audit(core): prototype-chain dictionary lookups — systematic sweep, shared guard, regression net

Problem

Plain-object dictionary lookups that read through the prototype chain keep
recurring in the fork's core. Ten instances have been filed individually —
a lookup keyed by an external string (a plan name, effort name, route
name, header, table name) hits constructor / toString / __proto__
and returns an inherited value instead of missing. Fixes are landing
one at a time (a per-site Object.hasOwn guard, e.g. PR #794), and the
class keeps producing new instances faster than the drip closes it.

Known instances (verify current status at triage): #774, #791, #792,
#793, #804 (fixed), #805 (fixed), #819 (fixed), #824 (fix PR open),
#830, #831. #831 shows the sharpest symptom so far: a route named
'constructor' crashes the governance gate outright.

Proposal

Stop fixing these one by one:

Sweep: grep-driven audit of packages/core (and other packages
with externally-keyed plain-object reads) for the pattern classes:
obj[key] / obj[key] ?? fallback where obj is a plain object or
object literal used as a dictionary and key is externally supplied
(names from config, plans, providers, routes, efforts, headers).
File or fix each hit.
Shared guard: one blessed way to do dictionary reads — a helper
(own-property lookup) or a convention (Map / Object.create(null) /
Object.hasOwn) applied at the sweep sites, so the next author copies
the safe shape.
Regression net: a lint rule or a targeted test convention that
flags new bare dictionary reads on plain objects in core, so the
class stays closed.

Acceptance

The audit's search patterns and hit list are recorded on this issue.
Every confirmed hit is fixed or split into its own issue.
The shared guard exists and the sweep sites use it.
A lint/test mechanism (or a documented reason one is impractical) is
in place.

Filed by the operator after the tenth instance (#831) landed; the
individual fix issues remain the lanes' work — this issue owns the
class, not the instances.

Acceptance criteria

A grep-driven sweep of packages/core (and any other package with externally-keyed plain-object reads) is recorded on this issue: every hit is fixed, filed as its own issue, or explicitly dispositioned as safe.
A shared guard exists per the proposal, and swept sites use it where it fits instead of new per-site one-offs.
Each known instance (fix(core): AISDKNative package tables read through the prototype chain — a package named "constructor" resolves to a function, not a package string #774, fix(core): ModelRouteSchedule day names read through the prototype chain — "constructor" and "__proto__" parse as valid days #791, fix(core): ShellParse ARITY table reads through the prototype chain — a "constructor" command head yields an empty permission prefix and a " *" saved pattern #792, fix(core): MessagingTemplate.constant reads config vars through the prototype chain — "{constructor}" resolves to a function and crashes rendering when any messaging.vars are configured #793, fix(core): QuotaBurnRate priors lookup reads through the prototype chain — an effort named 'constructor' returns a function as percentPerSession #830, fix(core): ModelGovernance route and variant lookups read through the prototype chain — a route or variant named 'constructor' crashes the governance gate #831; fix(core): ConfigVariable {env:} substitution reads through the prototype chain — "{env:constructor}" injects the Object function source and ":-" fallbacks are ignored for prototype names #804/fix(codemode): CodeMode fetch response headers read through the prototype chain — get("constructor") returns the Object function and has("__proto__") is true for headers the server never sent #805/fix(core,ai): ModelRouteLimits.windows crashes on rate-limit windows named after Object.prototype members — sibling limit/reset lookups read through the prototype chain #819 already fixed) is verified fixed/closed or linked to its fix.
A regression test shows a constructor / __proto__ key missing cleanly instead of returning an inherited value.

OPENCODE-187

agent-note:v1
state: filed
Agent: main (operator)
Found via: the tenth prototype-chain instance (#831) filed 2026-10-29;
operator filed this umbrella so the class gets closed, not just the
instances. Triage: verify each listed instance's status, pin the sweep
patterns, and route the guard + sweep as follow-up packets.

agent-note:v1
state: picked-up
Agent: repo-worker-opencode (queue task 3141, triage)
Found via: queue claim repo-health-opencode-pilot
Next: verify instance statuses, pin sweep patterns + packages/core hit list on this issue, route guard/regression-net follow-ups. No hard-stop labels present.

agent-note:v1
state: triaged
Agent: repo-worker-opencode (queue task 3141, triage)
Verified at: 2026-10-29, laptop primary main 71608cb (includes PR #843)

Instance status — all ten verified fresh (2026-10-29)

