@browsercore/http2

HTTP/2 framing over any duplex byte stream.

Responsibility

Frame parsing/serialization, HPACK header compression, stream lifecycle management, flow control (connection + stream level), SETTINGS exchange, GOAWAY graceful shutdown, PING, and PUSH_PROMISE handling. The package knows nothing about the underlying transport — it could be plain TCP, TLS, a pipe, or a test double.

What it does NOT know about

• TLS / ALPN
• TCP, DNS, or sockets
• HTTP/1.1
• Browser fingerprints

Public API

import { connectHttp2, GoawayReceivedError } from "@browsercore/http2";

const conn = await connectHttp2({
    transport,
    events,
    initialSettings: { ENABLE_PUSH: 0 },
});

const res = await conn.request({
    method: "GET",
    scheme: "https",
    authority: "example.com",
    path: "/index.html",
    headers: new Map([["accept", "text/html"]]),
    body: undefined,
});

console.log(res.statusCode, res.body);
await conn.ping();
await conn.close();

Types

| Export | Kind | Purpose | | --- | --- | --- | | Http2Connection | interface | Public contract higher layers depend on | | connectHttp2() | function | Wrap a transport with HTTP/2 | | Frame | discriminated union | Every HTTP/2 frame variant | | FrameType | const object | RFC 7540 frame type ids | | StreamState | discriminated union | RFC 7540 §5.1 states | | FlowControlWindow | interface | Per-stream/connection send window | | Http2Error | class | Base typed error | | GoawayReceivedError | class | Peer sent GOAWAY | | RstStreamError | class | Peer reset a stream | | FlowControlError | class | Send exceeded window | | FrameParseError | class | Malformed frame | | SettingsAckTimeoutError | class | SETTINGS ACK timed out | | HpackEncoderOptions | interface | HPACK encoder config (table size, Huffman toggle) | | EncodeHeadersOptions | interface | encodeHeaders() options (indexing, Huffman, table size) | | PriorityFrameSpec | interface | PRIORITY frame spec for preface sequencing | | generateHttp2GreaseValue() | function | RFC 8701 GREASE value generator (0x?a?a pattern) |

Browser impersonation

connectHttp2() accepts impersonation options that control every ordering vector in the HTTP/2 wire fingerprint:

await connectHttp2({
    transport,
    crypto,
    // SETTINGS frame: explicit id order + optional GREASE
    settingsOrder: [0x1, 0x3, 0x4, 0x5, 0x6],
    settingsGrease: true,
    // Connection-level WINDOW_UPDATE (Chrome sends one early)
    connectionWindowUpdate: 1_572_864,
    // PRIORITY frames for dependency tree setup
    priorityFrames: [
        { streamId: ID(3), streamDependency: ID(0), exclusive: false, weight: 255 },
    ],
    // Pseudo-header order in request HEADERS frames
    pseudoHeaderOrder: [":method", ":authority", ":scheme", ":path"],
    // Regular header order in request HEADERS frames
    headerOrder: ["cookie", "accept", "user-agent"],
    // HPACK encoder configuration
    hpackMaxTableSize: 4096,
    hpackHuffman: true,
    hpackIndexing: false,
});

Dependency graph

@browsercore/http2
  ├─ @browsercore/transport
  │     └─ node:net / node:dns / node:crypto
  └─ @browsercore/contracts

@browsercore/contracts supplies the EventProvider interface the package implements (injected, never imported from a concrete node:events backend). No other @browsercore/* packages are imported.

Position in BrowserCore

Application
      │
   @browsercore/http2
      │
   @browsercore/tls
      │
@browsercore/transport
      │
     TCP

Every higher networking layer communicates with the network exclusively through the layers below it.