Use this skill to operate Jev for the coding-agent environment that loaded it. The harness returns decisions; optional host integrations apply selected results. Loading this Agent Skill alone does not register or activate those integrations. Report the exact host, profile, runtime mode, hook trust, and observed result before claiming automatic behavior.
When to use this skill
Use it when installing or configuring Jev for one runtime, checking or toggling that runtime's profile, selecting a backend, or invoking an approved routing, pruning, or review command. Jev is optional. Keep each profile isolated and fail closed when a selected operation has no usable backend.
Select the current agent profile
Use a unique lower-kebab-case profile ID for each independent agent environment, such as jeopi, gjc, or aside-u0. --profile selects Jev state; --agent selects the Agent Skill destination. Never silently switch profiles or fall back to another profile or the legacy shared config.
Check the exact profile before every live operation:
node ~/.agents/jev/jev-harness.mjs --profile jeopi status
Status exit 2 means inactive or unconfigured; skip Jev gates and follow the host's normal permission policies. Exit 3 means fail closed: the configuration is invalid, or an evaluated operation chain has no usable backend; a down backend that no evaluated chain references never causes it. Exit 0 means the requested chain is not known unavailable, not that model quality or host enforcement is proven. Use --operation route-skills|prune-context|review for one operation; otherwise all three chains are evaluated.
Configure one environment with jev-plugin.mjs
For initial setup or updates, use jev-plugin.mjs with preview-then-apply pattern:
# Preview configuration (shows what will be set, no changes)
node ~/.agents/jev/jev-plugin.mjs configure --agent jeopi --profile jeopi --backend api --key-env JEV_API_KEY
# Apply configuration (invokes setup and writes files)
node ~/.agents/jev/jev-plugin.mjs configure --agent jeopi --profile jeopi --backend api --key-env JEV_API_KEY --apply
# Enable profile (preview then apply)
node ~/.agents/jev/jev-plugin.mjs enable --agent jeopi --profile jeopi
node ~/.agents/jev/jev-plugin.mjs enable --agent jeopi --profile jeopi --apply
# Disable profile
node ~/.agents/jev/jev-plugin.mjs disable --agent jeopi --profile jeopi --apply
# Check profile status (always read-only)
node ~/.agents/jev/jev-plugin.mjs status --agent jeopi --profile jeopi
configure with --agent and --backend prepares or updates a profile. Without --apply, it validates the request and returns a preview without changes. With --apply, it invokes configuration-only setup and writes files without downloads or inference; new profiles start OFF. API configuration requires --key-env naming an existing non-empty environment variable in the invoking process unless the selected profile's API backend already has a saved key; omit --key-env to preserve that key. Use the variable name, never a literal credential. enable and disable toggle JEV_ENABLED; without --apply they preview the change, with --apply they write it. status shows saved configuration without reaching any backend.
The backend registry has exactly five kinds: api, local, ollama, lmstudio, and systemone.
api: TypeSafePOST <JEV_API_ENDPOINT>with{state, model, questions}andAuthorization: Bearer JEV_API_KEY.local: existing Python/v1/systemoneserver reading base-model logits.ollama: native/api/chatJSON-from-chat adapter.lmstudio: OpenAI-compatible/v1/chat/completionsJSON-from-chat adapter.systemone:JEV_SYSTEMONE_DRIVER=typesafe(default),decide(<endpoint>/v1/decide), orvllm-jev-decision(<endpoint>/v1/completionswith logprobs).
Optional native session integration
# Read-only session-load plan; does not install, register, load, or enable anything
node ~/.agents/jev/jev-plugin.mjs host-plan --agent claude --profile claude
# Advisory model argv only; never executes the plan
node ~/.agents/jev/jev-plugin.mjs model-plan --agent jeopi --profile jeopi --advice advice.json
Profiles default to JEV_RUNTIME_MODE=advisory and JEV_REVIEW_MODE=off. Explicit configure --runtime-mode assist enables trusted selected skill instruction loading in a registered, enabled integration. Skill bodies include source paths for resolving referenced files. They must match the trusted catalog and remain within its skill root; files exceeding 64 KiB or the 96 KiB combined budget are skipped whole, never partially injected.
| Host integration | Automatic behavior after activation |
|---|---|
| Claude | Prompt-time selected skill instruction injection; no automatic history pruning or action enforcement. |
| jeopi / OMP / Pi | Prompt-time skill injection as a Jev custom message; context callbacks may remove only older Jev custom messages from model input. The newest skill instructions and all user, system, assistant, tool, and other extensions' messages are preserved. Persisted history is unchanged. |
| Codex 0.162.1 | UserPromptSubmit skill injection and optional PreToolUse review for registered tool matchers; no automatic history pruning. Requires exact hook definitions to be trusted in /hooks. |
For Codex, after the harness is installed:
# JEV_API_KEY is already set; omit --key-env to preserve an existing profile key
node ~/.agents/jev/jev-plugin.mjs configure --agent codex --profile codex --backend api --key-env JEV_API_KEY --runtime-mode assist --review-mode advisory --apply
node ~/.agents/jev/jev-plugin.mjs enable --agent codex --profile codex --apply
node ~/.agents/jev/jev-plugin.mjs hooks-install --agent codex --profile codex --apply
Review and trust the generated definitions in Codex /hooks; changed definitions need renewed trust. Installation, trust, and JEV_ENABLED are separate. Review mode off performs no action review; advisory reports a verdict; explicit enforce denies unless the result is permit from a validated backend. Even then, the hook never returns a host permission grant. Host failures, skipped or untrusted hooks, and timeouts can fail open: this is not an OS security boundary. Jev does not execute tests when reviewing an action, and successful transport does not prove calibration or decision quality.
