skill-lab

Skill Lab

Build and improve Runx skills through one authoring surface. Keep judgment in bounded agent acts and mechanics in native tools:

inspect target files, catalog ownership, and native/shared tools
→ decide ownership, execution lanes, effects, budgets, and proof
→ bind that architecture to the inspected package digest in native code
→ compose existing capabilities before authoring code
→ author only bounded writes, explicit deletions, and output intent
→ bind those bytes to the admitted architecture in native code
→ validate paths, secret posture, and the complete candidate
→ inspect and safely replay the exact staged package
→ commit that validated bundle through one native transaction

Use the generic host skill-creator for platform-wide authoring guidance when it is available. Do not reproduce Runx package operations from that guidance; invoke the appropriate skill-lab runner so the work is bounded and receipted.

Runners

• design: read-only catalog-fit and architecture planning. It returns a native digest-bound plan and never authors package bytes. A later build re-inspects and replans against its exact target before any write.
• build (default): create or update a package after its exact staged bundle passes native parsing, inspection, and safe harness replay.
• improve: turn one receipt or harness failure into a bounded package update, then validate and commit the exact staged bytes.
• harness: add fixture files to an existing package and replay the safe native harness against the exact candidate before committing it.

build, improve, and harness write local workspace files. They never publish, install, push, or mutate an external provider. Native harness replay runs with isolated Runx home, receipts, and no operator credentials. Invalid staged packages stop before the target package is touched. Design, inspection, validation, and the bounded transactional workspace write do not add a human approval gate; the operator authorizes that reversible local mutation by invoking the mutating runner. Publication, installation, provider effects, and other consequential boundaries remain outside this skill and keep their own approval rules.

A validated local write is not a published skill. For a shared or public package, the validated X.yaml identity and the exact target_dir and package_digest in apply_result form the publication candidate. When the operator's objective includes shipping or registry availability, continue that exact candidate through the repository's canonical registry operator: publish under the intended existing owner/name, then independently read back the same version and digest. Do not call the work shipped while that sync is pending or unverified. Publication remains a separate authenticated act so Skill Lab never receives registry credentials or hides a remote mutation inside local authoring.