Issue	State	Fix in flight / landed
#774 AISDKNative package tables	CLOSED (status:done)	landed
#791 ModelRouteSchedule day names	CLOSED	PR #794 MERGED
#792 ShellParse ARITY	CLOSED	landed
#793 MessagingTemplate vars	CLOSED	landed
#804 ConfigVariable {env:}	CLOSED	landed
#805 CodeMode headers	CLOSED	landed
#819 ModelRouteLimits windows	CLOSED	landed
#824 QuotaSnapshot per-plan max-age	OPEN, status:in-review, queue/parked	Two competing PRs open: #825 and #835 (both for #824 — a duplicate pair; the shepherd for that task should close one)
#830 QuotaBurnRate priors	OPEN, status:in-review, queue/parked	PR #837 OPEN
#831 ModelGovernance route/variant	OPEN, status:in-review	PR #838 OPEN

Class is still expanding beyond the original ten: #839 (codemode std.pick — also with a duplicate PR pair #859/#861) and #856 (PR #858) were filed after this umbrella.

Sweep patterns pinned (packages/core/src, grep)

P-A uppercase plain-object tables, externally-keyed bracket read, no guard:
grep -rnE '\b[A-Z][A-Z_0-9]{2,}\[[a-zA-Z_]' packages/core/src --include='*.ts'
P-B in-operator membership on plain objects (prototype-inclusive):
grep -rnE ' in [a-zA-Z_.()]+' packages/core/src --include='*.ts' (high noise; only real for variable-length external keys)
P-C Record bracket read with ?? fallback — prototype values are not nullish, so the fallback never fires (the most dangerous shape):
grep -rnE '\[[a-zA-Z_.]+\] \?\?' packages/core/src --include='*.ts'
Guard census baseline: 96 Object.hasOwn uses in 49 files under packages/, 34 in packages/core/src; Object.create(null) appears nowhere in core; no shared helper exists.

Hit list from this sweep

New confirmed hits — split into their own issues:

variant.ts:30 PROTOCOLS[model.package] — plain Record, external package name, truthiness-only guard → split filed as fix(core): Variant PROTOCOLS table reads through the prototype chain — a model package named "constructor" resolves to the Object function #862.
model-plan.ts:247 store.pools[poolID] ?? {} — Schema.Record from the store file, external poolID → split filed as fix(core): ModelPlan setPool pools lookup reads through the prototype chain — a pool named "constructor" never takes the ?? {} fallback #863.
wellknown.ts:88 variables[name] ?? process.env[name] ?? "" — name from a remote manifest, same symptom as fix(core): ConfigVariable {env:} substitution reads through the prototype chain — "{env:constructor}" injects the Object function source and ":-" fallbacks are ignored for prototype names #804 in a different file → split filed as fix(core): WellKnown {env:} substitution reads through the prototype chain — "{env:constructor}" injects the Object function into remote-config URLs/headers #864.

Already-tracked hits still unguarded on main (fixes in flight, listed above): quota-snapshot.ts:84 (#824), quota-burn-rate.ts:132-133 (#830), session/model-governance.ts:200,219,234 (#831).

Candidates needing confirmation (routed to the guard/sweep follow-up, not split):

model-route-review.ts:238-252 weights[candidate] ?? 1 / excluded[reason] counters — weights come from persisted decision detail; a candidate/reason named constructor would poison sums/counters.
shell/select.ts:75 META[name(file)] — Windows-only, basename key; constructor file returns the Object function, deny check reads undefined → benign but a prototype read.
model-resolver.ts:326 / effect/websocket-constructor.ts:20 — process.env[...] / environment-object reads; env-family, covered in principle by the fix(core): ConfigVariable {env:} substitution reads through the prototype chain — "{env:constructor}" injects the Object function source and ":-" fallbacks are ignored for prototype names #804 pattern.

Examined and safe, with reason (do not re-file):

form.ts:479,482 + model-route-limits.ts:66,69 MONTH_NUMBERS — regex capture is constrained to (jan|feb|…) prefixes.
model-route-limits.ts:100,133 UNITS / RELATIVE_UNITS — key constrained by the amount regex (ms|s|m|h|d).
session/runner/publish-llm-event.ts:674 INPUT_FAILURES — key is the closed union InputFailureReason, internal only.
session/compaction.ts:444 SHRINK_STEPS, model-route-schedule.ts:315 DAY_LABELS, model-route.ts weights — numeric indexes.
model-route-schedule.ts:171 SHORT_DAYS — key from Intl weekday formatting, trusted.
ripgrep/binary.ts:97 PLATFORM — key is ${process.arch}-${process.platform}, internal.
shell/scan.ts:1606 BASH_ANSI_ESCAPES — single-char key (guarded by in; no single-char prototype member); scan.ts:2280 POWERSHELL_ESCAPES — single-char key, ?? char fallback sound for the same reason.
database/v1-migration.bun.ts:924-928 RENAMED_TOOLS — names derived from Object.keys(RENAMED_TOOLS) (own keys only).

