diff --git a/src/evidence-log.ts b/src/evidence-log.ts
new file mode 100644
index 0000000..da75ee2
--- /dev/null
+++ b/src/evidence-log.ts
@@ -0,0 +1,515 @@
+import { createHash } from "node:crypto";
+import { existsSync } from "node:fs";
+import { appendFile, mkdir, readFile, realpath, rename, rm, stat, writeFile } from "node:fs/promises";
+import { dirname } from "node:path";
+import { workspaceEvidenceLogPath, workspaceKey } from "./paths.ts";
+import { redactCredentials } from "./redaction.ts";
+
+export type EvidenceEventType =
+  | "extraction_candidate_accepted"
+  | "extraction_candidate_rejected"
+  | "explicit_memory_detected"
+  | "explicit_memory_ignored"
+  | "pending_memory_appended"
+  | "pending_memory_cleared"
+  | "promotion_promoted"
+  | "promotion_absorbed_exact"
+  | "promotion_absorbed_identity"
+  | "promotion_superseded"
+  | "promotion_rejected_capacity"
+  | "promotion_retry_scheduled"
+  | "promotion_retry_exhausted"
+  | "memory_reinforced"
+  | "render_selected"
+  | "render_omitted"
+  | "storage_corrupt_json_quarantined"
+  | "storage_stale_lock_recovered"
+  | "storage_lock_timeout"
+  | "hook_failed";
+
+export type EvidencePhase =
+  | "extraction"
+  | "explicit"
+  | "pending_journal"
+  | "promotion"
+  | "reinforcement"
+  | "render"
+  | "storage"
+  | "hook";
+
+export type EvidenceOutcome =
+  | "accepted"
+  | "rejected"
+  | "promoted"
+  | "absorbed"
+  | "superseded"
+  | "rendered"
+  | "omitted"
+  | "retried"
+  | "exhausted"
+  | "reinforced"
+  | "quarantined"
+  | "failed"
+  | "recovered";
+
+export type MemoryEvidenceRef = {
+  memoryId?: string;
+  memoryKeyHash?: string;
+  identityKeyHash?: string;
+  type?: "feedback" | "project" | "decision" | "reference";
+  source?: "explicit" | "compaction" | "manual";
+  status?: "active" | "superseded";
+};
+
+export type EvidenceRelation = {
+  role:
+    | "candidate"
+    | "pending"
+    | "promoted"
+    | "retained"
+    | "absorbed"
+    | "superseded"
+    | "superseded_by"
+    | "reinforced"
+    | "reinforced_by"
+    | "rendered"
+    | "omitted";
+  memory?: MemoryEvidenceRef;
+};
+
+export type EvidenceDetailValue = string | number | boolean | null | string[] | number[];
+
+export type EvidenceEventV1 = {
+  version: 1;
+  eventId: string;
+  createdAt: string;
+  workspaceKey: string;
+  workspaceRootHash: string;
+  sessionHash?: string;
+  messageHash?: string;
+  type: EvidenceEventType;
+  phase: EvidencePhase;
+  outcome: EvidenceOutcome;
+  memory?: MemoryEvidenceRef;
+  relations?: EvidenceRelation[];
+  reasonCodes: string[];
+  details?: Record<string, EvidenceDetailValue>;
+  textPreview?: string;
+};
+
+export type EvidenceEventInput = Omit<
+  EvidenceEventV1,
+  "version" | "eventId" | "createdAt" | "workspaceKey" | "workspaceRootHash"
+>;
+
+export type EvidenceQuery = {
+  since?: string;
+  until?: string;
+  types?: EvidenceEventType[];
+  phases?: EvidencePhase[];
+  outcomes?: EvidenceOutcome[];
+  memoryId?: string;
+  memoryKeyHash?: string;
+  identityKeyHash?: string;
+  sessionHash?: string;
+  limit?: number;
+  newestFirst?: boolean;
+};
+
+export type MemoryEvidenceSummary = {
+  memoryId?: string;
+  memoryKeyHash?: string;
+  latestOutcome?: EvidenceOutcome;
+  latestRenderStatus?: "rendered" | "omitted";
+  reasonCodes: string[];
+  eventIds: string[];
+  lastEventAt?: string;
+};
+
+export type MemoryLifecycleTrace = {
+  memoryId?: string;
+  memoryKeyHash?: string;
+  identityKeyHash?: string;
+  events: EvidenceEventV1[];
+  createdBy?: EvidenceEventV1;
+  acceptedBy?: EvidenceEventV1;
+  promotedBy?: EvidenceEventV1;
+  absorbedBy?: EvidenceEventV1;
+  supersededBy?: EvidenceEventV1;
