fix: label TLS-backend timeouts ServerTimeoutError, flatten noble multi headers, ValueError on unknown profile (v0.1.5)

Both backends' asyncio.TimeoutError except-branch was dead code (neither curl_cffi
nor noble_tls raises it), so a real wire timeout fell through to the generic OSError
branch and got mislabeled a plain aiohttp.ClientError instead of aioweb's own
ServerTimeoutError contract; now detected via curl_cffi's Timeout type or Go-side
timeout text and re-wrapped correctly. Noble's multi-valued response headers (e.g.
two Set-Cookie lines) arrived as Python lists instead of strings, breaking any
downstream .split()/.lower() call; now comma-joined per RFC 7230. An unknown Noble
client profile string raised a raw AttributeError from the enum lookup; now a
ValueError listing the valid profile names. Also compresses essay-length docstrings
and narrating comments across the module with no behavior change.

Signed-off-by: disqualifier <dev@disqualifier.me>

.gitignore

@@ -1,5 +1,5 @@
 # claude
-CLAUDE.md
+.claude/
 
 # python
 __pycache__/

README.md

@@ -22,17 +22,17 @@ you want; importing the package never fails because an extra is missing.
 `requirements.txt` (pick the extra you need):
 
 ```
-aioweb_tls[curl]  @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.0
-aioweb_tls[noble] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.0
-aioweb_tls[all]   @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.0
+aioweb_tls[curl]  @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.5
+aioweb_tls[noble] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.5
+aioweb_tls[all]   @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.5
 ```
 
 Direct:
 
 ```bash
-pip install "aioweb_tls[curl] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.0"
-pip install "aioweb_tls[noble] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.0"
-pip install "aioweb_tls[all] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.0"
+pip install "aioweb_tls[curl] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.5"
+pip install "aioweb_tls[noble] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.5"
+pip install "aioweb_tls[all] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb_tls.git@v0.1.5"
 ```
 
 - `[curl]` → curl_cffi backend · `[noble]` → noble_tls backend · `[all]` → both.
@@ -44,6 +44,8 @@ pip install "aioweb_tls[all] @ git+ssh://git@git.rethinkstudios.io/rethink-publi
 Constructing a backend whose client isn't installed raises that `RuntimeError` at
 construction, never at import.
 
+Drop the `@v0.1.5` suffix from the line above to install the latest unpinned.
+
 ## curl_cffi backend
 
 ```python
@@ -55,9 +57,16 @@ async with TLSSession(backend=CurlCffi(impersonate="chrome"), proxies={"https":
         print(resp.json()["tls"]["ja3"])
 ```
 
-- `CurlCffi(impersonate="chrome")` sets the forged profile; override per call by
-  passing `impersonate=` to any request method.
+- `CurlCffi(impersonate="chrome")` sets the forged profile; override it per call by
+  passing `impersonate=` to the low-level `request()` (which forwards `**kwargs` to the
+  backend). `request_with_retries` has a fixed signature and does **not** accept extra
+  backend kwargs — passing `impersonate=` there raises `TypeError`; set the profile on
+  the `CurlCffi` instance for the retrying path.
 - curl_cffi forges JA3/JA4 + HTTP/2 fingerprints via the bundled curl-impersonate binary.
+- A wire-level timeout raises `aiohttp.ServerTimeoutError` (matching aioweb's own
+  contract), not a generic `aiohttp.ClientError` — both backends detect their
+  native timeout (curl_cffi's `Timeout` type, noble_tls's Go-side timeout text) and
+  re-wrap it before the fallback client-error path (v0.1.5).
 
 ## noble backend
 
@@ -71,10 +80,20 @@ async with TLSSession(backend=Noble(client="chrome_133")) as s:
         print(resp.json()["tls"]["ja3"])
 ```
 
-- `Noble(client="chrome_133")` — accepts a `noble_tls.Client` enum or a string name.
+- `Noble(client="chrome_133")` — accepts a `noble_tls.Client` enum or a string name;
+  an unknown string raises `ValueError` listing the valid profile names (v0.1.5).
 - noble_tls downloads a Go shared library on first use. `await s.setup()` fetches it
-  once at startup; if you skip it, the first request fetches it lazily (guarded to run
-  once).
