# Scaffold Harness > Audits and upgrades repositories to a reliable, maturity-appropriate Agentic Engineering harness without overwriting local truth. Use when bootstrapping or repairing agent instructions, designing local/MCP/RAG context routing, controlling token bloat, defining review, model, or quality gates, coordinating repositories, or evaluating agents for CI, overnight, specialist, chat, and observability work. - Skill: `ldaume/scaffold-harness` (Agent Skill, multi-file: 23 files) - Install (CLI): `npx skillmds@latest add ldaume/scaffold-harness` - Raw SKILL.md: https://api.skillmd.com/api/skills/ldaume/scaffold-harness/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: ldaume (https://skillmd.com/u/ldaume) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/ldaume/scaffold-harness --- # Scaffold Harness Build the smallest harness that makes delegated work reliable. Ideal means fit for the repository and its current maturity, not the largest artifact set. ## 1. Ground the Repository Inspect before proposing files: - instruction entrypoints and bridges: `AGENTS.md`, `CLAUDE.md`, `GEMINI.md`, `.cursor/rules/`, or local equivalents - repository and domain sources: `README.md`, `CONTEXT.md`, ADRs, specs, architecture docs, code, and tests - package manager, scripts, CI, infrastructure desired state and state backend, deployment, drift detection, observability, security controls, compliance policy, and evidence - actual Fast Check and Full Gates - repository boundaries, public integration contracts, owners, and consumers - existing Skills, Rules, Hooks, MCP configuration, memory, and evals - the portable Skill-authoring owner and any host-bundled creator, scaffolder, command, plugin, or validator that may overlap it - effective project and workspace roots, coordinator placement policy, managed private organization or team catalogs, public upstreams, user and global bootstrap roots, host precedence, and collisions - live agent-host capabilities, available model controls, orchestration support, and the freshness of any model, pricing, feature, or community guidance Resolve discoverable facts from repository evidence. Preserve user-written content and local naming. Complete grounding when existing sources, commands, boundaries, and gaps are identified without relying on invented product semantics. ## 2. Assess the Target State Read [REFERENCE.md](./REFERENCE.md). Read [MATURITY.md](./MATURITY.md) when assessing a level, moving beyond repository work, changing human oversight, or planning organizational transformation. Evaluate each maturity dimension independently: Select the smallest topology that matches real authority and coordination: - **Single repository:** local instructions, context, checks, and learnings are sufficient; do not add a coordinator. - **Multiple repositories:** use a coordinating harness only for durable relationships, public contracts, workflow state, oversight, and integration checks. Every member retains local truth and a session entrypoint. - **Multiple teams:** federate team-local harnesses through named decision rights, bounded contexts, public contracts, compatibility policy, cross-team evals, and escalation. A central coordinator does not become the product or domain authority for every team. - product and domain clarity - codebase changeability - feedback and quality - delivery and operations - repository context - agent operation - governance and security - learning system - currentness and economics - context architecture and economy Default to a reliable repository-level harness. Add grounded tools, stateful workflows, delivery automation, or product loops only when evidence supports the wider delegated unit. Complete assessment when the current level, target level, and evidence for each proposed addition are explicit. ## 3. Resolve Decisions Establish shared understanding for significant work. Use **grill-harness-with-docs** for unresolved intent, semantics, ownership, architecture, governance, consequential trade-offs, risk, or oversight transitions in any topic. Route resolved material decisions and changes through fresh-context agent critique. Research facts first. Put genuine decisions to the human one at a time with options, trade-offs, reversibility, evidence, and a recommendation. Wait before implementing the dependent branch. Complete decision work when every branch is resolved or explicitly blocked. ## 4. Plan the Smallest Upgrade Match the requested mode: audit reports the current state, propose presents the smallest viable options, and apply makes only authorized reversible changes. Map existing files to the ownership model in `REFERENCE.md`. Prefer updating an existing source over creating a parallel preferred name. For every proposed artifact state: - the observed problem it solves - its single owning concern - its consumers - the smallest verification - why a reference or existing control is insufficient Use templates only for missing artifacts. Create optional artifacts lazily. Merge `.serena/` into the target `.gitignore`; never commit Serena's local project state and never overwrite existing ignore rules. Read [CURRENTNESS.md](./CURRENTNESS.md) before proposing model