tawasuyu/brahman

- Daemon escribe append-only a $XDG_STATE_HOME/shipote/audit.log además
  del tracing. Single-line: ts=<ms> uid=<peer> action=<verb> <detail>.
  Rotación simple a .log.1 al pasar 1 MiB.
- shipote-gateway: TCP listener 127.0.0.1:7378 default. POST /rpc traduce
  JSON ↔ postcard contra daemon socket. GET / health text. HTTP parser
  ad-hoc (~70 LOC), sin dep de hyper/axum. Sin auth — bind a localhost
  + SHIPOTE_TRUST_ANYONE=1 en prod.

E2E: curl --noproxy '*' POST /rpc → "Pong", Health JSON, Capabilities
JSON. Audit log persiste mutaciones con uid del peer.

85 tests pasan (features nuevos son binarios, no library mods).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

diff --git a/Cargo.lock b/Cargo.lock
index 1d597cc..a0f255d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -9661,6 +9661,18 @@ dependencies = [
  "toml 0.8.23",
 ]
 
+[[package]]
+name = "shipote-gateway"
+version = "0.1.0"
+dependencies = [
+ "anyhow",
+ "serde_json",
+ "shipote-protocol",
+ "tokio",
+ "tracing",
+ "tracing-subscriber",
+]
+
 [[package]]
 name = "shipote-protocol"
 version = "0.1.0"
diff --git a/Cargo.toml b/Cargo.toml
index 11e2a1d..454787c 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -109,6 +109,7 @@ members = [
     "crates/apps/brahman-demo",
     "crates/apps/shipote-daemon",
     "crates/apps/shipote-cli",
+    "crates/apps/shipote-gateway",
     "crates/apps/shipote-shell",
 ]
 
diff --git a/crates/apps/shipote-daemon/src/main.rs b/crates/apps/shipote-daemon/src/main.rs
index 5709b64..d4fa0b6 100644
--- a/crates/apps/shipote-daemon/src/main.rs
+++ b/crates/apps/shipote-daemon/src/main.rs
@@ -297,6 +297,44 @@ async fn handle_client(
     }
 }
 
+/// Path canónico del audit log: `$XDG_STATE_HOME/shipote/audit.log` o
+/// fallback `$HOME/.local/state/shipote/audit.log`.
+fn default_audit_log_path() -> std::path::PathBuf {
+    if let Ok(state) = std::env::var("XDG_STATE_HOME") {
+        return std::path::PathBuf::from(state).join("shipote/audit.log");
+    }
+    if let Ok(home) = std::env::var("HOME") {
+        return std::path::PathBuf::from(home).join(".local/state/shipote/audit.log");
+    }
+    std::path::PathBuf::from("/tmp/shipote-audit.log")
+}
+
+/// Cap del audit log antes de rotar a `audit.log.1`. 1 MiB.
+const AUDIT_LOG_MAX_BYTES: u64 = 1 << 20;
+
+/// Append + rotate (mueve a `.1` si supera el cap). Append-only, sin
+/// reordenar. Sync: cada line, fsync no — el log es defensive, no
+/// transactional.
+fn append_audit_line(path: &std::path::Path, line: &str) -> std::io::Result<()> {
+    use std::io::Write;
+    // Rotar si pasa el cap.
+    if let Ok(meta) = std::fs::metadata(path) {
+        if meta.len() >= AUDIT_LOG_MAX_BYTES {
+            let rotated = path.with_extension("log.1");
+            let _ = std::fs::rename(path, &rotated);
+        }
+    }
+    if let Some(parent) = path.parent() {
+        let _ = std::fs::create_dir_all(parent);
+    }
+    let mut f = std::fs::OpenOptions::new()
+        .create(true)
+        .append(true)
+        .open(path)?;
+    writeln!(f, "{line}")?;
+    Ok(())
+}
+
 /// Loguea cada mutación con target="audit" y el peer uid. Reads (ping,
 /// list, stats) se omiten para no inundar el log.
 fn audit_request(peer_uid: u32, req: &Request) {
@@ -330,6 +368,17 @@ fn audit_request(peer_uid: u32, req: &Request) {
         | Request::Capabilities => return,
     };
     info!(target: "audit", uid = peer_uid, action, detail = %detail, "audit");
+    // Append a file. Failure no es fatal — sólo se pierde la entry.
+    let ts = std::time::SystemTime::now()
+        .duration_since(std::time::UNIX_EPOCH)
+        .map(|d| d.as_millis())
+        .unwrap_or(0);
+    let line = format!("ts={ts} uid={peer_uid} action={action} {detail}");
+    let path = default_audit_log_path();
+    if let Err(e) = append_audit_line(&path, &line) {
+        // Sólo loguear si el filesystem está roto. No reportar al cliente.
+        tracing::debug!(?e, path = %path.display(), "audit file write failed");
+    }
 }
 