+  once at startup; if you skip it, the first request fetches it lazily. The fetch is
+  guarded by a lock, so even concurrent first requests download it exactly once.
+- Binary bodies (images, zips, PDFs, protobuf) round-trip as true bytes: noble_tls
+  returns response bodies as a UTF-8 JSON string by default, which mangles non-UTF-8
+  bytes (`U+FFFD` replacement, wrong length) even on a 200 response — the Noble
+  backend always requests `is_byte_response=True` and decodes the resulting
+  base64 data-URI back into raw bytes, so `resp.content` is never lossy.
+- Multi-valued response headers (e.g. two `Set-Cookie` lines) arrive from noble_tls's
+  Go side as a Python list — the Noble backend flattens them to a single
+  comma-joined string per RFC 7230, so `resp.headers[...]` is always a plain string
+  (v0.1.5).
 
 ## Writing your own backend (the `TLSBackend` protocol)
 
@@ -94,6 +113,9 @@ for the authoritative contract):
 | `raw_request` | **required** | `async (session, method, url, **kwargs) -> aioweb.Response` | send one request; adapt the client's response into an `aioweb.Response` |
 | `is_closed` | **required** | `(session) -> bool` | whether the session is closed |
 | `cookies_for_url` | optional | `(session, url) -> dict` | cookies for `preview()`; defaults to `{}` |
+| `set_cookie` | optional | `(session, name, value, domain=None, path="/") -> None` | backs `TLSSession.set_cookie()`; raises `NotImplementedError` if absent |
+| `get_cookies` | optional | `(session) -> dict` | backs `TLSSession.get_cookies()`; raises `NotImplementedError` if absent |
+| `clear_cookies` | optional | `(session) -> None` | backs `TLSSession.clear_cookies()`; raises `NotImplementedError` if absent |
 | `setup` | optional | `async () -> None` | one-time prep (e.g. fetch a native lib); idempotent |
 | `close` | optional | `async (session) -> None` | close the session; defaults to `await session.close()` |
 
@@ -151,8 +173,9 @@ async with TLSSession(backend=GoTLSBackend("http://localhost:8080")) as s:
 ## Inherited features work unchanged
 
 aioweb's overwrite/domain/ephemeral/proxy/retry/preview logic operates on plain dicts
-and never touches the HTTP backend — only the seams do. Every aioweb feature behaves
-identically on any backend:
+and never touches the HTTP backend — only the seams do. Header overwrites, domain
+rewriting, ephemeral headers, proxies, retries, and previews behave identically on
+any backend:
 
 ```python
 async with TLSSession(backend=CurlCffi(impersonate="chrome")) as s:
@@ -162,6 +185,19 @@ async with TLSSession(backend=CurlCffi(impersonate="chrome")) as s:
     print(s.preview("GET", "https://internal.local/x").as_curl())   # reflects all of the above
 ```
 
+Session-default headers are never baked into the underlying client (neither
+`CurlCffi` nor `Noble` passes `headers=` to their client's constructor) — they flow
+through aioweb's own per-request `_default_headers` merge instead. That keeps
+`update_headers()` / `clear_headers()` accurate for both backends: what
+`get_headers()` and `preview()` report is what actually goes out on the wire, with
+no stale, already-baked value resurfacing after a clear.
+
+The mutable cookie API — `set_cookie()` / `get_cookies()` / `clear_cookies()` — is
+also backend-aware: `CurlCffi` and `Noble` each route it through their own client's
+cookie store (both expose a `requests`-style `session.cookies` with `set()` /
+`items()` / `clear()`), so these calls work the same way they do on the base
+`aioweb.ExtendedSession`, not just `_cookies_for_url()` (used by `preview()`).
+
 ## Honesty note
 
 TLS fingerprinting changes one layer — the TLS/HTTP fingerprint. It does **not** by
@@ -170,4 +206,4 @@ are separate signals. Use this as one component, not a complete anti-bot solutio
 
 ## Versioning
 
-Tagged `vX.Y.Z`. Pin the tag in `requirements.txt`.
+Releases are tagged `vX.Y.Z`. The install line above pins a release; drop the `@vX.Y.Z` suffix to install the latest unpinned. Pin deliberately for reproducible installs.