routing, multi-agent orchestration, provider features, or a community Golden Path. Read [CONTEXT-ARCHITECTURE.md](./CONTEXT-ARCHITECTURE.md) when deciding what belongs locally or behind MCP, RAG, search, projections, or memory; or when large tool output, long sessions, handoffs, instruction growth, token pressure, RTK, Context Mode, Headroom, or another compression layer affects the design. Read [CAPABILITY-GATES.md](./CAPABILITY-GATES.md) on every significant harness stewardship pass: decide whether Graphify-class discovery, Headroom/Context Mode economy tools, or memory systems should enter, stay parked, or be removed. Do not add them without an observed failure mode. Read [RUNTIMES.md](./RUNTIMES.md) before adding agents to CI, schedules, overnight windows, durable services, specialist roles, chat, or production observability. Use **build-autonomous-agents** after the runtime gate passes and a bounded workload is ready for implementation. Use **run-product-engineering** when an L5-L7 delegated unit spans product signals, delivery, production feedback, incidents, outcomes, or investment decisions. Use **product-craft** when the target needs value-defined issues or an honest Now/Next/Later/Never investment view. Use **integrate-product-compliance** only for confirmed security, contractual, certification, TISAX, PCI, or other control scope. Use **manage-infrastructure-as-code** when agents create, change, provision, or reconcile infrastructure desired state. ## 5. Apply - Keep root agent instructions concise and reference detailed owners. - Resolve the current human's preferred collaboration language from explicit preference or conversation evidence; ask once only when it remains unclear. Store personal preference in user-scoped or untracked state unless it is a shared repository rule. Chat language never changes artifact language. - Write harness artifacts in US English with plain punctuation (straight quotes, hyphen `-`, `...`) unless the human explicitly requests another language for a named artifact. Do not introduce curly or angle quotes, the dash family, ellipsis characters, exotic or no-break spaces, invisible format and direction characters, or decorative separators. This is not an ASCII-only rule: natural-language letters in any script, arrows, box drawing, and math or currency signs stay allowed where they carry meaning. Ban a character only when its ASCII spelling is strictly better. - Preserve an existing repository voice or style owner. Repository prose should be direct and concrete: lead with the problem or working model, state trade-offs and system effects, and remove generic hype, defensive setup, and text that changes no decision or action. - Reserve first person for artifacts that explicitly speak for the repository owner. Keep agent instructions and operating procedures neutral and imperative. - Add a harness operating contract for proactive, evidence-backed evolution. - Add domain context only when confirmed language or invariants exist. - Add a context map only for multiple contexts, repositories, or source routes. - Keep repository membership, discovery, relationships, source authority, and checks in that one context map. Do not add a parallel `HARNESS-MAP.md`. Route every member to the coordinator sync document, and route that document to the context map through a local path plus a stable remote fallback. - In a cross-repository context map, record every non-local remote as a full canonical HTTPS discovery URL including its host. It need not match a credentialed Git `origin`. Never infer a host from an `owner/repository` shorthand, another row, or local Git configuration. Use `local / no origin` only when no remote exists, and make the coordinator Fast Check reject ambiguous remote values. - Add learnings when a durable evidence loop is needed. - Add `STATUS.md` when cross-session or cross-repo work needs mid-flight state. - Add a sync protocol and thin member pointers when several repositories must discover one coordinator. - Require a session-safe local agent entrypoint in every listed member, including experiments. Session discovery does not grant unattended autonomy; autonomy remains gated by local checks, recovery, permissions, and status. - Create the human `README.md` projection from the template when no adequate local equivalent exists, and keep it accurate when purpose, cycle, membership, working-root rules, or delegated operating level change. It must explain the current human and agent roles by product phase and operating level, the smaller loops nested inside the current delegated unit, technical controls, engineering method, why that allocation fits the evidence, and the trigger for wider delegation without duplicating the agent control plane. - Design canonical instructions, context, state, contracts, and failures for agent comprehension first. Keep README and reference views legible for humans, but do not reproduce human ceremony in the agent control plane. - Add ADRs only for accepted consequential trade-offs. - Use Skills for repeated probabilistic procedures. - Install `write-a-skill` with the managed bootstrap in every effective host scope when agents may create or change Skills. Treat