Authoring rules

• Start from the operator's recurring job, not the requested package name, bounty wording, provider, or implementation sketch. Establish what becomes materially easier or newly possible for the operator, what judgment the skill contributes, and what durable result it returns. A package that merely restates ordinary agent behavior, renames one native call, or produces a document with no usable next step is not a valuable skill even when every contract and harness passes.
• Treat prior implementations, accepted bounty text, issue suggestions, and named integrations as evidence about the intended capability, not binding architecture. Preserve the real user outcome and compatibility obligations; replace stale ownership, unnecessary providers, and accidental workflow shapes when the current catalog has a cleaner canonical route.
• Treat SKILL.md as the product manual for both the human operator and the operating agent. A person opening it cold must understand what the capability does, why and when to use it, what happens end to end, and where it stops. Do not reduce that manual to terse model directives, field lists, or a task contract.
• Preserve the useful context in an existing skill: its mental model, procedure, examples, trade-offs, chain relationships, evidence rules, and recovery posture. Rewrite statements that no longer match the implementation; never delete the surrounding explanation merely because the executable profile now enforces part of it.
• A complete public skill explains, in a structure natural to the capability: the recurring job and outcome; when and when not to use it; the operating model and sequence; upstream and downstream skill relationships; meaningful input and output semantics; authority, approval, evidence, finality, and recovery; and relevant edge cases and stop conditions. Include a concrete example when it materially clarifies a non-obvious workflow. Do not force ceremonial sections onto a simple facade or internal rail.
• Put task-specific agent clauses after the human-readable operating guide. They sharpen individual agent acts; they do not replace the guide or carry the product's voice by themselves.
• Explain meaningful upstream and downstream skill relationships naturally in the operator guide. Do not maintain a second machine-readable dependency registry in SKILL.md: native execution-closure inspection owns the exact edge set and operator preflight surfaces it. Prose explains why the chain exists; the runtime proves what it actually calls.
• Design capability chains by responsibility, not by whichever integration is easiest to name:
  • The domain skill owns domain evidence, interpretation, policy, and the truthful domain result.
  • A canonical capability or authority skill owns a reusable decision such as authorizing a send, spending funds, or preparing a release.
  • A provider adapter owns the bounded external API effect and independent readback. Do not collapse these roles into one package, and do not make a provider adapter a required part of a provider-neutral capability. Pin an adapter only when the objective genuinely requires provider-specific behavior; otherwise return a stable handoff that an operator can route to the selected adapter. For example, a meeting skill may produce grounded task proposals and a follow-up message; communication then goes through send-as, while task creation goes through the operator's selected task adapter. n8n, Zapier, or any other automation provider is optional unless the requested capability is explicitly about that provider.
• Search the catalog by operator outcome and authority owner, not only by words present in the request. Consider every material result independently: a workflow may need different next lanes for a message, task proposal, payment, publication, or unresolved ambiguity. Reuse the canonical capability at each boundary and explain why it owns that decision. Do not hide an unhandled outcome behind a generic "handoff" claim.
• Preserve the context that makes the next operator or skill intelligent. Handoffs carry the bounded evidence, decision rationale, unresolved ambiguity, stable content or proposal, intended audience or target, and effect status needed by the next lane. Do not squash these into a digest, terse status, or provider payload. Digests bind context; they do not replace it. Conversely, do not forward unrelated source material or secrets.
• Make finality explicit at every boundary. Distinguish observed evidence, model interpretation, draft, proposal, authorized action, attempted effect, provider-confirmed effect, and independently read-back effect. A downstream route is not proof it ran; a sealed plan is not approval; an adapter request is not delivery. The public result and operator guide must say what actually happened and what still has to happen.
• A skill declares domain procedure and policy. Runx owns generic input, packet, evidence, approval, request, credential, effect, and receipt mechanics.
• Place the capability in its real owner before choosing an implementation. Reusable skills, end-user and domain-operator commands and UX, local host loops, local queues, and default local-state orchestration belong in Runx OSS or the owning product repository. runx/cloud is not precedent for those concerns: it may provide the hosted control plane, custody provider credentials, resolve authoritative grants, and execute a fixed bounded provider operation. Using Hosted Connect does not move the surrounding skill, procedure, operator decision, or state into Cloud. If that operator surface is missing, return work to OSS or the product owner; never extend a Cloud script or hosted service as a substitute.
