Two bugs identified from article "Claude Code封号真相":
1. cch=00000 never replaced (fix):
signBillingHeaderCCH was gated by enableCCH (default false), so the
cch=00000 placeholder injected by buildBillingAttributionBlockJSON was
sent to Anthropic as-is — an obvious fake signal. The function already
guards itself via regex match, so the enableCCH gate is removed.
2. NormalizeSystemPromptEnv was dead code (fix):
Platform/Shell/OS Version/Working directory fields in user system prompts
leaked real machine info (e.g. "Darwin 25.3.0", "/Users/win/...") that
Anthropic could use to correlate requests across accounts. Now normalized
to canonical values before injecting into the messages pair.
(*net.OpError).Error() concatenates Source/Addr fields, so the previous
disconnectMsg surfaced internal source IP/port and upstream server address
to clients via SSE error frames and UpstreamFailoverError.ResponseBody
(reported by @Wei-Shaw on PR #2066).
- Add sanitizeStreamError that maps known errors (io.ErrUnexpectedEOF,
context.Canceled, syscall.ECONNRESET/EPIPE/ETIMEDOUT/...) to fixed
descriptions and falls back to a generic placeholder, with an explicit
*net.OpError branch that drops Source/Addr fields entirely.
- Use sanitized message in client-facing disconnectMsg; full ev.err is
still preserved in the existing operator log line for diagnosis.
- Tests cover net.OpError redaction, the failover ResponseBody path, and
every known sanitized error mapping.
Adds an opt-in tier-based fallback scheduling path for Anthropic accounts:
- accountTierLevel(): derives tier from account type without DB migration
(tier-0=OAuth/SetupToken, tier-1=APIKey, tier-2=Bedrock)
- enableTierFallbackChain(): new config flag
gateway.scheduling.enable_tier_fallback_chain (default false)
- selectAccountWithTierFallback(): loads all Anthropic accounts, groups by
tier, honors sticky sessions, applies all existing schedulability guards,
then tries tiers 0→1→2 in order via tryAcquireByLegacyOrder
- Wired into SelectAccountForModelWithExclusions: Anthropic platform +
tier fallback enabled → calls new path instead of mixed scheduling
- Fix pre-existing unit-test build break: NewGatewayService now requires
*RPMTokenBucketService (added in Task #5); add missing nil param
- 7 tests: tier mapping, config toggle, subscription preference,
APIKey fallback, exclusion handling, empty-pool error, Bedrock last resort
- New context_compressor.go: pure functions operating on raw JSON body
(gjson/sjson pattern). approxTokens uses chars/4 heuristic.
- compressMessages: removes oldest messages from front, treating
consecutive assistant(tool_use)+user(tool_result) pairs as atomic units
to prevent orphaned tool_result blocks.
- Hooked into Forward() after StripEmptyTextBlocks, gated on
account.Credentials[enable_context_compression].
- Config: gateway.context_compression.max_tokens (default 190000).
- 8 unit tests covering: approx tokens, no-op when under budget,
oldest-message trimming, tool pair preservation, atomic pair removal,
body passthrough, body trimming.
- Centralize Claude CLI fingerprint constants (UA, x-stainless-*) in
pkg/claude with BuildCLI/CodeUserAgent helpers
- Reuse constants in DefaultHeaders, identity_service defaults, and
antigravity identity defaults to keep all callers in sync
- Extend ClaudeCodeValidator to accept both claude-cli/ and claude-code/
UA prefixes (transport/helper requests use the latter)
- Update related tests to cover the new UA prefix and version
Two follow-ups to PR #2066's failover-wrap fix:
1. Failover ResponseBody (`UpstreamFailoverError.ResponseBody`) was encoded
as `{"error": "<msg>"}` (string field). `ExtractUpstreamErrorMessage`
probes for `error.message`, `detail`, or top-level `message` only — so
`handleFailoverExhausted` and downstream passthrough rules saw an empty
message, losing the EOF root cause in ops logs. Re-encode as the
Anthropic standard shape `{"type":"error","error":{"type":"upstream_disconnected","message":"..."}}`.
