package-lock.json

@@ -25,6 +25,9 @@
         "react-redux": "^9.2.0"
       },
       "bin": {
+        "abode-export": "dist/bin/abode-export.cjs",
+        "abode-import": "dist/bin/abode-import.cjs",
+        "abode-inspect": "dist/bin/abode-inspect.cjs",
         "abode-migrate": "dist/bin/abode-migrate.cjs",
         "abode-repl": "dist/bin/abode-repl.cjs",
         "abode-tui": "dist/bin/abode-tui.cjs",

package.json

@@ -9,7 +9,10 @@
     "abode-migrate": "dist/bin/abode-migrate.cjs",
     "abode-repl": "dist/bin/abode-repl.cjs",
     "abode-web": "dist/bin/abode-web.cjs",
-    "abode-tui": "dist/bin/abode-tui.cjs"
+    "abode-tui": "dist/bin/abode-tui.cjs",
+    "abode-export": "dist/bin/abode-export.cjs",
+    "abode-import": "dist/bin/abode-import.cjs",
+    "abode-inspect": "dist/bin/abode-inspect.cjs"
   },
   "scripts": {
     "repl": "tsx --import ./src/meta/dev/register.ts",
@@ -18,6 +21,9 @@
     "abode-web": "tsx --import ./src/meta/dev/register.ts --import ./src/meta/dev/webhot.ts src/bin/abode-web.ts",
     "abode-tui": "tsx --import ./src/meta/dev/register.ts --import ./src/meta/dev/silenthot.ts src/bin/abode-tui.ts",
     "abode-sources": "tsx --import ./src/meta/dev/register.ts src/bin/abode-sources.ts",
+    "abode-export": "tsx --import ./src/meta/dev/register.ts src/bin/abode-export.ts",
+    "abode-import": "tsx --import ./src/meta/dev/register.ts src/bin/abode-import.ts",
+    "abode-inspect": "tsx --import ./src/meta/dev/register.ts src/bin/abode-inspect.ts",
     "build": "NODE_ENV=production npm run build:impl",
     "build:impl": "rm -rf dist && tsx node_modules/.bin/webpack && chmod +x dist/bin/* && chmod -x dist/bin/*.*",
     "test": "node --import tsx/esm --import ./src/meta/dev/register.ts --test $(find test -name '*.test.ts' | sort)",

src/bin/abode-export.ts

@@ -0,0 +1,97 @@
+import { createWriteStream } from "node:fs";
+import { pipeline } from "node:stream/promises";
+import { getDbInterface } from "../db/index.js";
+import { isExportable, type ExportFilter } from "../db/types/ExportImport.js";
+import { isExportKind } from "../db/export/filter.js";
+
+const args = process.argv.slice(2);
+
+function printUsage(err: boolean | string = false): never {
+  const log = (err ? console.error : console.log).bind(console);
+  if (typeof err === "string") {
+    log(`Error: ${err}`);
+    log("");
+  }
+  log("Usage:");
+  log("\tabode-export --help");
+  log(
+    "\tabode-export <database-url> [--kinds=user,abode,...] [--exclude-kinds=...] \\",
+  );
+  log("\t             [--abodes=aid,...] [--users=uid,...] [--out=file|-]");
+  process.exit(err ? 1 : 0);
+}
+
+if (["-h", "--help", "help"].some((x) => args.includes(x))) printUsage();
+
+let url: string | undefined;
+const flags = new Map<string, string>();
+for (const arg of args) {
+  if (arg.startsWith("--")) {
+    const eq = arg.indexOf("=");
+    if (eq === -1) printUsage(`invalid flag: ${arg}`);
+    flags.set(arg.slice(2, eq), arg.slice(eq + 1));
+  } else if (url === undefined) {
+    url = arg;
+  } else {
+    printUsage("too many arguments");
+  }
+}
+if (!url) printUsage("missing <database-url>");
+
+const knownFlags = ["kinds", "exclude-kinds", "abodes", "users", "out"];
+for (const key of flags.keys()) {
+  if (!knownFlags.includes(key)) printUsage(`unknown flag: --${key}`);
+}
+
+function parseList(value: string | undefined): string[] | undefined {
+  if (value === undefined) return undefined;
+  return value.split(",").filter(Boolean);
+}
+function parseKinds(value: string | undefined) {
+  const list = parseList(value);
+  if (!list) return undefined;
+  const bad = list.filter((k) => !isExportKind(k));
+  if (bad.length) printUsage(`invalid kind(s): ${bad.join(", ")}`);
+  return list.filter(isExportKind);
+}
+
+const filter: ExportFilter = {};
+const kinds = parseKinds(flags.get("kinds"));
+if (kinds) filter.kinds = kinds;
+const excludeKinds = parseKinds(flags.get("exclude-kinds"));
+if (excludeKinds) filter.excludeKinds = excludeKinds;
+const abodes = parseList(flags.get("abodes"));
+if (abodes) filter.abodes = abodes;
+const users = parseList(flags.get("users"));
+if (users) filter.users = users;
+
+const db = await getDbInterface(url);
+if (!isExportable(db)) {
+  console.error(`Error: backend '${db.name}' does not support export`);
+  process.exit(1);
+}
+
+const out = flags.get("out") ?? "-";
+const dest =
+  out === "-" ? process.stdout : createWriteStream(out, { encoding: "utf8" });
+
+const ac = new AbortController();
+const onSignal = () => ac.abort();
+process.on("SIGINT", onSignal);
+process.on("SIGTERM", onSignal);
+
+try {
+  await pipeline(db.export({ filter, signal: ac.signal }), dest);
+} catch (e) {
+  if (ac.signal.aborted) {
+    console.error("Export aborted");
+    process.exit(130);
+  }
+  throw e;
+} finally {
+  process.off("SIGINT", onSignal);
+  process.off("SIGTERM", onSignal);
+  await db.close().catch(() => {});
+}
+
+process.exit(0);

src/bin/abode-import.ts

@@ -0,0 +1,111 @@
+import { createReadStream } from "node:fs";
+import { getDbInterface } from "../db/index.js";
+import { isExportKind } from "../db/export/filter.js";
+import { isImportable, type ExportFilter } from "../db/types/ExportImport.js";
+
+const args = process.argv.slice(2);
+
+function printUsage(err: boolean | string = false): never {
+  const log = (err ? console.error : console.log).bind(console);
+  if (typeof err === "string") {
+    log(`Error: ${err}`);
+    log("");
+  }
+  log("Usage:");
+  log("\tabode-import --help");
+  log("\tabode-import <database-url> <input-file|-> [--kinds=...] \\");
+  log(
+    "\t             [--exclude-kinds=...] [--abodes=aid,...] [--users=uid,...]",
+  );
+  log("");
+  log(
+    "The target must be a local backend (sqlite or postgres), already migrated",
+  );
+  log("(run abode-migrate first). Remote (api) targets are not importable.");
+  process.exit(err ? 1 : 0);
+}
+
+if (["-h", "--help", "help"].some((x) => args.includes(x))) printUsage();
+
+const positional: string[] = [];
+const flags = new Map<string, string>();
+for (const arg of args) {
+  if (arg.startsWith("--")) {
+    const eq = arg.indexOf("=");
+    if (eq === -1) printUsage(`invalid flag: ${arg}`);
+    flags.set(arg.slice(2, eq), arg.slice(eq + 1));
+  } else {
+    positional.push(arg);
+  }
+}
+
+const url = positional[0];
+const input = positional[1];
+if (!url) printUsage("missing <database-url>");
+if (!input) printUsage("missing <input-file|->");
+if (positional.length > 2) printUsage("too many arguments");
+
+const knownFlags = ["kinds", "exclude-kinds", "abodes", "users"];
+for (const key of flags.keys()) {
+  if (!knownFlags.includes(key)) printUsage(`unknown flag: --${key}`);
+}
+
+function parseList(value: string | undefined): string[] | undefined {
+  if (value === undefined) return undefined;
+  return value.split(",").filter(Boolean);
+}
+function parseKinds(value: string | undefined) {
+  const list = parseList(value);
+  if (!list) return undefined;
+  const bad = list.filter((k) => !isExportKind(k));
+  if (bad.length) printUsage(`invalid kind(s): ${bad.join(", ")}`);
+  return list.filter(isExportKind);
+}
+
+const filter: ExportFilter = {};
+const kinds = parseKinds(flags.get("kinds"));
+if (kinds) filter.kinds = kinds;
+const excludeKinds = parseKinds(flags.get("exclude-kinds"));
+if (excludeKinds) filter.excludeKinds = excludeKinds;
+const abodes = parseList(flags.get("abodes"));
+if (abodes) filter.abodes = abodes;
+const users = parseList(flags.get("users"));
+if (users) filter.users = users;
+
+// Resolve the backend generically. Import lives on the local backends (sqlite,
+// postgres); the remote (api) interface has no `import`, so `isImportable`
+// keeps it from ever running over HTTP.
+const db = await getDbInterface(url);
+if (!isImportable(db)) {
+  console.error(`Error: backend '${db.name}' does not support import`);
+  await db.close().catch(() => {});
+  process.exit(1);
+}
+
+const source = input === "-" ? process.stdin : createReadStream(input);
+
+const ac = new AbortController();
+const onSignal = () => ac.abort();
+process.on("SIGINT", onSignal);
+process.on("SIGTERM", onSignal);
+
+try {
+  const result = await db.import(source, { filter, signal: ac.signal });
+  const total = Object.values(result.counts).reduce((a, b) => a + b, 0);
+  console.log(`Imported ${total} record(s):`);
+  for (const [kind, count] of Object.entries(result.counts)) {
+    console.log(`- ${kind}: ${count}`);
+  }
+} catch (e) {
+  if (ac.signal.aborted) {
+    console.error("Import aborted; no changes committed");
+    process.exit(130);
+  }
+  throw e;
+} finally {
+  process.off("SIGINT", onSignal);
+  process.off("SIGTERM", onSignal);
+  await db.close().catch(() => {});
+}
+
+process.exit(0);