pyproject.toml

@@ -0,0 +1,23 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "aioweb_tls"
+version = "0.1.5"
+description = "TLS-fingerprinting backends (curl_cffi / noble_tls) for aioweb via one injectable TLSSession, config-free, installable."
+requires-python = ">=3.10"
+dependencies = [
+    "aioweb @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioweb.git@v0.1.5",
+]
+
+[project.optional-dependencies]
+curl = ["curl_cffi>=0.15"]
+noble = ["noble-tls>=0.1.5"]
+all = ["curl_cffi>=0.15", "noble-tls>=0.1.5"]
+
+[tool.hatch.build.targets.wheel]
+packages = ["src/aioweb_tls"]
+
+[tool.hatch.metadata]
+allow-direct-references = true

src/aioweb_tls/__init__.py

@@ -0,0 +1,28 @@
+"""
+tls-fingerprinting backends for aioweb
+
+one session class, TLSSession, takes an injected backend that swaps the HTTP client
+(and thus the TLS/HTTP fingerprint) while inheriting every aioweb feature — header
+overwrites, domain rewriting, ephemeral headers, proxies, retries, previews —
+unchanged.
+
+    from aioweb_tls import TLSSession, CurlCffi, Noble
+
+    async with TLSSession(backend=CurlCffi(impersonate="chrome")) as s:   # [curl] extra
+        resp = await s.request_with_retries("GET", url)
+
+    async with TLSSession(backend=Noble(client="chrome_133")) as s:       # [noble] extra
+        await s.setup()                                                   # fetch Go lib once
+        resp = await s.request_with_retries("GET", url)
+
+the tls clients are optional extras, not base deps. importing this package never
+fails because an extra is missing; the matching RuntimeError is raised only when you
+construct a backend whose client isn't installed. custom backends implement the
+TLSBackend protocol and inject the same way.
+"""
+
+from .session import TLSSession
+from .backends import CurlCffi, Noble
+from .protocol import TLSBackend
+
+__all__ = ["TLSSession", "CurlCffi", "Noble", "TLSBackend"]

src/aioweb_tls/backends.py

@@ -0,0 +1,394 @@
+"""
+tls backends for TLSSession
+
+each backend is a stateless config+behavior object implementing the TLSBackend
+protocol (see protocol.py). it owns its own config vocabulary — CurlCffi takes
+impersonate=, Noble takes client= — so there is no shared kwarg-soup. TLSSession
+owns the live session object and passes it into every method here.
+
+the underlying tls clients are optional extras: constructing a backend whose client
+is not installed raises a clear RuntimeError naming the extra to install. importing
+this module never fails because an extra is missing.
+"""
+
+import asyncio
+import base64
+import logging
+import math
+
+import aiohttp
+from aioweb import Response
+
+log = logging.getLogger(__name__)
+
+
+def _as_client_error(error: Exception, backend: str) -> aiohttp.ClientError:
+    """wrap a backend-native network exception as an aiohttp.ClientError
+
+    curl_cffi raises RequestException(OSError), noble_tls raises
+    TLSClientException(IOError) — neither is an aiohttp.ClientError, which is all
+    aioweb's request() re-wraps; translating here gives both the same typed contract.
+    """
+    return aiohttp.ClientError(f"{backend} request failed: {error}")
+
+
+_TIMEOUT_TEXT = ("timeout", "timed out", "deadline exceeded")
+
+
+def _is_timeout_error(error: Exception) -> bool:
+    """whether a backend-native network error is a timeout
+
+    neither backend raises asyncio.TimeoutError for a wire timeout: curl_cffi's own
+    Timeout and noble_tls's Go-side TLSClientException are both plain OSError
+    subclasses with no dedicated timeout type — check curl_cffi's Timeout class by
+    name first (precise), then fall back to matching the error text (covers
+    noble_tls's Go messages, e.g. "context deadline exceeded").
+    """
+    timeout_type = getattr(error, "__class__", None)
+    if timeout_type is not None and any(base.__name__ == "Timeout" for base in timeout_type.__mro__):
+        return True
+    return any(needle in str(error).lower() for needle in _TIMEOUT_TEXT)
+
+
+def _as_timeout_error(error: Exception, backend: str) -> aiohttp.ServerTimeoutError:
+    """wrap a backend-native timeout as aiohttp.ServerTimeoutError
+
+    matches aioweb's own contract (a total timeout raises ServerTimeoutError, both a
+    ClientError and a TimeoutError) instead of surfacing as a generic client error.