(Addresses the inline review comment from copilot-pull-request-reviewer
on Wei-Shaw/sub2api#2066.)
2. The streaming `event: error` SSE frame for `response_too_large`,
`stream_read_error`, and `stream_timeout` was non-standard
(`{"error":"<reason>"}`). Anthropic SDKs (and Claude Code) expect
`{"type":"error","error":{"type":"...","message":"..."}}` and parse
`error.type`/`error.message` accordingly. Refactor `sendErrorEvent` to
take both reason and message, and emit the standard frame so client
SDKs surface a real diagnostic message instead of a generic stream error.
This does not by itself prevent task interruption on long-stream EOF
(SSE has no resume; client-side retry remains the only complete fix), but
it gives both server-side ops logs and client-side error UIs a meaningful
upstream message so users know the next step is to retry.
Tests updated to assert the new body shape on both branches plus a new
assertion that `ExtractUpstreamErrorMessage` returns a non-empty string.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Anthropic streaming path (gateway_service.go) returned a plain error on
upstream SSE read failure, so the handler-level UpstreamFailoverError check
never fired and the client received a bare `stream_read_error` event,
breaking long-running tasks even when no bytes had been written yet.
The most common trigger is HTTP/2 GOAWAY from api.anthropic.com edge
backends doing graceful rotation: Go's http.Transport surfaces this as
`unexpected EOF` and never auto-retries.
Mirror what the OpenAI and antigravity gateways already do: when the read
error happens before any byte has reached the client (`!c.Writer.Written()`),
return `*UpstreamFailoverError{StatusCode: 502, RetryableOnSameAccount: true}`
so the handler can retry on the same or another account. After client
output has begun, SSE has no resume protocol — keep the existing passthrough
behavior.
Tests cover both branches via streamReadCloser-based fixtures.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
PR #1914 unconditionally applied the full mimicry pipeline to all OAuth
accounts, including real Claude Code CLI clients. This replaced the
client's long system prompt (~10K+ tokens with stable cache_control
breakpoints) with a short ~45 token [billing, CC prompt] pair, which
falls below Anthropic's 1024-token minimum cacheable prefix threshold.
The result: every request created a new cache but never hit an existing
one.
Fix: restore the Claude Code client detection gate so that real CC
clients bypass body-level mimicry (system rewrite, message cache
management, tool name obfuscation). Non-CC third-party clients
(opencode, etc.) continue to receive full mimicry.
Also harden the detection logic:
- Make UA regex case-insensitive (align with claude_code_validator.go)
- Validate metadata.user_id format via ParseMetadataUserID() instead of
just checking non-empty, preventing third-party tools from spoofing
a claude-cli/* UA with an arbitrary user_id string to bypass mimicry
- staticcheck QF1001: apply De Morgan's law to the OAuth-mimic header
passthrough guard (`!(a && b)` → `a != ... || !b`).
- unused: drop `isClaudeCodeRequest`, which became dead after PR #1914
switched both `/v1/messages` and `/count_tokens` paths to unconditional
`account.IsOAuth()` mimicry. The lowercase helper `isClaudeCodeClient`
is kept (still referenced by `TestIsClaudeCodeClient`).
Root cause of persistent third-party detection: sub2api's
buildUpstreamRequest transparently forwards client headers via
allowedHeaders whitelist (addHeaderRaw) before applying mimicry
overrides. When third-party clients (opencode, etc.) send their own
anthropic-beta / user-agent / x-stainless-* / x-claude-code-session-id
values, these get appended to the request alongside our injected
headers, creating an inconsistent header set that Anthropic detects.
Parrot's build_upstream_headers constructs exactly 9 headers from
scratch and never forwards anything from the client. This is why
'same opencode version, some users work some don't' — different
opencode configs/versions send different header combinations.
Fix: when tokenType=oauth and mimicClaudeCode=true, skip the
client header passthrough loop entirely. The subsequent
applyClaudeCodeMimicHeaders + ApplyFingerprint + beta merge
pipeline constructs all necessary headers from our controlled values.