src/bin/abode-inspect.ts

@@ -0,0 +1,68 @@
+import { createReadStream } from "node:fs";
+import { inspectExportStream } from "../db/export/inspect.js";
+import { isExportKind } from "../db/export/filter.js";
+import type { ExportKind } from "../db/types/ExportImport.js";
+
+const args = process.argv.slice(2);
+
+function printUsage(err: boolean | string = false): never {
+  const log = (err ? console.error : console.log).bind(console);
+  if (typeof err === "string") {
+    log(`Error: ${err}`);
+    log("");
+  }
+  log("Usage:");
+  log("\tabode-inspect --help");
+  log("\tabode-inspect <input-file|-> [--stop-after=note,...]");
+  process.exit(err ? 1 : 0);
+}
+
+if (["-h", "--help", "help"].some((x) => args.includes(x))) printUsage();
+
+let input: string | undefined;
+const flags = new Map<string, string>();
+for (const arg of args) {
+  if (arg.startsWith("--")) {
+    const eq = arg.indexOf("=");
+    if (eq === -1) printUsage(`invalid flag: ${arg}`);
+    flags.set(arg.slice(2, eq), arg.slice(eq + 1));
+  } else if (input === undefined) {
+    input = arg;
+  } else {
+    printUsage("too many arguments");
+  }
+}
+if (!input) printUsage("missing <input-file|->");
+
+for (const key of flags.keys()) {
+  if (key !== "stop-after") printUsage(`unknown flag: --${key}`);
+}
+
+let stopAfterKinds: ExportKind[] | undefined;
+const rawStop = flags.get("stop-after");
+if (rawStop !== undefined) {
+  const list = rawStop.split(",").filter(Boolean);
+  const bad = list.filter((k) => !isExportKind(k));
+  if (bad.length) printUsage(`invalid kind(s): ${bad.join(", ")}`);
+  stopAfterKinds = list.filter(isExportKind);
+}
+
+const source = input === "-" ? process.stdin : createReadStream(input);
+
+const { counts, meta } = await inspectExportStream(source, { stopAfterKinds });
+
+if (meta) {
+  console.log("Meta:");
+  console.log(`- format version: ${meta.v ?? "?"}`);
+  console.log(`- exported at: ${meta.exportedAt ?? "?"}`);
+  console.log(`- source backend: ${meta.source ?? "?"}`);
+  if (meta.filter && Object.keys(meta.filter).length) {
+    console.log(`- effective filter: ${JSON.stringify(meta.filter)}`);
+  }
+}
+console.log("Counts:");
+const entries = Object.entries(counts);
+if (!entries.length) console.log("(none)");
+for (const [kind, count] of entries) console.log(`- ${kind}: ${count}`);
+
+process.exit(0);

src/db/api/ApiInterface.ts

@@ -25,8 +25,11 @@ import type {
   CreateUser,
   UpdateUser,
 } from "../types/User.js";
+import { Readable } from "node:stream";
+import type { ReadableStream as WebReadableStream } from "node:stream/web";
+import type { Exportable, ExportOptions } from "../types/ExportImport.js";
 
-export class ApiInterface implements DbInterface {
+export class ApiInterface implements DbInterface, Exportable {
   #root: string;
   #headers: Record<string, string>;
   #readonly: boolean;
@@ -296,4 +299,45 @@ export class ApiInterface implements DbInterface {
   async listNotesByUserId(uid: string): Promise<PartialNote[]> {
     return this.#call("GET", "/users/:uid/notes", { params: { uid } });
   }
+
+  export(options: ExportOptions = {}): NodeJS.ReadableStream {
+    // Streaming NDJSON bypasses the JSON-only `#call` helper: the raw
+    // `fetch` gets the caller's `signal` directly, so aborting cancels the
+    // underlying HTTP request itself.
+    const { filter, signal } = options;
+    const sp = new URLSearchParams();
+    if (filter?.kinds) sp.set("kinds", filter.kinds.join(","));
+    if (filter?.excludeKinds)
+      sp.set("excludeKinds", filter.excludeKinds.join(","));
+    if (filter?.abodes) sp.set("abodes", filter.abodes.join(","));
+    if (filter?.users) sp.set("users", filter.users.join(","));
+    const query = sp.toString();
+    const url = this.#root + "/export" + (query ? `?${query}` : "");
+    const headers = { ...this.#headers };
+
+    async function* generate(): AsyncGenerator<Buffer | Uint8Array> {
+      const res = await fetch(url, { method: "GET", headers, signal });
+      if (!res.ok) {
+        const text = await res.text();
+        switch (res.status) {
+          case 400:
+            throw new InvalidAbodeError();
+          case 401:
+            throw new NotAuthorizedAbodeError();
+          case 403:
+            throw new ReadonlyAbodeError();
+          case 404:
+            throw new NotFoundAbodeError();
+          case 409:
+            throw new ConflictAbodeError();
+          default:
+            throw new Error(`${res.status} ${res.statusText} ${text}`);
+        }
+      }
+      if (!res.body) return;
+      yield* Readable.fromWeb(res.body as WebReadableStream<Uint8Array>);
+    }
+
+    return Readable.from(generate());
+  }
 }

src/db/export/filter.ts

@@ -0,0 +1,82 @@
+import {
+  EXPORT_KIND_ORDER,
+  type ExportFilter,
+  type ExportKind,
+} from "../types/ExportImport.js";
+
+const EXPORT_KINDS = new Set<ExportKind>(EXPORT_KIND_ORDER);
+
+export function isExportKind(x: unknown): x is ExportKind {
+  return typeof x === "string" && EXPORT_KINDS.has(x as ExportKind);
+}
+
+/** Whether a `kind` survives a filter's `kinds`/`excludeKinds` rules. */
+export function kindAllowed(
+  filter: ExportFilter | undefined,
+  kind: ExportKind,
+): boolean {
+  if (!filter) return true;
+  if (filter.kinds && !filter.kinds.includes(kind)) return false;
+  if (filter.excludeKinds && filter.excludeKinds.includes(kind)) return false;
+  return true;
+}
+
+/**
+ * Whether an individual record passes a filter's `abodes`/`users`/`apikeys`
+ * allowlists. `abodes` scopes abode/resident/note (by aid); `users` scopes user
+ * (by uid); `apikey` records are scoped by `apikeys` when present, else by
+ * `users`. An absent allowlist means "unrestricted".
+ */
+export function recordAllowed(
+  filter: ExportFilter | undefined,
+  kind: ExportKind,
+  record: { uid?: string; aid?: string },
+): boolean {
+  if (!filter) return true;
+  switch (kind) {
+    case "user":
+      return !filter.users || filter.users.includes(record.uid as string);
+    case "apikey": {
+      const allow = filter.apikeys ?? filter.users;
+      return !allow || allow.includes(record.uid as string);
+    }
+    case "abode":
+    case "resident":
+    case "note":
+      return !filter.abodes || filter.abodes.includes(record.aid as string);
+  }
+}
+
+function intersectList<T extends string>(a?: T[], b?: T[]): T[] | undefined {
+  if (!a) return b;
+  if (!b) return a;
+  const bs = new Set(b);
+  return a.filter((x) => bs.has(x));
+}
+
+function unionList<T extends string>(a?: T[], b?: T[]): T[] | undefined {
+  if (!a) return b;
+  if (!b) return a;
+  return [...new Set([...a, ...b])];
+}
+
+/**
+ * Combine two filters as a hard intersection: the result can never permit more
+ * than either input. An absent allowlist is treated as "unrestricted", so
+ * intersecting it with a present one yields the present one. `excludeKinds`
+ * are unioned (either exclusion still excludes).
+ */
+export function intersectExportFilters(
+  a: ExportFilter | null | undefined,
+  b: ExportFilter | null | undefined,
+): ExportFilter {
+  if (!a) return b ?? {};
+  if (!b) return a;
+  return {
+    kinds: intersectList(a.kinds, b.kinds),
+    excludeKinds: unionList(a.excludeKinds, b.excludeKinds),
+    abodes: intersectList(a.abodes, b.abodes),
+    users: intersectList(a.users, b.users),
+    apikeys: intersectList(a.apikeys, b.apikeys),
+  };
+}

src/db/export/inspect.ts

@@ -0,0 +1,60 @@
+import readline from "node:readline";
+import type {
+  ExportFilter,
+  ExportKind,
+  ExportMeta,
+} from "../types/ExportImport.js";
+import { isExportKind } from "./filter.js";
+
+export type InspectResult = {
+  counts: Partial<Record<ExportKind, number>>;
+  meta?: Partial<ExportMeta> & { filter?: ExportFilter };
+};
+
+/**
+ * Tally the kinds/counts contained in an NDJSON export stream without ever
+ * touching a database. Works on any stream — a file, {@link ApiInterface}'s
+ * export, or a pipe straight from {@link SqliteInterface}'s export.
+ *
+ * If `stopAfterKinds` is given, reading stops as soon as at least one record of
+ * every requested kind has been seen, rather than draining to EOF — useful for
+ * probing large dumps ("does this contain notes at all?").
+ */
+export async function inspectExportStream(
+  source: NodeJS.ReadableStream,
+  options: { signal?: AbortSignal; stopAfterKinds?: ExportKind[] } = {},
+): Promise<InspectResult> {
+  const { signal, stopAfterKinds } = options;
+  const counts: Partial<Record<ExportKind, number>> = {};
+  let meta: InspectResult["meta"];
+
+  const rl = readline.createInterface({
+    input: source,
+    crlfDelay: Infinity,
+    signal,
+  });
+  try {
+    for await (const raw of rl) {
+      signal?.throwIfAborted();
+      const line = raw.trim();
+      if (!line) continue;
+      let parsed: { kind?: unknown; data?: unknown };
+      try {
+        parsed = JSON.parse(line);
+      } catch {
+        continue;
+      }
+      if (parsed.kind === "meta") {
+        meta = parsed.data as InspectResult["meta"];
+        continue;
+      }
+      if (!isExportKind(parsed.kind)) continue;
+      counts[parsed.kind] = (counts[parsed.kind] ?? 0) + 1;
+      if (stopAfterKinds && stopAfterKinds.every((k) => counts[k])) break;
+    }
+  } finally {
+    rl.close();
+  }
+
+  return { counts, meta };
+}

src/db/postgres/PostgresInterface.ts

@@ -43,8 +43,22 @@ import type {
   UpdateNote,
 } from "../types/Note.js";
 import type { WrappedPgClient } from "./pool.js";
+import { Readable } from "node:stream";
+import readline from "node:readline";
+import {
+  EXPORT_KIND_ORDER,
+  type Exportable,
+  type ExportKind,
+  type ExportOptions,
+  type Importable,
+  type ImportOptions,
+  type ImportResult,
+} from "../types/ExportImport.js";
+import { isExportKind, kindAllowed, recordAllowed } from "../export/filter.js";
 
