diff --git a/src/adapters/file-jsonl/adapter.ts b/src/adapters/file-jsonl/adapter.ts
new file mode 100644
index 0000000..e625d9b
--- /dev/null
+++ b/src/adapters/file-jsonl/adapter.ts
@@ -0,0 +1,76 @@
+import { createWriteStream } from 'fs';
+import { readFile } from 'fs/promises';
+import { ADAPTER_ID } from './common';
+
+export interface CreateAdapterParams {
+  type: typeof ADAPTER_ID;
+  path: string;
+}
+
+class Adapter<Entry = unknown, Query extends Record<string, unknown> = Record<string, unknown>> {
+  private data?: Entry[];
+
+  private readonly path: string;
+
+  constructor(path: string) {
+    this.path = path;
+  }
+
+  async connect() {
+    const buf = await readFile(this.path);
+    const str = buf.toString('utf-8');
+    const json = str.split('\n');
+    this.data = json.map((j) => JSON.parse(j) as Entry);
+  }
+
+  async createIngester() {
+    return Promise.resolve(createWriteStream(this.path));
+  }
+
+  async search(query: Query): Promise<Entry[]> {
+    if (!this.data) {
+      throw new Error('Adapter not initialized.');
+    }
+
+    const results = this.data.filter((dd) => (
+      Object.entries(query).reduce(
+        (prevFilterResult, [key, value]) => {
+          const d = dd as Record<string, unknown>;
+          if (typeof d[key] === 'string') {
+            const dString = d[key] as string;
+            return (
+              prevFilterResult
+              && dString.toLowerCase().includes((value as string).toString().toLowerCase())
+            );
+          }
+          if (typeof d[key] === 'number') {
+            return prevFilterResult && Number(d[key]) === Number(value);
+          }
+          return prevFilterResult && d[key] === value;
+        },
+        true,
+      )
+    ));
+
+    return Promise.resolve(results);
+  }
+}
+
+export const createAdapter = async (params: Omit<CreateAdapterParams, 'type'>) => {
+  const { path } = params;
+
+  const adapter = new Adapter(path);
+  await adapter.connect();
+};
+
+export interface CreateIngesterParams {
+  type: typeof ADAPTER_ID;
+  path: string;
+}
+
+export const createIngester = async (params: Omit<CreateIngesterParams, 'type'>) => {
+  const { path } = params;
+
+  const adapter = new Adapter(path);
+  return adapter.createIngester();
+};
diff --git a/src/adapters/file-jsonl/common.ts b/src/adapters/file-jsonl/common.ts
new file mode 100644
index 0000000..7119d90
--- /dev/null
+++ b/src/adapters/file-jsonl/common.ts
@@ -0,0 +1 @@
+export const ADAPTER_ID = 'file-jsonl' as const;
diff --git a/src/adapters/file-jsonl/index.ts b/src/adapters/file-jsonl/index.ts
new file mode 100644
index 0000000..b15c44d
--- /dev/null
+++ b/src/adapters/file-jsonl/index.ts
@@ -0,0 +1,2 @@
+export * from './common';
+export * from './adapter';
diff --git a/src/adapters/index.ts b/src/adapters/index.ts
new file mode 100644
index 0000000..6ae6cc8
--- /dev/null
+++ b/src/adapters/index.ts
@@ -0,0 +1 @@
+export * as FileJsonl from './file-jsonl';
diff --git a/src/index.ts b/src/index.ts
index 77d3f65..3d782b2 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,42 +1,48 @@
-import * as KanjidicImpl from './sources/kanjidic';
-import * as JMdictImpl from './sources/jmdict';
-import * as JMnedictImpl from './sources/jmnedict';
-import * as RadKFileImpl from './sources/radkfile';
-import * as KRadFileImpl from './sources/kradfile';
-
-const SUPPORTED_SOURCES = [
-  KanjidicImpl,
-  JMdictImpl,
-  JMnedictImpl,
-  RadKFileImpl,
-  KRadFileImpl,
-] as const;
+import * as SupportedSources from './sources';
+import * as SupportedAdapters from './adapters';
+
+export * as Sources from './sources';
+export * as Adapters from './adapters';
+export * from './streams';
 
 export type CreateDownloaderParams = (
-  KanjidicImpl.CreateDownloaderParams
-  | JMdictImpl.CreateDownloaderParams
-  | JMnedictImpl.CreateDownloaderParams
-  | RadKFileImpl.CreateDownloaderParams
-  | KRadFileImpl.CreateDownloaderParams
+  SupportedSources.Kanjidic.CreateDownloaderParams
+  | SupportedSources.JMdict.CreateDownloaderParams
+  | SupportedSources.JMnedict.CreateDownloaderParams
+  | SupportedSources.RadKFile.CreateDownloaderParams
+  | SupportedSources.KRadFile.CreateDownloaderParams
 );
 
-export * as Kanjidic from './sources/kanjidic';
-export * as JMdict from './sources/jmdict';
-export * as JMnedict from './sources/jmnedict';
-export * as RadKFile from './sources/radkfile';
-export * as KRadFile from './sources/kradfile';
-export * from './streams';
-
 export const createDownloader = (params: CreateDownloaderParams) => {
   const { type: sourceType, ...etcParams } = params;
+  const theSupportedSources = Object.values(SupportedSources);
 
-  const theSourceModule = SUPPORTED_SOURCES
+  const theSourceModule = theSupportedSources
     .find((videoTypeModule) => videoTypeModule.SOURCE_ID === sourceType);
 
   if (!theSourceModule) {
-    const validSourceTypes = SUPPORTED_SOURCES.map((videoTypeModule) => videoTypeModule.SOURCE_ID).join(', ');
+    const validSourceTypes = theSupportedSources.map((videoTypeModule) => videoTypeModule.SOURCE_ID).join(', ');
     throw new TypeError(`Invalid source type: "${sourceType}". Valid values are: ${validSourceTypes}`);
   }
 
   return theSourceModule.createDownloader(etcParams);
 };
+
+export type CreateAdapterParams = (
+  SupportedAdapters.FileJsonl.CreateAdapterParams
+);
+
+export const createAdapter = (params: CreateAdapterParams) => {
+  const { type: adapterType, ...etcParams } = params;
+  const theSupportedAdapters = Object.values(SupportedAdapters);
+
+  const theAdapterModule = theSupportedAdapters
+    .find((adapterTypeModule) => adapterTypeModule.ADAPTER_ID === adapterType);
+
+  if (!theAdapterModule) {
+    const validAdapterTypes = theSupportedAdapters.map((adapterTypeModule) => adapterTypeModule.ADAPTER_ID).join(', ');
+    throw new TypeError(`Invalid adapter type: "${adapterType}". Valid values are: ${validAdapterTypes}`);
+  }
+
+  return theAdapterModule.createAdapter(etcParams);
+};
diff --git a/src/sources/index.ts b/src/sources/index.ts
new file mode 100644
index 0000000..3193012
--- /dev/null
+++ b/src/sources/index.ts
@@ -0,0 +1,5 @@
+export * as Kanjidic from './kanjidic';
+export * as JMdict from './jmdict';
+export * as JMnedict from './jmnedict';
+export * as RadKFile from './radkfile';
+export * as KRadFile from './kradfile';
diff --git a/src/sources/kanjidic/index.ts b/src/sources/kanjidic/index.ts
index c888de8..22fa288 100644
--- a/src/sources/kanjidic/index.ts
+++ b/src/sources/kanjidic/index.ts
@@ -1,3 +1,2 @@
 export * from './common';
 export * from './downloader';
-