 async fn dispatch(
diff --git a/crates/apps/shipote-gateway/Cargo.toml b/crates/apps/shipote-gateway/Cargo.toml
new file mode 100644
index 0000000..8a10a91
--- /dev/null
+++ b/crates/apps/shipote-gateway/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+name = "shipote-gateway"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+authors.workspace = true
+publish.workspace = true
+description = "HTTP/JSON gateway para shipote — traduce JSON ↔ postcard contra el admin socket."
+
+[[bin]]
+name = "shipote-gateway"
+path = "src/main.rs"
+
+[dependencies]
+shipote-protocol = { path = "../../modules/shipote/shipote-protocol" }
+anyhow = { workspace = true }
+serde_json = { workspace = true }
+tokio = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true }
diff --git a/crates/apps/shipote-gateway/src/main.rs b/crates/apps/shipote-gateway/src/main.rs
new file mode 100644
index 0000000..77a00d8
--- /dev/null
+++ b/crates/apps/shipote-gateway/src/main.rs
@@ -0,0 +1,168 @@
+//! `shipote-gateway` — HTTP/JSON adapter para el daemon.
+//!
+//! Acepta `POST /rpc` con body JSON serializado como `shipote_protocol::Request`,
+//! hace round-trip al admin socket via postcard, devuelve `Response` como JSON.
+//!
+//! Diseñado para clients no-Rust (curl, Python, web app) que no pueden
+//! hablar postcard directo. NO es un proxy completo — sólo translation
+//! layer del protocolo.
+//!
+//! Sin dep de axum/hyper: HTTP parser ad-hoc, suficiente para 1 endpoint.
+
+use shipote_protocol::{default_socket_path, read_frame, write_frame, Request, Response};
+use std::sync::Arc;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::{TcpListener, TcpStream, UnixStream};
+use tracing::{info, warn};
+
+const DEFAULT_LISTEN: &str = "127.0.0.1:7378";
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    init_tracing();
+    let listen = std::env::var("SHIPOTE_GATEWAY_LISTEN").unwrap_or_else(|_| DEFAULT_LISTEN.into());
+    let daemon_sock = Arc::new(default_socket_path());
+    let listener = TcpListener::bind(&listen).await?;
+    info!(listen = %listen, daemon = %daemon_sock.display(), "shipote-gateway listening");
+
+    loop {
+        match listener.accept().await {
+            Ok((stream, peer)) => {
+                let sock = daemon_sock.clone();
+                tokio::spawn(async move {
+                    if let Err(e) = handle_http(stream, sock).await {
+                        warn!(?e, ?peer, "request error");
+                    }
+                });
+            }
+            Err(e) => {
+                warn!(?e, "accept failed");
+                tokio::time::sleep(std::time::Duration::from_millis(100)).await;
+            }
+        }
+    }
+}
+
+async fn handle_http(mut stream: TcpStream, daemon_sock: Arc<std::path::PathBuf>) -> anyhow::Result<()> {
+    // Parser HTTP mínimo: read hasta `\r\n\r\n`, parsear request line +
+    // Content-Length, después leer body exacto.
+    let mut buf = Vec::with_capacity(4096);
+    let mut tmp = [0u8; 4096];
+    let header_end;
+    loop {
+        let n = stream.read(&mut tmp).await?;
+        if n == 0 {
+            return Ok(()); // closed
+        }
+        buf.extend_from_slice(&tmp[..n]);
+        if let Some(pos) = find_double_crlf(&buf) {
+            header_end = pos + 4;
+            break;
+        }
+        if buf.len() > 64 * 1024 {
+            return write_error(&mut stream, 413, "headers too large").await;
+        }
+    }
+
+    let header_str = std::str::from_utf8(&buf[..header_end - 4])?;
+    let mut lines = header_str.lines();
+    let request_line = lines.next().unwrap_or("");
+    let mut parts = request_line.split_whitespace();
+    let method = parts.next().unwrap_or("");
+    let path = parts.next().unwrap_or("");
+    let mut content_length: usize = 0;
+    for line in lines {
+        if let Some(v) = line.strip_prefix("Content-Length:").or_else(|| line.strip_prefix("content-length:")) {