• For hosted provider work, compose native provider.read or provider.mutate; declare exact scopes and provider operations, and require provider readback. provider.mutate owns the exact human approval at the effect boundary, so never add an adjacent graph approval for the same action. Use an explicit graph approval only for a consequential action whose native capability does not already own one. One action has one approval owner. Use expected_result to bind the returned resource identity and result_fields to admit only the fields the receipt needs. Secret-adjacent operations must project their result. Pass mutation retry identity through the native idempotency_key input; do not copy it into the provider payload. Never add a package token loader or request client.
• Never model human authority as a caller-supplied approval string, boolean, or reference. A native approval gate must summarize the exact target and effect; its host-attested packet is the only approval input a credentialed provider tool may accept. If a provider API requires its own approval reference, derive the claim- or resource-bound value inside that tool after verifying approved: true, actor: human, the exact gate id, and the action-specific gate type. An agent-authored answers value must fail before provider execution.
• run: approval is a human gate. Agent provenance is rejected by the runtime; use agent-task for model judgment and keep its result distinct from human authority.
• Treat the selected runner's typed execution requirements as the complete permission request. Put opaque scope strings, exact non-secret environment names, the named credential requirement, and runtime metadata on their canonical runner or source fields—never under runx, in prose, or in a package loader. Runx resolves and records those declarations without inventing a scope vocabulary; the native capability or provider that owns a scope enforces it.
• Make every public runner contract recursively complete at the authoring boundary. X.yaml owns nested properties, closed objects, enums, bounds, and complete parser-validated invocation examples; runx skill inspect, MCP, agent tools, and generated exports must project that same declaration. When an identical input declaration is used by multiple runners, define it once with the manifest's exact input-definition reference rather than copy it or invent merge overrides. JavaScript may enforce irreducible relationships between otherwise valid fields, but must not repeat structural validation already owned by the profile.
• Dogfood the result through the real agent-facing surface, not only the package harness. A cold agent must be able to inspect the selected runner, construct a valid call without reading source or fixtures, understand a path-specific rejection, and continue from the resulting context. Exercise every materially different runner; a default-only export cannot certify a multi-runner skill. For an existing target, use authoring_context.target_inspection as the canonical runner-contract and execution-closure evidence. An invalid inspection is repair context, not permission to guess: read the declared target files, correct the owning contract, and validate the complete candidate.
• Design evidence admission around the operator's job, not the first provider implementation. When analysis is useful over local admitted files or artifacts as well as remote sources, support both through their canonical evidence boundaries; do not require HTTPS, Hosted Connect, or another provider merely to analyze evidence already available on the operator's machine. Provider-specific acquisition remains a separate runner or upstream skill when it adds real readback value.
• Make permission claims executable through the existing package harness. Permission-bearing native and provider paths need a realistic admitted case and, where the harness can exercise that owner, a refusal case with the required scope or grant withheld. The harness must call the same catalog, dispatcher, and capability/provider implementation as a real run; never add a mock permission evaluator, scope vocabulary, or parallel verification report. This proves enforcement owned by Runx capabilities and providers. It cannot prove that trusted host code avoided undeclared filesystem, network, or syscall access, so report that boundary as trusted rather than confined.
• Tool fixtures inherit the exact scopes declared by the canonically resolved manifest and pass declared packets through the production packet verifier. Use expect.output.matches_packet only when the whole fixture output is one self-described packet; named artifact packets are already verified from the manifest and should not be asserted through a second fixture path.
• Search the inspected native-tool and skill catalogs before designing files. Prefer an existing core tool or canonical skill over executable package code.
• Make every public runner input constructible from inspection. Use ordinary schema for runner-owned nested values. When an input is exactly one canonical Runx packet, declare type: json plus packet: <packet-id> and let the runtime resolve the catalog-owned schema into inspection, validation, exports, registry bundles, and harnesses. Never copy that packet schema into the consumer. If the canonical schema is too weak to make the input usable, improve the producing packet contract first; a packet reference is not a substitute for a complete schema. Do not mint a packet id for a runner-local nested value, graph intermediate, or one-run implementation detail. A packet exists only for the complete value crossing a named reusable skill, runtime, SDK, provider, receipt, or registry boundary, and it must have one active producer and consumer or an explicit public native owner. Remove the generated artifact when that ownership disappears. Every public runner still needs at least one realistic, copy-valid example unless its inputs are empty.