Also: remove systemIncludesClaudeCodePrompt gate — OAuth accounts
now unconditionally rewrite system (even if client already sent a
Claude Code-style prompt), ensuring billing attribution block is
always present.
Before: isClaudeCodeRequest() checked whether the client looks like a
real Claude Code CLI (UA, system prompt, X-App header, metadata format).
If it looked like Claude Code, all mimicry was skipped — the assumption
being that a real CLI needs no help.
Problem: third-party tools like opencode partially impersonate Claude
Code (sending claude-cli UA + claude-code beta + CC system prompt) but
miss critical details (billing attribution block, tool-name obfuscation,
cache breakpoints, full beta set). Some users' opencode instances pass
the isClaudeCodeRequest check, causing sub2api to skip mimicry entirely,
while Anthropic still detects the request as third-party.
This explains why 'same opencode version, some users work, some don't'
— it depends on which opencode features/config trigger the validator.
Fix: OAuth accounts now unconditionally run the full mimicry pipeline,
matching Parrot's behavior (Parrot never checks client identity).
This is safe because our mimicry is strictly more complete than any
third-party client's partial impersonation.
Changed:
- /v1/messages path: remove isClaudeCode gate
- /v1/messages/count_tokens path: same
The previous commit only wired stripMessageCacheControl,
addMessageCacheBreakpoints, and tool-name obfuscation into
applyClaudeCodeOAuthMimicryToBody (used by /chat/completions and
/responses). The native /v1/messages path and count_tokens path
have their own independent mimicry code blocks and were missed.
Now all three entry points share the same D/E/F pipeline:
- /v1/messages (gateway_service.go forwardAnthropic)
- /v1/messages/count_tokens (gateway_service.go countTokens)
- OpenAI compat (applyClaudeCodeOAuthMimicryToBody)
Implements the remaining three parity items with Parrot cc_mimicry:
D) Tool-name obfuscation
- Dynamic mapping when tools.length > 5 (matches Parrot threshold).
Fake names follow {prefix}{name[:3]}{i:02d} (e.g. 'manage_bas00').
Go port of random.Random(hash(tuple(names))) uses fnv64a seed +
math/rand; byte-exact reproduction is impossible (Python hash vs
Go hash), but the two invariants that matter are preserved:
* same input tool_names yield identical mapping (cache hit)
* prefix pool is shuffled (names look distributed)
- Static prefix map (sessions_ -> cc_sess_, session_ -> cc_ses_)
applied as fallback, matching Parrot TOOL_NAME_REWRITES verbatim.
- Server tools (web_search_20250305, computer_*, etc.) are NOT
renamed; only type=='function' and type=='custom' tools are.
- tool_choice.name is rewritten in sync (only when type=='tool').
- Response side: bytes-level replace on every SSE chunk / JSON
body at 6 injection points (standard stream/non-stream,
passthrough stream/non-stream, chat_completions stream +
non-stream, responses stream + non-stream). Reverse mapping
applied longest-fake-name-first to prevent substring conflicts
(parity with Parrot _restore_tool_names_in_chunk).
- tool_choice is no longer unconditionally deleted in
normalizeClaudeOAuthRequestBody — Parrot passes it through.
E) tools[-1] cache_control breakpoint
- Injected as {type:ephemeral, ttl:<DefaultCacheControlTTL>} when
the last tool has no cache_control. Client-provided ttl is
passed through unchanged (repo-wide policy).
F) messages cache_control strategy
- stripMessageCacheControl removes every client-provided
messages[*].content[*].cache_control (multi-turn stability).
- addMessageCacheBreakpoints then injects two stable breakpoints:
(1) last message, and (2) second-to-last user turn when
messages.length >= 4.
- Combined with the system block breakpoint and tools[-1]
breakpoint, this gives exactly the 4 breakpoints Anthropic
allows per request.
