Grill Round — issue #1390: Config loader: redact secret-bearing values from debug diagnostics

Subject: Architect (architect.yaml) | Griller: Griller (griller.yaml) | Orchestrator: Butler
Repo: gosharplite/tell-me-go | Date: 2026-08-18
Round: 9 questions + round-complete declaration at the Q10 slot (cap 10)

Opening Statement (Architect)

I have completed the bootstrap (README, Makefile, domain models, environments docs, INTENTIONAL_NON_FIXES, issue #1390 + #1389, and all cited source) and verified every line reference. Here is my opening statement.

SUBJECT Opening Statement — Issue #1390 (Config loader: redact secret-bearing values from debug diagnostics)

1. Understanding of the gap

Issue #1390 is a tracked follow-up from the #1389 MCP Basic-auth grill round (ADR-067 §4 amendment item 3). Two debug-gated dumps in internal/infrastructure/config/config.go serialize the entire credential surface of the system when the default slog logger is at Debug level, violating the scoped mcp-token-not-logged invariant (docs/domain-model/tell-me-go.modelith.yaml:513-514) on a reachable path. Verified against source:

Dump 1 — raw content, config.go:147: slog.Debug("raw content", slog.String("content", string(data[:min(len(data), 1000)]))) in readConfigFile (:137). It fires before v.ReadConfig (:150), so a file-literal API_KEY: "sk-…", TOKEN:, or USERNAME: value lands verbatim in the diagnostics. Note the critical ordering property: because it precedes ReadConfig, it is the only content diagnostic when the YAML is invalid (the parsed-key dump never runs).
Dump 2 — viper parsed keys, config.go:156-158: slog.Debug("viper parsed keys") + per-key slog.Any("value", v.Get(key)). Because configureViper wires SetEnvPrefix("TELL_ME") (:121), the ::→_ replacer, and AutomaticEnv() (:124), v.Get on an env-overridden key returns the live secret (e.g. the value behind TELL_ME_MCP_SERVERS_ATLASSIAN_TOKEN), not the file literal — so ${ENV_VAR} references do not protect this path. TestLoad_WrapWidth_EnvOnly in config_test.go already pins this AutomaticEnv behavior.

Scope is confirmed repo-wide: a grep of internal/ finds no other slog.Debug that serializes config values — only :147 and :156-158. The config finder.go logs error paths only; watcher.go logs no values. The MCP plumbing itself is clean: di/mcp_factory.go resolveServerToken/Build log only server names and errors (mcp_client_init_failed, mcp_token_resolution_skipped), never tokens; internal/infrastructure/mcp/client.go injects headers purely in transport (bearerTokenTransport :319-331, basicAuthTransport :349-362) with zero logging. So the loader dumps are the sole exposure.

2. Redaction semantics (the design decision)

Parsed-entry dump (:156-158) — redact the value, keep the key. For a key matching the deny-list, log slog.Any("value", redactedValue) where redactedValue = "[REDACTED]"; the key remains visible so debug utility is preserved (you learn which keys are set/overridden, not what they hold). Key-based, applied to any value type (string/number/map) — no value-shape heuristics.

Raw-content dump (:147) — redact, do not drop. Dropping would remove the only diagnostic for invalid YAML (ordering property above) — a regression of the exact debug scenario. Redact by line: extract key: rest per line, and for deny-list keys replace the value portion after the colon with [REDACTED], suppressing subsequent more-indented continuation lines (block-scalar case, e.g. API_KEY: |). Non-matching lines pass through byte-for-byte.

The deny-list is suffix-anchored on the leaf segment (after the last ::), case-insensitive: (?i)(api[_-]?key|auth[_-]?token|authorization|token|password|passwd|secret|credential|credentials|username|key)$. This is the crux of the semantic: a naive substring match on token would false-positive MAX_TOKENS/max_history_tokens — non-secret integer limits the issue explicitly requires to stay visible ("redaction must not break debug utility for non-secret values"). Suffix anchoring on token$ matches github_token/x-api-token but not max_tokens (ends in tokens). It covers the shipped README's google_application_credentials (credentials$), deepseek_api_key, hyphenated header names (x-api-key via api[_-]?key$), and the Authorization header name — the wildcard HEADERS map (domain/config/config.go:62) being the residual surface. Documented limitation: a secret under an innocuous key name (e.g. HEADERS: x-custom: value) is not caught — deny-list-by-key is the issue's agreed semantic; entropy/sk--prefix value heuristics are rejected as false-positive-prone on legit values (URLs, model names). USER_ID (config.go:74) is deliberately not redacted — it is a content-safety identifier, validated [a-zA-Z0-9\-_]+, not a credential.

3. Helper location and testing

New unexported helpers in a dedicated file internal/infrastructure/config/redact.go (same package, keeping config.go focused): isSecretKey(key string) bool (leaf extraction + deny regex), redactRawContent(s string) string (line-based + continuation suppression), and const redactedValue. Deliberately unexported: single caller; avoids an exported API and any modelith-drift flag on new exports. No internal/pkg move — ADR-062 Decision 2's triage targets cross-layer utilities; a future second consumer can promote it per that ADR without touching the loader.

Tests (hand-rolled table tests, no testify — ADR-021; capture-based, no time.Sleep — ADR-036): unit tests in redact_test.go for isSecretKey (positives: api_key, token, username, x-api-key, github_token, google_application_credentials, authorization; negatives: max_tokens, url, auth, mode, user_id, thinking_budget) and redactRawContent (inline, quoted, block-scalar continuation, non-secret passthrough). Integration assertions in config_test.go extend the existing TestReadConfigFile_WithDebugEnabled pattern (which currently uses slog.SetDefault + io.Discard) by swapping the discard handler for a bytes.Buffer-backed slog.TextHandler at Debug with t.Cleanup restore, then asserting: (a) file-literal API_KEY: "sk-super-secret" renders [REDACTED] in both dumps and the raw secret never appears; (b) env-override live secret — YAML MCP_SERVERS: atlassian: … TOKEN: file-token + t.Setenv("TELL_ME_MCP_SERVERS_ATLASSIAN_TOKEN", "env-super-secret") → parsed dump shows [REDACTED], not the env value (this is the AutomaticEnv path the issue calls out); (c) non-secret preservation + false-positive guard: MAX_TOKENS: 32000 and MODE: test remain visible.

4. ADR-067 §4 / domain-model touchpoints

The mcp-token-not-logged invariant wording stays unchanged — it is scoped to the MCP credential plumbing (config validation, DI factory, client transport), there is no enforcement gate on invariant prose (modelith lint checks structure, not semantics), and keeping it scoped avoids a modelith re-render while keeping modelith-check green. The correct record is the ADR: ADR-067 §4 amendment item 3 is updated from "known exception + tracked follow-up #1390" to RESOLVED, noting the loader now redacts secret-bearing values in both dumps (including env-overridden live secrets) via internal/infrastructure/config/redact.go, referencing this issue, and noting the loader satisfies the invariant's intent on the MCP surface as a side effect of general diagnostics hardening. No INTENTIONAL_NON_FIXES entry — this is a fix, not an accepted gap (issue plan item 4); the sole catalog reference to the file (INTENTIONAL_NON_FIXES.md:587, the rejected "Config.load() io.Reader Extraction" design entry) cites function names, not line numbers, so no re-anchor is triggered by the drift policy.

5. Acceptance criteria and gates

All four checkboxes map to concrete artifacts: (1) parsed-entry redaction pinned by the env-override + file-literal tests; (2) raw-content redaction pinned by the line/block-scalar tests; (3) ADR-067 §4 item 3 updated to RESOLVED referencing #1390; (4) make check-full green. Gate compliance: new functions CC ≤ 10 (isSecretKey ~2, redactRawContent ~6); ADR-036 no time.Sleep; ADR-021 no testify/mock; ADR-022 no "testing" import in redact.go; verify-adr-index unaffected (filename unchanged, content edit); verify-nonfix-catalog untouched; test-coverage sees the new helpers fully covered by unit tests. Housekeeping in the same change: config_test.go comments citing drifted config.go lines (131, 134-136, 143-147, 164-166, 212 — the intOverflowHook pin) are refreshed, since edits in the readConfigFile/configureViper region shift everything below. No domain-model YAML edit, so no modelith-render/modelith-check churn.

