diff --git a/.oxfmtrc.json b/.oxfmtrc.json
index 9b946b60..05540aaa 100644
--- a/.oxfmtrc.json
+++ b/.oxfmtrc.json
@@ -7,6 +7,7 @@
     "**/.zig-cache/**",
     "**/zig-pkg/**",
     "packages/core/src/lib/tree-sitter/default-parsers.ts",
-    "packages/web/public/recordings/*.json"
+    "packages/web/public/recordings/*.json",
+    "packages/core/src/lib/stdin-parser.conformance.json"
   ]
 }
diff --git a/packages/core/src/lib/parse.keypress-kitty.test.ts b/packages/core/src/lib/parse.keypress-kitty.test.ts
index bb66bcb0..cd868f48 100644
--- a/packages/core/src/lib/parse.keypress-kitty.test.ts
+++ b/packages/core/src/lib/parse.keypress-kitty.test.ts
@@ -4,6 +4,7 @@ import { parseKeypress, type ParseKeypressOptions } from "./parse.keypress.js"
 test("parseKeypress - Kitty keyboard protocol disabled by default", () => {
   // Kitty sequences should fall back to regular parsing when disabled
   const result = parseKeypress("\x1b[97u")!
+  // 044: pins main; the conformance vectors make an unrecognized CSI sequence a response, not a key.
   expect(result.name).toBe("")
   expect(result.code).toBeUndefined()
 })
@@ -236,6 +237,7 @@ test("parseKeypress - Kitty keyboard invalid codepoint", () => {
   const options: ParseKeypressOptions = { useKittyKeyboard: true }
   const result = parseKeypress("\x1b[1114112u", options)! // Invalid codepoint > 0x10FFFF
   // Should fall back to regular parsing when Kitty fails
+  // 044: pins main; the conformance vectors make an unrecognized CSI sequence a response, not a key.
   expect(result.name).toBe("")
   expect(result.ctrl).toBe(true)
   expect(result.meta).toBe(true)
diff --git a/packages/core/src/lib/parse.mouse.test.ts b/packages/core/src/lib/parse.mouse.test.ts
index 2dc9e008..efb1d7a3 100644
--- a/packages/core/src/lib/parse.mouse.test.ts
+++ b/packages/core/src/lib/parse.mouse.test.ts
@@ -314,6 +314,7 @@ describe("MouseParser SGR mode", () => {
     test("scroll release (m) is not classified as scroll", () => {
       // Some terminals send release for scroll too; the parser should not
       // report that as a scroll event.
+      // 044: pins main; the conformance vectors make a wheel release a response with no mouse event.
       const e = parser.parseMouseEvent(encodeSGR(64, 10, 5, false))!
       expect(e.type).not.toBe("scroll")
     })
diff --git a/packages/core/src/lib/stdin-parser.conformance.json b/packages/core/src/lib/stdin-parser.conformance.json
new file mode 100644
index 00000000..3752cb61
--- /dev/null
+++ b/packages/core/src/lib/stdin-parser.conformance.json
@@ -0,0 +1,51 @@
+{
+  "format": [
+    "Input parser conformance vectors. A row is [name, steps, expected, issue?].",
+    "A step is one read: a string (its UTF-8 bytes), an array of byte values, or null (the Escape timeout passes).",
+    "After the last step the timeout passes once more. The result must not change when each step arrives one byte at a time.",
+    "expected lists every event in order: key(NAME ctrl meta shift release), mouse(TYPE X,Y bBUTTON), response(SEQUENCE), paste(TEXT).",
+    "NAME, SEQUENCE, and TEXT are JSON strings as JavaScript JSON.stringify writes them (C0 controls as lowercase \\u00xx, non-ASCII literal).",
+    "SEQUENCE is the response bytes read as latin1 (one code point per byte); TEXT is the paste bytes read as UTF-8.",
+    "A row with an issue id is wrong on main; its test is a todo until the native port fixes it."
+  ],
+  "rows": [
+    ["ESC + SGR mouse motion", ["\u001b\u001b[<35;10;5M"], ["key(\"escape\")", "mouse(move 9,4 b0)"], "044"],
+    ["ESC, then SGR mouse motion in a 2nd read", ["\u001b", "\u001b[<35;10;5M"], ["key(\"escape\")", "mouse(move 9,4 b0)"], "044"],
+    ["ESC + X10 press", ["\u001b\u001b[M !!"], ["key(\"escape\")", "mouse(down 0,0 b0)"], "044"],
+    ["ESC + Kitty flags reply", ["\u001b\u001b[?1u"], ["key(\"escape\")", "response(\"\\u001b[?1u\")"], "044"],