-export class PostgresInterface implements BackendDbInterface {
+export class PostgresInterface
+  implements BackendDbInterface, Exportable, Importable
+{
   #db: WrappedPgClient;
 
   constructor(db: WrappedPgClient) {
@@ -508,4 +522,200 @@ export class PostgresInterface implements BackendDbInterface {
   async listNotesByUserId(_uid: string): Promise<PartialNote[]> {
     throw new Error("Unimplemented");
   }
+
+  export(options: ExportOptions = {}): NodeJS.ReadableStream {
+    const { filter, signal } = options;
+    const db = this.#db;
+    const source = this.name;
+
+    // Emission follows the FK-safe EXPORT_KIND_ORDER (part of the wire
+    // contract; see ExportImport.ts). `note` has no loader: the postgres
+    // backend has no note CRUD yet, so a pg database can hold none. Each
+    // `load()` is a single query, run lazily and skipped once the destination
+    // aborts.
+    const loaders: Partial<
+      Record<ExportKind, () => Promise<{ uid?: string; aid?: string }[]>>
+    > = {
+      user: () => selectClientUsers(db),
+      abode: () => selectAbodes(db),
+      resident: () => selectResidents(db),
+      apikey: () => selectClientApikeys(db),
+    };
+
+    async function* generate(): AsyncGenerator<string> {
+      if (signal?.aborted) return;
+      yield JSON.stringify({
+        kind: "meta",
+        data: {
+          v: 1,
+          exportedAt: new Date().toISOString(),
+          source,
+          filter: filter ?? {},
+        },
+      }) + "\n";
+      try {
+        for (const kind of EXPORT_KIND_ORDER) {
+          if (signal?.aborted) return;
+          const load = loaders[kind];
+          if (!load) continue;
+          if (!kindAllowed(filter, kind)) continue;
+          for (const row of await load()) {
+            if (signal?.aborted) return;
+            if (recordAllowed(filter, kind, row)) {
+              yield JSON.stringify({ kind, data: row }) + "\n";
+            }
+          }
+        }
+      } catch (e) {
+        if (signal?.aborted) return;
+        yield JSON.stringify({
+          kind: "error",
+          data: {
+            message: e instanceof Error ? e.message : String(e),
+            code: e instanceof Error ? e.name : undefined,
+          },
+        }) + "\n";
+      }
+    }
+
+    return Readable.from(generate());
+  }
+
+  async import(
+    source: NodeJS.ReadableStream,
+    options: ImportOptions = {},
+  ): Promise<ImportResult> {
+    this.#checkReadonly();
+    const { filter, signal } = options;
+    const counts: Partial<Record<ExportKind, number>> = {};
+
+    const rl = readline.createInterface({
+      input: source,
+      crlfDelay: Infinity,
+      signal,
+    });
+
+    // Postgres holds FK enforcement (unlike sqlite, which we toggle off): the
+    // FK-safe insertion order — user, abode, resident, apikey — keeps a full
+    // dump valid. `notes` are skipped entirely (unsupported on this backend).
+    // The transaction commits only if the whole stream is consumed cleanly; an
+    // error/abort rolls it back via `multi`.
+    try {
+      await this.#db.rethrow(() =>
+        this.#db.multi(async (tx) => {
+          for await (const raw of rl) {
+            signal?.throwIfAborted();
+            const line = raw.trim();
+            if (!line) continue;
+            let parsed: { kind?: unknown; data?: unknown };
+            try {
+              parsed = JSON.parse(line);
+            } catch {
+              throw new InvalidAbodeError();
+            }
+            if (parsed.kind === "meta") continue;
+            if (parsed.kind === "error") {
+              throw new Error(
+                `export stream reported an error: ${
+                  (parsed.data as { message?: string })?.message ?? "unknown"
+                }`,
+              );
+            }
+            if (!isExportKind(parsed.kind)) continue;
+            if (parsed.kind === "note") continue; // unsupported on postgres
+            if (!kindAllowed(filter, parsed.kind)) continue;
+            const data = parsed.data as { uid?: string; aid?: string };
+            if (!recordAllowed(filter, parsed.kind, data)) continue;
+            await this.#importRecord(tx, parsed.kind, parsed.data);
+            counts[parsed.kind] = (counts[parsed.kind] ?? 0) + 1;
+          }
+          // An abort while blocked on the source closes readline without
+          // throwing, so re-check before the transaction commits.
+          signal?.throwIfAborted();
+        }),
+      );
+    } finally {
+      rl.close();
+    }
+
+    return { counts };
+  }
+
+  async #importRecord(
+    tx: WrappedPgClient,
+    kind: ExportKind,
+    data: unknown,
+  ): Promise<void> {
+    switch (kind) {
+      case "user": {
+        const u = data as ClientUser;
+        // `password` is never exported; imported users land on the schema
+        // default ('#unset') and must reset before they can log in.
+        await tx.run(sql`
+          INSERT INTO "users"("uid", "email", "name", "flags", "created_at", "updated_at")
+          VALUES(
+            ${{ uuid: u.uid }},
+            ${{ text: u.email }},
+            ${{ text: u.name }},
+            ${{ jsonb: u.flags }},
+            ${{ date: u.created_at }},
+            ${{ date: u.updated_at }}
+          )
+        `);
+        break;
+      }
+      case "abode": {
+        const a = data as Abode;
+        await tx.run(sql`
+          INSERT INTO "abodes"("aid", "name", "created_at", "created_by", "updated_at", "updated_by")
+          VALUES(
+            ${{ uuid: a.aid }},
+            ${{ text: a.name }},
+            ${{ date: a.created_at }},
+            ${a.created_by ? { uuid: a.created_by } : { null: true }},
+            ${{ date: a.updated_at }},
+            ${a.updated_by ? { uuid: a.updated_by } : { null: true }}
+          )
+        `);
+        break;
+      }
+      case "resident": {
+        const r = data as Resident;
+        await tx.run(sql`
+          INSERT INTO "residents"("uid", "aid", "flags", "created_at", "created_by", "updated_at", "updated_by")
+          VALUES(
+            ${{ uuid: r.uid }},
+            ${{ uuid: r.aid }},
+            ${{ jsonb: r.flags }},
+            ${{ date: r.created_at }},
+            ${r.created_by ? { uuid: r.created_by } : { null: true }},
+            ${{ date: r.updated_at }},
+            ${r.updated_by ? { uuid: r.updated_by } : { null: true }}
+          )
+        `);
+        break;
+      }
+      case "apikey": {
+        const k = data as ClientApikey;
+        // `token` is never exported; mint a fresh unique one so the record's
+        // metadata (kid/permissions/expiry) survives even though the original
+        // secret cannot.
+        await tx.run(sql`
+          INSERT INTO "apikeys"("uid", "kid", "token", "name", "permissions", "created_at", "expires_at")
+          VALUES(
+            ${{ uuid: k.uid }},
+            ${{ uuid: k.kid }},
+            ${{ text: createApikeyToken() }},
+            ${{ text: k.name }},
+            ${{ jsonb: k.permissions }},
+            ${{ date: k.created_at }},
+            ${k.expires_at ? { date: k.expires_at } : { null: true }}
+          )
+        `);
+        break;
+      }
+      case "note":
+        break; // unsupported on postgres; skipped before reaching here
+    }
+  }
 }

src/db/postgres/query.ts

@@ -130,10 +130,10 @@ export async function selectClientApikey(
 }
 export async function selectClientApikeys(
   db: WrappedPgClient,
-  where: SqlCode,
+  where?: SqlCode,
 ): Promise<ClientApikey[]> {
   const rows = await db.all<RawClientApikey>(
-    sql`${sqlClientApikey} WHERE ${where}`,
+    where ? sql`${sqlClientApikey} WHERE ${where}` : sqlClientApikey,
   );
   return rows.map(pgToClientApikey);
 }

src/db/sqlite/SqliteInterface.ts

@@ -34,6 +34,7 @@ import {
   selectClientUser,
   selectClientUsers,
   selectNote,
+  selectNotes,
   selectPartialNotes,
   selectResident,
   selectResidents,
@@ -45,8 +46,22 @@ import type {
   UpdateNote,
 } from "../types/Note.js";
 import type { WrappedDb } from "./impl/types.js";
+import { Readable } from "node:stream";
+import readline from "node:readline";
+import {
+  EXPORT_KIND_ORDER,
+  type Exportable,
+  type ExportKind,
+  type ExportOptions,
+  type Importable,
+  type ImportOptions,
+  type ImportResult,
+} from "../types/ExportImport.js";
+import { isExportKind, kindAllowed, recordAllowed } from "../export/filter.js";
 
-export class SqliteInterface implements BackendDbInterface {
+export class SqliteInterface
+  implements BackendDbInterface, Exportable, Importable
+{
   #db: WrappedDb;
 
