Alibaba Model Studio (Dashscope) tiered pricing is all-or-nothing: the tier is
selected by a request's total input tokens and every token, input and output, is
billed at that one tier's rate. The reservation path used graduated slicing and,
worse, picked the output tier from the output-token count, so a long-context
request with a large output allowance reserved far less than the provider charges
and could slip past a depleted budget. Select the tier from input tokens and apply
its rates to all input and output tokens.
Reservation also read tiered pricing from only the first deployment in a model
group. A caller could hit an alias whose cheaper deployment was listed first and
exceed the budget once routed to a costlier sibling. Estimate against every
eligible deployment's pricing and reserve the maximum.
Co-authored-by: Cursor <cursoragent@cursor.com>
The envelope arm reloaded the identity and ran _run_centralized_common_checks
but skipped RouteChecks.should_call_route, which the standard pipeline runs
between the builder and common_checks. Because the centralized checks treat MCP
as an inference route and never re-check allowed_routes, a key barred from MCP
routes could mint an envelope at the token endpoint (not itself an MCP route)
and replay it against MCP. Run the route gate before admitting, and clear the
request-scoped budget_reservation, matching the wrapper's sequence; a disallowed
route now surfaces the gate's own 403.
* feat: add silent CLI token refresh for apiKeyHelper support
lite auth print-token prints a valid proxy credential for use as Claude
Code's apiKeyHelper, transparently refreshing it first if the cached JWT
is stale. This unblocks MDM-managed apiKeyHelper deployments (managed
via `lite auth print-token`) that need silent mid-session credential
rotation without restarting the client.
Refresh capability is backed by a virtual key minted with an empty model
list and cli_refresh metadata, kept strictly separate from the actual
(short-lived, real-model-scoped) call credential -- so a leak of the
credential that flows through every LLM request and subprocess env var
can't also self-renew. The refresh flow is single-use: /sso/cli/refresh
mints a fresh JWT + refresh token pair and blocks the presented refresh
token immediately, so a replay can't mint a second pair from it.
Server: /sso/cli/refresh (rotate) and /sso/cli/logout (revoke) endpoints.
lite login now also stores a refresh token; lite logout revokes it
server-side instead of only clearing the local file.
* fix: allow non-admin users to hit CLI refresh routes; resolve apiKeyHelper base_url from token.json
Found via a live end-to-end test against a real proxy + real Claude Code
session: /sso/cli/refresh and /sso/cli/logout were unreachable for any
non-proxy-admin caller, since Depends(user_api_key_auth) pulls in a
route-RBAC gate that 403s any route not on an explicit allowlist. That
made the feature unusable for actual end users, who authenticate as
internal_user. Add both routes to internal_user_routes; the handlers
already do their own fine-grained check (metadata.cli_refresh) same as
/key/block does today.
Also: `lite auth print-token` required an explicit --base-url/
LITELLM_PROXY_URL matching the stored token's origin, defaulting to
localhost:4000 otherwise. But apiKeyHelper is configured bare (no
flags), so this always mismatched a real deployment. Track whether
--base-url was explicitly passed (via click's ParameterSource) and, if
not, resolve the server from token.json directly instead of the CLI
default.
* test: mock refresh-token minting in test_cli_poll_key_tolerates_missing_user_row
Landed on litellm_internal_staging after this branch's refresh-key minting
change; needs the same mock as the other cli_poll_key tests since minting
now runs unconditionally whenever a JWT is generated.
* fix(ci): update test_cli_auth.py for refresh_token contract, regenerate schema.d.ts
_poll_for_authentication now always includes "refresh_token" in its
returned dict, and _handle_team_selection_during_polling returns a dict
instead of a bare JWT string -- test_cli_auth.py predates this branch's
refresh-token work and still asserted the old shapes.
schema.d.ts regenerated via `npm run gen:api` to pick up the new
/sso/cli/refresh and /sso/cli/logout routes (plus unrelated drift from
other PRs merged since it was last generated).
* fix(ci): apply CI's own schema.d.ts diff (enterprise routes I can't generate locally)
Local `npm run gen:api` only sees OSS routes -- this machine's
litellm_enterprise editable install points at a now-deleted temp
directory, so it silently drops enterprise-only routes from the spec.
Applied the exact diff CI's own generation produced instead of
re-running the generator locally.
* fix: close refresh-token race, fail closed on DB down, fix logout base_url
Addresses Greptile review findings on the CLI refresh-token PR:
- cli_refresh_token minted a new JWT + refresh token BEFORE blocking the
presented one. Two concurrent requests bearing the same refresh token
could both pass auth and both mint fresh pairs, yielding four live
credentials from one consumed token. Now the presented token is
consumed atomically first via update_many (only succeeding if it flips
blocked from False/None to True); the loser gets count=0 and is
rejected before anything is minted.