Q1 (Griller)

I have everything I need for Q1. Verified so far: all line citations in the issue and the subject's opening match the source (isDebug :23, raw dump :147, parsed dump :156-158, SetEnvPrefix :121, AutomaticEnv :124); my live viper v1.21.0 experiment confirms the parsed dump surfaces live env secrets (leaf-only keys, lowercased — no parent-map subtree leak); the MCP plumbing and metrics_tracker dumps carry no secrets; the invariant and ADR-067 §4 item 3 read as recorded; and the catalog entry cites function names only (no line pins, so no re-anchor).

Q1: Your opening calls the deny-list "the issue's agreed semantic," but the issue's plan item 1 actually delegates this — "Architect to adjudicate" — with a substring example list (token|apikey|api_key|password|secret|credential|username), which you have silently replaced with a suffix-anchored leaf regex that drops substring matching and adds key$, authorization, passwd, auth[_-]?token. I verified the anchor's purpose is legitimate (substring token would redact the shipped non-secret MAX_TOKENS/MAX_HISTORY_TOKENS, which the issue requires to stay visible), but the anchor has a concrete cost your opening never enumerates: every plural secret leaf now escapes redaction in both dumps — API_KEYS, AUTH_TOKENS, SECRETS, PASSWORDS, TOKEN_LISTS — e.g. PROVIDERS.vertex-flash.API_KEYS: [sk-a, sk-b] passes unredacted in the raw-content dump (line key API_KEYS matches nothing) and in the parsed dump (leaf providers::vertex-flash::api_keys matches neither api[_-]?key$ nor key$). Your coverage claim ("It covers the shipped README's …") lists only positives; your test table lists max_tokens as a negative but no plural-secret positives.

Is the suffix-anchored list the ratified semantic, or should the plan add the non-colliding plural forms (secrets?, passwords?, keys? — note tokens? is barred because max_tokens collides) and record the residual plural gap as a documented limitation in the same class as the HEADERS residual? And since the issue explicitly left this to the architect's adjudication rather than pre-agreeing it, where is this decision recorded for the ADR amendment?

A1 (Architect)

Q1: The griller's point holds on both counts. I retract the "agreed semantic" characterization and concede the plural gap, with verification.

Retraction on provenance. The issue's plan item 1 does not ratify any semantic — it says verbatim: "Decide redaction semantics — the design decision: (a) redact values for a deny-list of secret-bearing keys (e.g. keys matching token|apikey|api_key|password|secret|credential|username case-insensitively) … Architect to adjudicate; redaction must not break debug utility for non-secret values." The substring list is prefixed with "e.g." and is defective as stated — substring token would redact the shipped non-secret MAX_TOKENS/MAX_HISTORY_TOKENS, contradicting the very constraint the issue attaches to the adjudication. My suffix-anchored leaf regex is therefore my adjudication, not the issue's agreement. I mislabeled it. What the issue did agree is the constraint (non-secret debug utility preserved) and the shape (deny-list by key name), not the anchor.

API_KEYS: in the raw dump: redactRawContent extracts key API_KEYS; api[_-]?key$ fails (ends "keys"), key$ fails ("keys" ≠ "key") → the line passes through byte-for-byte.
providers::vertex-flash::api_keys in the parsed dump: viper lowercases AllKeys to api_keys; neither api[_-]?key$ nor key$ matches → slog.Any("value", v.Get(...)) logs the live value.

One precision: "every plural" is slightly overbroad — credentials (plural) is already covered by my explicit credentials$. The escaping set is api_keys, auth_tokens, secrets, passwords, usernames, token_lists — the griller's core claim is substantively correct.

Revised, ratified semantic. I accept the griller's fix. The deny regex becomes:

Added: keys?, secrets?, passwords?, usernames?, credentials? (already present as plural), auth[_-]?tokens? (plural-safe: auth_tokens has no non-secret collision). keys?$ subsumes api_key(s)/x-api-key/access_key(s); kept explicit for readability.
Barred, as the griller notes: tokens? — max_tokens/max_history_tokens end in "tokens", so plural-token matching would redact the exact non-secret limits the issue requires visible. token$ singular stays.
Collision re-verified against canonical leaves: max_tokens, max_history_tokens, auth (MCP AUTH mode — auth[_-]?tokens?$ needs the token(s) suffix), url, model, mode, person, user_id, reasoning_effort, pricing::hit/miss/comp, selected_provider — none match. The residual false-positive class (MONKEY, HOCKEY-style top-level keys ending in "key") is accepted with an explicit bias rationale: a false positive costs cosmetic debug visibility, a false negative costs a credential leak — the deny-list errs toward over-redaction.
Test table updated: plural positives api_keys, auth_tokens, secrets, passwords, usernames, access_keys; negatives unchanged (max_tokens, max_history_tokens, url, auth, mode, user_id, thinking_budget).

Residual gap — recorded where the griller demands. The plural-compound residual (token_lists, api_keys_list) joins the innocuous-key-name residual (e.g. HEADERS: x-custom: value) as one documented limitation class, recorded in three places: (1) the ADR-067 §4 amendment item 3 resolution text — which is the architect's decision record and already the agreed vehicle per the issue's plan item 3 — will state the suffix-anchored leaf semantic, the explicitly barred tokens?, and the residual class verbatim, so the adjudication is traceable without a new ADR (consistent with how §4 amendments 1–4 record decisions inline; verify-adr-index is unaffected); (2) a code comment at the deny-list definition in internal/infrastructure/config/redact.go citing the ADR section; (3) a boundary-pin test TestIsSecretKey_ResidualPluralCompound that asserts the current non-match for token_lists with a comment pointing at the ADR record, so the residual is a deliberate, documented contract rather than an unnoticed hole. No INTENTIONAL_NON_FIXES entry — this is a design-boundary record, not an accepted code gap, consistent with the issue's plan item 4.

Q2 (Griller)

The Q1 answer is fully conceded and verified — the revised regex checks out against the shipped leaves (auth stays visible via auth[_-]?tokens? requiring the token suffix; api_keys/secrets/passwords now caught; max_tokens still protected), and the three-place residual record (ADR text, code comment, boundary-pin test) closes the traceability demand. Moving to the next branch of the decision tree: the raw-content redactor's line-parser contract, which your opening left underspecified.

Quoted keys — "API_KEY": "sk-123" is legal YAML. If the parser doesn't strip the surrounding quotes before matching, the key string is "api_key" — ends with ", so every alternative fails → the line passes byte-for-byte.
Whitespace before the colon — API_KEY : "sk-123" is legal YAML. A naive key: rest split yields API_KEY with a trailing space → api_key fails the suffix anchor → leak.
Flow-style inline maps — HEADERS: {Authorization: Bearer sk-123} is a single line whose leading key is HEADERS, not deny-listed → the whole line passes, leaking a deny-listed name's value in the raw dump while your parsed dump would redact the same leaf (providers::…::headers::authorization). Your opening's claim that only innocuous header names are the "residual surface" is wrong for flow-style: even Authorization leaks there.

Plus the continuation-suppression rule needs a precise indent contract: for API_KEY: | followed by block-scalar lines, "more-indented" relative to what — and what happens in the invalid-YAML case (the exact scenario the raw dump exists to diagnose), e.g. API_KEY: | with a column-0 continuation line: equal indent → not suppressed → the raw secret leaks in the one diagnostic that still runs when parsing fails.

Q2: What is the exact redactRawContent parser contract — does it strip quotes and trim whitespace from the extracted key before matching, does it handle flow-style inline maps (either by parsing them or by documented residual), and precisely how is "more-indented" defined for continuation suppression including the invalid-YAML de-indented case? Concretely: which of these four shapes are (a) handled and pinned by tests, vs. (b) folded into the same documented-residual class with a boundary-pin test as you did for the plural gap?