   constructor(db: WrappedDb) {
@@ -534,4 +549,221 @@ export class SqliteInterface implements BackendDbInterface {
   async listNotesByUserId(uid: string): Promise<PartialNote[]> {
     return selectPartialNotes(this.#db, sql`n."created_by" = ${{ uuid: uid }}`);
   }
+
+  export(options: ExportOptions = {}): NodeJS.ReadableStream {
+    const { filter, signal } = options;
+    const db = this.#db;
+    const source = this.name;
+
+    // Per-table full materialization + JS-side per-record yielding (each
+    // `load()` is exactly one `WrappedDb.all()`). Kept lazy so the first query
+    // only fires once the destination starts pulling, and skipped entirely
+    // once the signal is aborted — no further reads after the destination
+    // goes away. Emission follows the FK-safe EXPORT_KIND_ORDER (part of the
+    // wire contract; see ExportImport.ts).
+    const loaders: Record<ExportKind, () => { uid?: string; aid?: string }[]> =
+      {
+        user: () => selectClientUsers(db),
+        abode: () => selectAbodes(db),
+        resident: () => selectResidents(db),
+        apikey: () => selectClientApikeys(db),
+        note: () => selectNotes(db),
+      };
+
+    async function* generate(): AsyncGenerator<string> {
+      if (signal?.aborted) return;
+      yield JSON.stringify({
+        kind: "meta",
+        data: {
+          v: 1,
+          exportedAt: new Date().toISOString(),
+          source,
+          filter: filter ?? {},
+        },
+      }) + "\n";
+      try {
+        for (const kind of EXPORT_KIND_ORDER) {
+          if (signal?.aborted) return;
+          if (!kindAllowed(filter, kind)) continue;
+          for (const row of loaders[kind]()) {
+            if (signal?.aborted) return;
+            if (recordAllowed(filter, kind, row)) {
+              yield JSON.stringify({ kind, data: row }) + "\n";
+            }
+          }
+        }
+      } catch (e) {
+        // Aborts unwind via early `return`, never here; a genuine mid-stream
+        // failure is surfaced as a trailing sentinel line (HTTP 200 headers
+        // are already flushed, so `convertError` can no longer apply).
+        if (signal?.aborted) return;
+        yield JSON.stringify({
+          kind: "error",
+          data: {
+            message: e instanceof Error ? e.message : String(e),
+            code: e instanceof Error ? e.name : undefined,
+          },
+        }) + "\n";
+      }
+    }
+
+    return Readable.from(generate());
+  }
+
+  async import(
+    source: NodeJS.ReadableStream,
+    options: ImportOptions = {},
+  ): Promise<ImportResult> {
+    this.#checkReadonly();
+    const { filter, signal } = options;
+    const db = this.#db;
+    const counts: Partial<Record<ExportKind, number>> = {};
+
+    const rl = readline.createInterface({
+      input: source,
+      crlfDelay: Infinity,
+      signal,
+    });
+
+    // Bulk restore trusts the export's referential integrity, and a filtered
+    // dump may legitimately reference `created_by`/`updated_by` users outside
+    // its scope. Suppress FK enforcement for the duration (can only be toggled
+    // outside a transaction) and restore it in `finally`.
+    db.run(sql`PRAGMA foreign_keys = OFF`);
+    db.run(sql`BEGIN`);
+    try {
+      for await (const raw of rl) {
+        signal?.throwIfAborted();
+        const line = raw.trim();
+        if (!line) continue;
+        let parsed: { kind?: unknown; data?: unknown };
+        try {
+          parsed = JSON.parse(line);
+        } catch {
+          throw new InvalidAbodeError();
+        }
+        if (parsed.kind === "meta") continue;
+        if (parsed.kind === "error") {
+          throw new Error(
+            `export stream reported an error: ${
+              (parsed.data as { message?: string })?.message ?? "unknown"
+            }`,
+          );
+        }
+        if (!isExportKind(parsed.kind)) continue;
+        if (!kindAllowed(filter, parsed.kind)) continue;
+        const data = parsed.data as { uid?: string; aid?: string };
+        if (!recordAllowed(filter, parsed.kind, data)) continue;
+        this.#importRecord(parsed.kind, parsed.data);
+        counts[parsed.kind] = (counts[parsed.kind] ?? 0) + 1;
+      }
+      // An abort while blocked on the source closes readline without throwing,
+      // so re-check before committing to guarantee no partial commit.
+      signal?.throwIfAborted();
+      db.run(sql`COMMIT`);
+    } catch (e) {
+      try {
+        db.run(sql`ROLLBACK`);
+      } catch {
+        /* already rolled back */
+      }
+      throw e;
+    } finally {
+      rl.close();
+      db.run(sql`PRAGMA foreign_keys = ON`);
+    }
+
+    return { counts };
+  }
+
+  #importRecord(kind: ExportKind, data: unknown): void {
+    const db = this.#db;
+    switch (kind) {
+      case "user": {
+        const u = data as ClientUser;
+        // `password` is never exported; imported users land on the schema
+        // default ('#unset') and must reset before they can log in.
+        db.run(sql`
+          INSERT INTO "users"("uid", "email", "name", "flags", "created_at", "updated_at")
+          VALUES(
+            ${{ uuid: u.uid }},
+            ${{ text: u.email }},
+            ${{ text: u.name }},
+            ${{ jsonb: u.flags }},
+            ${{ date: u.created_at }},
+            ${{ date: u.updated_at }}
+          )
+        `);
+        break;
+      }
+      case "abode": {
+        const a = data as Abode;
+        db.run(sql`
+          INSERT INTO "abodes"("aid", "name", "created_at", "created_by", "updated_at", "updated_by")
+          VALUES(
+            ${{ uuid: a.aid }},
+            ${{ text: a.name }},
+            ${{ date: a.created_at }},
+            ${a.created_by ? { uuid: a.created_by } : { null: true }},
+            ${{ date: a.updated_at }},
+            ${a.updated_by ? { uuid: a.updated_by } : { null: true }}
+          )
+        `);
+        break;
+      }
+      case "resident": {
+        const r = data as Resident;
+        db.run(sql`
+          INSERT INTO "residents"("uid", "aid", "flags", "created_at", "created_by", "updated_at", "updated_by")
+          VALUES(
+            ${{ uuid: r.uid }},
+            ${{ uuid: r.aid }},
+            ${{ jsonb: r.flags }},
+            ${{ date: r.created_at }},
+            ${r.created_by ? { uuid: r.created_by } : { null: true }},
+            ${{ date: r.updated_at }},
+            ${r.updated_by ? { uuid: r.updated_by } : { null: true }}
+          )
+        `);
+        break;
+      }
+      case "apikey": {
+        const k = data as ClientApikey;
+        // `token` is never exported; mint a fresh unique one so the record's
+        // metadata (kid/permissions/expiry) survives even though the original
+        // secret cannot.
+        db.run(sql`
+          INSERT INTO "apikeys"("uid", "kid", "token", "name", "permissions", "created_at", "expires_at")
+          VALUES(
+            ${{ uuid: k.uid }},
+            ${{ uuid: k.kid }},
+            ${{ text: createApikeyToken() }},
+            ${{ text: k.name }},
+            ${{ jsonb: k.permissions }},
+            ${{ date: k.created_at }},
+            ${k.expires_at ? { date: k.expires_at } : { null: true }}
+          )
+        `);
+        break;
+      }
+      case "note": {
+        const n = data as Note;
+        db.run(sql`
+          INSERT INTO "notes"("nid", "aid", "name", "content", "properties", "created_at", "created_by", "updated_at", "updated_by")
+          VALUES(
+            ${{ uuid: n.nid }},
+            ${{ uuid: n.aid }},
+            ${{ text: n.name }},
+            ${{ text: n.content ?? "" }},
+            ${{ jsonb: n.properties }},
+            ${{ date: n.created_at }},
+            ${n.created_by ? { uuid: n.created_by } : { null: true }},
+            ${{ date: n.updated_at }},
+            ${n.updated_by ? { uuid: n.updated_by } : { null: true }}
+          )
+        `);
+        break;
+      }
+    }
+  }
 }

src/db/sqlite/query.ts

@@ -118,10 +118,10 @@ export function selectClientApikey(
 }
 export function selectClientApikeys(
   db: WrappedDb,
-  where: SqlCode,
+  where?: SqlCode,
 ): ClientApikey[] {
   const rawApikeys = db.all<RawClientApikey>(
-    sql`${sqlClientApikey} WHERE ${where}`,
+    where ? sql`${sqlClientApikey} WHERE ${where}` : sqlClientApikey,
   );
   return rawApikeys.map(sqliteToClientApikey);
 }

src/db/types/ExportImport.ts

@@ -0,0 +1,110 @@
+import type { DbInterface } from "./DbInterface.js";
+
+/**
+ * The kinds of records that can travel through an export/import stream.
+ *
+ * `Session` is intentionally excluded: it has no CRUD/list surface in
+ * {@link DbInterface} and is ephemeral/non-portable between instances.
+ */
+export type ExportKind = "user" | "abode" | "resident" | "apikey" | "note";
+
+/**
+ * Canonical order in which record kinds are emitted into an export stream, and
+ * the order in which an importer may safely apply them.
+ *
+ * This ordering is **part of the wire contract**, not an implementation
+ * detail. It is FK-safe: every foreign key points only at a kind that appears
+ * earlier (or at the same kind, earlier in the stream), so an importer that
+ * inserts records one-by-one with referential integrity enforced never
+ * forward-references a row it hasn't inserted yet:
+ *
+ * - `abode.created_by`/`updated_by` → `user`
+ * - `resident.uid` → `user`, `resident.aid` → `abode`
+ * - `apikey.uid` → `user`
+ * - `note.aid` → `abode`, `note.created_by`/`updated_by` → `user`
+ *
+ * The sqlite backend can afford to relax this (it suspends FK enforcement for
+ * the load), but the postgres backend relies on it: it inserts sequentially
+ * with constraints live. Every {@link Exportable} MUST emit in this order, and
+ * reordering it is a breaking change to the format.
+ */
+export const EXPORT_KIND_ORDER = [
+  "user",
+  "abode",
+  "resident",
+  "apikey",
+  "note",
+] as const satisfies readonly ExportKind[];
+
+export type ExportFilter = {
+  /** Include only these kinds; omit = all kinds. */
+  kinds?: ExportKind[];
+  /** Excluded after `kinds` is applied. */
+  excludeKinds?: ExportKind[];
+  /** aid allowlist — scopes abode/resident/note. */
+  abodes?: string[];
+  /** uid allowlist — scopes user (and apikey, unless `apikeys` is set). */
+  users?: string[];
+  /**
+   * uid allowlist scoping apikey records specifically. When set it takes
+   * precedence over `users` for the `apikey` kind — used to export a
+   * non-admin's own keys while still exporting co-residents' *user* records
+   * for referential integrity, without leaking their apikey metadata. Absent =
+   * fall back to `users`.
+   */
+  apikeys?: string[];
+};
+
+export interface ExportOptions {
+  filter?: ExportFilter;
+  signal?: AbortSignal;
+}
+
+export interface Exportable {
+  /** Produce a stream of NDJSON lines (one JSON envelope per line). */
+  export(options?: ExportOptions): NodeJS.ReadableStream;
+}
+
+export interface ImportOptions {
+  filter?: ExportFilter;
+  signal?: AbortSignal;
+}
+
+export interface ImportResult {
+  counts: Partial<Record<ExportKind, number>>;
+}
+
+export interface Importable {
+  import(
+    source: NodeJS.ReadableStream,
+    options?: ImportOptions,
+  ): Promise<ImportResult>;
+}
+
+/**
+ * The NDJSON envelope written/read for every line. The leading line is a
+ * `meta` record; the record lines that follow are grouped by kind in
+ * {@link EXPORT_KIND_ORDER} (an FK-safe order importers may rely on); a
+ * trailing `error` record may appear if the source failed after streaming had
+ * already begun.
+ */
+export type ExportEnvelope =
+  | { kind: "meta"; data: ExportMeta }
+  | { kind: ExportKind; data: unknown }
+  | { kind: "error"; data: { message: string; code?: string } };
+
+export type ExportMeta = {
+  v: number;
+  exportedAt: string;
+  source: string;
+  /** The *effective* filter actually applied (may be narrower than requested). */
+  filter: ExportFilter;
+};
+
+export function isExportable(db: DbInterface): db is DbInterface & Exportable {
+  return typeof (db as Partial<Exportable>).export === "function";
+}
+
+export function isImportable(db: DbInterface): db is DbInterface & Importable {
+  return typeof (db as Partial<Importable>).import === "function";
+}

src/webapi/apirouter.ts

@@ -16,6 +16,29 @@ import {
 } from "../schema/validators.js";
 import { authenticate } from "./middleware/authenticate.js";
 import { InvalidAbodeError, NotFoundAbodeError } from "../db/types/errors.js";
+import { isExportable } from "../db/types/ExportImport.js";
+import type { ExportFilter, ExportKind } from "../db/types/ExportImport.js";
+import { intersectExportFilters, isExportKind } from "../db/export/filter.js";
+import { computeForcedExportFilter } from "./exportScope.js";
+
+function parseExportFilter(query: Record<string, unknown>): ExportFilter {
+  const list = (v: unknown): string[] | undefined => {
+    if (typeof v !== "string" || !v) return undefined;
+    return v.split(",").filter(Boolean);
+  };
+  const kinds = (v: unknown): ExportKind[] | undefined =>
+    list(v)?.filter(isExportKind);
+  const filter: ExportFilter = {};
+  const k = kinds(query.kinds);
+  if (k) filter.kinds = k;
+  const ek = kinds(query.excludeKinds);
+  if (ek) filter.excludeKinds = ek;
+  const abodes = list(query.abodes);
+  if (abodes) filter.abodes = abodes;
+  const users = list(query.users);
+  if (users) filter.users = users;
+  return filter;
+}
 
 export function apirouter(db: BackendDbInterface): KoaRouter {
   const router = new KoaRouter();
@@ -42,6 +65,31 @@ export function apirouter(db: BackendDbInterface): KoaRouter {
     ctx.status = 204;
   });
 