Routing

Sweep fixes: split issues filed for the three new confirmed hits (fix(core): Variant PROTOCOLS table reads through the prototype chain — a model package named "constructor" resolves to the Object function #862, fix(core): ModelPlan setPool pools lookup reads through the prototype chain — a pool named "constructor" never takes the ?? {} fallback #863, fix(core): WellKnown {env:} substitution reads through the prototype chain — "{env:constructor}" injects the Object function into remote-config URLs/headers #864); open-instance fixes (fix(core): QuotaSnapshot per-plan max-age lookup reads through the prototype chain — a plan named 'constructor' never goes stale #824/fix(core): QuotaBurnRate priors lookup reads through the prototype chain — an effort named 'constructor' returns a function as percentPerSession #830/fix(core): ModelGovernance route and variant lookups read through the prototype chain — a route or variant named 'constructor' crashes the governance gate #831) stay with their existing PRs — note the fix(core): read quota snapshot per-plan max age as an own property #825/fix(core): resolve QuotaSnapshot per-plan max-age with own-property semantics (#824) #835 duplicate pair on fix(core): QuotaSnapshot per-plan max-age lookup reads through the prototype chain — a plan named 'constructor' never goes stale #824.
Shared guard + regression net: follow-up issue filed as audit(core): shared own-property guard + regression net for prototype-chain dictionary reads (#833 follow-up) #865 (guard helper/convention + CI lint/grep net or a documented impracticality reason). Queue packets for fix(core): Variant PROTOCOLS table reads through the prototype chain — a model package named "constructor" resolves to the Object function #862, fix(core): ModelPlan setPool pools lookup reads through the prototype chain — a pool named "constructor" never takes the ?? {} fallback #863, fix(core): WellKnown {env:} substitution reads through the prototype chain — "{env:constructor}" injects the Object function into remote-config URLs/headers #864, audit(core): shared own-property guard + regression net for prototype-chain dictionary reads (#833 follow-up) #865 enqueued from this triage (task 3141 result lists their task ids).

Triage verdict: the class is real, per-site drip is working for filed instances (7/10 closed, 3/10 with PRs open), but the sweep found 3 new sites in one pass — the guard + net follow-up is the load-bearing item, not more instance fixes.

agent-note:v1
state: done (triage)
Agent: repo-worker-opencode (queue task 3141)
Result: triage verdict + instance statuses + sweep patterns/hit list recorded in comment 6494535137 above. Splits filed: #862 (task 3393), #863 (task 3394), #864 (task 3396); guard + regression net: #865 (task 3397). This umbrella stays open — #865 owns closing the class. Noted for the #824 shepherd: PRs #825 and #835 are a duplicate pair.

Intake review (fleet monitor, 2026-10-29 run):

Related: known instances fix(core): AISDKNative package tables read through the prototype chain — a package named "constructor" resolves to a function, not a package string #774, fix(core): ModelRouteSchedule day names read through the prototype chain — "constructor" and "__proto__" parse as valid days #791, fix(core): ShellParse ARITY table reads through the prototype chain — a "constructor" command head yields an empty permission prefix and a " *" saved pattern #792, fix(core): MessagingTemplate.constant reads config vars through the prototype chain — "{constructor}" resolves to a function and crashes rendering when any messaging.vars are configured #793, fix(core): QuotaBurnRate priors lookup reads through the prototype chain — an effort named 'constructor' returns a function as percentPerSession #830, fix(core): ModelGovernance route and variant lookups read through the prototype chain — a route or variant named 'constructor' crashes the governance gate #831 open at filing; fix(core): ConfigVariable {env:} substitution reads through the prototype chain — "{env:constructor}" injects the Object function source and ":-" fallbacks are ignored for prototype names #804/fix(codemode): CodeMode fetch response headers read through the prototype chain — get("constructor") returns the Object function and has("__proto__") is true for headers the server never sent #805/fix(core,ai): ModelRouteLimits.windows crashes on rate-limit windows named after Object.prototype members — sibling limit/reset lookups read through the prototype chain #819 fixed; fix(core): QuotaSnapshot per-plan max-age lookup reads through the prototype chain — a plan named 'constructor' never goes stale #824's fix PR was open at filing — verify each instance's current status at triage, as the body itself instructs. Per-site precedent: PR fix(core): use own-property lookup for ModelRouteSchedule day names (#791) #794's Object.hasOwn guard.
Still live: yes — the audit/sweep itself has not been done; individual fixes landing do not close the class.
Notes/risks: sweep breadth is the risk (every plain-object read in core is a lot of surface); bound the sweep to externally-keyed reads as the proposal states, and disposition-don't-fix anything ambiguous.
Suggested approach: land the shared guard first, run the grep classes from the proposal, file/fix per hit, and record the sweep table here.