+    """
+    return aiohttp.ServerTimeoutError(f"{backend} request timed out: {error}")
+
+
+try:
+    from curl_cffi import AsyncSession as _CurlAsyncSession
+    _CURL_ERROR = None
+except ImportError as error:
+    _CurlAsyncSession = None
+    _CURL_ERROR = error
+
+try:
+    import noble_tls
+    from noble_tls import Client as _NobleClient
+    _NOBLE_ERROR = None
+except ImportError as error:
+    noble_tls = None
+    _NobleClient = None
+    _NOBLE_ERROR = error
+
+
+def _coerce_timeout(value):
+    """unwrap aioweb's aiohttp ClientTimeout (or a plain number) to a number
+
+    aioweb.request() wraps a numeric timeout in aiohttp.ClientTimeout before the seam
+    sees it; the tls clients want a bare number.
+    """
+    total = getattr(value, "total", value)
+    return total if isinstance(total, (int, float)) else None
+
+
+def _noble_timeout_seconds(value):
+    """coerce a raw or wrapped timeout into whole seconds for noble's Go int field
+
+    single source of truth for both Noble timeout paths (session-default and
+    per-call): the Go field timeoutSeconds is an int, so a sub-second float truncates
+    to 0 (= no timeout) and a non-integer fails Go-side JSON unmarshal outright.
+    rounds up so a sub-second timeout still waits at least 1s. None if uncoercible.
+    """
+    timeout = _coerce_timeout(value)
+    if timeout is None:
+        return None
+    return max(1, math.ceil(timeout))
+
+
+def _noble_content(response) -> bytes:
+    """extract true response bytes from a noble_tls response fetched with is_byte_response
+
+    with is_byte_response=True, noble_tls's Go side returns the body as a
+    `data:<mime>;base64,<payload>` URI string in response.text (the whole Go response
+    is UTF-8-decoded before JSON parsing, so raw bytes travel as base64) —
+    response.content just re-encodes that string, so decode the data-URI here
+    instead. falls back to a plain utf-8 encode if the body isn't a data-URI.
+    """
+    text = getattr(response, "text", "") or ""
+    if text.startswith("data:") and ";base64," in text:
+        _, _, payload = text.partition(";base64,")
+        return base64.b64decode(payload)
+    return text.encode()
+
+
+def _flatten_headers(headers) -> dict:
+    """flatten a Go-style map[str][]str header dict into plain str values
+
+    noble_tls keeps a multi-valued header (e.g. two Set-Cookie lines) as a Python
+    list, breaking any downstream .split()/.lower() call; join with ", " per RFC 7230
+    field-value combination, leaving single values untouched.
+    """
+    return {
+        key: ", ".join(value) if isinstance(value, list) else value
+        for key, value in headers.items()
+    }
+
+
+def _jar_to_dict(session):
+    """best-effort map of a requests-style cookie jar on session to a plain dict
+
+    feeds preview() only; the two backends expose differently-shaped jars and a
+    cookie read must never crash a request, so a jar that fails to iterate degrades
+    to {} rather than raising.
+    """
+    jar = getattr(session, "cookies", None)
+    if not jar:
+        return {}
+    try:
+        return {k: v for k, v in jar.items()}
+    except Exception:
+        return {}
+
+
+class CurlCffi:
+    """curl_cffi backend: forges JA3/JA4 + HTTP/2 via the curl-impersonate binary
+
+    config:
+        impersonate: browser profile to forge (default "chrome"); override per call
+            by passing impersonate= to the low-level request()/_raw_request path
+            (forwards **kwargs to the backend) — NOT request_with_retries, whose
+            fixed signature has no **kwargs and raises TypeError. for the retrying
+            path, set the profile on the CurlCffi instance instead.
+
+    requires the [curl] extra (pip install "aioweb_tls[curl]").