+  router.get("/export", authenticate(db), async (ctx) => {
+    // Everything that can throw a domain error runs *before* any byte is
+    // written, so `convertError` still applies. Once `ctx.body` is a stream,
+    // a mid-stream failure surfaces as a trailing `error` NDJSON line instead.
+    const forced = await computeForcedExportFilter(db, {
+      user: ctx.user!,
+      session: ctx.session!,
+    });
+    const effective = intersectExportFilters(
+      parseExportFilter(ctx.query),
+      forced,
+    );
+    if (!isExportable(db)) {
+      ctx.status = 501;
+      ctx.body = { ok: false, error: "export_unsupported" };
+      return;
+    }
+    const ac = new AbortController();
+    ctx.res.on("close", () => {
+      if (!ctx.res.writableEnded) ac.abort();
+    });
+    ctx.type = "application/x-ndjson";
+    ctx.body = db.export({ filter: effective, signal: ac.signal });
+  });
+
   router.use("/users", authenticate(db));
   router.get("/users", async (ctx) => {
     ctx.body = await db.listUsers();

src/webapi/exportScope.ts

@@ -0,0 +1,64 @@
+import type { Context } from "koa";
+import type { BackendDbInterface } from "../db/types/DbInterface.js";
+import type { ClientUser } from "../db/types/User.js";
+import type { ExportFilter } from "../db/types/ExportImport.js";
+
+/**
+ * Compute the export scope that must be *forced* on a caller, independent of
+ * anything they requested. Returns `null` when the caller is unrestricted (a
+ * global admin whose credential imposes no narrowing) — their own filter, if
+ * any, is then honored verbatim as a voluntary narrowing.
+ *
+ * Otherwise returns `{ abodes, users, apikeys }`: the abodes the caller resides
+ * in, the users needed to keep that data referentially whole (the caller plus
+ * every co-resident of those abodes), and — scoped tighter than `users` —
+ * apikeys limited to the caller alone, so a non-admin never exports another
+ * user's apikey metadata even though that user's record is included. This is
+ * the maximum a non-admin may export; the route intersects it with any
+ * caller-supplied filter (never a union).
+ */
+export async function computeForcedExportFilter(
+  db: BackendDbInterface,
+  ctx: { user: ClientUser; session: NonNullable<Context["session"]> },
+): Promise<ExportFilter | null> {
+  const { user, session } = ctx;
+
+  if (user.flags.admin) {
+    if (session.source !== "apikey") return null;
+    const p = session.key.permissions;
+    const unrestricted =
+      !!p.admin &&
+      !!p.all &&
+      !p.restrict_users?.length &&
+      !p.restrict_abodes?.length;
+    if (unrestricted) return null;
+  }
+
+  const residencies = await db.listResidentsByUserId(user.uid);
+  const abodeSet = new Set(residencies.map((r) => r.aid));
+  const userSet = new Set<string>([user.uid]);
+  for (const aid of abodeSet) {
+    for (const u of await db.listUsersByAbodeId(aid)) userSet.add(u.uid);
+  }
+
+  let abodes = [...abodeSet];
+  let users = [...userSet];
+  // apikeys are self-only for non-admins, regardless of co-residency.
+  let apikeys = [user.uid];
+
+  // An apikey can only narrow what its owning user could otherwise export.
+  if (session.source === "apikey") {
+    const p = session.key.permissions;
+    if (p.restrict_abodes?.length) {
+      const allow = new Set(p.restrict_abodes);
+      abodes = abodes.filter((a) => allow.has(a));
+    }
+    if (p.restrict_users?.length) {
+      const allow = new Set(p.restrict_users);
+      users = users.filter((u) => allow.has(u));
+      apikeys = apikeys.filter((u) => allow.has(u));
+    }
+  }
+
+  return { abodes, users, apikeys };
+}

test/backends/postgres/export-import.test.ts

@@ -0,0 +1,314 @@
+import { describe, it } from "node:test";
+import assert from "node:assert/strict";
+import { Readable } from "node:stream";
+import { PostgresInterface } from "../../../src/db/postgres/PostgresInterface.js";
+import type { WrappedPgClient } from "../../../src/db/postgres/pool.js";
+import type { SqlCode } from "../../../src/db/postgres/sql.js";
+import {
+  EXPORT_KIND_ORDER,
+  type ExportKind,
+} from "../../../src/db/types/ExportImport.js";
+
+// The postgres backend has no CI database, so these tests drive the real
+// PostgresInterface.export/import code paths against an in-memory fake client.
+// They verify control flow (NDJSON shape, meta.source, filtering, note
+// skipping, counts, insert dispatch, abort -> rollback); the SQL-arg forms are
+// the same {uuid}/{text}/{jsonb}/{date} patterns the pg backend's own CRUD
+// already exercises against real Postgres.
+
+interface Rows {
+  users?: Record<string, unknown>[];
+  abodes?: Record<string, unknown>[];
+  residents?: Record<string, unknown>[];
+  apikeys?: Record<string, unknown>[];
+}
+
+class FakePg implements WrappedPgClient {
+  readonly = false;
+  inserts: { table: string; vars: unknown[] }[] = [];
+  committed = false;
+  rolledBack = false;
+  #rows: Rows;
+
+  constructor(rows: Rows = {}) {
+    this.#rows = rows;
+  }
+
+  async destroy(): Promise<void> {}
+
+  async all<R>(stmt: SqlCode): Promise<R[]> {
+    const s = stmt._sql;
+    if (s.includes('FROM "users"')) return (this.#rows.users ?? []) as R[];
+    if (s.includes('FROM "abodes"')) return (this.#rows.abodes ?? []) as R[];
+    if (s.includes('FROM "residents"'))
+      return (this.#rows.residents ?? []) as R[];
+    if (s.includes('FROM "apikeys"')) return (this.#rows.apikeys ?? []) as R[];
+    return [] as R[];
+  }
+
+  async get<R>(stmt: SqlCode): Promise<R | null> {
+    const rows = await this.all<R>(stmt);
+    return rows[0] ?? null;
+  }
+
+  async run(stmt: SqlCode): Promise<{ changes: number }> {
+    const table = stmt._sql.match(/INSERT INTO "(\w+)"/)?.[1] ?? "?";
+    this.inserts.push({ table, vars: stmt._vars });
+    return { changes: 1 };
+  }
+
+  async multi<R>(fn: (tx: WrappedPgClient) => Promise<R>): Promise<R> {
+    try {
+      const r = await fn(this);
+      this.committed = true;
+      return r;
+    } catch (e) {
+      this.rolledBack = true;
+      throw e;
+    }
+  }
+
+  async rethrow<R>(fn: () => Promise<R>): Promise<R> {
+    return fn();
+  }
+}
+
+const iso = "2026-01-02T03:04:05.000Z";
+
+function seededRows(): Rows {
+  return {
+    users: [
+      {
+        uid: "11111111-1111-1111-1111-111111111111",
+        email: "u1@test.example",
+        name: "User One",
+        flags: {},
+        created_at: new Date(iso),
+        updated_at: new Date(iso),
+      },
+    ],
+    abodes: [
+      {
+        aid: "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaa1",
+        name: "Abode One",
+        created_at: new Date(iso),
+        created_by: "11111111-1111-1111-1111-111111111111",
+        updated_at: new Date(iso),
+        updated_by: null,
+      },
+      {
+        aid: "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaa2",
+        name: "Abode Two",
+        created_at: new Date(iso),
+        created_by: null,
+        updated_at: new Date(iso),
+        updated_by: null,
+      },
+    ],
+    residents: [
+      {
+        uid: "11111111-1111-1111-1111-111111111111",
+        aid: "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaa1",
+        flags: {},
+        created_at: new Date(iso),
+        created_by: null,
+        updated_at: new Date(iso),
+        updated_by: null,
+      },
+    ],
+    apikeys: [
+      {
+        uid: "11111111-1111-1111-1111-111111111111",
+        kid: "kkkkkkkk-kkkk-kkkk-kkkk-kkkkkkkkkkk1",
+        name: "key one",
+        permissions: {},
+        created_at: new Date(iso),
+        expires_at: null,
+      },
+    ],
+  };
+}
+
+async function streamToString(s: NodeJS.ReadableStream): Promise<string> {
+  let out = "";
+  for await (const chunk of s) out += chunk;
+  return out;
+}
+function parseLines(ndjson: string): { kind: string; data: any }[] {
+  return ndjson
+    .split("\n")
+    .filter(Boolean)
+    .map((l) => JSON.parse(l));
+}
+function line(kind: string, data: unknown): string {
+  return JSON.stringify({ kind, data }) + "\n";
+}
+
+describe("postgres export", () => {
+  it("streams meta + the four supported kinds, never note", async () => {
+    const db = new PostgresInterface(new FakePg(seededRows()));
+    const lines = parseLines(await streamToString(db.export()));
+
+    const meta = lines.find((l) => l.kind === "meta");
+    assert.ok(meta);
+    assert.equal(meta!.data.source, "postgres");
+    assert.equal(meta!.data.v, 1);
+
+    const kinds = new Set(lines.map((l) => l.kind));
+    assert.ok(kinds.has("user"));
+    assert.ok(kinds.has("abode"));
+    assert.ok(kinds.has("resident"));
+    assert.ok(kinds.has("apikey"));
+    assert.ok(!kinds.has("note"), "note is unsupported on postgres");
+  });
+
+  it("emits record kinds grouped in FK-safe EXPORT_KIND_ORDER", async () => {
+    const db = new PostgresInterface(new FakePg(seededRows()));
+    const lines = parseLines(await streamToString(db.export()));
+    assert.equal(lines[0]?.kind, "meta", "first line is meta");
+    const rank = (k: string) => EXPORT_KIND_ORDER.indexOf(k as ExportKind);
+    let last = -1;
+    for (const { kind } of lines.slice(1)) {
+      const r = rank(kind);
+      assert.notEqual(r, -1, `unexpected kind ${kind}`);
+      assert.ok(r >= last, `kind ${kind} out of FK-safe order`);
+      last = r;
+    }
+  });
+
+  it("applies the kinds filter", async () => {
+    const db = new PostgresInterface(new FakePg(seededRows()));
+    const lines = parseLines(
+      await streamToString(db.export({ filter: { kinds: ["abode"] } })),
+    );
+    const kinds = new Set(
+      lines.filter((l) => l.kind !== "meta").map((l) => l.kind),
+    );
+    assert.deepEqual(kinds, new Set(["abode"]));
+  });
+
+  it("applies the abodes allowlist to abode/resident records", async () => {
+    const db = new PostgresInterface(new FakePg(seededRows()));
+    const lines = parseLines(
+      await streamToString(
+        db.export({
+          filter: { abodes: ["aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaa1"] },
+        }),
+      ),
+    );
+    const abodeAids = lines
+      .filter((l) => l.kind === "abode")
+      .map((l) => l.data.aid);
+    assert.deepEqual(abodeAids, ["aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaa1"]);
+  });
+});
+
+describe("postgres import", () => {
+  it("dispatches inserts per kind, skips note, and commits", async () => {
+    const fake = new FakePg();
+    const db = new PostgresInterface(fake);
+    const source = Readable.from([
+      line("meta", { v: 1 }),
+      line("user", {
+        uid: "11111111-1111-1111-1111-111111111111",
+        email: "u1@test.example",
+        name: "User One",
+        flags: {},
+        created_at: iso,
+        updated_at: iso,
+      }),
+      line("abode", {
+        aid: "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaa1",
+        name: "Abode One",
+        created_at: iso,
+        created_by: "11111111-1111-1111-1111-111111111111",
+        updated_at: iso,
+        updated_by: null,
+      }),
+      line("apikey", {
+        uid: "11111111-1111-1111-1111-111111111111",
+        kid: "kkkkkkkk-kkkk-kkkk-kkkk-kkkkkkkkkkk1",
+        name: "key one",
+        permissions: {},
+        created_at: iso,
+        expires_at: null,
+      }),
+      // note lines are silently skipped on postgres
+      line("note", {
+        nid: "nnnnnnnn-nnnn-nnnn-nnnn-nnnnnnnnnnn1",
+        aid: "aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaa1",
+        name: "Note",
+        content: "x",
+        properties: {},
+        created_at: iso,
+        created_by: null,
+        updated_at: iso,
+        updated_by: null,
+      }),
+    ]);
+
+    const result = await db.import(source);
+    assert.deepEqual(result.counts, { user: 1, abode: 1, apikey: 1 });
+    assert.ok(fake.committed);
+    assert.deepEqual(fake.inserts.map((i) => i.table).sort(), [
+      "abodes",
+      "apikeys",
+      "users",
+    ]);
+    assert.ok(!fake.inserts.some((i) => i.table === "notes"), "no note insert");
+    // apikey gets a freshly-minted token (never exported)
+    const apikeyInsert = fake.inserts.find((i) => i.table === "apikeys")!;
+    assert.ok(
+      apikeyInsert.vars.some(
+        (v) => typeof v === "string" && v.startsWith("at_"),
+      ),
+      "apikey insert carries a fresh token",
+    );
+  });
+
+  it("rejects and rolls back when the stream carries an error sentinel", async () => {
+    const fake = new FakePg();
+    const db = new PostgresInterface(fake);
+    const source = Readable.from([
+      line("meta", { v: 1 }),
+      line("user", {
+        uid: "11111111-1111-1111-1111-111111111111",
+        email: "u1@test.example",
+        name: "User One",
+        flags: {},
+        created_at: iso,
+        updated_at: iso,
+      }),
+      line("error", { message: "boom" }),
+    ]);
+
+    await assert.rejects(() => db.import(source), /boom/);
+    assert.ok(fake.rolledBack);
+    assert.ok(!fake.committed);
+  });
+
+  it("rejects and rolls back on signal abort", async () => {
+    const fake = new FakePg();
+    const db = new PostgresInterface(fake);
+    const ac = new AbortController();
+    const source = Readable.from(
+      (async function* () {
+        yield line("meta", { v: 1 });
+        yield line("user", {
+          uid: "11111111-1111-1111-1111-111111111111",
+          email: "u1@test.example",
+          name: "User One",
+          flags: {},
+          created_at: iso,
+          updated_at: iso,
+        });
+        ac.abort();
+        await new Promise((r) => setTimeout(r, 1000));
+      })(),
+    );
+
+    await assert.rejects(() => db.import(source, { signal: ac.signal }));
+    assert.ok(fake.rolledBack);
+    assert.ok(!fake.committed);
+  });
+});