A2 (Architect)

Q2: The parser contract was genuinely underspecified, and the griller's four shapes are all valid-YAML-legal (quoted keys, key : value with pre-colon whitespace, flow-style maps — I verified each against YAML block/flow mapping rules). I adopt the corrected contract below; three of the four shapes become handled-and-pinned, one is folded into the residual class, and I explicitly retract the "only innocuous names" residual claim for flow style.

Exact redactRawContent contract (spec, to be implemented in internal/infrastructure/config/redact.go):

Line decomposition — splitBlockKey(line) (key, rest, ok): trim the line; strip a leading - prefix (sequence-item mappings like - API_KEY: sk); find the first :; take everything before it, strings.TrimSpace it, and if the result is quoted ("..." or '...') strip the surrounding quotes. ok=false when there is no colon or the candidate key is empty. This closes shapes 1 and 2: "API_KEY": "sk-123" → key api_key (quote-stripped), API_KEY : "sk-123" → key api_key (whitespace-trimmed) — both match the deny-list and the line renders …: [REDACTED].
Indent definition: indent = len(line) − len(strings.TrimLeft(line, " \t")).
Primary branch: if ok && isSecretKey(key) → replace the value portion (everything after the first :), set suppress=true, suppressIndent=indent, continue.
Continuation suppression state machine (this is the precise "more-indented" contract, including the invalid-YAML case):
- line with indent > suppressIndent → suppress (valid block-scalar continuations);
- line with indent == suppressIndent → suppress iff it does not parse as a block key (ok=false); a key-shaped equal-indent line terminates suppression (it is a new mapping entry, e.g. MODE: test after the malformed block);
- line with indent < suppressIndent → terminate suppression. This closes the griller's de-indented case: API_KEY: | at column 0 followed by a column-0 raw-secret line — equal indent, non-key-shaped → suppressed, not leaked, in exactly the invalid-YAML scenario where the raw dump is the only diagnostic.
Secondary deny-name scan (new — handles flow style): for a non-secret leading key line, scan rest for (?i)(api[_-]?keys?|auth[_-]?tokens?|authorization|token|passwords?|secrets?|credentials?|usernames?|keys?)\s*:; on a match, redact the entire value portion (post-colon). HEADERS: {Authorization: Bearer sk-123} → HEADERS: [REDACTED]. The \s*: suffix makes this safe against max_tokens: (after "token" comes "s", not :), and the barred set is unchanged — no bare tokens?. This is over-redaction of the whole flow map (non-secret siblings hidden too) — accepted per the Q1 fail-closed bias: a false positive costs cosmetic debug visibility; a false negative costs a credential leak.

Shape classification — (a) handled and pinned by tests: quoted keys; whitespace-before-colon; sequence-item prefix; flow-style inline maps (via the secondary scan); block-scalar continuation in both the valid deeper-indent form and the invalid de-indented equal-indent form. Each gets a table case in redact_test.go plus an integration assertion through readConfigFile with the buffer-backed Debug handler.

(b) folded into the documented-residual class with a boundary-pin test (per the Q1 precedent, recorded in the ADR-067 §4 item 3 resolution text, a code comment at the deny-list, and a boundary-pin test): (i) secrets embedded in a plain scalar with an innocuous leading key and no deny-name+colon inside (PAYLOAD: sk-1234) — the pure innocuous-name residual, unchanged; (ii) a key-shaped equal-indent line inside a malformed block scalar (e.g. sk-123: abc at column 0 after API_KEY: |) terminating suppression — narrow, pinned; (iii) a bare tokens: sub-key inside flow style — deliberately barred so that max_tokens: in a flow map is not false-positived, and therefore escapes by design, pinned and cross-referenced to the plural decision in Q1. Note the residual class for the raw dump is now strictly narrower than my opening claimed: Authorization in flow style is handled, not residual.

CC and record: splitBlockKey (~5), the deny-name scanner (~2), and the loop (~6–7) each stay ≤ 10; the ADR amendment text will carry this parser contract summary plus the residual class verbatim so the adjudication is fully traceable, matching where Q1's plural decision is recorded.

Q3 (Griller)

The Q2 answer is verified and solid: I checked the revised contract against the regex and YAML rules — the secondary \s*: scan is safe against max_tokens: (after "token" comes "s", not ":"), the equal-indent suppression rule correctly handles the invalid-YAML de-indented case (raw-secret at column 0 is non-key-shaped → suppressed), and the residual class is now honestly narrower than the opening claimed (flow-style Authorization is handled, not residual). The remaining residual items (innocuous-name PAYLOAD: sk-1234, key-shaped malformed-block content, barred tokens: in flow style) are each pinned and cross-referenced — consistent with the Q1 precedent.

Moving to the diagnosis branch, where your opening holds a contradiction I verified against the ADR text:

Your §1 states the loader dumps "violate the scoped mcp-token-not-logged invariant on a reachable path," but ADR-067 §4 amendment item 3 (which I read in full) records them as "a known exception to the mcp-token-not-logged scope" — an exception to the scope is, by definition, outside the invariant's literal reach. An out-of-scope path does not violate an invariant; it evades it. Your §4 then keeps the invariant wording unchanged and plumbing-scoped ("there is no enforcement gate on invariant prose"), which is consistent with out-of-scope — but then §1's "violating the invariant" is imprecise, and the issue's own summary inherited the same looseness from the grill transcript. The issue's plan item 3 explicitly left this open: "extend or reference the scoped mcp-token-not-logged wording if the invariant should also cover the config loader post-fix."

Q3: Which is it — (i) the loader was within the invariant's scope, in which case the invariant's wording should be extended post-fix to cover the config loader (the issue's "extend" option, at the cost of a modelith YAML edit + re-render + the mcp-token-not-logged statement gaining the loader), or (ii) the loader was an out-of-scope exception, in which case §1's "violating the invariant" and the issue summary's framing are wrong and the ADR-067 §4 item 3 RESOLVED text must explicitly state that the loader now honors the invariant's intent as a side effect of general diagnostics hardening while remaining outside its literal plumbing scope — and the "violation" language should be corrected wherever it propagates (issue summary, your §1, the ADR)? Pick one, commit to the exact RESOLVED wording for acceptance criterion 3, and state whether any invariant-scope or wording change is part of this change's diff.

A3 (Architect)

Q3: I commit to option (ii) — the loader was an out-of-scope exception, not a violation — and I retract my §1 phrasing. Verified the propagation surface first: the invariant is recorded in exactly three places — docs/domain-model/tell-me-go.modelith.yaml:513-514 (statement), its generated .md, and the ADR exception record at docs/adr/2026-08-mcp-client-architecture.md:96 ("recorded here as a known exception to the mcp-token-not-logged scope"). There is no invariant-audit row in docs/domain-model/README.md for this invariant, so no fourth surface exists.

The reading. ADR-067 §4 item 3 does not record a violation; it records an exception to the scope, and it defines that scope: "The invariant's scope is the MCP credential plumbing (config validation, DI factory, client transport)." The invariant's subject is that plumbing — the code that handles credentials to build clients (mcp_config.go validate(), di/mcp_factory.go resolveServerToken, infrastructure/mcp/client.go transports), none of which logs. The loader's debug dumps are a general diagnostics facility, pre-existing, MCP-unaware, and not part of that plumbing. An out-of-scope path evades an invariant; it does not violate it. My §1's "violating the scoped invariant on a reachable path" was imprecise, and the issue summary inherited the same looseness from the grill transcript — the griller's characterization is accurate.

Why not (i) — extend the invariant. Extending mcp-token-not-logged to cover the loader would mis-scope a general config-diagnostics concern under an MCP-specific invariant; the honest model would be a new invariant (e.g. config-diagnostics-redacted), but that fails on three grounds: the issue's plan item 4 frames this as a fix with no model change; no enforcement gate reads invariant prose (modelith lint checks structure, not semantics), so a new statement adds documentation surface with zero enforceable guarantee; and it would force a modelith YAML edit + re-render + modelith-check churn for a record that belongs in the ADR, which is the gate-adjacent record (verify-adr-index). The ADR amendment is the correct, sufficient home.