• A named packet must expose its semantic fields or reference a canonical typed contract. Bare type: object, unconstrained {}, and opaque property bags do not make a runner inspectable and must be repaired at the producing contract, not documented around in prose. Open JSON is admissible only as an explicitly named protocol extension or generic data payload inside an otherwise bounded semantic envelope.
• Apply that rule recursively. Every nested type: object declares meaningful properties or an explicit additionalProperties policy. If the value is intentionally arbitrary JSON, declare type: json; do not make an object declaration imply structure that the contract does not provide.
• Put a producer's nested output shape in that output declaration's schema. Do not hand-maintain the same shape in a packet file, fixture, exporter, or consumer: native parsing, agent context, runtime validation, packet generation, registry packaging, and harness replay all consume the producer's declaration.
• Express orchestration through X.yaml; keep all static agent operating knowledge and task contracts in SKILL.md. Never put model instructions in manifests, fixtures, or duplicated prompt fragments.
• Declare every harness-only support file explicitly in harness.files using a normalized profile-relative path under fixtures/. Runx stages only those declared files into the isolated harness workspace; it never guesses dependencies from arbitrary input strings. Do not turn the declaration into a second source tree or include unconsumed helpers.
• Put every typed output and packet contract on the step that actually produces it. A graph runner is composition and its receipt proves that composition; it must not declare a second runner-level outputs or artifacts contract with ambiguous ownership. Every graph runner declares graph.result_from as the intentional public result boundary. Name the final provider readback or package/finalize step, not every leaf: approvals, evidence gathering, and intermediate writes remain available in operator context and receipts without polluting the result. Multiple producers are valid only for mutually exclusive branches or when their distinct contracts are intentionally returned together; simultaneous producers may not emit the same key. When a graph needs one public result, end it with an explicit package/finalize step and let that producer own the packet schema.
• Add executable code only for irreducible deterministic domain computation. Explain its domain boundary and why native tools plus a declarative graph cannot express it. Do not add code merely to transform Runx contracts.
• For a genuinely separate CLI or protocol tool, keep one canonical manifest.json. It owns source, inputs and defaults, artifact projection, scopes, retry/idempotency, and mutation metadata. Never persist generated runtime, output, runx, hash, or toolkit fields beside that contract. runx tool build validates and reports derived hashes without rewriting the package. The extension SDK may carry the already-materialized JSON request and response across a process boundary; it must not become a second manifest or input-contract owner. The declared entrypoint must execute on the repository's supported runtime without probing for generated files or importing uncompiled TypeScript. A bundled tool lives at tools/<namespace>/<name>/manifest.json, its dotted manifest name must match that path, and aggregate package admission must bind every static local source dependency before the package can run or publish.
• Local CLI tools, process MCP servers, and process adapters are trusted host code. Runx controls their exact invocation, delivered environment and credentials, lifecycle, bounded output, and evidence; it does not turn declared scopes into portable filesystem, network, or syscall confinement. Use this lane only when the operation is genuinely irreducible to native capabilities, provider adapters, declarative composition, or deterministic JavaScript. Never author a sandbox declaration, wrapper, or fallback flag.
• When that computation is JavaScript, use the native type: javascript source. Prefer one cohesive module named for the skill with focused named exports of the form (inputs, context) => JSON; split it only when the computations have genuinely separate ownership. Runx owns input delivery, output serialization, errors, wall limits, and isolation. Do not add fake operation inputs, Node command declarations, per-runner wrapper files, or stdout/environment plumbing. Pure JavaScript receives only its validated in-memory module bundle, JSON input, and a frozen context.environment object containing the exact names declared in the runner's environment.required and environment.optional lists. A missing required name stops before worker execution; an absent optional name is omitted. Values never enter the manifest, agent context, inspection output, or receipts. Environment declarations are for non-secret runtime configuration; credentials stay on the native credential/provider boundary. The worker process itself has an empty ambient environment and no workspace path, filesystem, network, clock, randomness, subprocess, credential, or provider surface. The default wall limit is two seconds; a runner may declare timeout_seconds from 1 through 30 when irreducible computation genuinely needs it. The worker is ECMAScript, not a browser: use the frozen Runx.parseUrl(value) helper for absolute URLs and do not assume Web or Node globals exist.
• Classify volume before authoring. Small typed control values belong in normal runner inputs; runx skill --inputs is only a bounded transport for one complete control object. Large immutable local content belongs behind artifact.admit/bounded pages. Durable history belongs behind data.read_events cursors or a compact projection. A graph must not carry an archive, growing event history, or completed-id array simply because one CLI call can parse it.