test/tools/export-import.test.ts

@@ -0,0 +1,794 @@
+import { describe, it, before, after } from "node:test";
+import assert from "node:assert/strict";
+import readline from "node:readline";
+import { Readable } from "node:stream";
+import { createServer } from "node:http";
+import type { AddressInfo } from "node:net";
+import Koa from "koa";
+import { createTestDb, type TestDb } from "../helpers/sqlite.js";
+import { apirouter } from "../../src/webapi/apirouter.js";
+import { computeForcedExportFilter } from "../../src/webapi/exportScope.js";
+import {
+  intersectExportFilters,
+  recordAllowed,
+  kindAllowed,
+} from "../../src/db/export/filter.js";
+import { inspectExportStream } from "../../src/db/export/inspect.js";
+import { hashPassword } from "../../src/util/hash.js";
+import type { ClientUser } from "../../src/db/types/User.js";
+import {
+  EXPORT_KIND_ORDER,
+  type ExportKind,
+} from "../../src/db/types/ExportImport.js";
+
+/**
+ * Assert the record lines of a parsed export are grouped in FK-safe
+ * EXPORT_KIND_ORDER: the leading line is `meta`, and every record kind's
+ * position in the order is non-decreasing down the stream.
+ */
+function assertFkSafeOrder(lines: { kind: string }[]): void {
+  assert.equal(lines[0]?.kind, "meta", "first line is meta");
+  const rank = (k: string) => EXPORT_KIND_ORDER.indexOf(k as ExportKind);
+  let last = -1;
+  for (const { kind } of lines.slice(1)) {
+    if (kind === "error") continue;
+    const r = rank(kind);
+    assert.notEqual(r, -1, `unexpected kind ${kind}`);
+    assert.ok(
+      r >= last,
+      `kind ${kind} (order ${r}) appears after a later kind (order ${last})`,
+    );
+    last = r;
+  }
+}
+
+// ---------------------------------------------------------------------------
+// helpers
+// ---------------------------------------------------------------------------
+
+async function streamToString(s: NodeJS.ReadableStream): Promise<string> {
+  let out = "";
+  for await (const chunk of s) out += chunk;
+  return out;
+}
+
+function parseLines(ndjson: string): { kind: string; data: any }[] {
+  return ndjson
+    .split("\n")
+    .filter(Boolean)
+    .map((l) => JSON.parse(l));
+}
+
+/** Normalise `*_at` fields to epoch ms so formatting never breaks equality. */
+function norm(obj: Record<string, unknown>): Record<string, unknown> {
+  const out: Record<string, unknown> = {};
+  for (const [k, v] of Object.entries(obj)) {
+    out[k] = k.endsWith("_at")
+      ? v == null
+        ? null
+        : new Date(v as string).getTime()
+      : v;
+  }
+  return out;
+}
+function normSorted(
+  arr: Record<string, unknown>[],
+  key: (x: any) => string,
+): Record<string, unknown>[] {
+  return arr.map(norm).sort((a, b) => key(a).localeCompare(key(b)));
+}
+
+interface Seed {
+  admin: ClientUser;
+  normal: ClientUser;
+  co: ClientUser;
+  aid1: string;
+  aid2: string;
+  nid1: string;
+  nid2: string;
+}
+
+async function seed(db: TestDb["db"]): Promise<Seed> {
+  const pw = await hashPassword("password");
+  const admin = await db.createUser({
+    email: "admin@test.example",
+    name: "Admin",
+    password: pw,
+    flags: { admin: true },
+  });
+  const normal = await db.createUser({
+    email: "normal@test.example",
+    name: "Normal",
+    password: pw,
+    flags: {},
+  });
+  const co = await db.createUser({
+    email: "co@test.example",
+    name: "Co Resident",
+    password: pw,
+    flags: {},
+  });
+  const abode1 = await db.createAbode(
+    { name: "Abode One" },
+    { uid: admin.uid },
+  );
+  const abode2 = await db.createAbode(
+    { name: "Abode Two" },
+    { uid: admin.uid },
+  );
+  await db.createResident(
+    { uid: normal.uid, aid: abode1.aid, flags: {} },
+    { uid: admin.uid },
+  );
+  await db.createResident(
+    { uid: co.uid, aid: abode1.aid, flags: {} },
+    { uid: admin.uid },
+  );
+  await db.createResident(
+    { uid: admin.uid, aid: abode2.aid, flags: { admin: true } },
+    { uid: admin.uid },
+  );
+  await db.createApikey({
+    uid: normal.uid,
+    name: "normal key",
+    permissions: {},
+    expires_at: null,
+  });
+  await db.createApikey({
+    uid: co.uid,
+    name: "co key",
+    permissions: {},
+    expires_at: null,
+  });
+  const note1 = await db.createNote(
+    {
+      aid: abode1.aid,
+      name: "Note One",
+      content: "hello",
+      properties: { type: "note" },
+    },
+    { uid: normal.uid },
+  );
+  const note2 = await db.createNote(
+    {
+      aid: abode2.aid,
+      name: "Note Two",
+      content: "world",
+      properties: { type: "note" },
+    },
+    { uid: admin.uid },
+  );
+  return {
+    admin,
+    normal,
+    co,
+    aid1: abode1.aid,
+    aid2: abode2.aid,
+    nid1: note1.nid,
+    nid2: note2.nid,
+  };
+}
+
+// ---------------------------------------------------------------------------
+// 0. wire-format ordering invariant
+// ---------------------------------------------------------------------------
+
+describe("export ordering (FK-safe wire contract)", () => {
+  it("EXPORT_KIND_ORDER is the FK-safe dependency order", () => {
+    // Change-detector: reordering is a breaking change to the format and must
+    // keep every kind after the kinds it references (see ExportImport.ts).
+    assert.deepEqual(EXPORT_KIND_ORDER, [
+      "user",
+      "abode",
+      "resident",
+      "apikey",
+      "note",
+    ]);
+  });
+
+  it("sqlite export emits record kinds grouped in EXPORT_KIND_ORDER", async () => {
+    const src = await createTestDb();
+    try {
+      await seed(src.db);
+      const lines = parseLines(await streamToString(src.db.export()));
+      // every kind must be present so the ordering is actually exercised
+      const kinds = new Set(lines.map((l) => l.kind));
+      for (const k of EXPORT_KIND_ORDER) {
+        assert.ok(kinds.has(k), `stream contains ${k}`);
+      }
+      assertFkSafeOrder(lines);
+    } finally {
+      src.close();
+    }
+  });
+});
+
+// ---------------------------------------------------------------------------
+// 1. round-trip
+// ---------------------------------------------------------------------------
+
+describe("export/import: sqlite -> sqlite round-trip", () => {
+  it("reproduces users, abodes, residents, apikeys, notes", async () => {
+    const src = await createTestDb();
+    const dst = await createTestDb();
+    try {
+      const s = await seed(src.db);
+
+      const result = await dst.db.import(src.db.export());
+      assert.ok(result.counts.user && result.counts.user >= 3);
+      assert.ok(result.counts.note && result.counts.note >= 2);
+
+      assert.deepEqual(
+        normSorted(await dst.db.listUsers(), (u) => u.uid),
+        normSorted(await src.db.listUsers(), (u) => u.uid),
+      );
+      assert.deepEqual(
+        normSorted(await dst.db.listAbodes(), (a) => a.aid),
+        normSorted(await src.db.listAbodes(), (a) => a.aid),
+      );
+      assert.deepEqual(
+        normSorted(await dst.db.listResidents(), (r) => r.uid + r.aid),
+        normSorted(await src.db.listResidents(), (r) => r.uid + r.aid),
+      );
+      // apikeys: token is regenerated on import, so the ClientApikey view
+      // (which omits token) must still match exactly.
+      assert.deepEqual(
+        normSorted(await dst.db.listApikeysByUser(s.normal.uid), (k) => k.kid),
+        normSorted(await src.db.listApikeysByUser(s.normal.uid), (k) => k.kid),
+      );
+      // notes (full, with content)
+      const srcNote = await src.db.getNoteById(s.nid1);
+      const dstNote = await dst.db.getNoteById(s.nid1);
+      assert.deepEqual(norm(dstNote), norm(srcNote));
+    } finally {
+      src.close();
+      dst.close();
+    }
+  });
+});
+
+// ---------------------------------------------------------------------------
+// 2. filter narrowing
+// ---------------------------------------------------------------------------
+
+describe("export/import: filter narrowing", () => {
+  it("scopes abode/resident/note to the requested abodes", async () => {
+    const src = await createTestDb();
+    try {
+      const s = await seed(src.db);
+      const ndjson = await streamToString(
+        src.db.export({ filter: { abodes: [s.aid1] } }),
+      );
+      const lines = parseLines(ndjson);
+
+      const abodeAids = lines
+        .filter((l) => l.kind === "abode")
+        .map((l) => l.data.aid);
+      assert.deepEqual(abodeAids, [s.aid1]);
+
+      const noteAids = new Set(
+        lines.filter((l) => l.kind === "note").map((l) => l.data.aid),
+      );
+      assert.ok(noteAids.has(s.aid1));
+      assert.ok(!noteAids.has(s.aid2));
+
+      const residentAids = new Set(
+        lines.filter((l) => l.kind === "resident").map((l) => l.data.aid),
+      );