Non-trivial implementation details to be aware of when rebasing:
* Two new files, no upstream collision:
gateway_tool_rewrite.go (D + E algorithms)
gateway_messages_cache.go (F strip + breakpoints)
* Two new feature calls bolted onto the tail of
applyClaudeCodeOAuthMimicryToBody in gateway_service.go — rebase
conflicts will be ~10 lines maximum.
* Response-side injection points all wrap their existing write with
reverseToolNamesIfPresent(c, ...), preserving original behavior
when no mapping is stored (static prefix rollback still runs).
* Non-stream chat/responses switched from c.JSON to
json.Marshal + c.Data so bytes-level replace is possible.
* Retry bodies (FilterThinkingBlocksForRetry,
FilterSignatureSensitiveBlocksForRetry, RectifyThinkingBudget)
only prune blocks — they preserve the already-obfuscated tool
names, so no extra mapping re-application is needed.
Manual QA: end-to-end scenario verified with 6 tools (above threshold)
and tool_choice.type=='tool'. Obfuscation + restore roundtrip shown
in test logs; then removed the temp test file.
Tests (16 new):
- buildDynamicToolMap stability + below-threshold guard
- sanitizeToolName precedence (dynamic > static)
- restoreToolNamesInBytes longest-first + static rollback
- applyToolNameRewriteToBody skips server tools + syncs tool_choice
- applyToolsLastCacheBreakpoint defaults to 5m + passes client ttl
- stripMessageCacheControl + addMessageCacheBreakpoints in the
1/4/string-content cases + second-to-last user turn selection
- buildToolNameRewriteFromBody ReverseOrdered is desc-by-fake-length
- fake name shape follows Parrot {prefix}{head3}{i:02d}
Three field-level alignments in normalizeClaudeOAuthRequestBody to
match real Claude Code CLI traffic byte-for-byte:
1. temperature: previously deleted unconditionally; now passes
through client value, defaults to 1 when absent (real CLI
always sends temperature, default 1).
2. max_tokens: defaults to 128000 when absent (real CLI default).
3. context_management: when thinking.type is enabled/adaptive
and the client did not provide context_management, inject
{"edits":[{"type":"clear_thinking_20251015","keep":"all"}]}
to mirror real CLI behavior.
tool_choice removal is unchanged (Claude Code OAuth credentials
do not allow client-supplied tool_choice).
Tests updated:
- gateway_body_order_test.go: temperature/max_tokens are now
expected in output; tool_choice still removed.
- gateway_prompt_test.go: system array is now 2 blocks
(billing + cc prompt), assertions adjusted.
- gateway_anthropic_apikey_passthrough_test.go: same 2-block
assertion.
Real Claude Code CLI always sends a 2-block system array:
[0] {"type":"text", "text":"x-anthropic-billing-header: cc_version=X.Y.Z.{fp}; cc_entrypoint=cli; cch=00000;"}
[1] {"type":"text", "text":"You are Claude Code...", "cache_control":{...}}
Before this commit, sub2api's mimicry path only produced block [1].
The missing billing block is one of the primary third-party detection
signals Anthropic uses for Claude-Code-scoped OAuth tokens.
New file gateway_billing_block.go ports the fingerprint algorithm
(byte-for-byte from Parrot cc_mimicry.py:compute_fingerprint):
pick chars at positions [4,7,20] of the first user text, then
`sha256(SALT + chars + cc_version)[:3]`.
- claude/constants.go: CLICurrentVersion = "2.1.92" (must match UA)
- gateway_billing_block.go: computeClaudeCodeFingerprint +
buildBillingAttributionBlockJSON + extractFirstUserText
- gateway_service.go: rewriteSystemForNonClaudeCode now emits both
blocks in order; cch=00000 is filled in later by
signBillingHeaderCCH in buildUpstreamRequest.
Downstream compat note: syncBillingHeaderVersion's regex
`cc_version=\d+\.\d+\.\d+` only matches the semver triple,
leaving the `.{fp}` suffix intact when rewriting in buildUpstreamRequest.