a platform-bundled creator as a thin adapter for native metadata, scaffolding, or validation; it does not own portable Skill behavior. Do not infer cross-host discovery from a successful Codex, Claude Code, Cursor, Gemini, Pi, or CI session. - When copied bootstrap Skills are managed, create or update the target-owned dependency manifest with the exact public source, immutable per-Skill tag, resolved commit, and effective host targets. A one-off Skills CLI install is a pilot, not the reproducible dependency contract. - Route from the goal and current lifecycle stage to one owning Skill plus only the needed local or managed private or public complements. Do not require the user to name Skills or prescribe a permanent Skill stack. - Distinguish project-local semantics, private organization or team catalogs, private coordinator policy, public upstream Skills, and the small user or global bootstrap. Inspect host precedence, pin managed dependencies, and keep one semantic owner per workflow; public availability never grants private authority. - Resolve the host's effective project, workspace, managed private and public, user, global, bundled, and plugin Skill scopes. When a selected loop needs a missing complement, prefer an approved managed source; for a new public candidate, follow `CURRENTNESS.md` to discover, evaluate, install project-locally, and invoke it. Never claim an uninstalled Skill was used. - Derive the actual stack and major versions from target evidence. Keep core craft methods separate from technology profiles, and use `update-harness` for the stack capability loop: reuse an owned profile, pilot a current public candidate, work directly for a one-off gap, or create the smallest project-local Skill only after repeated need provides examples and checks. - Use **update-harness** in hygiene mode to keep repository-specific Skills local, retain only justified reusable global Skills, preserve host-managed packages, and reconcile duplicate or conflicting effective installations. - Compare overlapping public workflow collections before activation. Use upstream `ponytail` only as an optional, piloted implementation-style guardrail when repeated overengineering justifies it; do not weaken validation, security, accessibility, data integrity, recovery, or necessary error handling. - Use Hooks, CI, tests, and platform controls for deterministic enforcement. - Match activation to how each host actually selects behavior, because "installed" is not "used". Where a host reads instruction files as behavior, a rule in `AGENTS.md` is enough. Where a host selects a Skill as a tool from its name and description against the task at hand - Claude Code does - a rule competes with everything else in the instruction chain and routinely loses: an observed session there loaded no Skill across roughly forty tool calls while writing a Skill and making five commits, with the routing rule in context the whole time. On such a host, put the routing in a Hook at the moment of the decision instead. Three moments carry it: session start for the routing table, the first file edit for the starting point (default branch, foreign uncommitted work, a checkout behind the remote, other worktrees), and the commit for the completion gate. Add a post-merge reminder where worktrees are the isolation default, since deleting the branch leaves the worktree. Keep every one of them silent unless something is actually off, non-blocking, and committed to the repository so contributors get them with the clone; a user-scope copy covers repositories that ship none, and it must stay quiet where a repository-local copy exists. - Keep repeatable infrastructure desired state in version control. Route infrastructure changes through **manage-infrastructure-as-code** for plan, policy checks, protected state, controlled apply, drift, and recovery. Treat emergency console work as an incident action that must be reconciled or reversed, not as a second configuration source. Name GitOps, GitOps-near, or bounded IaC honestly; do not add a controller only to improve the label. - Keep canonical semantics host-neutral. Use `AGENTS.md` as the portable owner and install the thin baseline bridges for Claude Code (`CLAUDE.md` import), Gemini CLI (`GEMINI.md` import), and Google Antigravity (`.agents/rules/harness.md`). Codex, Cursor, and Pi consume `AGENTS.md` directly. Verify the declared host matrix; add other bridges only for hosts the repository actually uses. Reference canonical owners instead of copying policy, and verify precedence, permissions, and behavior per host. - Classify source authority, freshness, locality, shape, activation, persistence, access, and verification before adding MCP, RAG, memory, or a local projection. Keep stable session-critical routing local and query live systems only for task-relevant current information or actions. - Retrieve at the lowest sufficient resolution and keep raw bulk output outside the active context when the host supports it. Use one filtering owner per data path; add compression only after a representative baseline exposes a residual problem. - Add event-triggered self-review, independent review, currentness review, and autonomy review only