+      assert.ok(!residentAids.has(s.aid2));
+    } finally {
+      src.close();
+    }
+  });
+
+  it("imports the narrowed dump into a fresh db with the same scope", async () => {
+    const src = await createTestDb();
+    const dst = await createTestDb();
+    try {
+      const s = await seed(src.db);
+      await dst.db.import(src.db.export({ filter: { abodes: [s.aid1] } }));
+
+      const abodes = await dst.db.listAbodes();
+      assert.deepEqual(
+        abodes.map((a) => a.aid),
+        [s.aid1],
+      );
+      const notes = await dst.db.listNotesByAbodeId(s.aid1);
+      assert.equal(notes.length, 1);
+      assert.equal((await dst.db.listNotesByAbodeId(s.aid2)).length, 0);
+    } finally {
+      src.close();
+      dst.close();
+    }
+  });
+
+  it("kinds filter selects only the requested kinds", async () => {
+    const src = await createTestDb();
+    try {
+      await seed(src.db);
+      const ndjson = await streamToString(
+        src.db.export({ filter: { kinds: ["abode"] } }),
+      );
+      const kinds = new Set(parseLines(ndjson).map((l) => l.kind));
+      assert.ok(kinds.has("abode"));
+      assert.ok(!kinds.has("user"));
+      assert.ok(!kinds.has("note"));
+    } finally {
+      src.close();
+    }
+  });
+});
+
+// ---------------------------------------------------------------------------
+// 3. forced-filter enforcement
+// ---------------------------------------------------------------------------
+
+describe("exportScope: computeForcedExportFilter", () => {
+  it("returns null for a global admin on a basic/session credential", async () => {
+    const t = await createTestDb();
+    try {
+      const s = await seed(t.db);
+      const forced = await computeForcedExportFilter(t.db, {
+        user: s.admin,
+        session: { source: "basic" },
+      });
+      assert.equal(forced, null);
+    } finally {
+      t.close();
+    }
+  });
+
+  it("returns null for a global admin with an unrestricted apikey", async () => {
+    const t = await createTestDb();
+    try {
+      const s = await seed(t.db);
+      const forced = await computeForcedExportFilter(t.db, {
+        user: s.admin,
+        session: {
+          source: "apikey",
+          key: {
+            kid: "k",
+            uid: s.admin.uid,
+            name: "k",
+            permissions: { admin: true, all: true },
+            created_at: new Date().toISOString(),
+            expires_at: null,
+          },
+        },
+      });
+      assert.equal(forced, null);
+    } finally {
+      t.close();
+    }
+  });
+
+  it("forces a non-admin to their abodes + co-residents", async () => {
+    const t = await createTestDb();
+    try {
+      const s = await seed(t.db);
+      const forced = await computeForcedExportFilter(t.db, {
+        user: s.normal,
+        session: { source: "basic" },
+      });
+      assert.ok(forced);
+      assert.deepEqual(forced!.abodes, [s.aid1]);
+      assert.deepEqual(
+        new Set(forced!.users),
+        new Set([s.normal.uid, s.co.uid]),
+      );
+      assert.ok(!forced!.users!.includes(s.admin.uid));
+      // apikeys are self-only, even though co is a co-resident whose user
+      // record is exported for referential integrity.
+      assert.deepEqual(forced!.apikeys, [s.normal.uid]);
+
+      // A caller requesting a wider abode never gets it: intersection, not union.
+      const effective = intersectExportFilters(
+        { abodes: [s.aid1, s.aid2] },
+        forced,
+      );
+      assert.deepEqual(effective.abodes, [s.aid1]);
+      assert.ok(!effective.abodes!.includes(s.aid2));
+    } finally {
+      t.close();
+    }
+  });
+
+  it("intersects a non-admin apikey with restrict_abodes", async () => {
+    const t = await createTestDb();
+    try {
+      const s = await seed(t.db);
+      const forced = await computeForcedExportFilter(t.db, {
+        user: s.normal,
+        session: {
+          source: "apikey",
+          key: {
+            kid: "k",
+            uid: s.normal.uid,
+            name: "k",
+            permissions: { restrict_abodes: [s.aid2] },
+            created_at: new Date().toISOString(),
+            expires_at: null,
+          },
+        },
+      });
+      // normal resides only in aid1; restrict to aid2 => empty intersection.
+      assert.deepEqual(forced!.abodes, []);
+    } finally {
+      t.close();
+    }
+  });
+});
+
+// ---------------------------------------------------------------------------
+// 4. cancellation, export side
+// ---------------------------------------------------------------------------
+
+describe("export cancellation", () => {
+  it("stops querying tables after the destination aborts", async () => {
+    const t = await createTestDb();
+    try {
+      const pw = await hashPassword("password");
+      // Enough users that the first table can't be buffered in one go, so the
+      // generator backpressures mid-`user` and never reaches later tables.
+      for (let i = 0; i < 400; i++) {
+        await t.db.createUser({
+          email: `bulk-${i}@test.example`,
+          name: `Bulk ${i}`,
+          password: pw,
+          flags: {},
+        });
+      }
+
+      let allCalls = 0;
+      const orig = t.wrapped.all.bind(t.wrapped);
+      (t.wrapped as { all: unknown }).all = (stmt: never) => {
+        allCalls++;
+        return orig(stmt);
+      };
+
+      const ac = new AbortController();
+      const stream = t.db.export({ signal: ac.signal });
+      const rl = readline.createInterface({ input: stream });
+
+      let lines = 0;
+      let callsAtAbort = -1;
+      for await (const _ of rl) {
+        lines++;
+        if (lines === 3) {
+          ac.abort();
+          callsAtAbort = allCalls;
+        }
+      }
+
+      assert.ok(callsAtAbort >= 1, "at least the first table was queried");
+      assert.equal(allCalls, callsAtAbort, "no further queries after abort");
+      assert.ok(allCalls < 5, "did not materialise all five tables");
+    } finally {
+      t.close();
+    }
+  });
+});
+
+// ---------------------------------------------------------------------------
+// 5. cancellation, import side
+// ---------------------------------------------------------------------------
+
+describe("import cancellation", () => {
+  it("rolls back and leaves no dangling transaction when the source errors", async () => {
+    const dst = await createTestDb();
+    try {
+      function line(kind: string, data: unknown): string {
+        return JSON.stringify({ kind, data }) + "\n";
+      }
+      const now = new Date().toISOString();
+      const mkUser = (i: number) => ({
+        uid: crypto.randomUUID(),
+        email: `imp-${i}@test.example`,
+        name: `Imp ${i}`,
+        flags: {},
+        created_at: now,
+        updated_at: now,
+      });
+
+      // Emits a couple of valid user records, then throws mid-stream.
+      const source = Readable.from(
+        (async function* () {
+          yield line("meta", { v: 1 });
+          yield line("user", mkUser(1));
+          yield line("user", mkUser(2));
+          throw new Error("source exploded");
+        })(),
+      );
+
+      await assert.rejects(() => dst.db.import(source), /source exploded/);
+
+      // ROLLBACK happened: nothing persisted.
+      assert.equal((await dst.db.listUsers()).length, 0);
+
+      // No lingering open transaction: a follow-up write succeeds immediately.
+      const pw = await hashPassword("password");
+      const created = await dst.db.createUser({
+        email: "after@test.example",
+        name: "After",
+        password: pw,
+        flags: {},
+      });
+      assert.ok(created.uid);
+    } finally {
+      dst.close();
+    }
+  });
+
+  it("aborts cleanly via signal and commits nothing", async () => {
+    const dst = await createTestDb();
+    try {
+      const ac = new AbortController();
+      const now = new Date().toISOString();
+      const source = Readable.from(
+        (async function* () {
+          yield JSON.stringify({ kind: "meta", data: { v: 1 } }) + "\n";
+          yield JSON.stringify({
+            kind: "user",
+            data: {
+              uid: crypto.randomUUID(),
+              email: "abort@test.example",
+              name: "Abort",
+              flags: {},
+              created_at: now,
+              updated_at: now,
+            },
+          }) + "\n";
+          ac.abort();
+          // Keep the stream alive so abort — not EOF — ends the import.
+          await new Promise((r) => setTimeout(r, 1000));
+        })(),
+      );
+
+      await assert.rejects(() => dst.db.import(source, { signal: ac.signal }));
+      assert.equal((await dst.db.listUsers()).length, 0);
+    } finally {
+      dst.close();