+    """
+
+    def __init__(self, impersonate: str = "chrome"):
+        if _CurlAsyncSession is None:
+            raise RuntimeError(
+                "curl_cffi is not installed; install the extra with "
+                "pip install \"aioweb_tls[curl]\""
+            ) from _CURL_ERROR
+        self.impersonate = impersonate
+
+    def create_session(self, headers, timeout, **kwargs):
+        """build the curl_cffi AsyncSession
+
+        deliberately does NOT pass `headers`: curl_cffi bakes a constructor
+        `headers=` into the client and re-merges it under per-request headers,
+        which would desync update_headers()/clear_headers() from what's actually on
+        the wire — aioweb's session-default headers already apply per request via
+        the base's _default_headers merge (see ExtendedSession._create_session).
+        """
+        return _CurlAsyncSession(timeout=timeout, **kwargs)
+
+    async def raw_request(self, session, method, url, **kwargs) -> Response:
+        """send via curl_cffi and adapt the result into an aioweb.Response"""
+        impersonate = kwargs.pop("impersonate", self.impersonate)
+
+        timeout = _coerce_timeout(kwargs.pop("timeout", None))
+        if timeout is not None:
+            kwargs["timeout"] = timeout
+
+        proxy = kwargs.pop("proxy", None)
+        if proxy:
+            kwargs["proxy"] = proxy
+
+        try:
+            response = await session.request(method, url, impersonate=impersonate, **kwargs)
+        except aiohttp.ClientError:
+            raise
+        except asyncio.TimeoutError:
+            raise
+        except OSError as error:
+            # RequestException (incl. curl_cffi's own Timeout) subclasses OSError, never
+            # asyncio.TimeoutError — check for a timeout first so it surfaces as
+            # ServerTimeoutError; narrowed from bare Exception so a real bug surfaces
+            if _is_timeout_error(error):
+                raise _as_timeout_error(error, "curl_cffi") from error
+            raise _as_client_error(error, "curl_cffi") from error
+        content = response.content if response.content is not None else b""
+        return Response(
+            status_code=response.status_code,
+            headers=dict(response.headers),
+            content=content,
+            url=str(response.url),
+            reason=getattr(response, "reason", None),
+            cookies=getattr(response, "cookies", None),
+        )
+
+    def is_closed(self, session) -> bool:
+        """whether the curl_cffi session is closed
+
+        curl_cffi tracks closed state in the private `_closed` (no public `closed`);
+        fall back to a public `closed` if a future version adds one. TLSSession's own
+        `_closed` flag is the primary signal — this is a best-effort out-of-band check.
+        """
+        closed = getattr(session, "_closed", None)
+        if closed is None:
+            closed = getattr(session, "closed", False)
+        return bool(closed)
+
+    def cookies_for_url(self, session, url) -> dict:
+        """cookies curl_cffi would send for url (best-effort)"""
+        return _jar_to_dict(session)
+
+    def set_cookie(self, session, name, value, domain=None, path="/") -> None:
+        """set a cookie in curl_cffi's own cookie store"""
+        session.cookies.set(name, value, domain=domain or "", path=path)
+
+    def get_cookies(self, session) -> dict:
+        """all cookies stored in curl_cffi's cookie store"""
+        return dict(session.cookies.items())
+
+    def clear_cookies(self, session) -> None:
+        """clear curl_cffi's cookie store"""
+        session.cookies.clear()
+
+    async def close(self, session) -> None:
+        """close the curl_cffi session"""
+        await session.close()
+
+
+class Noble:
+    """noble_tls backend: forges a browser TLS fingerprint via the tls-client Go lib
+
+    config:
+        client: noble_tls Client profile (enum or string, default "chrome_133").
+
+    noble_tls downloads a Go shared library on first use; setup() fetches it once
+    (run via TLSSession.setup() or lazily before the first request).
+
+    requires the [noble] extra (pip install "aioweb_tls[noble]").
+    """
+
+    def __init__(self, client="chrome_133"):
+        if noble_tls is None:
+            raise RuntimeError(
+                "noble_tls is not installed; install the extra with "
+                "pip install \"aioweb_tls[noble]\""
+            ) from _NOBLE_ERROR
+        self.client = self._resolve_client(client)
+        self._updated = False
+        self._setup_lock = asyncio.Lock()
+
+    @staticmethod
+    def _resolve_client(client):
+        """turn a string or Client enum into a noble_tls Client value
+
+        raises ValueError naming the valid profiles for an unknown string, instead of
+        letting getattr's raw AttributeError leak the enum's internal lookup mechanics.