Exact RESOLVED wording for acceptance criterion 3 (replacing the item-3 exception text in docs/adr/2026-08-mcp-client-architecture.md):

Config-loader debug-dump exception — RESOLVED (issue #1390). The config loader's debug dumps (config.go raw-content dump and viper parsed-key dump with slog.Any) previously serialized all config values — including live environment secrets — when debug logging was enabled. That exposure was recorded here as a known exception to the mcp-token-not-logged scope, not a violation of it: the invariant's subject is the MCP credential plumbing (config validation, DI factory, client transport), which never logs or serializes credentials or derived headers, and the loader's debug diagnostics were — and remain — outside that plumbing scope. Issue #1390 does not extend the invariant's scope; it removes the exception as general config-diagnostics hygiene: both dumps now redact secret-bearing values (suffix-anchored leaf deny-list per the #1390 adjudication, [REDACTED] placeholder, implemented in internal/infrastructure/config/redact.go). Post-fix the loader honors the invariant's intent on the MCPServer credential surface as a side effect of that general hardening while remaining outside its literal plumbing scope; the invariant statement and the modelith model are unchanged.

Diff scope. No invariant-scope or invariant-wording change is part of this change's diff: no tell-me-go.modelith.yaml edit, no modelith render, no statement change — modelith-check stays green. The only wording change in the diff is the ADR amendment item 3 text above (which acceptance criterion 3 already requires) plus the PR description carrying the corrected framing. The issue summary on GitHub is a historical artifact not editable via the PR diff; I will not rewrite it, and the corrected framing propagates through the ADR (authoritative) and the PR description, with an optional one-line issue comment noting the correction after merge — that is the full propagation surface, per the verified three-location record.

Q4 (Griller)

Verified both claims before answering: the README propagation-surface claim holds (zero mcp-token-not-logged matches in docs/domain-model/README.md), and the invariant's "config validation" arm is clean — MCPServerConfig.validate() (mcp_config.go:88-118) serializes only the server name, timeout value, and auth mode in its error messages, never TOKEN/USERNAME values. So Q3's (ii) commitment is accepted.

Q4 targets acceptance criterion 1's env half — your test (b) as specified does not pin what it claims to pin. Two verified problems:

Routing. The existing TestReadConfigFile_WithDebugEnabled pattern you say you're extending calls readConfigFile(v, viper.New()) directly — a bare viper has no SetEnvPrefix/AutomaticEnv wiring. That wiring lives in configureViper, reached only via load(). So the TELL_ME_MCP_SERVERS_ATLASSIAN_TOKEN override in your test (b) only flows if the test calls load(), not if it mirrors the existing readConfigFile pattern.
Vacuity. Even correctly routed, an assertion that merely checks [REDACTED] appears in the parsed dump cannot distinguish the env value from the file value — the dump renders [REDACTED] identically whether the secret came from file-token (bare viper, no AutomaticEnv) or env-super-secret (configured viper). Your test would pass unchanged if AutomaticEnv() were deleted from configureViper — i.e., it does not pin the "live secret via AutomaticEnv" path the issue explicitly calls out, despite your §3 naming it "the AutomaticEnv path the issue calls out."

Q4: Will test (b) (i) route through load() — or otherwise wire SetEnvPrefix + AutomaticEnv — so the env override is actually live in the dump, and (ii) add a liveness probe: set an env override on a non-deny key (e.g. TELL_ME_MCP_SERVERS_ATLASSIAN_URL=env-url) and assert the same dump shows env-url for that leaf — proving the dump reads env-overridden values — while the deny-listed token leaf shows [REDACTED]? That pair is what actually pins the AutomaticEnv exposure; a [REDACTED]-only assertion is satisfied vacuously. Do you accept the routing fix and the liveness probe, and what does the test name/assertion set look like?

A4 (Architect)

Q4: Both problems verified against the code, and both fixes accepted. My §3 mis-cited the routing precedent — retracted.

Routing — confirmed, fix accepted. The env wiring lives exclusively in configureViper (config.go:108-133: SetEnvPrefix("TELL_ME") at :121, replacer, AutomaticEnv() at :124), reached only via load(). TestReadConfigFile_WithDebugEnabled calls readConfigFile(v, viper.New()) directly with a bare viper — no prefix, no AutomaticEnv — so TELL_ME_MCP_SERVERS_ATLASSIAN_TOKEN would never reach v.Get under that pattern, and my test (b) would pin nothing. The correct precedent is TestLoad_ModelDebugLogging, which calls load(configPath) with slog.SetDefault(debugLogger) + t.Cleanup restore; the only thing borrowed from TestReadConfigFile_WithDebugEnabled is the capture mechanism (buffer-backed TextHandler at Debug instead of io.Discard). Test (b) routes through load(); the YAML is a valid MCP-only config (MCP_SERVERS: atlassian: URL: … TOKEN: file-token — key atlassian passes ^[a-z0-9-]{1,24}$, non-empty URL passes validate(), so ValidateMCPServers in load() succeeds, per the TestLoad_ValidateMCPServersError precedent that MCP-only configs reach that point cleanly).

Vacuity — confirmed, liveness probe accepted. A [REDACTED]-only assertion is satisfiable by the file-literal redaction alone: if AutomaticEnv() were deleted from configureViper, the token leaf would render the file value file-token, still [REDACTED] post-deny-list, and the assertion passes unchanged. The discriminator is a non-deny leaf with an env override: the same dump must show the env value for a leaf the deny-list leaves alone. That pair is what pins "env-overridden live values reach the dump and deny-listed leaves are redacted."

Test name and assertion set. TestLoad_ParsedDump_EnvOverriddenValues — one load() call with both env vars set, two named subtests over the captured buffer:

Setup: t.Setenv("TELL_ME_MODE", "") (ambient neutralization per TestLoad), t.Setenv("TELL_ME_MCP_SERVERS_ATLASSIAN_TOKEN", "env-super-secret"), t.Setenv("TELL_ME_MCP_SERVERS_ATLASSIAN_URL", "env-url"); YAML MCP_SERVERS: atlassian: {URL: "https://file-url", TOKEN: "file-token"}; debug handler writing to bytes.Buffer; t.Cleanup restore.

Subtest "redacts env-overridden token": locate the log line containing key=mcp_servers::atlassian::token and assert it contains value=[REDACTED]; assert the buffer does not contain env-super-secret; assert the buffer does not contain file-token (the file value must be masked too, so the redaction is not merely the env value failing to load).
Subtest "shows env-overridden non-secret leaf (liveness)": locate the line containing key=mcp_servers::atlassian::url and assert it contains value=env-url — proving v.Get on the parsed dump reads the AutomaticEnv override, which makes the redaction assertion non-vacuous and fails if AutomaticEnv() is removed from configureViper.

Per-line (not whole-buffer) assertions: the TextHandler joins msg+attrs on one line, so key=… and value=… are co-located; splitting the buffer on newlines and asserting per-line pairs is deterministic (ADR-036: no time.Sleep, pure capture), and t.Setenv restores automatically. File-literal test (a) stays on the bare readConfigFile path — it pins the deny-list mechanism in isolation, no env involved, and does not need the wiring.

Q5 (Griller)

Q4 is fully accepted — routing through load() (the TestLoad_ModelDebugLogging precedent, which I verified calls load() with slog.SetDefault + t.Cleanup) and the url-leaf liveness probe together make the env-override pin non-vacuous; my own viper experiment confirms mcp_servers::atlassian::url is a leaf that would render env-url under AutomaticEnv. The per-line assertion strategy is deterministic per ADR-036. Test (a) staying on the bare readConfigFile path for mechanism-isolation is sound.

Q5 presses the last unspecified hole in the Q2 raw-redactor contract — the colonless line, in the exact scenario your redact-not-drop decision exists to serve. Your splitBlockKey spec routes any line with no colon to ok=false, and neither the primary branch nor the suppression state machine nor the secondary deny-name scan (which requires a key: rest split) touches a colonless line — so it passes through byte-for-byte. Concrete case: a user debugging an invalid config writes TOKEN sk-super-secret (forgot the colon — the precise failure mode the raw dump is the only diagnostic for, since the parsed dump never runs when ReadConfig fails). The line contains a deny-listed name adjacent to a live secret, yet the redactor emits it verbatim. Same for the sequence-item variant - API_KEY sk-123. Your Q2 answer listed residuals (innocuous-name scalar, key-shaped malformed-block content, barred tokens: in flow style) — this shape is in none of them; it's an unlisted hole in the contract as delivered.