• Use deterministic pages only for irreducible record transforms over one admitted JSON-array artifact. The runtime owns artifact admission, page framing, snapshot digest, record boundaries, offsets, retries, and the page loop; the module owns only decoding and domain selection. Treat runx_page.artifact_ref as an opaque, runtime-local read capability that belongs in receipt provenance; never place it in a plan or idempotency digest. Bind deterministic domain output to runx_page.whole_digest, which is stable for identical content. Keep continuation state proportional to the bounded result. Do not add a package file reader, manual byte cursor, hashing loop, high-volume profile, or raised worker limit. If safe framing or bounded state is impossible, choose needs_core or a genuinely separate protocol tool rather than smuggling filesystem authority into JavaScript.
• Prove a volume path at two materially different scales through the production owner. The result must be identical across page sizes, cursors must advance, process count must stay stable where session reuse applies, and failures must remain distinguishable from empty pages. A larger fixture alone is not performance evidence.
• A missing generic primitive is not permission for package code. Return needs_core with no writes and identify either a runtime/security invariant or two independent existing consumers.
• Never add package-local raw RUNX_INPUTS_* parsing, generic packet or evidence hashing, packet wrapping, generic status construction, or provider simulation when a shared Runx boundary can own it. Package code may retain a canonical hash only when that hash is an intrinsic field of an established domain or wire protocol, not as a substitute for receipt or effect integrity. State that exception at the computation boundary.
• Keep packages concise: normally SKILL.md, X.yaml, and focused fixtures; add narrowly scoped references, assets, tools, or domain code only when consumed.
• Judge the whole capability, not proxy metrics. Native reuse, fewer files, shorter code, green harnesses, and low resource ceilings are valuable only when the result remains understandable, useful, truthful, and complete. Keep JavaScript when it performs irreducible domain computation; remove it when it reimplements runtime mechanics. Never trade away domain semantics or operator context merely to reduce line count.
• Keep shared computation DRY. A helper used by multiple skills belongs in its existing native owner or a justified shared primitive, never copied scripts.
• Count the whole replacement and delete displaced scripts, manifests, schemas, fixtures, and tests in the same change. Do not leave dual paths.
• Do not add package READMEs, changelogs, installation guides, strategy files, generated state, or credentials.
• Match the documented capability to the execution profile and truthful terminal state.
• Review the documentation diff for semantic loss. A shorter SKILL.md is an improvement only when the removed material was false, duplicated, or irrelevant and the remaining document still passes the cold-operator test.
• Treat the catalog's manual check as an anti-stub backstop, not a writing target. The structural title/section/prose floor does not prove a guide is substantive. Do not pad prose to satisfy a word floor or turn natural operating guidance into a template checklist.
• Prefer extending an existing owner over adding a near-duplicate skill.
• Preserve registry identity as part of capability ownership. Inspect the live registry before publishing a shared package; update the intended existing owner/name rather than creating a first-party neighbor beside an older name. Preserve an accepted contributor's namespace in the registry_owner field of SKILL.md frontmatter; absence means the Runx-owned runx namespace. A deliberate rename must migrate or retire the prior identity through the registry operator. Never transfer a contributor's community-owned row into the first-party namespace unless that ownership transfer is explicit.
• Treat registry portability as execution truth, not a publish-time smoke test. A local cross-package skill edge must be present in the digest-bound registry package bundle, and the publish harness must execute that exact materialized package. Never copy sibling source beside a harness while omitting it from the published artifact, rewrite the source graph for registry-only execution, or certify a package that needs the original checkout to run.
• Include a realistic happy path and refusal, stop, or error path.
• Never treat supplied agent answers as provider-effect proof.
• For every public package, make the native readiness report the acceptance boundary. One executable standalone journey must select the actual default runner and name at least two existing nearby public skills as confusors. One executable composed journey must consume named prior evidence and state the work or effects it must not repeat. A journey on a convenient phase runner cannot prove the standalone default. A graph-level harness may use exercises_runner only to identify the public runner it really invokes.
• Read semantic_report.readiness from runx skill inspect; do not recreate its classification in package code, prose, or a second test script. Public work is not ready unless evaluated, coldSelection, standaloneDefault, and composedReuse are true and native semantic diagnostics are empty.
• Keep provider proof labels exact. Deterministic replay is harness, not live. A sealed provider-readback case supplied through caller agent answers does not prove provider execution. Harnesses must not inherit local Runx grants, tokens, credential delivery, or global configuration; every fake binding must be explicit in the fixture, and live proof must come from a separately identified provider run.