+  reinforcedBy: EvidenceEventV1[];
+  latestRender?: EvidenceEventV1;
+  currentStatus:
+    | "accepted"
+    | "pending"
+    | "promoted"
+    | "absorbed"
+    | "superseded"
+    | "rendered"
+    | "omitted"
+    | "rejected"
+    | "unknown";
+};
+
+export const EVIDENCE_LOG_LIMITS = {
+  maxAgeDays: 90,
+  maxEventsPerWorkspace: 5000,
+  maxBytesPerWorkspace: 2 * 1024 * 1024,
+  pruneEveryAppendCount: 100,
+} as const;
+
+const appendCounts = new Map<string, number>();
+const HASH_PATTERN = /^[a-f0-9]{16}$/i;
+const DAY_MS = 24 * 60 * 60 * 1000;
+const MAX_DETAIL_STRING_CHARS = 240;
+const MAX_DETAIL_ARRAY_ITEMS = 25;
+
+function evidenceHash(value: string): string {
+  return createHash("sha256").update(value).digest("hex").slice(0, 16);
+}
+
+function normalizeHashValue(value: string | undefined): string | undefined {
+  if (!value) return undefined;
+  return HASH_PATTERN.test(value) ? value.toLowerCase() : evidenceHash(value);
+}
+
+async function resolvedRoot(root: string): Promise<string> {
+  return realpath(root).catch(() => root);
+}
+
+function evidenceTextPreview(text: string, maxChars = 120): string {
+  return redactCredentials(text).replace(/\s+/g, " ").trim().slice(0, maxChars);
+}
+
+function sanitizeReasonCode(reason: string): string {
+  return reason.replace(/[^a-zA-Z0-9_.:-]/g, "_").slice(0, 120);
+}
+
+function sanitizeMemoryRef(memory: MemoryEvidenceRef | undefined): MemoryEvidenceRef | undefined {
+  if (!memory) return undefined;
+  const sanitized: MemoryEvidenceRef = {};
+  if (typeof memory.memoryId === "string" && memory.memoryId) sanitized.memoryId = memory.memoryId.slice(0, 160);
+  if (memory.memoryKeyHash) sanitized.memoryKeyHash = normalizeHashValue(memory.memoryKeyHash);
+  if (memory.identityKeyHash) sanitized.identityKeyHash = normalizeHashValue(memory.identityKeyHash);
+  if (memory.type) sanitized.type = memory.type;
+  if (memory.source) sanitized.source = memory.source;
+  if (memory.status) sanitized.status = memory.status;
+  return Object.keys(sanitized).length > 0 ? sanitized : undefined;
+}
+
+function sanitizeRelations(relations: EvidenceRelation[] | undefined): EvidenceRelation[] | undefined {
+  if (!relations) return undefined;
+  const sanitized = relations
+    .map(relation => ({
+      role: relation.role,
+      memory: sanitizeMemoryRef(relation.memory),
+    }))
+    .slice(0, 25);
+  return sanitized.length > 0 ? sanitized : undefined;
+}
+
+function sanitizeDetailString(value: string): string {
+  return evidenceTextPreview(value, MAX_DETAIL_STRING_CHARS);
+}
+
+function sanitizeDetails(details: EvidenceEventInput["details"]): EvidenceEventV1["details"] {
+  if (!details) return undefined;
+  const sanitized: Record<string, EvidenceDetailValue> = {};
+
+  for (const [rawKey, rawValue] of Object.entries(details).slice(0, 50)) {
+    const key = rawKey.replace(/[^a-zA-Z0-9_.:-]/g, "_").slice(0, 80);
+    if (!key) continue;
+
+    if (typeof rawValue === "string") {
+      sanitized[key] = sanitizeDetailString(rawValue);
+    } else if (typeof rawValue === "number") {
+      if (Number.isFinite(rawValue)) sanitized[key] = rawValue;
+    } else if (typeof rawValue === "boolean" || rawValue === null) {
+      sanitized[key] = rawValue;
+    } else if (Array.isArray(rawValue)) {
+      if (rawValue.every(item => typeof item === "string")) {
+        sanitized[key] = rawValue.slice(0, MAX_DETAIL_ARRAY_ITEMS).map(item => sanitizeDetailString(item));
+      } else if (rawValue.every(item => typeof item === "number" && Number.isFinite(item))) {
+        sanitized[key] = rawValue.slice(0, MAX_DETAIL_ARRAY_ITEMS) as number[];
+      }
+    }
+  }
+
+  return Object.keys(sanitized).length > 0 ? sanitized : undefined;