+            content_length = v.trim().parse().unwrap_or(0);
+        }
+    }
+
+    // Rutas:
+    if method == "GET" && (path == "/" || path == "/health") {
+        return write_text(&mut stream, 200, "shipote-gateway ok\n").await;
+    }
+    if method != "POST" || path != "/rpc" {
+        return write_error(&mut stream, 404, "use POST /rpc").await;
+    }
+
+    // Leer body.
+    let mut body = buf[header_end..].to_vec();
+    while body.len() < content_length {
+        let n = stream.read(&mut tmp).await?;
+        if n == 0 {
+            break;
+        }
+        body.extend_from_slice(&tmp[..n]);
+    }
+    body.truncate(content_length);
+
+    // Parsear JSON → Request.
+    let req: Request = match serde_json::from_slice(&body) {
+        Ok(r) => r,
+        Err(e) => return write_error(&mut stream, 400, &format!("bad json: {e}")).await,
+    };
+
+    // Round-trip al daemon.
+    let resp = match round_trip_daemon(&daemon_sock, &req).await {
+        Ok(r) => r,
+        Err(e) => return write_error(&mut stream, 502, &format!("daemon: {e}")).await,
+    };
+
+    // Serializar Response → JSON.
+    let body_json = serde_json::to_vec(&resp)?;
+    write_response(&mut stream, 200, "application/json", &body_json).await
+}
+
+async fn round_trip_daemon(sock: &std::path::Path, req: &Request) -> anyhow::Result<Response> {
+    let mut stream = UnixStream::connect(sock).await?;
+    write_frame(&mut stream, req).await?;
+    let resp: Response = read_frame(&mut stream).await?;
+    Ok(resp)
+}
+
+fn find_double_crlf(buf: &[u8]) -> Option<usize> {
+    buf.windows(4).position(|w| w == b"\r\n\r\n")
+}
+
+async fn write_response(
+    stream: &mut TcpStream,
+    code: u16,
+    content_type: &str,
+    body: &[u8],
+) -> anyhow::Result<()> {
+    let status = match code {
+        200 => "OK",
+        400 => "Bad Request",
+        404 => "Not Found",
+        413 => "Payload Too Large",
+        502 => "Bad Gateway",
+        _ => "Unknown",
+    };
+    let head = format!(
+        "HTTP/1.1 {code} {status}\r\n\
+         Content-Type: {content_type}\r\n\
+         Content-Length: {}\r\n\
+         Connection: close\r\n\
+         \r\n",
+        body.len()
+    );
+    stream.write_all(head.as_bytes()).await?;
+    stream.write_all(body).await?;
+    stream.flush().await?;
+    Ok(())
+}
+
+async fn write_text(stream: &mut TcpStream, code: u16, body: &str) -> anyhow::Result<()> {
+    write_response(stream, code, "text/plain", body.as_bytes()).await
+}
+
+async fn write_error(stream: &mut TcpStream, code: u16, msg: &str) -> anyhow::Result<()> {
+    let body = serde_json::json!({ "error": msg }).to_string();
+    write_response(stream, code, "application/json", body.as_bytes()).await
+}
+
+fn init_tracing() {
+    use tracing_subscriber::{fmt, EnvFilter};
+    let filter = EnvFilter::try_from_env("SHIPOTE_GATEWAY_LOG").unwrap_or_else(|_| EnvFilter::new("info"));
+    fmt().with_env_filter(filter).init();
+}
diff --git a/crates/modules/shipote/docs/ARCHITECTURE.md b/crates/modules/shipote/docs/ARCHITECTURE.md
index f4f4781..ced31d7 100644
--- a/crates/modules/shipote/docs/ARCHITECTURE.md
+++ b/crates/modules/shipote/docs/ARCHITECTURE.md
@@ -67,6 +67,7 @@
 - **`crates/apps/shipote-daemon`** — long-running. Escucha admin socket, ejecuta el dispatch, reaper periódico.
 - **`crates/apps/shipote-cli`** — `shipote` (clap). Para administración + scripting.
 - **`crates/apps/shipote-shell`** — GUI con `yahweh_launcher`. Dashboard: estado, workspaces, comandos, flows, quotas, sparkline.
+- **`crates/apps/shipote-gateway`** — HTTP/JSON adapter. `POST /rpc` con body JSON `Request` → traduce a postcard, round-trip al daemon, retorna JSON. Default `127.0.0.1:7378`.
 
 ### Consumidores del discerner (externos a shipote pero usándolo)
 - **`crates/modules/ui_engine/libs/providers/fs`** — `FileDataProvider` ahora puebla `mime_type` con `DiscernPipeline`.