where their evidence can change a decision. - When a recurring bounded workflow has a justified human-on-the-loop target, make the smallest missing promotion gate part of each qualifying run. Keep the promotion index in the target's existing state owner, link authoritative evidence, prevent a changed gate from certifying itself, and present a ready promote-or-hold decision immediately. Fail closed to human-in-the-loop after a boundary, observability, or recovery failure. - Use a capable current parent model for decomposition and integration. Route bounded worker tasks to the least expensive current model that passes representative checks; never optimize token price independently of retries, review cost, latency, and failure impact. Default repeated subagents to the current Balanced tier, use the Efficient tier for clear mechanical work, and reserve Frontier for ambiguity, consequential integration, or material critique. A fresh Frontier reviewer can close material work produced by cheaper workers; routine review stays on the least expensive proven tier. Keep model capability separate from provider speed or priority service tiers. Never enable premium Fast Mode (`-fast`, `High Fast`, `fast=true`, or host equivalents) for parents or spawned workers. Subagents remain allowed; if the host defaults a child to Fast, cancel and re-spawn without Fast. Efficient means a cheaper capability-tier model, never Fast. - Add `ORCHESTRATION.md` only for repeated multi-agent work, model routing, or cross-repository coordination. Discover live runtime controls before writing host-specific configuration. Keep the role contract provider-neutral and create a thin native adapter for every active host that supports model routing. Resolve the current model map through [CURRENTNESS.md](./CURRENTNESS.md): Codex project agents, Claude Code agent definitions or per-invocation controls, Cursor custom subagents, Gemini CLI agent overrides, and later hosts remain separate adapters. When a host cannot enforce the route, record inheritance or use a separate bounded runtime instead of pretending the optimization is active. - Add an agent runtime only for a bounded repeated workload. Prefer existing CI and scheduler controls, open-source self-hostable components, explicit isolation, budgets, cancellation, evals, and target-owned telemetry. Require durable checkpoints, wake conditions, reconciliation, failure ownership, and stall alerts so routine progress never depends on a later human prompt. Keep required human decisions as durable correlated waits with deadlines and escalation; never auto-approve them. - Treat currentness as an evolution contract, not a frozen research note. When evidence expires, a host or tool changes, or representative tasks expose a mismatch, re-evaluate the affected owner and keep, change, remove, supersede, or rebuild it. Do not preserve incremental structure when replacement is the smaller reliable system. - At L6-L7, close the product loop from attributable signals through delivery, production observation, incident and bug feedback, outcome review, and an explicit next decision. Release alone is not completion. - For product work that uses shared investment or issue tracking, at any level, treat Now/Next/Later/Never as investment decisions rather than date promises. Keep Later coarse, record Never with rationale and a revisit trigger, and create decision or delivery issues only for sufficiently sharp Now or Next work. Raw intake records may remain without becoming commitments. The delegation level determines who maintains and approves these decisions, not whether the semantics apply. - For product engineering, reject specification -> implementation -> testing -> deployment as a handoff pipeline. Use **run-product-engineering** for pull-based learning cycles, evolutionary DDD, bounded spikes, vertical TDD, shift-left security/operability, production feedback, and repeated evolution. - Keep frontend and backend craft independently installable and useful. Route shared end-to-end discipline through **coding-discipline**, while each craft Skill retains its own thin-UI, boundary, data, operability, and experience guidance. - Integrate compliance through target-owned risk, controls, evidence, and release policy. Encode stable enforceable controls as tested policy through **integrate-product-compliance**; keep interpretation, scope, risk acceptance, and assurance claims with named humans. - For cross-repository work, preserve repository-local truth and coordinate through public contracts, owners, compatibility checks, and shared evals. Use **scaffold-distributed-context** when shared domain language, projections, or retrieval layers need their own cross-repository design. - For multi-team work, record the team or role owning each bounded context, contract, policy, risk acceptance, and release decision. Version shared harness policy and Skills, but let team-local owners choose implementation and checks within their authority. Add cross-team escalation and integration evidence without creating a central ticket or documentation bureaucracy. ## 6. Verify 1. Run the documented Fast Check and relevant Full Gates. 