Native session loading is available for Claude, jeopi, OMP, and Pi. host-plan remains read-only with executed: false; a package-load command loads only that session. Copying package assets is not persistent registration, and package toggles do not change JEV_ENABLED. A registered OFF hook returns neutral before stdin, catalog, or backend work. model-plan returns advisory argv and never changes the host model. Do not claim all hosts were exercised live based on callback tests.
Every kind defaults to tier unvalidated. A response or loopback fixture proves transport only. Tier validated requires an exact served-model attestation in the kind env file, JEV_<KIND>_VALIDATED_MODEL=<model id>, and is honored only for calibrated decision-head drivers: api and systemone (typesafe, decide, vllm-jev-decision). local, Ollama, and LM Studio are System 2 paths and can never be validated (attestation.eligible: false), so they can never permit. Stale or mismatched attestations are unvalidated. Oversized review input is rejected as unavailable rather than trimmed.
Per-operation policy and resolution
The base profile stores JEV_ENABLED, JEV_MODE, JEV_RUNTIME_MODE (advisory or assist), JEV_REVIEW_MODE (off, advisory, or enforce), and optional operation keys:
JEV_ROUTE_SKILLS_BACKEND,JEV_PRUNE_CONTEXT_BACKEND,JEV_REVIEW_BACKENDJEV_ROUTE_SKILLS_FALLBACK,JEV_PRUNE_CONTEXT_FALLBACK,JEV_REVIEW_FALLBACK
Each fallback is an ordered comma-separated allow-list; only those kinds may be attempted. Resolution is CLI --backend <kind> (must be eligible), then the operation backend, then JEV_MODE, then api. --model <id> overrides the resolved model for that invocation. No cross-profile fallback is allowed. Envelopes report backend: {kind, model, tier} and attempted kinds.
Run approved operations
node ~/.agents/jev/jev-harness.mjs --profile jeopi route-skills --top-k 3 "<task>"
node ~/.agents/jev/jev-harness.mjs --profile jeopi prune-context < blocks.jsonl
node ~/.agents/jev/jev-harness.mjs --profile jeopi review "<task>" '<proposal-json>'
route-skills adds selection and advisory routing. Gate and fit thresholds are both 0.30. Gate failure is explicit none (topK: [], selection.reason: "gate") with publicRegistryFallback; fit failure is explicit none with selection.reason: "fits". The strategy is sharded when ceil(catalogSize / choiceCap) <= 4, otherwise shortlist. routing reads optional skills.json model_policies and uses provider/model vocabulary (for example openai/gpt-6.1-sol); model advice remains advisory, with the resolved policy and provenance: {backend: {kind, driver, model, tier}}. The command itself does not install skills or change the coding model. Token savings are estimates rather than measured host usage.
prune-context sends {blocks:[{id,text}...]} with position-keyed questions essential::<index> per request, so duplicate block IDs are safe. Blocks are batched within the answering backend's state limit so none is judged unseen; an oversized single block is returned as keep with a reason. Batch-capable drivers send one request per batch; other drivers loop. Keep blocks unless the answer is no with confidence at least 0.8.
Review results bind backend: {kind, model, tier}. Any proposed permit on a non-validated tier becomes proposal_only with reason Backend tier 'unvalidated' cannot authorize autonomous execution. Receipt v2 is the SHA-256 of JSON.stringify({v:2, task, proposal, decision, backend:{kind, model, tier}}); preserve it as the audit binding.
Every command accepts --backend <kind> and --model <id>. smoke [--backend <kind>] [--task "<text>"] runs route/prune/review with three golden tasks, never permits, and warns for unvalidated tiers. self-test --mock remains offline and must print N/N checks passed; --mock never permits autonomous action.
Missing credentials, unreachable backends, contract errors, malformed responses, and timeouts are unavailable. Request approval before transmitting task/context/proposal data to hosted services or downloading models. Treat output as a proposal and apply the host's own confirmation policies.
Profile boundaries and examples
An install without --profile may use the intentional legacy ~/.agents/jev/.env; a selected profile never falls back to it. Keep profile files private and out of source control.
bash ~/.agents/jev/jev-setup.sh --profile jeopi --agent jeopi --mode api
bash ~/.agents/jev/jev-setup.sh --profile gjc --agent gjc --mode local
node ~/.agents/jev/jev-harness.mjs --profile jeopi status
node ~/.agents/jev/jev-harness.mjs --profile gjc status
References
- Backend setup and limits:
jev/README.mdin thejeo-skillscheckout. - Host integration contract:
jev/jev-control-plane.rule.mdin thejeo-skillscheckout.