+}
+
+function buildEvidenceEvent(
+  input: EvidenceEventInput,
+  workspaceKeyValue: string,
+  workspaceRootHash: string,
+): EvidenceEventV1 {
+  const textPreviewMax = input.type === "extraction_candidate_rejected" ? 80 : 120;
+  const event: EvidenceEventV1 = {
+    version: 1,
+    eventId: `evt_${Date.now()}_${Math.random().toString(36).slice(2, 10).padEnd(8, "0")}`,
+    createdAt: new Date().toISOString(),
+    workspaceKey: workspaceKeyValue,
+    workspaceRootHash,
+    type: input.type,
+    phase: input.phase,
+    outcome: input.outcome,
+    reasonCodes: input.reasonCodes.map(sanitizeReasonCode).filter(Boolean).slice(0, 25),
+  };
+
+  const memory = sanitizeMemoryRef(input.memory);
+  const relations = sanitizeRelations(input.relations);
+  const details = sanitizeDetails(input.details);
+  if (input.sessionHash) event.sessionHash = normalizeHashValue(input.sessionHash);
+  if (input.messageHash) event.messageHash = normalizeHashValue(input.messageHash);
+  if (memory) event.memory = memory;
+  if (relations) event.relations = relations;
+  if (details) event.details = details;
+  if (input.textPreview) event.textPreview = evidenceTextPreview(input.textPreview, textPreviewMax);
+
+  return event;
+}
+
+async function safeAppendEvidenceLine(path: string, line: string): Promise<void> {
+  try {
+    await mkdir(dirname(path), { recursive: true });
+    await appendFile(path, `${line}\n`, "utf8");
+  } catch (error) {
+    const message = error instanceof Error ? error.message : String(error);
+    console.error(`[memory] failed to write evidence event: ${message}`);
+  }
+}
+
+async function maybePruneEvidenceLog(path: string): Promise<void> {
+  const nextCount = (appendCounts.get(path) ?? 0) + 1;
+  appendCounts.set(path, nextCount);
+  if (nextCount % EVIDENCE_LOG_LIMITS.pruneEveryAppendCount !== 0) return;
+
+  try {
+    await pruneEvidenceLogPath(path);
+  } catch (error) {
+    const message = error instanceof Error ? error.message : String(error);
+    console.error(`[memory] failed to prune evidence log: ${message}`);
+  }
+}
+
+export async function appendEvidenceEvent(root: string, event: EvidenceEventInput): Promise<EvidenceEventV1> {
+  const records = await appendEvidenceEvents(root, [event]);
+  return records[0];
+}
+
+export async function appendEvidenceEvents(root: string, events: EvidenceEventInput[]): Promise<EvidenceEventV1[]> {
+  const path = await workspaceEvidenceLogPath(root);
+  const rootPath = await resolvedRoot(root);
+  const workspaceRootHash = evidenceHash(rootPath);
+  const workspaceKeyValue = await workspaceKey(root);
+  const records = events.map(event => buildEvidenceEvent(event, workspaceKeyValue, workspaceRootHash));
+
+  for (const record of records) {
+    await safeAppendEvidenceLine(path, JSON.stringify(record));
+    await maybePruneEvidenceLog(path);
+  }
+
+  return records;
+}
+
+type ParsedEvidenceLine = {
+  event: EvidenceEventV1;
+  index: number;
+};
+
+function parseEvidenceLine(line: string): EvidenceEventV1 | null {
+  try {
+    const parsed = JSON.parse(line) as Partial<EvidenceEventV1>;
+    if (parsed.version !== 1 || !parsed.eventId || !parsed.createdAt || !parsed.type) return null;
+    return parsed as EvidenceEventV1;
+  } catch {
+    return null;
+  }
+}
+
+async function readEvidenceLines(path: string, warnInvalid: boolean): Promise<{ valid: ParsedEvidenceLine[]; invalid: string[] }> {
+  if (!existsSync(path)) return { valid: [], invalid: [] };
+  const raw = await readFile(path, "utf8");
+  const valid: ParsedEvidenceLine[] = [];
+  const invalid: string[] = [];
+
+  raw.split(/\n/).forEach((line, index) => {
+    if (!line.trim()) return;