Q5: For colonless lines, will the contract add a third scan — leading deny-name check on the whitespace-delimited first token (e.g. TOKEN sk-123 → suppress or redact the line; MAX_TOKENS 32000 → passes, since max_tokens is not deny-listed) — pinned by a redact_test.go case for both the plain and - -prefixed forms? Or is the colonless-deny-prefixed line deliberately folded into the documented residual class with a boundary-pin test (per the Q1/Q2 precedent), cross-referenced from the ADR record? Note the bias calculus from Q1 cuts one way: this is a false-negative (credential leak) in the very diagnostic the redaction was justified to preserve, so the residual option carries a heavier burden than the innocuous-name case. Which is it, and what is the CC impact on the loop if you add the scan?

A5 (Architect)

Q5: The hole is real — a colonless deny-named line passes splitBlockKey with ok=false, and neither the primary branch, the suppression state machine, nor the secondary scan (which requires a key: rest split) touches it, so TOKEN sk-super-secret and - API_KEY sk-123 emit verbatim in the one diagnostic that still runs when ReadConfig fails. The griller's bias calculus is decisive: this is a false negative in the exact scenario that justified redact-not-drop, and the fix is nearly free. Decision: Option A — add the third scan. Not residual.

The scan (and why it's one branch, not a parser). On the ok=false path only (colonless line), take the whitespace-delimited first token of the - -stripped, leading-whitespace-trimmed line — strings.Fields(body)[0] — normalize it through the same quote-strip used by splitBlockKey's candidate (share one normalizeKeyToken helper so "TOKEN" sk-123 behaves like TOKEN sk-123), and run it through the existing isSecretKey (which for a bare token has no ::, so leaf == token, and the suffix-anchored deny regex applies directly). On match, redact the remainder after the first token, keeping the token visible: TOKEN sk-super-secret → TOKEN [REDACTED], - API_KEY sk-123 → - API_KEY [REDACTED]. The scan fires only after the suppression state machine, so a colonless line already inside a suppress block is handled as continuation (per Q2) and never reaches it.

Verification against the griller's examples and the deny list: TOKEN sk-123 → token token → token$ ✓ redacted. - API_KEY sk-123 → api_key → api[_-]?keys?$ ✓ redacted. MAX_TOKENS 32000 → max_tokens ends in "tokens" — token$ fails, keys?$ fails → passes through, exactly as the griller requires. MODE test-mode → passes. TOKEN:sk-123 (colon, no space — a plain scalar in YAML) is already handled by the primary branch (the colon exists, TOKEN extracts and denies) ✓. sk-1234 bare with an innocuous first token → passes — this remains the innocuous-name residual, unchanged.

CC impact: one if on the loop's ok==false path (+1), reusing isSecretKey and the shared quote-strip helper — loop CC goes from ~7 to ~8, comfortably under the ≤10 gate; the helpers each stay ≤5. No extraction needed; if the loop ever creeps, the colonless check isolates cleanly into redactColonless(line) (string, bool), but I don't expect it to.

Pinned by tests (redact_test.go table cases plus one integration case):

TOKEN sk-super-secret → renders TOKEN [REDACTED], secret absent;
- API_KEY sk-123 → renders - API_KEY [REDACTED], secret absent;
"TOKEN" sk-123 (quoted colonless first token) → redacted;
MAX_TOKENS 32000 → byte-identical passthrough (negative pin);
MODE test-mode → passthrough;
Integration TestRawContentDump_InvalidYAML_ColonlessSecretRedacted: write an invalid YAML file containing a colonless TOKEN sk-super-secret line, call readConfigFile with the buffer-backed Debug handler, assert the dump shows the redacted form and not the secret — readConfigFile returns the viper parse error, which is exactly the point: the raw dump is the only content diagnostic on that path, and it must not leak.

Record: the ADR-067 §4 item 3 resolution text's parser-contract summary gains the colonless rule; the residual class is unchanged in size — the colonless case was an unlisted hole, now handled, so the three documented residuals (innocuous-name scalar, key-shaped malformed-block content, barred tokens: flow sub-key) stand as the complete list, each with its boundary-pin test and code comment as previously committed.

Q6 (Griller)

Q5's Option A is verified — the colonless scan's token extraction and deny matching check out against the regex (TOKEN sk-123 → token$ ✓, - API_KEY sk-123 → api[_-]?keys?$ ✓, MAX_TOKENS 32000 → passthrough ✓, and the suppress-block ordering correctly swallows colonless continuations before the scan runs). The CC math (+1 → ~8) is fine.

But the accepted contract as specified contains a panic-level bug on the very path you just added. Your spec: "take the whitespace-delimited first token of the - -stripped, leading-whitespace-trimmed line — strings.Fields(body)[0]" — on the ok=false path. splitBlockKey returns ok=false for any line with no colon or an empty candidate — which includes:

Blank lines between keys — the most common line in any config file (the shipped butler.yaml has blank lines within the first 1000 bytes). Trimmed body is "" → strings.Fields("") returns an empty slice → [0] panics with index-out-of-range.
The trailing element of a \n split — every well-formed file ends with a newline; splitting the 1000-byte snippet on \n yields a final empty element, which is ok=false and hits the same panic. So the redactor would crash on every config with a trailing newline, not just contrived inputs.

This panic sits in the debug logging path inside readConfigFile, which runs during config load — an unrecovered panic in isDebug() mode would take down the process at startup, and it would trip every test that runs readConfigFile/load with a Debug handler against a realistic fixture. The suppression state machine does not rescue these: a blank line outside a suppress block (indent 0 with no active suppression) reaches the scan directly.

Q6: Will the contract add the guard — if len(fields) == 0 { pass the line through } (or equivalent empty-body check before Fields) — plus a splitter rule for the trailing-newline empty element, with redact_test.go cases for (a) a blank line between keys, (b) a file ending in \n, and (c) a whitespace-only line? And confirm the ordering: the colonless scan must be reachable only with a non-empty body. If the guard is accepted, what does the one-line amended rule look like — fields := strings.Fields(body); if len(fields) == 0 { return line, false }?

A6 (Architect)

Q6: Accepted — the unguarded strings.Fields(body)[0] is a genuine index-out-of-range panic on the path I added, and the griller's reachability analysis is correct. Verified against splitBlockKey: a blank line, a whitespace-only line, and the trailing empty element from splitting a \n-terminated snippet all yield ok=false (no colon / empty candidate), reach the colonless scan with body == "", and strings.Fields("") returns an empty slice — [0] panics. The suppression state machine does not rescue these: outside an active suppress block (indent 0, no suppression), a blank line goes straight to the scan. Since the raw dump fires in isDebug() during config load and the shipped butler.yaml has blank lines and a trailing newline, the unguarded spec would crash on realistic fixtures — including the existing TestReadConfigFile_WithDebugEnabled fixture ("MODE: debug-test\n", trailing newline) once it gains a capture handler. I retract the unguarded rule.

Amended rule (accepted, with the griller's exact shape):

fields := strings.Fields(body)
if len(fields) == 0 {
    out += line + "\n"   // blank / whitespace-only / trailing-newline element: no token to match
    continue
}
if isSecretKey(normalizeKeyToken(fields[0])) {
    out += line[:len(line)-len(body)] + fields[0] + " [REDACTED]\n"
    continue
}

Ordering confirmed: the colonless scan is reachable only with a non-empty body — len(fields) == 0 short-circuits before any token is read, and since strings.Fields already discards leading/trailing whitespace, the one guard covers all three empty classes (blank, whitespace-only, trailing element) without a separate TrimSpace pre-check or a splitter rule. No separate trailing-element normalization is needed: the empty element passes through as an empty line and the output shape is unchanged.

