Adds a new chatgpt-web provider that routes through chatgpt.com's internal
backend-api using a Plus/Pro subscription session cookie, enabling access
to GPT-5.x models without an OpenAI API key.
Heavier than perplexity-web/grok-web because chatgpt.com layers more bot
protection — this PR builds out the full pipeline needed to look like a
real browser session.
## New executor: open-sse/executors/chatgpt-web.ts
Auth/request pipeline (per chat completion):
1. exchangeSession() GET /api/auth/session cookie -> JWT (cached ~5min)
2. fetchDpl() GET / scrape data-build + script src
3. runSessionWarmup() GET /backend-api/me, /conversations, /models
4. POST /sentinel/chat-requirements/prepare -> prepare_token
5. POST /sentinel/chat-requirements -> chat-requirements-token + PoW seed/diff
6. solveProofOfWork() SHA3-512 loop -> "gAAAAAB..." sentinel proof token
7. POST /backend-api/f/conversation with all sentinel headers
8. parse SSE stream -> OpenAI chat.completion[.chunk] format
Notable details:
- 18-element prekey config matching chat2api/openai-sentinel (browser fingerprint
values, U+2212 MINUS SIGN in `webdriver−false`). Thin shapes get escalated to
mandatory Turnstile.
- Two-stage Sentinel handshake (/prepare + /chat-requirements) — sending only
the prepare result returns a 403 "Unusual activity" response.
- `turnstile.required: true` from Sentinel is treated as advisory; the conv
endpoint accepts requests without a Turnstile token as long as PoW + chat-
requirements-token are valid. Optional bring-your-own Turnstile via
`providerSpecificData.turnstileToken` for accounts that hard-require it.
- SSE parser tracks message_id and resets the accumulator on a new turn —
chatgpt.com echoes prior assistant messages (with status finished_successfully)
before sending the new turn.
- entity["...","value", ...] internal markup stripped from output (browser
renders these client-side).
- Conversation-continuity cache disabled by default: we send
history_and_training_disabled: true (Temporary Chat mode) and those
conversation_ids expire too fast to reuse — re-using returned 404. Each
request now sends conversation_id: null and replays full history, matching
what Open WebUI and OpenAI-API-style clients send anyway.
## TLS impersonation: open-sse/services/chatgptTlsClient.ts
ChatGPT's Cloudflare config pins cf_clearance to JA3/JA4 TLS fingerprint +
HTTP/2 SETTINGS frame. Plain Node Undici fetch always returns
cf-mitigated: challenge regardless of cookies. The wrapper module loads
`tls-client-node` (Firefox 148 fingerprint) in native runtime mode (.so via
koffi) — managed mode spawns a sidecar that conflicts with OmniRoute's
global fetch proxy patch.
- Lazy singleton TLSClient with process exit hooks
- Streaming-capable (file tail) and non-streaming modes
- Test injection point: __setTlsFetchOverrideForTesting() lets unit tests mock
the client without touching globalThis.fetch
## Provider wiring
- open-sse/executors/index.ts — register ChatGptWebExecutor with cgpt-web alias
- open-sse/config/providerRegistry.ts — registry entry, format=openai,
authHeader=cookie, model gpt-5.3-instant
- src/shared/constants/providers.ts — WEB_COOKIE_PROVIDERS UI metadata
(icon, color, authHint)
- src/lib/providers/validation.ts — validateChatGptWebProvider hits
/api/auth/session via the TLS client, detects cf-mitigated/HTML responses
and returns a clear "paste full Cookie line" hint instead of a generic
"Invalid"
- next.config.mjs — mark tls-client-node, koffi, tough-cookie as external
packages (Turbopack can't bundle the native .so)
## Cookie format
Validator and executor accept any of:
- bare value: "eyJhbGc..."
- unchunked cookie line: "__Secure-next-auth.session-token=eyJ..."
- chunked cookie line: "__Secure-next-auth.session-token.0=...; __Secure-next-auth.session-token.1=..."
- full DevTools Cookie header line: "Cookie: __Secure-next-auth.session-token.0=...; cf_clearance=...; ..."
NextAuth chunks the JWE when it exceeds 4KB; chunked cookies pass through
verbatim (NextAuth reassembles server-side). Recommend pasting the full
DevTools Cookie line so cf_clearance, __cf_bm, _cfuvid, _puid travel along —
without cf_clearance, Cloudflare blocks the request before NextAuth sees it.
## Tests
tests/unit/chatgpt-web.test.ts — 27 tests, all passing:
- Registration + alias resolution
- Token exchange (cookie -> Bearer flow)
- Token cache TTL
- Refreshed cookie surfaced via onCredentialsRefreshed callback
- Sentinel call ordering (session -> prepare -> chat-requirements -> conv)
- Sentinel chat-requirements-token forwarded on conv request
- PoW token has gAAAAAB prefix
- Turnstile.required: true does NOT block conv (passes through)
- Non-streaming chat.completion JSON
- Streaming SSE chunks ending with [DONE]
- Cumulative-parts diffing yields non-overlapping deltas
- Errors: 401 session, 403 sentinel, 429 conv rate-limit
- Empty messages -> 400 without any fetch
- Missing apiKey -> 401 without any fetch
- Cookie format: bare value, unchunked, chunked, "Cookie: ..." DevTools line
- Conversation continuity: each call starts a fresh conversation
- Browser-like headers on conv POST (UA, Origin, Sec-Fetch-Site, Accept)
- Payload shape (action, model=gpt-5-3, history_and_training_disabled)
- Provider registry contains chatgpt-web with gpt-5.3-instant model
Verification: typecheck:core clean, lint clean (no new warnings),
end-to-end manually verified across single-turn, multi-turn (memory
preserved), streaming, and Open WebUI-style sequential growing-history
flows.
## References
- bogdanfinn/tls-client (Go) — TLS impersonation upstream
- fatihkabakk/tls-client-node — Node bindings
- lanqian528/chat2api — Sentinel/PoW/prekey reference impl (Python)
- leetanshaj/openai-sentinel — Prekey config + SHA3-512 solver
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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