+    }
+  });
+});
+
+// ---------------------------------------------------------------------------
+// 6. api export endpoint
+// ---------------------------------------------------------------------------
+
+describe("GET /export endpoint", () => {
+  let t: TestDb;
+  let s: Seed;
+  let url: string;
+  let close: () => Promise<void>;
+
+  const basic = (email: string) =>
+    "Basic " + Buffer.from(`${email}:password`).toString("base64");
+
+  before(async () => {
+    t = await createTestDb();
+    s = await seed(t.db);
+    const app = new Koa();
+    const router = apirouter(t.db);
+    app.use(router.routes());
+    app.use(router.allowedMethods());
+    const server = createServer(app.callback());
+    await new Promise<void>((r) => server.listen(0, "127.0.0.1", r));
+    const { port } = server.address() as AddressInfo;
+    url = `http://127.0.0.1:${port}`;
+    close = () =>
+      new Promise<void>((resolve, reject) =>
+        server.close((err) => (err ? reject(err) : resolve())),
+      );
+  });
+
+  after(async () => {
+    await close();
+    t.close();
+  });
+
+  it("global admin exports everything", async () => {
+    const res = await fetch(`${url}/export`, {
+      headers: { Authorization: basic(s.admin.email) },
+    });
+    assert.equal(res.status, 200);
+    const lines = parseLines(await res.text());
+    const abodeAids = new Set(
+      lines.filter((l) => l.kind === "abode").map((l) => l.data.aid),
+    );
+    assert.ok(abodeAids.has(s.aid1));
+    assert.ok(abodeAids.has(s.aid2));
+    const userUids = new Set(
+      lines.filter((l) => l.kind === "user").map((l) => l.data.uid),
+    );
+    assert.ok(userUids.has(s.admin.uid));
+    assert.ok(userUids.has(s.normal.uid));
+  });
+
+  it("non-admin is force-scoped even when requesting wider abodes", async () => {
+    const res = await fetch(`${url}/export?abodes=${s.aid1},${s.aid2}`, {
+      headers: { Authorization: basic(s.normal.email) },
+    });
+    assert.equal(res.status, 200);
+    const lines = parseLines(await res.text());
+
+    const abodeAids = new Set(
+      lines.filter((l) => l.kind === "abode").map((l) => l.data.aid),
+    );
+    assert.ok(abodeAids.has(s.aid1));
+    assert.ok(!abodeAids.has(s.aid2), "aid2 forced out of scope");
+
+    const userUids = new Set(
+      lines.filter((l) => l.kind === "user").map((l) => l.data.uid),
+    );
+    assert.ok(userUids.has(s.normal.uid));
+    assert.ok(userUids.has(s.co.uid));
+    assert.ok(!userUids.has(s.admin.uid), "admin not a co-resident of aid1");
+
+    // apikeys are self-only: the caller's own key is exported, but a
+    // co-resident's key metadata is NOT, even though their user record is.
+    const apikeyUids = lines
+      .filter((l) => l.kind === "apikey")
+      .map((l) => l.data.uid);
+    assert.deepEqual(new Set(apikeyUids), new Set([s.normal.uid]));
+    assert.ok(
+      !apikeyUids.includes(s.co.uid),
+      "co-resident apikey metadata must not leak",
+    );
+
+    // The meta line records the *effective* (narrowed) filter.
+    const meta = lines.find((l) => l.kind === "meta");
+    assert.ok(meta);
+    assert.deepEqual(meta!.data.filter.abodes, [s.aid1]);
+  });
+
+  it("stops server-side querying shortly after the client aborts", async () => {
+    // Dedicated db/server. Rows are deliberately large (and inserted in bulk so
+    // the seed stays fast) so the users table alone can't fit in the socket
+    // buffer — the export generator backpressures mid-`user` and never reaches
+    // later tables while the client is still holding the connection open.
+    const big = await createTestDb();
+    let server: ReturnType<typeof createServer> | undefined;
+    try {
+      const pw = await hashPassword("password");
+      await big.db.createUser({
+        email: "a@test.example",
+        name: "A",
+        password: pw,
+        flags: { admin: true },
+      });
+      const { sql, db: raw } = big.db._;
+      // ~32MB of user rows — far more than any socket/kernel buffer can hold,
+      // so the generator is guaranteed to still be suspended mid-`user` (never
+      // having queried a later table) when the client aborts.
+      const bigName = "x".repeat(16000);
+      raw.multi(() => {
+        for (let i = 0; i < 2000; i++) {
+          raw.run(sql`
+            INSERT INTO "users"("uid", "email", "name", "flags")
+            VALUES(
+              ${{ uuid: crypto.randomUUID() }},
+              ${{ text: `b-${i}@test.example` }},
+              ${{ text: bigName }},
+              ${{ jsonb: {} }}
+            )
+          `);
+        }
+      });
+
+      let allCalls = 0;
+      const orig = big.wrapped.all.bind(big.wrapped);
+      (big.wrapped as { all: unknown }).all = (stmt: never) => {
+        allCalls++;
+        return orig(stmt);
+      };
+
+      const app = new Koa();
+      app.on("error", () => {}); // swallow the expected ECONNRESET on abort
+      const router = apirouter(big.db);
+      app.use(router.routes());
+      app.use(router.allowedMethods());
+      server = createServer(app.callback());
+      await new Promise<void>((r) => server!.listen(0, "127.0.0.1", r));
+      const { port } = server.address() as AddressInfo;
+
+      const ac = new AbortController();
+      const res = await fetch(`http://127.0.0.1:${port}/export`, {
+        headers: { Authorization: basic("a@test.example") },
+        signal: ac.signal,
+      });
+      const reader = res.body!.getReader();
+      await reader.read(); // first chunk — server has begun streaming users
+      const callsWhileStreaming = allCalls;
+      assert.ok(callsWhileStreaming >= 1, "server queried the first table");
+      ac.abort();
+      await reader.cancel().catch(() => {});
+
+      await new Promise((r) => setTimeout(r, 250));
+      const settled = allCalls;
+      await new Promise((r) => setTimeout(r, 250));
+      assert.equal(allCalls, settled, "no further queries after abort");
+      assert.ok(allCalls < 5, "did not materialise all five tables");
+    } finally {
+      if (server) await new Promise<void>((r) => server!.close(() => r()));
+      big.close();
+    }
+  });
+});
+
+// ---------------------------------------------------------------------------
+// 7. inspect utility
+// ---------------------------------------------------------------------------
+
+describe("inspectExportStream", () => {
+  it("tallies counts and reads meta without a db", async () => {
+    const src = await createTestDb();
+    try {
+      await seed(src.db);
+      const ndjson = await streamToString(src.db.export());
+      const { counts, meta } = await inspectExportStream(
+        Readable.from([ndjson]),
+      );
+      assert.equal(meta?.v, 1);
+      assert.equal(meta?.source, "sqlite");
+      assert.ok((counts.user ?? 0) >= 3);
+      assert.ok((counts.abode ?? 0) >= 2);
+      assert.ok((counts.note ?? 0) >= 2);
+    } finally {
+      src.close();
+    }
+  });
+
+  it("stopAfterKinds short-circuits once every requested kind is seen", async () => {
+    const src = await createTestDb();
+    try {
+      await seed(src.db);
+      const ndjson = await streamToString(src.db.export());
+      const { counts } = await inspectExportStream(Readable.from([ndjson]), {
+        stopAfterKinds: ["user"],
+      });
+      assert.ok((counts.user ?? 0) >= 1);
+      // stopped as soon as the first user was seen, before later kinds.
+      assert.equal(counts.note ?? 0, 0);
+    } finally {
+      src.close();
+    }
+  });
+});
+
+// ---------------------------------------------------------------------------
+// filter unit checks
+// ---------------------------------------------------------------------------
+
+describe("filter helpers", () => {
+  it("kindAllowed respects kinds/excludeKinds", () => {
+    assert.equal(kindAllowed({ kinds: ["abode"] }, "abode"), true);
+    assert.equal(kindAllowed({ kinds: ["abode"] }, "user"), false);
+    assert.equal(kindAllowed({ excludeKinds: ["note"] }, "note"), false);
+    assert.equal(kindAllowed(undefined, "note"), true);
+  });
+
+  it("recordAllowed scopes by aid/uid per kind", () => {
+    assert.equal(
+      recordAllowed({ abodes: ["a1"] }, "abode", { aid: "a1" }),
+      true,
+    );
+    assert.equal(
+      recordAllowed({ abodes: ["a1"] }, "abode", { aid: "a2" }),
+      false,
+    );
+    assert.equal(
+      recordAllowed({ users: ["u1"] }, "apikey", { uid: "u1" }),
+      true,
+    );
+    assert.equal(
+      recordAllowed({ users: ["u1"] }, "apikey", { uid: "u2" }),
+      false,
+    );
+    // abodes allowlist does not constrain user records
+    assert.equal(
+      recordAllowed({ abodes: ["a1"] }, "user", { uid: "u9" }),
+      true,
+    );
+  });
+});