+    const event = parseEvidenceLine(line);
+    if (event) {
+      valid.push({ event, index });
+    } else {
+      invalid.push(line);
+      if (warnInvalid) console.warn(`[memory] skipped invalid evidence log line ${index + 1}`);
+    }
+  });
+
+  return { valid, invalid };
+}
+
+function eventTimeMs(event: EvidenceEventV1): number {
+  const ms = new Date(event.createdAt).getTime();
+  return Number.isFinite(ms) ? ms : 0;
+}
+
+async function atomicWriteText(path: string, text: string): Promise<void> {
+  await mkdir(dirname(path), { recursive: true });
+  const tmp = `${path}.${process.pid}.${Date.now()}.${Math.random().toString(36).slice(2, 10)}.tmp`;
+  try {
+    await writeFile(tmp, text, { encoding: "utf8", mode: 0o600 });
+    await rename(tmp, path);
+  } catch (error) {
+    await rm(tmp, { force: true }).catch(() => undefined);
+    throw error;
+  }
+}
+
+function serializeEvents(events: EvidenceEventV1[]): string {
+  return events.map(event => JSON.stringify(event)).join("\n") + (events.length > 0 ? "\n" : "");
+}
+
+function trimEventsToByteLimit(events: EvidenceEventV1[]): EvidenceEventV1[] {
+  let kept = [...events];
+  while (kept.length > 0 && Buffer.byteLength(serializeEvents(kept), "utf8") > EVIDENCE_LOG_LIMITS.maxBytesPerWorkspace) {
+    kept = kept.slice(1);
+  }
+  return kept;
+}
+
+async function pruneEvidenceLogPath(path: string): Promise<void> {
+  if (!existsSync(path)) return;
+  const stats = await stat(path);
+  if (stats.isDirectory()) return;
+
+  const { valid, invalid } = await readEvidenceLines(path, false);
+  if (invalid.length > 0) {
+    const corruptPath = `${path}.corrupt-lines-${Date.now()}.jsonl`;
+    await writeFile(corruptPath, invalid.join("\n") + "\n", { encoding: "utf8", mode: 0o600 }).catch(error => {
+      const message = error instanceof Error ? error.message : String(error);
+      console.error(`[memory] failed to quarantine invalid evidence lines: ${message}`);
+    });
+  }
+
+  const cutoff = Date.now() - EVIDENCE_LOG_LIMITS.maxAgeDays * DAY_MS;
+  let events = valid
+    .filter(item => eventTimeMs(item.event) >= cutoff)
+    .sort((a, b) => eventTimeMs(a.event) - eventTimeMs(b.event) || a.index - b.index)
+    .map(item => item.event);
+
+  if (events.length > EVIDENCE_LOG_LIMITS.maxEventsPerWorkspace) {
+    events = events.slice(events.length - EVIDENCE_LOG_LIMITS.maxEventsPerWorkspace);
+  }
+
+  events = trimEventsToByteLimit(events);
+  await atomicWriteText(path, serializeEvents(events));
+}
+
+function memoryRefMatches(memory: MemoryEvidenceRef | undefined, query: Pick<EvidenceQuery, "memoryId" | "memoryKeyHash" | "identityKeyHash">): boolean {
+  if (!memory) return false;
+  const memoryKeyHash = normalizeHashValue(query.memoryKeyHash);
+  const identityKeyHash = normalizeHashValue(query.identityKeyHash);
+  if (query.memoryId && memory.memoryId === query.memoryId) return true;
+  if (memoryKeyHash && memory.memoryKeyHash === memoryKeyHash) return true;
+  if (identityKeyHash && memory.identityKeyHash === identityKeyHash) return true;
+  return false;
+}
+
+function eventMatchesMemory(event: EvidenceEventV1, query: Pick<EvidenceQuery, "memoryId" | "memoryKeyHash" | "identityKeyHash">): boolean {
+  if (!query.memoryId && !query.memoryKeyHash && !query.identityKeyHash) return true;
+  if (memoryRefMatches(event.memory, query)) return true;
+  return (event.relations ?? []).some(relation => memoryRefMatches(relation.memory, query));
+}
+
+export async function queryEvidenceEvents(
+  root: string,
+  query: EvidenceQuery = {},
+): Promise<EvidenceEventV1[]> {
+  const path = await workspaceEvidenceLogPath(root);
+  const { valid } = await readEvidenceLines(path, true);