Before admitting an architecture, perform a cold-operator trial against the actual proposed result:

1. Can the operator tell what the skill concluded and which evidence supports it?
2. Can they distinguish missing or ambiguous information from a negative result?
3. Can they tell which effects happened, which are only proposed or authorized, and which remain unattempted?
4. Can they continue each material outcome through the correct canonical skill and the declared provider-selection boundary without reconstructing lost context?
5. Does one clear owner hold each decision, approval, mutation, and readback?
6. Would this still be the architecture chosen from scratch against the current Runx catalog?
7. Can a cold agent actually invoke every public runner from inspection alone, using local or remote evidence appropriate to the job, without source-diving, guessed JSON, or an unnecessary provider dependency?

If any answer is no, the package is not ready even if its schemas, tests, and budgets pass. Fix the capability design or return no_skill/needs_core; do not compensate with more fixtures, prose padding, or a bespoke wrapper.

Outputs

• architecture_decision: the agent's closed ownership and execution design.
• architecture_plan: that decision bound by native code to the exact inspection digest. Design stops here.
• change_draft: package bytes and intent authored against the admitted plan; it contains no model-authored integrity values.
• change_bundle: the native, digest-bound transaction candidate produced from the plan and draft.
• apply_result: unchanged, needs-core, or validated-and-applied, with exact changed/deleted paths, package digest, focused proof, and line/file deltas. For a shared/public package, this is the exact local half of the registry publication handoff; registry publish and readback evidence remain separate.

Inputs

• objective (required): capability or improvement to deliver.
• package_name (optional, build): explicit identity for a newly requested package; use it for SKILL.md and X.yaml even when the target directory has a different basename.
• repo_root (optional): workspace root; defaults to the caller workspace.
• target_dir (required for mutating runners): repo-relative package directory.
• project_context (optional): product, repository, and operator constraints.
• receipt_id, receipt_summary, harness_output, failure_packet (improve): failure evidence, including the stable packet from diagnose-skill-run.

Agent task contracts

skill-lab-architecture

Call runx_final_result with exactly one root field, {"architecture_decision": <decision>}. The inner decision uses runx.skill.architecture_decision.v1. Choose build, extend_existing, no_skill, or needs_core. Explain the operator value and the manual's knowledge contract: purpose, required evidence, decision logic, stop conditions, and recovery. Assign every required behavior to exactly one real execution lane (manual, graph, agent_task, native_capability, domain_module, cli_tool, or provider_adapter). A native lane names a selected capability; a domain module supplies a specific justification. Record inspected, selected, and genuinely missing native capabilities; use needs_core only for a runtime or security invariant or a primitive with two independent existing consumers. Before calling runx_final_result, call runx.skill.plan once with the exact authoring_context.base_digest and candidate architecture_decision. Repair any deterministic architecture error it returns, then submit the same validated decision. For every native_capability behavior, reuse_ref must be exactly one entry from native_reuse.selected_capabilities; split a behavior when it needs more than one capability. This prevalidation is read-only and does not replace the graph's native digest-binding step. When package_name is supplied, treat it as the requested package identity; do not silently rename the package from its target path.

Inspect an existing target in one bounded pass. Use the target file list and repository root in authoring_context to read the relevant files together with fs.read_bundle; do not crawl them one at a time or reread files already present in context. Once the evidence is sufficient, return the declared architecture decision instead of spending the remaining round budget on optional discovery.

For every build or extend_existing decision, make the identity decision explicit. Record the current and proposed name, choose keep, rename, create, or internalize, state whether the package is public or internal, and explain why that name is the operation a cold agent will reach for. A rename or internalization is a clean cutover: identify every consumer and do not plan aliases or duplicate discovery rows. Internal packages have no public direct-use contract.