2. Verify every referenced local file and command exists. For every mapped repository, verify the recorded remote is either a full canonical HTTPS discovery URL or the explicit `local / no origin` marker. Trace one member's local and remote discovery path through the coordinator sync document to the canonical context map. 3. Confirm each active host resolves the intended Skill versions without collisions and agent instructions remain concise. When Skill authoring is in scope, verify that `write-a-skill` is the resolved portable owner and any native creator remains an adapter. The public catalog currently install-tests Codex, Cursor, Claude Code, and Gemini CLI. Treat Pi, CI, and later runtimes as candidate hosts until the target has a native adapter and a representative bootstrap check. 4. Review the diff for overwritten local truth, speculative layers, and customer or product assumptions. 5. Verify volatile claims have a source, check date, and re-check trigger; do not retain copied price tables or assumed model availability. 6. For a context-economy change, verify the complete routing path and compare successful-task quality, tokens, latency, retries, and recovery with the baseline. 7. State the operating level, remaining gaps, and next evidence trigger. The scaffold is complete only when: - instructions and source routing are discoverable, - the declared host matrix is backed by verified thin bridges or an explicit non-interactive adapter that loads `AGENTS.md`, - every listed repository has a local session entrypoint and safe coordinator fallback, independent of its autonomy level, - every listed repository remote is host-explicit or explicitly local-only, - every member can resolve the canonical context map locally or through its stable remote fallback without a second relationship map, - every declared host can discover the managed bootstrap, including `write-a-skill` wherever agents may maintain Skills, - a human README or local equivalent explains where to start, the current operating envelope, phase responsibilities, rationale, and graduation gates, - domain facts and decisions have explicit owners, - a real Fast Check and Full Gates are named, - uncertainty and escalation behavior are defined, - cross-session learning has one durable owner, - shared understanding has an explicit entry and exit frame, - review loops route resolved material work to fresh-agent critique and genuine unresolved decisions to a human, with triggers, stop conditions, and an action when they fail, including evidence-gated dependency-bot PR handling (inspect jump, run checks, merge or comment - never silent-merge or silent-ignore), - model and worker routing is either live-discovered or explicitly absent, - context routing has one owner per data path, visible authority and freshness, and preserves required evidence, - scheduled or service execution has bounded authority, cost, isolation, recovery, cancellation, and observability, - infrastructure automation has an owned desired state, reviewable plan, protected state, policy gates, drift path, runtime verification, and credible recovery, - all introduced artifacts have a demonstrated purpose, - multi-team systems expose decision rights, contract ownership, compatibility checks, escalation, and team-local authority, - verification results are reported. ## Templates | Artifact | Template | |---|---| | Human operating guide | [templates/README.md](./templates/README.md) | | Root instructions | [templates/AGENTS.md](./templates/AGENTS.md) | | Claude Code bridge | [templates/CLAUDE.md](./templates/CLAUDE.md) | | Gemini CLI bridge | [templates/GEMINI.md](./templates/GEMINI.md) | | Google Antigravity bridge | [templates/.agents/rules/harness.md](./templates/.agents/rules/harness.md) | | Harness contract | [templates/HARNESS.md](./templates/HARNESS.md) | | Domain language | [templates/CONTEXT.md](./templates/CONTEXT.md) | | Context routing | [templates/CONTEXT-MAP.md](./templates/CONTEXT-MAP.md) | | Multi-agent routing | [templates/ORCHESTRATION.md](./templates/ORCHESTRATION.md) | | Durable learnings | [templates/LEARNINGS.md](./templates/LEARNINGS.md) | | Open workflow state | [templates/STATUS.md](./templates/STATUS.md) | | Member/coordinator sync | [templates/SYNC.md](./templates/SYNC.md) | | Tool entrypoints | [templates/TOOLS.md](./templates/TOOLS.md) | | Project Skills | [templates/skills-README.md](./templates/skills-README.md) | | Local tool state ignore | [templates/.gitignore](./templates/.gitignore) | ## Related Skills - **grill-harness-with-docs** - ground, critique, and resolve material decisions - **agent-sync** - evolve the harness from evidence across sessions - **scaffold-distributed-context** - establish domain context and contracts across repositories - **build-autonomous-agents** - implement a bounded product or SDLC agent - **run-product-engineering** - operate a closed signal-to-outcome value stream - **integrate-product-compliance** - integrate confirmed control scope and evidence - **manage-infrastructure-as-code** - manage desired state, plans, state, policy checks, apply, drift, and recovery - **coding-discipline** - make minimal implementation changes - **completion-gate** - verify before claiming completion