+  const sinceMs = query.since ? new Date(query.since).getTime() : undefined;
+  const untilMs = query.until ? new Date(query.until).getTime() : undefined;
+  const sessionHash = normalizeHashValue(query.sessionHash);
+
+  let events = valid.map(item => item.event).filter(event => {
+    const createdAtMs = eventTimeMs(event);
+    if (Number.isFinite(sinceMs) && createdAtMs < sinceMs) return false;
+    if (Number.isFinite(untilMs) && createdAtMs > untilMs) return false;
+    if (query.types && !query.types.includes(event.type)) return false;
+    if (query.phases && !query.phases.includes(event.phase)) return false;
+    if (query.outcomes && !query.outcomes.includes(event.outcome)) return false;
+    if (sessionHash && event.sessionHash !== sessionHash) return false;
+    if (!eventMatchesMemory(event, query)) return false;
+    return true;
+  });
+
+  if (query.newestFirst) events = events.slice().reverse();
+  if (typeof query.limit === "number" && query.limit >= 0) events = events.slice(0, query.limit);
+  return events;
+}
+
+export async function summarizeMemoryEvidence(
+  root: string,
+  input: { memoryId?: string; memoryKeyHash?: string },
+): Promise<MemoryEvidenceSummary> {
+  const events = await queryEvidenceEvents(root, input);
+  const latest = events.at(-1);
+  const latestRender = events.filter(event => event.phase === "render").at(-1);
+  const reasonCodes = new Set<string>();
+  for (const event of events) {
+    for (const reason of event.reasonCodes) reasonCodes.add(reason);
+  }
+
+  return {
+    memoryId: input.memoryId,
+    memoryKeyHash: normalizeHashValue(input.memoryKeyHash),
+    latestOutcome: latest?.outcome,
+    latestRenderStatus: latestRender?.outcome === "rendered" || latestRender?.outcome === "omitted"
+      ? latestRender.outcome
+      : undefined,
+    reasonCodes: [...reasonCodes],
+    eventIds: events.map(event => event.eventId),
+    lastEventAt: latest?.createdAt,
+  };
+}
+
+function currentStatusFromEvent(event: EvidenceEventV1 | undefined): MemoryLifecycleTrace["currentStatus"] {
+  if (!event) return "unknown";
+  if (event.outcome === "accepted") return "accepted";
+  if (event.outcome === "promoted") return "promoted";
+  if (event.outcome === "absorbed") return "absorbed";
+  if (event.outcome === "superseded") return "superseded";
+  if (event.outcome === "rendered") return "rendered";
+  if (event.outcome === "omitted") return "omitted";
+  if (event.outcome === "rejected") return "rejected";
+  if (event.type === "pending_memory_appended") return "pending";
+  return "unknown";
+}
+
+export async function traceMemoryLifecycle(
+  root: string,
+  input: { memoryId?: string; memoryKeyHash?: string; identityKeyHash?: string },
+): Promise<MemoryLifecycleTrace> {
+  const events = await queryEvidenceEvents(root, input);
+  const createdBy = events.find(event => event.type === "explicit_memory_detected" || event.type === "pending_memory_appended");
+  const acceptedBy = events.find(event => event.type === "extraction_candidate_accepted" || event.type === "explicit_memory_detected");
+  const promotedBy = events.find(event => event.type === "promotion_promoted");
+  const absorbedBy = events.find(event => event.outcome === "absorbed");
+  const supersededBy = events.find(event => event.outcome === "superseded");
+  const reinforcedBy = events.filter(event => event.type === "memory_reinforced" || event.outcome === "reinforced");
+  const latestRender = events.filter(event => event.phase === "render").at(-1);
+  const latest = events.at(-1);
+
+  return {
+    memoryId: input.memoryId,
+    memoryKeyHash: normalizeHashValue(input.memoryKeyHash),
