diff --git a/src/server/index.ts b/src/server/index.ts
index f281ceb..fc139ce 100644
--- a/src/server/index.ts
+++ b/src/server/index.ts
@@ -87,7 +87,7 @@ apiRouter.loadAPIMethods().then(() => {
     console.log("API OK!")
 
     // moved here to ensure it's matched last
-    app.get("/:fileId", (ctx) => app.fetch(ctx.req.raw, ctx.env, ctx.executionCtx))
+    app.get("/:fileId", async (ctx) => app.fetch(ctx.req.raw, ctx.env))
 
     // listen on 3000 or MONOFILE_PORT
     // moved here to prevent a crash if someone manages to access monofile before api routes are mounted
diff --git a/src/server/lib/files.ts b/src/server/lib/files.ts
index 09b8aef..207a00f 100644
--- a/src/server/lib/files.ts
+++ b/src/server/lib/files.ts
@@ -70,6 +70,8 @@ export interface FilePointer {
     visibility?: FileVisibility
     reserved?: boolean
     chunkSize?: number
+    lastModified?: number
+    md5?: string
 }
 
 export interface StatusCodeError {
@@ -315,6 +317,8 @@ export class UploadStream extends Writable {
 
     error?: Error
 
+    hash: crypto.Hash = crypto.createHash("md5")
+
     constructor(files: Files, owner?: string) {
         super()
         this.owner = owner
@@ -328,6 +332,8 @@ export class UploadStream extends Writable {
         if (this.filled + data.byteLength > (this.files.config.maxDiscordFileSize*this.files.config.maxDiscordFiles))
             return this.destroy(new WebError(413, "maximum file size exceeded"))
 
+        this.hash.update(data)
+
         // cut up the buffer into message sized chunks
 
         let position = 0
@@ -431,7 +437,10 @@ export class UploadStream extends Writable {
             // so that json.stringify doesnt include tag:undefined
             ...((ogf||{}).tag ? {tag:ogf.tag} : {}),
 
-            chunkSize: this.files.config.maxDiscordFileSize
+            chunkSize: this.files.config.maxDiscordFileSize,
+
+            md5: this.hash.digest("hex"),
+            lastModified: Date.now()
         }
 
         delete this.files.locks[this.uploadId!]
diff --git a/src/server/routes/api/v0/primaryApi.ts b/src/server/routes/api/v0/primaryApi.ts
index 4bb3726..1dfe106 100644
--- a/src/server/routes/api/v0/primaryApi.ts
+++ b/src/server/routes/api/v0/primaryApi.ts
@@ -32,6 +32,8 @@ export default function (files: Files) {
             ctx.header("Access-Control-Allow-Origin", "*")
             ctx.header("Content-Security-Policy", "sandbox allow-scripts")
             ctx.header("Content-Disposition", `${ctx.req.query("attachment") == "1" ? "attachment" : "inline"}; filename="${encodeURI(file.filename.replaceAll("\n","\\n"))}"`)
+            ctx.header("ETag", file.md5)
+            //if (file.lastModified) ctx.header("Last-Modified", new Date(file.lastModified).toTimeString())
 
             if (file) {
                 if (file.visibility == "private") {