+        """
+        if not isinstance(client, str):
+            return client
+        name = client.upper()
+        resolved = getattr(_NobleClient, name, None)
+        if resolved is None:
+            valid = ", ".join(member.name for member in _NobleClient)
+            raise ValueError(f"unknown noble_tls client profile {client!r}; valid profiles: {valid}")
+        return resolved
+
+    async def setup(self) -> None:
+        """fetch the noble_tls Go shared library once; idempotent and concurrency-safe
+
+        uses noble_tls.download_if_necessary (fetches on first use, no-ops if
+        present); falls back to update_if_necessary on older noble_tls.
+
+        guarded by an asyncio.Lock with a check-lock-recheck so concurrent first
+        requests don't both run the fetch — only the first caller through the lock
+        does the work, the rest see _updated already set.
+        """
+        if self._updated:
+            return
+        async with self._setup_lock:
+            if self._updated:
+                return
+            download = getattr(noble_tls, "download_if_necessary", None)
+            if download is not None:
+                await download()
+            elif hasattr(noble_tls, "update_if_necessary"):
+                await noble_tls.update_if_necessary()
+            self._updated = True
+
+    def create_session(self, headers, timeout, **kwargs):
+        """build the noble_tls Session, honoring the session-default timeout
+
+        noble_tls.Session takes neither headers nor timeout in its constructor.
+        deliberately does NOT bake `headers` into session.headers, same rationale as
+        CurlCffi.create_session — aioweb's per-request _default_headers merge already
+        applies them, so baking here would desync update_headers()/clear_headers().
+
+        the coerced timeout IS applied here (matching raw_request's per-call path):
+        noble's Go field timeoutSeconds is an int, so an uncoerced sub-second/float
+        session-default would fail Go-side JSON unmarshal on any request that doesn't
+        override it per call; max(1, ceil()) mirrors raw_request's own guard.
+        """
+        session = noble_tls.Session(client=self.client, **kwargs)
+        timeout_seconds = _noble_timeout_seconds(timeout)
+        if timeout_seconds is not None:
+            session.timeout_seconds = timeout_seconds
+        return session
+
+    async def raw_request(self, session, method, url, **kwargs) -> Response:
+        """send via noble_tls and adapt the result into an aioweb.Response"""
+        await self.setup()
+
+        timeout_seconds = _noble_timeout_seconds(kwargs.pop("timeout", None))
+        if timeout_seconds is not None:
+            kwargs["timeout_seconds"] = timeout_seconds
+
+        proxy = kwargs.pop("proxy", None)
+        if proxy:
+            kwargs["proxy"] = proxy
+
+        # byte-safe transport: without this, noble_tls's Go side returns the body as a
+        # plain UTF-8 JSON string (U+FFFD-mangling any binary payload on a 200 response);
+        # see _noble_content() for the base64 data-URI decode this pairs with.