Real Claude CLI traffic sends cache_control as
`{"type":"ephemeral","ttl":"1h"}`. Our previous payload only
sent `{"type":"ephemeral"}`, which is a bytewise mismatch with
the official CLI and one more third-party detection signal.
Policy: client-provided ttl is always passed through unchanged.
Proxy-generated cache_control blocks default to 5m (vs Parrot's 1h)
to avoid burning the 1h cache budget on automatic breakpoints while
still aligning with the `ttl` field being present.
- claude/constants.go: DefaultCacheControlTTL = "5m"
- apicompat/types.go: new AnthropicCacheControl type with TTL field;
AnthropicTool gains optional CacheControl pointer so the mimicry
path can attach a cache breakpoint to tools[-1] later.
- service/gateway_service.go: anthropicCacheControlPayload gains TTL;
marshalAnthropicSystemTextBlock and rewriteSystemForNonClaudeCode
emit ttl=5m by default.
The previous commit added FullClaudeCodeMimicryBetas() but the two
call sites in buildUpstreamRequest still hardcoded the old 3-token
subset. Anthropic now checks the complete set of beta tokens to
decide if a request qualifies as Claude Code. Wire them up:
- /v1/messages mimic path: requiredBetas = FullClaudeCodeMimicryBetas()
- /v1/messages/count_tokens mimic path: same + BetaTokenCounting
Haiku models keep the 2-token exemption (BetaOAuth + InterleaveThinking).
Before: the OpenAI-compat forwarders only called injectClaudeCodePrompt,
which prepends the Claude Code banner but leaves the rest of the body
in its original non-Claude-Code shape. The codebase already admits this
is insufficient (see the comment on rewriteSystemForNonClaudeCode in
gateway_service.go: "仅前置追加 Claude Code 提示词无法通过检测").
Effect: OAuth accounts served through /v1/chat/completions or /v1/responses
were detected as third-party apps and bled plan quota with:
Third-party apps now draw from your extra usage, not your plan limits.
Fix:
- apicompat.AnthropicRequest: add Metadata json.RawMessage so metadata
survives the OpenAI->Anthropic->Marshal round trip; without it the
downstream rewrite has no user_id to work with.
- service: extract applyClaudeCodeOAuthMimicryToBody, a ParsedRequest-free
variant of the /v1/messages mimicry pipeline
(rewriteSystemForNonClaudeCode + normalizeClaudeOAuthRequestBody +
metadata.user_id injection) so the OpenAI-compat forwarders can reuse it.
- service: add buildOAuthMetadataUserIDFromBody + hashBodyForSessionSeed
for the same reason (no ParsedRequest at the call site).
- ForwardAsChatCompletions / ForwardAsResponses: replace the 3-line
prompt-prepend with the full mimicry pipeline.
- applyClaudeCodeMimicHeaders: set x-client-request-id per-request
(real Claude CLI always does); missing/duplicated values are one more
third-party fingerprint signal.
No change to the native /v1/messages path: it already called the full
pipeline, we only lift those helpers into a reusable function.
Tests:
- go build ./... passes
- go test ./internal/service/... ./internal/pkg/apicompat/... passes
- lsp_diagnostics clean on all touched files
- pre-existing failures in internal/config are unrelated (env-sensitive
tests that also fail on upstream main)
Add quota exceeded check to IsSchedulable() and refactor
shouldClearStickySession to delegate to IsSchedulable(), eliminating
duplicated logic and fixing missed overload/rate-limit/expired checks.
Frontend displays quota exceeded status independently via quota fields.
Subscription-mode billing was consuming quota at TotalCost (raw) instead of
ActualCost (TotalCost * RateMultiplier), so per-group rate multipliers —
including free subscriptions (multiplier = 0) — were silently ignored.
Switch the three subscription cost writes in buildUsageBillingCommand,
finalizePostUsageBilling, and the legacy postUsageBilling fallback to
ActualCost, and add a table-driven test covering 2x / 0.5x / free multipliers
plus a balance-mode regression check.