+    ["ESC + bracketed paste", ["\u001b\u001b[200~hi\u001b[201~"], ["key(\"escape\")", "paste(\"hi\")"], "044"],
+    ["ESC + OSC 11 reply", ["\u001b\u001b]11;rgb:0000/0000/0000\u0007"], ["key(\"escape\")", "response(\"\\u001b]11;rgb:0000/0000/0000\\u0007\")"], "044"],
+    ["ESC + cursor position report", ["\u001b\u001b[12;1R"], ["key(\"escape\")", "response(\"\\u001b[12;1R\")"], "044"],
+    ["ESC + DA1 reply", ["\u001b\u001b[?62;22c"], ["key(\"escape\")", "response(\"\\u001b[?62;22c\")"], "044"],
+    ["ESC + focus-in", ["\u001b\u001b[I"], ["key(\"escape\")", "response(\"\\u001b[I\")"], "044"],
+    ["ESC + Alt+a", ["\u001b\u001ba"], ["key(\"escape\")", "key(\"a\" meta)"], "044"],
+    ["ESC ESC ESC", ["\u001b\u001b\u001b"], ["key(\"escape\")", "key(\"escape\" meta)"], "044"],
+    ["ESC + mouse, ESC + reply", ["\u001b\u001b[<0;1;1M\u001b\u001b[?1u"], ["key(\"escape\")", "mouse(down 0,0 b0)", "key(\"escape\")", "response(\"\\u001b[?1u\")"], "044"],
+    ["ESC + Alt+!", ["\u001b\u001b!"], ["key(\"escape\")", "key(\"!\" meta)"], "044"],
+    ["Alt+.", ["\u001b."], ["key(\".\" meta)"], "044"],
+    ["Alt+/", ["\u001b/"], ["key(\"/\" meta)"], "044"],
+    ["Alt+,", ["\u001b,"], ["key(\",\" meta)"], "044"],
+    ["Alt+;", ["\u001b;"], ["key(\";\" meta)"], "044"],
+    ["Alt+<", ["\u001b<"], ["key(\"<\" meta)"], "044"],
+    ["Alt+>", ["\u001b>"], ["key(\">\" meta)"], "044"],
+    ["Alt+!", ["\u001b!"], ["key(\"!\" meta)"], "044"],
+    ["8-bit Alt+@ (0xC0), then A", [[192, 65]], ["key(\"@\" meta)", "key(\"a\" shift)"], "044"],
+    ["Alt+é", ["\u001bé"], ["key(\"é\" meta)"], "044"],
+    ["Alt+ж", ["\u001bж"], ["key(\"ж\" meta)"], "044"],
+    ["Alt+中", ["\u001b中"], ["key(\"中\" meta)"], "044"],
+    ["SGR wheel-up release", ["\u001b[<64;11;6m"], ["response(\"\\u001b[<64;11;6m\")"], "044"],
+    ["SGR wheel-down release", ["\u001b[<65;11;6m"], ["response(\"\\u001b[<65;11;6m\")"], "044"],
+    ["press, drag, wheel-up, its release, drag", ["\u001b[<0;1;1M\u001b[<32;4;1M\u001b[<64;4;1M\u001b[<64;4;1m\u001b[<32;9;1M"], ["mouse(down 0,0 b0)", "mouse(drag 3,0 b0)", "mouse(scroll 3,0 b0)", "response(\"\\u001b[<64;4;1m\")", "mouse(drag 8,0 b0)"], "044"],
+    ["X10 press at column and row 223 (byte 0)", [[27, 91, 77, 32, 0, 0]], ["mouse(down 223,223 b0)"], "044"],
+    ["X10 report cut short by ESC [ A", ["\u001b[M \u001b[A"], ["response(\"\\u001b[M \")", "key(\"up\")"], "044"],
+    ["OSC string cut short by ESC [ A", ["\u001b]foo\u001b[A"], ["response(\"\\u001b]foo\")", "key(\"up\")"], "044"],
+    ["unrecognized CSI ESC [ < 0 M", ["\u001b[<0M"], ["response(\"\\u001b[<0M\")"], "044"],
+    ["unrecognized CSI ESC [ h", ["\u001b[h"], ["response(\"\\u001b[h\")"], "044"],
+    ["SGR mouse motion", ["\u001b[<35;10;5M"], ["mouse(move 9,4 b0)"]],
+    ["Alt+a", ["\u001ba"], ["key(\"a\" meta)"]],
+    ["ESC ESC (Alt+Escape)", ["\u001b\u001b"], ["key(\"escape\" meta)"]],
+    ["ESC ESC [A (Alt+Up)", ["\u001b\u001b[A"], ["key(\"up\" meta)"]],
+    ["ESC, timeout, ESC, timeout, ESC", ["\u001b", null, "\u001b", null, "\u001b"], ["key(\"escape\")", "key(\"escape\")", "key(\"escape\")"]],
+    ["ESC, timeout, SGR wheel-up without ESC", ["\u001b", null, "[<64;38;15M"], ["key(\"escape\")", "mouse(scroll 37,14 b0)"]]
+  ]
+}
diff --git a/packages/core/src/lib/stdin-parser.test.ts b/packages/core/src/lib/stdin-parser.test.ts
index 15c9f66f..06141cf3 100644
--- a/packages/core/src/lib/stdin-parser.test.ts
+++ b/packages/core/src/lib/stdin-parser.test.ts
@@ -4,6 +4,7 @@ import { ManualClock } from "../testing/manual-clock.js"
 import type { Clock, TimerHandle } from "./clock.js"
 import type { ScrollInfo } from "./parse.mouse.js"
 import { StdinParser, type StdinEvent, type StdinParserOptions } from "./stdin-parser.js"
+import conformance from "./stdin-parser.conformance.json" with { type: "json" }
 