+        kwargs.setdefault("is_byte_response", True)
+
+        try:
+            response = await session.execute_request(method=method.upper(), url=url, **kwargs)
+        except aiohttp.ClientError:
+            raise
+        except asyncio.TimeoutError:
+            raise
+        except OSError as error:
+            # TLSClientException subclasses IOError (== OSError); the Go side has no
+            # distinct timeout type either, just a text body ("context deadline
+            # exceeded") — check for one before the generic client-error wrap
+            if _is_timeout_error(error):
+                raise _as_timeout_error(error, "noble_tls") from error
+            raise _as_client_error(error, "noble_tls") from error
+        content = _noble_content(response)
+        return Response(
+            status_code=response.status_code,
+            headers=_flatten_headers(getattr(response, "headers", {}) or {}),
+            content=content,
+            url=str(getattr(response, "url", url)),
+            reason=getattr(response, "reason", None),
+            cookies=getattr(response, "cookies", None),
+        )
+
+    def is_closed(self, session) -> bool:
+        """noble_tls has no closed flag; closed state is tracked by TLSSession"""
+        return bool(getattr(session, "closed", False))
+
+    def cookies_for_url(self, session, url) -> dict:
+        """cookies noble_tls would send for url (best-effort)"""
+        return _jar_to_dict(session)
+
+    def set_cookie(self, session, name, value, domain=None, path="/") -> None:
+        """set a cookie in noble_tls's own cookie jar"""
+        session.cookies.set(name, value, domain=domain or "", path=path)
+
+    def get_cookies(self, session) -> dict:
+        """all cookies stored in noble_tls's cookie jar"""
+        return dict(session.cookies.items())
+
+    def clear_cookies(self, session) -> None:
+        """clear noble_tls's cookie jar"""
+        session.cookies.clear()
+
+    async def close(self, session) -> None:
+        """close the noble_tls session if it exposes a close"""
+        close = getattr(session, "close", None)
+        if close is None:
+            return
+        result = close()
+        if hasattr(result, "__await__"):
+            await result

src/aioweb_tls/protocol.py

@@ -0,0 +1,66 @@
+"""
+the tls backend protocol
+
+a backend is a stateless config+behavior object that teaches TLSSession how to talk
+to one HTTP client. TLSSession owns the live session object (built by create_session)
+and passes it into every backend call, so backends hold no per-request state.
+
+implement this protocol to add a custom backend (e.g. a local Go TLS server); inject
+it via TLSSession(backend=MyBackend(...)) and it inherits aioweb's domain / header /
+ephemeral / proxy / retry / preview logic unchanged — those operate on plain dicts
+and never touch the backend.
+
+required:
+    create_session(headers: dict, timeout, **kwargs) -> session
+        build and return the live client session object, stored as self.session and
+        passed to every method below.
+
+    async raw_request(session, method, url, **kwargs) -> aioweb.Response
+        send one request; adapt the client's response into an aioweb.Response built
+        from primitives (status_code, headers, content bytes, url, reason). kwargs
+        arrive aioweb-shaped: proxy resolved into kwargs["proxy"], headers merged
+        into kwargs["headers"], numeric timeout wrapped in aiohttp.ClientTimeout
+        (unwrap .total).
+
+    is_closed(session) -> bool
+        whether `session` is closed.
+
+optional:
+    cookies_for_url(session, url) -> dict
+        cookies the client would send for url, for preview(). default {}.
+
+    set_cookie(session, name, value, domain=None, path="/") -> None
+    get_cookies(session) -> dict
+    clear_cookies(session) -> None
+        back TLSSession's mutable cookie api. the aiohttp-only base reaches into
+        session.cookie_jar, which TLS backends lack, so an implementation without
+        these raises NotImplementedError instead of a private-attribute AttributeError.
+
+    async setup() -> None
+        one-time async preparation (e.g. fetch a native lib); idempotent. called via
+        TLSSession.setup() and lazily before the first request.
+
+    async close(session) -> None
+        close `session`. default awaits session.close() if present.
+"""
+
+from typing import Any, Protocol, runtime_checkable
+
+from aioweb import Response
+
+
+@runtime_checkable
+class TLSBackend(Protocol):
+    """the contract a TLSSession backend implements (see module docstring)"""
+
+    def create_session(self, headers: dict, timeout: Any, **kwargs) -> Any:
+        """build and return the live client session object"""
+        ...
+
+    async def raw_request(self, session: Any, method: str, url: str, **kwargs) -> Response:
+        """send one request and adapt the result into an aioweb.Response"""
+        ...
+
+    def is_closed(self, session: Any) -> bool:
+        """whether the session is closed"""
+        ...

src/aioweb_tls/session.py

@@ -0,0 +1,126 @@
+"""
+TLSSession — one aioweb session, any tls backend
+
+TLSSession subclasses aioweb.ExtendedSession and delegates only the four backend
+seams to an injected backend object (see protocol.py). everything else — header
+overwrites, domain rewriting, ephemeral headers, proxies, retries, previews — is
+inherited unchanged, since that logic operates on plain dicts and never touches
+the backend.
+
+    from aioweb_tls import TLSSession, CurlCffi, Noble
+
+    async with TLSSession(backend=CurlCffi(impersonate="chrome")) as s:
+        resp = await s.request_with_retries("GET", "https://tls.peet.ws/api/all")
+        if resp:
+            print(resp.json()["tls"]["ja3"])
+
+    s = TLSSession(backend=Noble(client="chrome_133"))
+    await s.setup()                            # fetch noble's Go lib once
+    ...
