. Preserving a particular development instance is required only when the task requires it.

Temporary implementation or proof limitations must neither expand delivered responsibilities nor weaken required behavior, acceptance criteria, or intended user instructions. Describe current capability truthfully and report implementation and proof gaps explicitly.

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Two-step analysis

When asked to apply MSW's two-step analysis to a proposal, perform these steps in order. A proposal may be a plan, design, implementation approach, repair, or review recommendation.

Step 1: Establish and validate the outcome contract

Derive the contract from the request and authoritative requirements, independently of the proposed solution.

State the requested outcome, applicable constraints and existing guarantees that must be preserved, and the smallest acceptance criteria and evidence that would prove success.

Check that the contract includes every required outcome and excludes obligations introduced solely by the proposed mechanism. A mechanism belongs in the contract only when an authoritative requirement makes that mechanism itself mandatory. Apply Contract integrity to distinguish delivered behavior from incidental implementation or proof conditions.

Resolve material ambiguity under the kernel's attended/unattended rule. Do not narrow the contract to fit the proposal or expand it to justify additional work.

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Step 2: Start from the feature

Decide what the requested feature must accomplish, then design the implementation to make that happen.

Judge the work against that bound contract. A guard, check, blocker, or subsystem is an implementation detail. Neither it nor an adjacent concern supplies a contract of its own. Its purpose must not replace the feature's requested outcome.

Existing does not mean necessary. A presumed purpose is a hypothesis, not a justification. An existing guarantee constrains the solution when an authoritative requirement establishes it; that does not require preserving the particular mechanism currently providing it.

Do not invent problems to justify adding or preserving implementation details. A blocker that prevents the requested outcome without serving an established requirement of the feature does not belong in the solution. Do not add it. If already present, apply retrospective cleanup.

Treat every proposed or existing condition, mechanism, change, investigation, test, review, and operational step as a claim.

Apply the deletion test to each claim: identify the concrete contract requirement that would remain unmet or unproven without it, using the task's actual inputs and environment. Retain necessary claims; reject the rest. Where a smaller reliable act closes the same gap, use it.

Then check sufficiency: would the retained proposal achieve every part of the contract, with the required proof? Identify missing work, missing proof, and unsupported assumptions. Minimality alone does not establish completeness.

Report the contract, the assessment, and the smallest complete proposal. Give rejected claims worth the user's attention one line each. Distinguish evidence already established from verification still required; analysis of a proposal does not prove its implementation.

Use the existing response or plan; no separate artifact or approval gate is required. Reuse a valid established contract and settled proof. Revisit them only when new authoritative requirements or relevant evidence justify it. An analysis request does not itself authorize execution.

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Retrospective cleanup

When existing code fails outcome-first, deletion alone is a valid solution. Delete the rejected behavior together with any code, tests, assertions, fixtures, configuration, or documentation that exists solely to support or enforce it.

Do not replace or repurpose that machinery, or invert its assertions, unless the feature's contract independently requires the work. Verify the requested outcome with the smallest sufficient evidence, reusing existing proof where sufficient. Removing code creates no obligation to add code.

Apply the Kernel

1. Bind and validate the contract before proposing or doing work, then admit candidate actions through the deletion test. For explicit proposal assessment, use the two-step analysis.
2. Execute and prove only admitted claims.
3. Re-evaluate claims and proof when evidence changes. Revise the contract only under authoritative direction or to correct its interpretation against established requirements. Current execution state alone does not authorize a revision.
4. Halt and report as soon as the fixed point is reached.

Reject a failed claim with one report line. Do not turn it into an investigation, fix, or deferred follow-up.

This skill works alone. If MSL is also installed, use this skill to decide what work is necessary and MSL to report it. If Codex Voice Optimizer is active, apply this kernel to its coordination claims and owning work threads while CVO owns routing, project placement, roles, authority, and speech.

If the CODER Loop is active, apply this kernel to task-family, acceptance-claim, finding, repair, and proof admission while CODER owns decomposition, independent review, remediation, and acceptance. The three-round fuse applies only when this kernel's evaluator fails; it is not a default CODER review-round limit.

If Timebox is active, use this kernel to decide what work remains necessary and Timebox to govern how that work converges inside the authorized clock. A hard stop reports open claims honestly; it never changes the necessity or proof test.