 type KeySnap = {
   type: "key"
@@ -172,6 +173,43 @@ function assertChunkInvariant(input: Uint8Array, opts?: StdinParserOptions) {
   }
 }
 
+// Conformance vectors for the native parser port (issue 044); the JSON file's `format` field defines them.
+// `bun test --todo src/lib/stdin-parser.test.ts` also runs the todo rows: a todo row that passes fails that run,
+// so remove its issue id once the port fixes it.
+type ConformanceRow = [name: string, steps: Array<string | number[] | null>, expected: string[], issue?: string]
+const CONFORMANCE = conformance.rows as ConformanceRow[]
+
+function notation(event: Snap): string {
+  switch (event.type) {
+    case "key": {
+      const flags = (["ctrl", "meta", "shift"] as const).filter((flag) => event[flag]).map((flag) => ` ${flag}`)
+      const kind = event.eventType === "press" ? "" : ` ${event.eventType}`
+      return `key(${JSON.stringify(event.name)}${flags.join("")}${kind})`
+    }
+    case "mouse":
+      return `mouse(${event.event.type} ${event.event.x},${event.event.y} b${event.event.button})`
+    case "response":
+      return `response(${JSON.stringify(event.sequence)})`
+    case "paste":
+      return `paste(${JSON.stringify(Buffer.from(event.bytes).toString())})`
+  }
+}
+
+function runConformance(steps: ConformanceRow[1]): string[] {
+  const { parser, clock } = createTimedParser()
+  const out: string[] = []
+  try {
+    for (const step of [...steps, null]) {
+      if (step === null) clock.advance(TEST_TIMEOUT_MS)
+      else parser.push(buf(step))
+      out.push(...snap(parser).map(notation))
+    }
+    return out
+  } finally {
+    parser.destroy()
+  }
+}
+
 describe("StdinParser", () => {
   describe("printable ASCII", () => {
     test("lowercase a-z", () => {
@@ -2101,25 +2139,6 @@ describe("StdinParser", () => {
       }
     })
 
-    test("multiple sequential timeouts", () => {
-      const { parser, clock } = createTimedParser()
-      try {
-        parser.push(Buffer.from("\x1b"))
-        clock.advance(10)
-        expect(snap(parser)).toEqual([k("escape", { raw: "\x1b" })])
-
-        parser.push(Buffer.from("\x1b"))
-        clock.advance(10)
-        expect(snap(parser)).toEqual([k("escape", { raw: "\x1b" })])
-
-        parser.push(Buffer.from("\x1b"))
-        clock.advance(10)
-        expect(snap(parser)).toEqual([k("escape", { raw: "\x1b" })])
-      } finally {
-        parser.destroy()
-      }
-    })
-
     test("custom timeout delay", () => {
       const { parser, clock } = createTimedParser({ timeoutMs: 50 })
       try {
@@ -2490,6 +2509,7 @@ describe("StdinParser", () => {
       }
     })
 
+    // The first, second, and fourth rows pin behavior on main that the 044 conformance vectors replace.
     table([
       ["CSI with unknown final byte produces empty-name key", "\x1b[h", [k("", { raw: "\x1b[h" })]],
       ["ESC followed by punctuation stays one empty-name key", "\x1b!", [k("", { raw: "\x1b!" })]],
@@ -2523,6 +2543,18 @@ describe("StdinParser", () => {
     })
   })
 
+  describe("conformance vectors", () => {
+    for (const [name, steps, expected, issue] of CONFORMANCE) {
+      const bytewise = steps.flatMap((step) => (step === null ? [null] : Array.from(buf(step), (byte) => [byte])))
+      const run = () => {
+        expect(runConformance(steps)).toEqual(expected)
+        expect(runConformance(bytewise)).toEqual(expected)
+      }
+      if (issue) test.todo(`${name} (${issue})`, run)
+      else test(name, run)
+    }
+  })
+
   describe("timer/clock disagreement race condition", () => {
     test("timeout callback flushes even when now() reports slightly less elapsed time than timeoutMs", () => {
       const inner = new ManualClock()