For every public package, declare both operator contexts before authoring:

• direct_use names realistic natural-language trigger and non-trigger requests, the default outcome, routine work the host should do normally, the exact boundary where Runx adds value, the terminal result, one actionable blocker behavior, and the context-preserving native escape path.
• chain_use names accepted typed inputs, the reusable result, prior evidence and effects that survive the boundary, and work that must not repeat.

The proof plan must contain distinct selection_trial, standalone_operator_journey, and composed_operator_journey entries for a public package. They are different claims: intuitive selection, useful direct completion, and evidence-preserving composition. A generic harness or sealed receipt may supplement them but cannot replace them. The selection trial names at least two real public catalog confusors; the standalone journey runs the actual default; and the composed journey names both reused prior evidence and work that must not repeat. The final package inspection must report all four native readiness facts true with no semantic diagnostics.

Declare effects, authority scopes, approval meaning, provider boundary, skill routes, resource ceilings, preservation obligations, exact intended deletions, and a proof plan. For every skill route, state the domain result being handed off, the canonical capability or authority owner, whether a provider adapter is required or operator-selected, the context that must survive the boundary, and the truthful effect state before and after that route. Cover every material outcome independently. Reject an unnecessary provider pin even when it appears in prior work or the request's implementation sketch. Apply the cold-operator trial to the proposed public result and chain before choosing a disposition. Classify every potentially large value as control input, immutable artifact, durable cursor/projection, or bounded domain result, and name its production owner plus small/large proof. Reads, drafts, local validation, and reversible package writes do not gain ceremonial human approval. Provider mutations and other consequential effects keep their real gates. Assign each consequential action exactly one approval owner; never pair an explicit graph approval with an effect-owned approval for the same action. Budgets are operational ceilings, not guesses to be widened after validation. Do not write files, calculate a digest, invent provider proof, or solve an ownership gap with package code.

For a shared/public package, also preserve its intended registry identity and state whether registry availability is in scope. If it is, the plan ends local authoring at the exact applied package and names the canonical registry operator as the separate publish-and-readback boundary. Do not plan embedded registry HTTP, credentials, auto-publish, or an adjacent owner/name.

For improve, diagnose only from supplied receipt or harness evidence and distinguish contract, implementation, fixture, environment, and operator failures. When evidence cannot justify a change, choose extend_existing and let the author return no_change. For harness, plan fixture-only changes and preserve all production behavior.

skill-lab-author

Receive the exact native architecture_plan and return one change_draft using runx.skill.change_draft.v1. Never copy or calculate base_digest, plan_digest, architecture, or any other integrity field; native bind owns those values. Choose write, no_skill, no_change, or needs_core in a way that agrees with the plan. A non-write draft has empty writes and deletes. A write contains the smallest complete target-relative file set, the exact planned deletions, a truthful summary and non-goals, and the outputs the package will actually produce.

When source bytes are needed, read the planned target files together with fs.read_bundle. Do not spend separate rounds reopening files already supplied by authoring_context or the architecture plan; reserve the final round for the complete change_draft.

When package_name is supplied, use it consistently in the SKILL.md frontmatter and the X.yaml skill field. The directory is a placement decision, not a second source of package identity.

Put static operating knowledge and task-specific agent rules in SKILL.md and execution structure in X.yaml. Compose selected native capabilities and declared skill routes first. Ensure the manual explains what each route is for, what context crosses it, and what remains unperformed; do not substitute an adapter name for that explanation. Add a domain module only when the architecture admits it, and keep the module inside its stated computation boundary. Include focused proof for a useful path and a stop, refusal, or regression path. In harness mode, every write or delete must be under fixtures/*.yaml. Preserve useful behavior and delete superseded implementation in the same draft. Never add auxiliary docs, generated state, credentials, placeholder modules, duplicated generic Runx mechanics, or an undeclared provider boundary. Registry publication code, credentials, and live-state claims are likewise outside the authored package; preserve only the canonical package identity needed by the later registry operator.