+
+a custom backend (e.g. a local Go TLS server) injects the same way — implement the
+TLSBackend protocol and pass it as backend=. one TLSSession is the only session
+class; the backend swaps the wire, not the session.
+"""
+
+import logging
+
+from aioweb import ExtendedSession
+
+log = logging.getLogger(__name__)
+
+
+class TLSSession(ExtendedSession):
+    """aioweb session whose HTTP backend is an injected, swappable tls client"""
+
+    def __init__(self, backend, *args, **kwargs):
+        """build a session over a tls backend
+
+        args:
+            backend: a TLSBackend (CurlCffi, Noble, or a custom one); owns its own
+                config vocabulary and the four seam behaviors
+            *args, **kwargs: forwarded to aioweb.ExtendedSession
+        """
+        self.backend = backend
+        self._closed = False
+        super().__init__(*args, **kwargs)
+
+    async def setup(self) -> None:
+        """run the backend's one-time setup if it has one (idempotent)
+
+        delegates to backend.setup() when defined (e.g. noble fetching its Go lib);
+        a no-op for backends without it. also invoked lazily before the first request
+        by backends that guard their own setup, so calling this is optional but lets
+        callers pre-warm at startup.
+        """
+        setup = getattr(self.backend, "setup", None)
+        if setup is not None:
+            await setup()
+
+    # -------------------------------------------------------------------------
+    #   the four backend seams, delegated to self.backend
+
+    def _create_session(self, headers, timeout, **kwargs):
+        """delegate session creation to the backend"""
+        return self.backend.create_session(headers, timeout, **kwargs)
+
+    async def _raw_request(self, method, url, **kwargs):
+        """delegate the wire request to the backend, returning its aioweb.Response"""
+        return await self.backend.raw_request(self.session, method, url, **kwargs)
+
+    def _cookies_for_url(self, url) -> dict:
+        """delegate preview cookie lookup to the backend (default {})"""
+        cookies_for_url = getattr(self.backend, "cookies_for_url", None)
+        if cookies_for_url is None:
+            return {}
+        return cookies_for_url(self.session, url)
+
+    def _is_closed(self) -> bool:
+        """closed if explicitly closed here or the backend reports it"""
+        if self._closed:
+            return True
+        return self.backend.is_closed(self.session)
+
+    # -------------------------------------------------------------------------
+    #   mutable cookie api — the base's set_cookie/get_cookies/clear_cookies reach
+    #   into self.session.cookie_jar (aiohttp-only), so TLS backends override them
+    #   to route through the backend instead of crashing with AttributeError
+
+    def set_cookie(self, name, value, domain=None, path="/"):
+        """set a cookie via the backend's own cookie store"""
+        set_cookie = getattr(self.backend, "set_cookie", None)
+        if set_cookie is None:
+            raise NotImplementedError(
+                f"{type(self.backend).__name__} does not support the mutable cookie api"
+            )
+        set_cookie(self.session, name, value, domain=domain, path=path)
+
+    def get_cookies(self) -> dict:
+        """all cookies stored in the backend's cookie store"""
+        get_cookies = getattr(self.backend, "get_cookies", None)
+        if get_cookies is None:
+            raise NotImplementedError(
+                f"{type(self.backend).__name__} does not support the mutable cookie api"
+            )
+        return get_cookies(self.session)
+
+    def clear_cookies(self) -> None:
+        """clear the backend's cookie store"""
+        clear_cookies = getattr(self.backend, "clear_cookies", None)
+        if clear_cookies is None:
+            raise NotImplementedError(
+                f"{type(self.backend).__name__} does not support the mutable cookie api"
+            )
+        clear_cookies(self.session)
+
+    # -------------------------------------------------------------------------
+    #   lifecycle — backends close differently, so route through the backend
+
+    async def close(self) -> None:
+        """close via the backend's close (falls back to session.close)"""
+        self._closed = True
+        close = getattr(self.backend, "close", None)
+        if close is not None:
+            await close(self.session)
+        else:
+            await self.session.close()