+    identityKeyHash: normalizeHashValue(input.identityKeyHash),
+    events,
+    createdBy,
+    acceptedBy,
+    promotedBy,
+    absorbedBy,
+    supersededBy,
+    reinforcedBy,
+    latestRender,
+    currentStatus: currentStatusFromEvent(latest),
+  };
+}
diff --git a/src/paths.ts b/src/paths.ts
index 85c4ae5..08ac976 100644
--- a/src/paths.ts
+++ b/src/paths.ts
@@ -24,6 +24,10 @@ export async function workspacePendingJournalPath(root: string): Promise<string>
   return join(await memoryRoot(root), "workspace-pending-journal.json");
 }
 
+export async function workspaceEvidenceLogPath(root: string): Promise<string> {
+  return join(await memoryRoot(root), "evidence", "events.jsonl");
+}
+
 export async function sessionStatePath(root: string, sessionID: string): Promise<string> {
   const safeSessionID = createHash("sha256").update(sessionID).digest("hex").slice(0, 32);
   return join(await memoryRoot(root), "sessions", `${safeSessionID}.json`);
diff --git a/tests/evidence-log.test.ts b/tests/evidence-log.test.ts
new file mode 100644
index 0000000..c8c252c
--- /dev/null
+++ b/tests/evidence-log.test.ts
@@ -0,0 +1,245 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { createHash } from "node:crypto";
+import { existsSync } from "node:fs";
+import { mkdir, mkdtemp, readFile, readdir, rm, writeFile } from "node:fs/promises";
+import { dirname, join } from "node:path";
+import { realpath } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import {
+  EVIDENCE_LOG_LIMITS,
+  appendEvidenceEvent,
+  appendEvidenceEvents,
+  queryEvidenceEvents,
+  summarizeMemoryEvidence,
+  traceMemoryLifecycle,
+  type EvidenceEventInput,
+  type EvidenceEventV1,
+} from "../src/evidence-log.ts";
+import { workspaceEvidenceLogPath, workspaceKey } from "../src/paths.ts";
+
+async function tempRoot(): Promise<string> {
+  return mkdtemp(join(tmpdir(), "opencode-evidence-log-"));
+}
+
+function eventInput(overrides: Partial<EvidenceEventInput> = {}): EvidenceEventInput {
+  return {
+    type: "promotion_promoted",
+    phase: "promotion",
+    outcome: "promoted",
+    reasonCodes: ["new_workspace_entry"],
+    memory: { memoryId: "mem-a", type: "decision", source: "explicit", status: "active" },
+    textPreview: "Use npm test before release",
+    ...overrides,
+  };
+}
+
+async function readLog(root: string): Promise<string> {
+  return readFile(await workspaceEvidenceLogPath(root), "utf8");
+}
+
+function privacyHash(value: string): string {
+  return createHash("sha256").update(value).digest("hex").slice(0, 16);
+}
+
+async function workspaceRootHash(root: string): Promise<string> {
+  const resolved = await realpath(root).catch(() => root);
+  return privacyHash(resolved);
+}
+
+function manualEvent(rootKey: string, rootHash: string, id: string, createdAt: string): EvidenceEventV1 {
+  return {
+    version: 1,
+    eventId: id,
+    createdAt,
+    workspaceKey: rootKey,
+    workspaceRootHash: rootHash,
+    type: "render_selected",
+    phase: "render",
+    outcome: "rendered",
+    memory: { memoryId: id, type: "decision" },
+    reasonCodes: ["within_caps", "within_char_budget"],
+  };
+}
+
+test("appendEvidenceEvent writes versioned JSONL with workspace hashes", async () => {
+  const root = await tempRoot();
+  try {
+    const event = await appendEvidenceEvent(root, eventInput({ sessionHash: "session-1", messageHash: "message-1" }));
+    const raw = await readLog(root);
+    const stored = JSON.parse(raw.trim()) as EvidenceEventV1;
+
+    assert.equal(stored.version, 1);
+    assert.match(stored.eventId, /^evt_\d+_[a-z0-9]{8}$/);
+    assert.equal(stored.eventId, event.eventId);
+    assert.equal(stored.workspaceKey, await workspaceKey(root));