CC impact, corrected: the guard adds a second branch to the colonless path (len check + deny check), so the loop moves to ~9 — still under the ≤10 gate. If CC pressure ever appears, the two branches collapse to one short-circuit (if len(fields) > 0 && isSecretKey(...)) at ~8; I commit to the explicit guard form for clarity unless the gate complains.

Pinned by tests (redact_test.go, added to the Q5 cases):

(a) blank line between keys — MODE: test\n\nTOKEN: sk-123 → blank line passes through byte-for-byte, TOKEN line redacted, no panic;
(b) file ending in \n — "MODE: test\n" → no panic, trailing element passes, MODE visible;
(c) whitespace-only line — " \nMODE: test\n" → passes through, no panic;
plus the existing Q5 positives (TOKEN sk-123, - API_KEY sk-123, "TOKEN" sk-123) and negatives (MAX_TOKENS 32000, MODE test-mode).

The integration case TestRawContentDump_InvalidYAML_ColonlessSecretRedacted writes an invalid-YAML fixture that includes blank lines and a trailing newline alongside the colonless secret line, so it exercises the guard on the realistic shape. The ADR-067 §4 item 3 parser-contract summary and the redact.go code comment gain one clause: the colonless scan applies only to non-empty bodies; blank/whitespace-only/trailing-newline elements pass through untouched.

Q7 (Griller)

Q6 is fully closed — the len(fields) == 0 guard covers all three empty classes in one branch (since strings.Fields discards whitespace, no separate splitter rule is needed), the reconstruction line[:len(line)-len(body)] + fields[0] + " [REDACTED]" preserves indent and the - prefix, ordering keeps the scan reachable only with non-empty body, CC lands at ~9, and the fixtures exercise the realistic shapes. Retraction accepted.

Q7 returns to the diagnosis branch — the last unaddressed false claim from your opening. Your §1 states: "Scope is confirmed repo-wide: a grep of internal/ finds no other slog.Debug that serializes config values — only :147 and :156-158." I ran that grep myself; it is demonstrably false within the very file you were scoping. config.go:62 and :64 — the load() debug block at :61-70 — are slog.Debug("cfg.Models count", …) and slog.Debug("model detail", slog.String("model", k), slog.Int("context_window", …), slog.Float64("pricing_comp/hit/miss", …)): they serialize parsed config values (model registry keys, context windows, per-model pricing) on every debug-enabled load(). They carry no credentials, so your substantive conclusion ("the two dumps are the sole secret-bearing exposure") survives — but the claim as written does not, and it is the predicate your ADR RESOLVED wording ("both dumps now redact secret-bearing values") rests on. A scan that missed two sites in the same file cannot be called "confirmed repo-wide" without redoing it under the correct predicate.

Q7: Will you re-run the scope scan under the corrected predicate — "serializes secret-bearing config values" — across all serialization surfaces (slog at every level, log.Printf, fmt.Errorf with interpolated values, mapstructure/viper error messages), and report the complete inventory with a verdict per site? Specifically: (i) confirm the load() model-detail block (:61-70) and the configureViper path/exists logs (:109-112) are deliberately out of scope because they carry no credential data — or state otherwise; (ii) confirm intOverflowHook/mapstructure error messages cannot carry credential values (I verified the MCP validate() arm is clean, but not these); and (iii) state whether the ADR RESOLVED text needs a word of precision — e.g. "the two secret-bearing dumps now redact …" — so the record doesn't overclaim coverage of dumps that were never in scope. Does the corrected inventory change any part of the fix's diff?

A7 (Architect)

Q7: Retraction accepted, and the corrected-predicate scan is complete. My original grep searched for the specific dump shapes (slog.Debug("raw…, slog.Any("value"…, AllKeys()), and I then overgeneralized it into "no other slog.Debug that serializes config values" — false within the very file, as the griller proved with config.go:62,64-69. The corrected inventory, under the predicate "serializes secret-bearing config values", across slog (all levels), log.Printf, and fmt.Errorf with interpolated values:

Secret-bearing serialization — exactly the two in-scope sites, unchanged:

config.go:147 (raw-content dump) and :156-158 (parsed-key dump). Everything else in the package carries no credential data.

(i) Confirmed out of scope — serializes config values but no credentials:

config.go:61-70 model-detail block (cfg.Models count :62, model detail :64-69) — model registry keys (identifiers), context_window int, pricing_comp/hit/miss floats. No credential data. Deliberately untouched; TestLoad_ModelDebugLogging continues to pin it unchanged.
config.go:109-112 configureViper banner/path/exists — file paths and a bool; a config path is not a credential.
finder.go:79,102,151 log.Printf — error paths (cwd, executable path, config dir); no config values at all.

(ii) Verified clean — cannot carry credential values:

intOverflowHook (config.go:207,210) — %v interpolates a float64 being decoded into an int field; a credential is a string and cannot reach a float64→int conversion. Numeric-only. Clean.
All bounds/validation errors (domain/config/config.go:118,125,289-310, mcp_config.go:93) — %d numeric values only.
mcp_config.go:90,101,106,110 — name, timeout, auth mode only; never TOKEN/USERNAME values (confirms the griller's own verification).
domain/config/config.go:198,273 — provider/server key names (validated shapes), not credentials.
One honest nuance: domain/config/config.go:128 interpolates USER_ID with %q — a config value in a validation-error message, but classified non-credential per the Q1 adjudication (content-safety identifier, [a-zA-Z0-9\-_]+ ≤ 512), and it is a misconfiguration-failure surface, not a debug serialization.
Not exhaustively audited, stated plainly: the generic viper failed to read config: %w (:152) and failed to unmarshal viper config: %w (:178) wraps — mapstructure/yaml decode errors can theoretically echo an offending value on a type-mismatch misconfiguration. These are validation-failure surfaces that surface to the operator who owns the config, not debug-gated serialization, and they are out of this issue's scope (which targets the two debug dumps, per the issue's own "Scope:" paragraph). I do not overclaim them clean.

(iii) ADR precision — accepted. The RESOLVED text's "both dumps now redact secret-bearing values" is ambiguous against the model-detail and path logs that were never in scope. Amend to: "the two secret-bearing debug dumps (raw-content, parsed-key) now redact secret-bearing values …" — one clause, removing any reading that the redaction scope includes :61-70 or :109-112.

Diff impact: none beyond that ADR clause. The two in-scope dumps, the redactor, and all tests are unchanged; the model-detail block and path logs are untouched by design; the corrected inventory does not move any site into or out of the fix.

Q8 (Griller)

Q7 is fully satisfied — the corrected-predicate inventory is honest and complete (I spot-checked the cited sites: finder.go's three log.Printf error paths carry no config values, intOverflowHook interpolates float64→int only so a string credential can't reach it, and the USER_ID %q nuance is correctly classified non-credential per the Q1 adjudication). The ADR clause amendment ("the two secret-bearing debug dumps …") removes the overclaim. Diagnosis branch closed.

Q8 returns to a tension you accepted in Q2 but never reconciled with the issue's own constraint text — and it's now untested. The issue's plan item 1 states the adjudication constraint verbatim: "redaction must not break debug utility for non-secret values." Your secondary deny-name scan (deny-name\s*: over rest, whole post-colon value redacted on match) can break debug utility for a non-secret value whenever prose or a URL contains a deny-name followed by a colon. Concrete, realistic cases:

PERSON: "You are an assistant. If the user asks for the token: decline politely." — the persona prompt (a non-secret value) is a legitimate, high-value debug artifact, yet the whole value renders PERSON: [REDACTED] because "token:" appears in the prose.
URL: "https://aiplatform.googleapis.com/v1beta1/projects/${GOOGLE_PROJECT_ID}/authorization:grants/..." or any URL path containing key:/token:/secret: — the endpoint (non-secret) is fully hidden in the raw dump.

Your Q1 bias rationale (fail-closed, "a false positive costs cosmetic debug visibility") was ratified for key matching, where the false-positive surface is narrow. The secondary scan extends it to value scanning, where the false-positive surface is arbitrary prose and URLs — and the cost is no longer cosmetic: it hides the exact non-secret diagnostics the issue requires preserved. The issue's constraint is key-scoped in intent, but your plan implements value-scoped over-redaction without recording that interpretation.