agent-note:v1
state: done — closing umbrella
Agent: issue sweep (issue-sweep-rotating)
Session/ID: issue-sweep-rotating run 2026-10-29 20:24 CDT (correction pass)

Closing #833 — acceptance verified complete 2026-10-29

Audit recorded: the queue triage (task 3141) recorded the sweep patterns and hit list on this issue (comment 6494535137), with per-instance statuses.
Every confirmed hit fixed or split, and all splits done: known instances fix(core): AISDKNative package tables read through the prototype chain — a package named "constructor" resolves to a function, not a package string #774, fix(core): ModelRouteSchedule day names read through the prototype chain — "constructor" and "__proto__" parse as valid days #791, fix(core): ShellParse ARITY table reads through the prototype chain — a "constructor" command head yields an empty permission prefix and a " *" saved pattern #792, fix(core): MessagingTemplate.constant reads config vars through the prototype chain — "{constructor}" resolves to a function and crashes rendering when any messaging.vars are configured #793, fix(core): ConfigVariable {env:} substitution reads through the prototype chain — "{env:constructor}" injects the Object function source and ":-" fallbacks are ignored for prototype names #804, fix(codemode): CodeMode fetch response headers read through the prototype chain — get("constructor") returns the Object function and has("__proto__") is true for headers the server never sent #805, fix(core,ai): ModelRouteLimits.windows crashes on rate-limit windows named after Object.prototype members — sibling limit/reset lookups read through the prototype chain #819, fix(core): QuotaSnapshot per-plan max-age lookup reads through the prototype chain — a plan named 'constructor' never goes stale #824, fix(core): QuotaBurnRate priors lookup reads through the prototype chain — an effort named 'constructor' returns a function as percentPerSession #830, fix(core): ModelGovernance route and variant lookups read through the prototype chain — a route or variant named 'constructor' crashes the governance gate #831 are all CLOSED; the triage splits fix(core): Variant PROTOCOLS table reads through the prototype chain — a model package named "constructor" resolves to the Object function #862, fix(core): ModelPlan setPool pools lookup reads through the prototype chain — a pool named "constructor" never takes the ?? {} fallback #863, fix(core): WellKnown {env:} substitution reads through the prototype chain — "{env:constructor}" injects the Object function into remote-config URLs/headers #864 are all CLOSED (completed, status:done).
Shared guard + regression net landed: audit(core): shared own-property guard + regression net for prototype-chain dictionary reads (#833 follow-up) #865 CLOSED (completed) via PR feat(core): shared own-property guard + prototype-chain read regression net #883 MERGED 2026-10-29 (merge commit 580c277) — "feat(core): shared own-property guard + prototype-chain read regression net".

All four acceptance points are met, so this umbrella is complete. (Correction note: an earlier sweep entry this run briefly recorded #864/#865 as still open from a stale read; fresh gh api reads show both closed/completed — the backlog entry has been corrected.)

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audit(core): prototype-chain dictionary lookups — systematic sweep, shared guard, regression net #833

Problem

Proposal

Acceptance

Acceptance criteria

Instance status — all ten verified fresh (2026-10-29)

Sweep patterns pinned (packages/core/src, grep)

Hit list from this sweep

Routing

Closing #833 — acceptance verified complete 2026-10-29

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audit(core): prototype-chain dictionary lookups — systematic sweep, shared guard, regression net #833

Description

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developing-today commented on Oct 29, 2026

dezren39 commented on Oct 29, 2026

dezren39 commented on Oct 29, 2026

dezren39 commented on Oct 29, 2026

Instance status — all ten verified fresh (2026-10-29)

Sweep patterns pinned (packages/core/src, grep)

Hit list from this sweep

Routing

dezren39 commented on Oct 29, 2026

dezren39 commented on Oct 30, 2026

dezren39 commented on Oct 30, 2026

Closing #833 — acceptance verified complete 2026-10-29

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