+    assert.equal(stored.workspaceRootHash, await workspaceRootHash(root));
+    assert.equal(stored.sessionHash, privacyHash("session-1"));
+    assert.equal(stored.messageHash, privacyHash("message-1"));
+    assert.equal(stored.type, "promotion_promoted");
+    assert.equal(stored.outcome, "promoted");
+  } finally {
+    await rm(root, { recursive: true, force: true });
+  }
+});
+
+test("appendEvidenceEvent redacts text previews before writing", async () => {
+  const root = await tempRoot();
+  try {
+    await appendEvidenceEvent(root, eventInput({
+      type: "extraction_candidate_rejected",
+      phase: "extraction",
+      outcome: "rejected",
+      reasonCodes: ["raw_error"],
+      textPreview: "password: sushi\nAdmin PIN 是 456123\nBearer abc.def.ghi\nThis candidate is rejected and should be short",
+      details: {
+        note: "password: sushi Admin PIN 是 456123 Bearer abc.def.ghi",
+      },
+    }));
+
+    const raw = await readLog(root);
+    const stored = JSON.parse(raw.trim()) as EvidenceEventV1;
+    assert.ok(!raw.includes("sushi"));
+    assert.ok(!raw.includes("456123"));
+    assert.ok(!raw.includes("abc.def.ghi"));
+    assert.ok(stored.textPreview?.includes("[REDACTED]"));
+    assert.ok((stored.textPreview?.length ?? 0) <= 80);
+  } finally {
+    await rm(root, { recursive: true, force: true });
+  }
+});
+
+test("queryEvidenceEvents filters by type outcome and memory id", async () => {
+  const root = await tempRoot();
+  try {
+    await appendEvidenceEvents(root, [
+      eventInput({ type: "promotion_promoted", outcome: "promoted", memory: { memoryId: "mem-a" } }),
+      eventInput({ type: "render_omitted", phase: "render", outcome: "omitted", reasonCodes: ["type_cap"], memory: { memoryId: "mem-a" } }),
+      eventInput({ type: "render_omitted", phase: "render", outcome: "omitted", reasonCodes: ["global_cap"], memory: { memoryId: "mem-b" } }),
+    ]);
+
+    const result = await queryEvidenceEvents(root, {
+      types: ["render_omitted"],
+      outcomes: ["omitted"],
+      memoryId: "mem-a",
+    });
+
+    assert.equal(result.length, 1);
+    assert.equal(result[0].type, "render_omitted");
+    assert.equal(result[0].memory?.memoryId, "mem-a");
+  } finally {
+    await rm(root, { recursive: true, force: true });
+  }
+});
+
+test("queryEvidenceEvents supports newestFirst and limit", async () => {
+  const root = await tempRoot();
+  try {
+    const events = await appendEvidenceEvents(root, [
+      eventInput({ memory: { memoryId: "oldest" } }),
+      eventInput({ memory: { memoryId: "middle" } }),
+      eventInput({ memory: { memoryId: "newest" } }),
+    ]);
+
+    const result = await queryEvidenceEvents(root, { newestFirst: true, limit: 2 });
+
+    assert.deepEqual(result.map(event => event.eventId), [events[2].eventId, events[1].eventId]);
+  } finally {
+    await rm(root, { recursive: true, force: true });
+  }
+});
+
+test("appendEvidenceEvent returns a record when appendFile fails", async () => {
+  const root = await tempRoot();
+  try {
+    const path = await workspaceEvidenceLogPath(root);
+    await mkdir(path, { recursive: true });
+
+    const event = await appendEvidenceEvent(root, eventInput());
+
+    assert.equal(event.version, 1);
+    assert.match(event.eventId, /^evt_\d+_[a-z0-9]{8}$/);
+    assert.equal(event.workspaceKey, await workspaceKey(root));
+  } finally {
+    await rm(root, { recursive: true, force: true });
+  }
+});
+
+test("evidence log pruning drops old events, caps count, and quarantines invalid lines", async () => {
+  const root = await tempRoot();
+  try {
+    const path = await workspaceEvidenceLogPath(root);
+    await mkdir(dirname(path), { recursive: true });