Q8: Will you (a) narrow the secondary scan — e.g. redact only the matched subkey's value inside the flow map (HEADERS: {Authorization: Bearer x} → HEADERS: {Authorization: [REDACTED]}, preserving non-secret siblings and prose), or restrict the scan to lines whose leading key is a known mapping container; (b) keep whole-value redaction but record in the ADR that the issue's "must not break debug utility" constraint is interpreted as key-scoped, with the prose/URL over-redaction accepted as a documented trade and pinned by a test (PERSON line containing token: renders [REDACTED] — an intentional, tested false positive); or (c) something else? Either way, the choice needs a test pin, because right now the false-positive side of the scan is untested and the ADR record is silent on which interpretation of the constraint governs.

A8 (Architect)

Q8: The griller's tension is real, and I accept it — my Q2 whole-value scan conflicts with the issue's literal constraint ("redaction must not break debug utility for non-secret values"), and the Q1 fail-closed rationale was ratified for key matching, whose false-positive surface is a line whose leading key is deny-listed (narrow). The value-scan's false-positive surface is arbitrary prose and URLs, and the cost is not cosmetic: PERSON — the persona prompt, arguably the single most valuable debug artifact, and the one the raw dump is uniquely positioned to show for invalid YAML — would vanish because prose contains "token:". Extending the Q1 bias to value-scanning was an unrecorded interpretation of the issue's constraint, exactly as the griller charges.

Decision: (a) — narrow the scan; (b) is rejected because recording whole-value over-redaction as a "key-scoped interpretation" of the constraint is an ADR reinterpretation of the issue's literal text, and it is unnecessary: a narrow fix exists that closes the flow-map leak while honoring the constraint without reinterpretation.

Narrowed contract — brace gate + flow-entry extent:

Gate: the value-scan fires only when the line's rest contains a { at or before the deny-name match — i.e., the value is a flow-style map. Prose and URLs (no brace) never trigger it: PERSON: "…the token: decline politely…" and URL: "…/authorization:grants/…" pass through byte-for-byte. This is the constraint-regression fix — the false positive is eliminated, not accepted-and-pinned-as-a-trade.
Extent: on a match inside flow context, redact from the matched deny-name through the end of its flow entry — to the next depth-0 , or } (or EOL), where depth is brace-depth relative to the line's opening {, best-effort skipping double-quoted spans. Everything before the deny-name — including non-secret sibling entries — is preserved:
- HEADERS: {Authorization: Bearer sk-123} → HEADERS: {Authorization: [REDACTED]}
- HEADERS: {X-Other: 1, Authorization: Bearer sk-123, Y: 2} → HEADERS: {X-Other: 1, Authorization: [REDACTED], Y: 2} — siblings preserved, per the griller's explicit requirement.
- PAYLOAD: {"token": "abc"} → PAYLOAD: {"token": [REDACTED]} — inline JSON subkeys caught as a bonus.
Residual class unchanged (still three items): the barred tokens: flow sub-key (a flow map with tokens: still matches nothing — the plural bar from Q1 holds inside flow context too), the innocuous-name scalar, and the key-shaped malformed-block content. One narrow new note added to the ADR: a URL containing a literal {token:-style path template is brace-gated and gets hidden in the raw dump — exotic, compensated in valid YAML by the parsed dump (leaf url is not deny-listed), and documented as a cosmetic false positive within the narrowed scan.

Test pins (the false-positive side is now tested, closing the griller's "untested" gap):

HEADERS: {Authorization: Bearer sk-123} → {Authorization: [REDACTED]}, secret absent;
HEADERS: {X-Other: 1, Authorization: Bearer sk-123, Y: 2} → siblings X-Other/Y preserved, secret absent;
PERSON: "You are an assistant. If the user asks for the token: decline politely." → byte-identical passthrough (the exact griller case, as a negative pin);
URL: "https://…/authorization:grants/…" → passthrough;
PAYLOAD: {"token": "abc"} → {"token": [REDACTED]};
nested HEADERS: {A: {token: x}, B: 1} → secret gone, B: 1 preserved (best-effort } handling documented).

CC: the brace gate adds one branch; the extent-walk moves into a dedicated helper redactFlowEntry(rest string) (string, bool) (CC ~6–8, under the gate), keeping the loop at ~8 — no extraction pressure on the main function.

ADR record: the §4 item 3 resolution text states the narrowed contract verbatim — value-scan fires only in flow-map context, redacts only the matched entry to the depth-0 comma/brace, preserves siblings and all non-flow prose/URLs — and records that the issue's "must not break debug utility for non-secret values" constraint is honored literally, with no interpretation change needed. The Q1 fail-closed bias remains scoped to key matching, as ratified.

Q9 (Griller)

Q8's narrowing is verified and largely sound — the brace gate eliminates the exact PERSON/URL false positives you tested as byte-identical passthroughs, the extent-walk preserves flow siblings (HEADERS: {X-Other: 1, Authorization: Bearer sk-123, Y: 2} → siblings kept), the nested-brace case stays balanced, and the ADR now records the constraint honored literally rather than reinterpreted.

But the narrowing trades one leak for another, and the new residual is unlisted — in the same invalid-YAML diagnostic class where you just fought two rounds. Trace the narrowed contract against a brace-less multi-colon line — invalid YAML (block context forbids a: b: c), so it reaches only the raw dump:

MCP_SERVERS: atlassian: TOKEN: file-token (a realistic forgotten-braces edit) — splitBlockKey yields leading key MCP_SERVERS (not deny), no active suppression, secondary scan would match TOKEN: in rest — but the brace gate requires { at or before the match, rest has no {, so the gate fails — the line passes with TOKEN: file-token visible.
HEADERS: Authorization: Bearer sk-123 — same trace: Authorization: matches the deny-name scan, brace gate fails, line passes verbatim.

So a deny-named subkey with a live secret in a brace-less line is fully exposed in the exact diagnostic the redactor was justified to preserve — while your Q5 colonless case (TOKEN sk-123) got a dedicated scan for the same reason ("false negative in the exact scenario that justified redact-not-drop"), and your Q8 answer re-affirmed the fail-closed bias "remains scoped to key matching." The asymmetry is unexplained: both are invalid-YAML, raw-dump-only shapes carrying deny-named secrets; one got a scan, the other got nothing — and it's absent from your three-item residual list.

Q9: Is the brace-less deny-named subkey (a) folded into the residual class as a documented fourth item with a boundary-pin test — MCP_SERVERS: atlassian: TOKEN: file-token renders [REDACTED]-free, i.e. the pin asserts the current non-redaction as a deliberate, ADR-cross-referenced boundary — consistent with the Q2/Q5/Q6 precedent that every hole found in this contract ends pinned; or (b) extended in the gate — e.g. fire the deny-name+colon scan when rest is not a brace-less quoted scalar, accepting the unquoted-URL false positive (URL: https://host/authorization:grants — legal YAML plain scalar — would be over-redacted) as the documented cosmetic trade? Either way, reconcile the Q5 asymmetry: if the colonless scan was worth adding, why is the brace-less subkey not worth the same treatment, and what is the CC/test impact of your choice?

A9 (Architect)

Q9: The hole is verified — both traces hold against the Q8 contract. MCP_SERVERS: atlassian: TOKEN: file-token and HEADERS: Authorization: Bearer sk-123 are invalid YAML (block context forbids a: b: c), so only the raw dump runs; splitBlockKey yields a non-deny leading key, suppression is inactive, the deny-name+colon scan matches TOKEN:/Authorization: in rest — and the brace gate (no { present) kills it, so both lines pass verbatim with live secrets. It is the same class as Q5's colonless case — a deny-named secret in the exact raw-dump-only diagnostic that justified redact-not-drop — and I created the asymmetry by gating on braces rather than on what actually distinguishes prose from structure. Retraction of the brace gate as stated.