+    const rootKey = await workspaceKey(root);
+    const rootHash = await workspaceRootHash(root);
+    const old = manualEvent(rootKey, rootHash, "old-event", new Date(Date.now() - 91 * 24 * 60 * 60 * 1000).toISOString());
+    const recentEvents = Array.from({ length: EVIDENCE_LOG_LIMITS.maxEventsPerWorkspace + 1 }, (_, i) =>
+      manualEvent(rootKey, rootHash, `recent-${i}`, new Date(Date.now() - (EVIDENCE_LOG_LIMITS.maxEventsPerWorkspace - i) * 1000).toISOString())
+    );
+    await writeFile(path, [
+      JSON.stringify(old),
+      "{not valid json",
+      ...recentEvents.map(event => JSON.stringify(event)),
+    ].join("\n") + "\n", "utf8");
+
+    const appended = await appendEvidenceEvents(root, Array.from({ length: EVIDENCE_LOG_LIMITS.pruneEveryAppendCount }, (_, i) =>
+      eventInput({ memory: { memoryId: `appended-${i}` }, reasonCodes: ["new_workspace_entry"] })
+    ));
+
+    const events = await queryEvidenceEvents(root);
+    const memoryIds = new Set(events.map(event => event.memory?.memoryId));
+    const files = await readdir(dirname(path));
+
+    assert.ok(events.length <= EVIDENCE_LOG_LIMITS.maxEventsPerWorkspace);
+    assert.equal(memoryIds.has("old-event"), false);
+    assert.equal(memoryIds.has("recent-0"), false, "oldest events over the count cap should be pruned");
+    assert.equal(memoryIds.has(appended.at(-1)?.memory?.memoryId), true);
+    assert.ok(files.some(file => file.startsWith("events.jsonl.corrupt-lines-")));
+  } finally {
+    await rm(root, { recursive: true, force: true });
+  }
+});
+
+test("memory evidence summary and lifecycle trace derive latest status", async () => {
+  const root = await tempRoot();
+  try {
+    await appendEvidenceEvents(root, [
+      eventInput({ type: "extraction_candidate_accepted", phase: "extraction", outcome: "accepted", reasonCodes: ["quality_gate_passed"], memory: { memoryId: "mem-life", memoryKeyHash: "raw-key" } }),
+      eventInput({ type: "promotion_promoted", phase: "promotion", outcome: "promoted", reasonCodes: ["new_workspace_entry"], memory: { memoryId: "mem-life", memoryKeyHash: "raw-key" } }),
+      eventInput({ type: "memory_reinforced", phase: "reinforcement", outcome: "reinforced", reasonCodes: ["duplicate_exact"], relations: [{ role: "reinforced", memory: { memoryId: "mem-life", memoryKeyHash: "raw-key" } }] }),
+      eventInput({ type: "render_selected", phase: "render", outcome: "rendered", reasonCodes: ["within_caps", "within_char_budget"], memory: { memoryId: "mem-life", memoryKeyHash: "raw-key" } }),
+    ]);
+
+    const summary = await summarizeMemoryEvidence(root, { memoryId: "mem-life" });
+    const trace = await traceMemoryLifecycle(root, { memoryId: "mem-life" });
+
+    assert.equal(summary.latestOutcome, "rendered");
+    assert.equal(summary.latestRenderStatus, "rendered");
+    assert.ok(summary.reasonCodes.includes("duplicate_exact"));
+    assert.equal(trace.currentStatus, "rendered");
+    assert.ok(trace.acceptedBy);
+    assert.ok(trace.promotedBy);
+    assert.equal(trace.reinforcedBy.length, 1);
+    assert.equal(trace.latestRender?.type, "render_selected");
+  } finally {
+    await rm(root, { recursive: true, force: true });
+  }
+});
+
+test("evidence relation roles reject sublimation placeholders at compile-time surface", () => {
+  const allowedRoles: Array<NonNullable<EvidenceEventInput["relations"]>[number]["role"]> = [
+    "candidate",
+    "pending",
+    "promoted",
+    "retained",
+    "absorbed",
+    "superseded",
+    "superseded_by",
+    "reinforced",
+    "reinforced_by",
+    "rendered",
+    "omitted",
+  ];
+
+  assert.equal(allowedRoles.includes("candidate"), true);
+});