Decision: (b) — extend the gate; the brace-less subkey gets the same treatment as the colonless scan, resolving the asymmetry. The gate's purpose is to protect quoted prose (PERSON/URL), not to require flow braces. The refined gate: the deny-name+colon value-scan fires whenever the trimmed rest is not a quoted scalar (does not begin with " or '). This subsumes the Q8 brace gate (flow maps are unquoted) and adds brace-less subkey chains:

MCP_SERVERS: atlassian: TOKEN: file-token → unquoted → scan fires → extent-walk (no depth-0 comma/brace → EOL) → MCP_SERVERS: atlassian: TOKEN: [REDACTED] — the griller's exact case, closed.
HEADERS: Authorization: Bearer sk-123 → unquoted → HEADERS: Authorization: [REDACTED] — closed.
PERSON: "…token: decline politely…" → quoted → scan skipped → byte-identical passthrough — the Q8 negative pin holds.
URL: "…/authorization:grants/…" → quoted → passthrough — holds.
HEADERS: {X-Other: 1, Authorization: Bearer sk-123, Y: 2} → unquoted (starts {) → extent-walk → siblings preserved — holds.
PAYLOAD: {"token": "abc"} → unquoted → {"token": [REDACTED]} — holds.
URL: https://host/authorization:grants (legal YAML plain scalar) → unquoted → over-redacted — the documented cosmetic trade the griller names, compensated in valid YAML by the parsed dump (leaf url not deny-listed), and fail-closed in the invalid-YAML case.

Reconciliation of the Q5 asymmetry, explicit: both shapes are false negatives (credential leaks) in the same raw-dump-only class, and both fixes are cheap; they are now treated uniformly — deny-named tokens are matched whether colon-bearing (TOKEN sk-123, Q5's first-token scan) or colon-bearing-subkey (…: TOKEN: …, Q9's value scan), gated only by the quoted-scalar prose protection. The class deserves scans, not residuals; folding Q9's shape into the residual list (option a) would have violated the Q5 rationale the griller correctly cites.

Residual class: still three items — the innocuous-name scalar, the key-shaped malformed-block content, and the barred tokens: flow sub-key. The quoted-secret-string case (HEADERS: "{Authorization: Bearer x}" → passthrough under the quote gate) is not a fourth item: it already leaks through the parsed dump's innocuous-leaf path (headers is not deny-listed), so it was already inside the Q1 innocuous-name residual before this change — the quote gate merely aligns the raw dump with that pre-existing boundary. The unquoted-URL over-redaction is an accepted cosmetic trade (a false positive, fail-closed), not a residual.

CC/test impact: the gate swaps a brace check for a quote check — one branch, no material change; the loop stays ~8, the extent-walk helper stays ~6–8 (its "no terminator → EOL" branch already falls out of the Q8 walk). New pins: MCP_SERVERS: atlassian: TOKEN: file-token → redacted, secret absent; HEADERS: Authorization: Bearer sk-123 → redacted, secret absent; URL: https://host/authorization:grants → over-redacted form pinned as the documented trade (test comment cross-referencing the ADR clause); HEADERS: "{Authorization: Bearer x}" → passthrough pinned with a comment tying it to the innocuous-leaf residual. All Q8 pins re-run unchanged. The ADR §4 item 3 contract summary replaces the "flow-map brace gate" wording with the quoted-scalar gate exactly as above, including the unquoted-URL trade and the residual-class statement.

Q10 / Round Declaration (Griller)

ROUND COMPLETE

The subject's diagnosis and plan survived adversarial verification across every branch of the decision tree, with the following corrections extracted and accepted along the way:

Verified against the repo (not taken on faith):

All cited line references in config.go (isDebug :23, raw dump :147, parsed dump :156-158, SetEnvPrefix :121, AutomaticEnv :124) and domain/config (HEADERS, USER_ID) hold.
Empirically (live viper v1.21.0 test): AllKeys() returns only leaf keys (no parent-map subtree leak), keys are lowercased, and env overrides surface live secrets — confirming the parsed-dump exposure and the leaf-key redaction design.
The MCP plumbing is clean (DI factory logs names/errors only; client transports set headers silently; MCPServerConfig.validate() error messages never serialize TOKEN/USERNAME values).
The invariant and ADR-067 §4 item 3 read as "exception to the scope," not a violation — the diagnosis framing was corrected accordingly (option ii, with exact RESOLVED wording and a verified three-surface propagation record).
The catalog entry cites function names only, so no re-anchor is triggered; the corrected-predicate scope inventory (model-detail block, configureViper path logs, finder.go log.Printf, intOverflowHook, mapstructure wraps) is complete and honest.

Corrections that changed the plan:

Deny-list provenance retracted ("agreed semantic" → architect's adjudication) and plural forms added (keys?, secrets?, passwords?, usernames?, auth[_-]?tokens?), with the tokens? bar and residuals recorded in ADR + code comment + boundary-pin tests.
Raw redactor contract specified: quote-strip + whitespace-trim key extraction, - prefix, suppression state machine with equal-indent non-key-shaped suppression (invalid-YAML safe), colonless deny-token scan, blank-line/trailing-newline guard (len(fields)==0 passthrough), and the quoted-scalar gate with flow-entry extent-walk — closing quoted keys, key : value, flow maps, colonless lines, and brace-less subkey chains while passing quoted prose/URLs byte-identically.
Test strategy: parsed-dump env-override test routed through load() (not bare readConfigFile) with a non-deny URL-leaf liveness probe making the [REDACTED] assertion non-vacuous.
Diagnosis scope claim corrected ("no other slog.Debug serializes config values" → "no other secret-bearing" serialization), with the ADR RESOLVED text narrowed to "the two secret-bearing debug dumps."

The final plan is internally consistent, gate-compliant (CC ≤ 10 with headroom, ADR-021/022/036, no modelith churn, no catalog re-anchor), fully test-pinned including the false-positive and residual boundaries, and the ADR record captures every adjudication verbatim. No material gap remains; the round is complete.

Verdict (Griller)

VERDICT: The diagnosis held up on its core — the two debug dumps are the sole secret-bearing exposure, the AutomaticEnv live-secret path is real (verified empirically), and the MCP plumbing is clean — but its precision did not: eight substantive corrections were extracted and accepted (deny-list provenance and plural coverage, the entire raw-redactor parser contract across five edge classes, the invariant "violation" framing, the test routing and liveness probe, and the scope-scan claim), all verified against the actual code before acceptance. Recommendation: proceed with the plan as corrected through Q1–Q9 — the integrated design (suffix-anchored plural-aware leaf deny-list, quoted-scalar-gated value scan with flow-entry extent, colonless and brace-less subkey handling, blank-line guard, load()-routed env test with liveness probe, ADR RESOLVED wording with the narrowed scope) is sound, gate-compliant, and fully test-pinned; no material gap remains.

Post-Grill Position (Architect)

POST-GRILL POSITION: I stand by the core design — deny-list redaction of both debug dumps with the raw dump redacted rather than dropped (it is the only diagnostic for invalid YAML), the ADR-067 §4 item 3 RESOLVED record with the mcp-token-not-logged scope and modelith model left unchanged, and the env-override liveness probe routed through load() that makes the parsed-dump pin non-vacuous. The grill revised the contract materially: the deny-list is now suffix-anchored on the leaf with non-colliding plurals (tokens? barred by max_tokens), the raw redactor gained quote/whitespace/sequence handling, a colonless deny-token scan, an empty-body guard (fixing the Q6 panic), and a quoted-scalar gate that closes brace-less subkey leaks while preserving PERSON/URL prose — with the unquoted-URL over-redaction accepted as a documented cosmetic trade and the residual class pinned at three items plus boundary tests. I also retracted two framing errors: the "agreed semantic" mislabel (the issue delegated adjudication) and the "violating the invariant" claim (the loader was an out-of-scope exception, corrected in the ADR wording). Open questions for implementation: whether the final consolidated redactor's CC stays ≤ 10 once the Q8/Q9 extent-walk and gate are merged (I expect ~8–9 but will verify), and confirmation that the post-merge issue comment correcting the "violation" framing on #1390 is in scope for the orchestrator.

gosharplite/issue-1390-grill.md

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