- When prisma_client is None, refresh silently returned a new JWT
without ever being able to mark the presented token consumed, leaving
it valid indefinitely. Now fails closed with a 500 instead.
- `lite logout` sent its revocation POST to ctx.obj["base_url"], which
defaults to localhost:4000 when --base-url isn't passed -- the same
bug print_token had before the base_url_explicit fix, just missed
here. Now resolves the same way: trust the stored token's origin
unless the caller explicitly overrode --base-url.
* fix(ci): satisfy ruff format and narrow token_data type in logout
* fix(security): never trust refresh-token metadata for authorization
Addresses a real privilege-escalation path Veria flagged: cli_refresh_token
read team_id, team_alias, and max_budget straight off the presented
token's own metadata and used them to authorize the new JWT. Since any
authenticated user can self-mint a virtual key with arbitrary metadata
via the ordinary /key/generate endpoint, a self-forged key with
{"cli_refresh": true, "team_id": "<any-team>", "max_budget": 999999999}
would sail through _require_cli_refresh_token's only check
(metadata.cli_refresh == True) and get a JWT scoped to a team the
caller never belonged to, with a budget it never had -- full
cross-team / budget bypass, and a removed team member could keep
refreshing team-scoped sessions indefinitely.
Metadata's team_id is now treated as an untrusted UX hint only: honored
solely if the CALLER (identified by the authenticated key's own
user_id, not client input) is a current member per a fresh
get_user_object lookup. team_alias and max_budget are never read back
from metadata at all -- team_alias comes from a live get_team_object
lookup and max_budget is recomputed with the exact same capping logic
the initial SSO login poll uses. _mint_cli_refresh_token no longer
accepts or stores team_alias/max_budget, only the team_id hint.
Added regression tests proving: a forged/stale team_id is dropped
(falls back to no team, not silently honored), and a forged max_budget
in metadata never reaches the issued JWT.
* fix(ci): catch HTTPException specifically instead of bare Exception (BLE001)
* fix: un-consume refresh token if minting the replacement fails
Greptile flagged a real reliability gap: cli_refresh_token blocks the
presented token atomically, then does several more DB calls before
returning a replacement (user lookup, team lookup, JWT mint, new
refresh-key mint). Since this endpoint exists specifically for fully
unattended apiKeyHelper operation, a single transient failure in that
window (DB hiccup, etc.) permanently stranded the user: their old
token was already dead and no new one was issued, with no recovery
path short of a full interactive browser re-login.
Wrap that window in try/except; on any failure, best-effort revert the
consumed token back to usable (blocked=False) before re-raising, so a
retry can succeed. Standard compensating-action pattern since
generate_key_helper_fn doesn't take an injectable transaction, so
wrapping the whole thing in a real DB transaction isn't practical here.
* fix(security): refresh key had unrestricted model access, not none
Critical bug: _mint_cli_refresh_token used models=[] intending "no LLM
access", but that's backwards in this codebase. Per
_check_model_access_helper: `len(filtered_models) == 0 and len(models)
== 0` -> all_model_access = True. An empty models list on a key with no
team_id means UNRESTRICTED access to every model, not zero access. The
CLI refresh token -- meant to be usable for nothing but silently
exchanging itself for a new JWT -- was actually a fully unrestricted
API key for its entire 90-day lifetime, completely undermining the
whole point of keeping it separate from the short-lived call
credential.
Fixed with two independent layers: allowed_routes hard-restricts the
key to exactly /sso/cli/refresh and /sso/cli/logout (the real enforced
boundary, checked in the shared user_api_key_auth dependency for every
route); models is set to an unmatchable sentinel string as
defense-in-depth in case any code path only consults the models field.
Added an end-to-end regression test that exercises the actual
model-access-control function against a key shaped like the minted
refresh token, rather than only asserting on what arguments were passed
to the key-generation call -- the latter kind of test is exactly what
let the original bug ship, since asserting `models == []` is equally
consistent with "no access" and "unrestricted access" without checking
what the access-control code actually does with that shape.
Also: the compensating-rollback added for reliability un-blocked a
consumed refresh token even when the underlying user no longer exists.
That's a permanent, intentional rejection, not a transient failure --
un-blocking it would let a stale refresh token become valid again for a
different account if the user_id is ever reused/re-registered. Moved
the user-existence check outside the rollback-on-failure block so it
stays permanently blocked.
* refactor: rotate CLI refresh tokens via regenerate_key_fn instead of hand-rolled consume/rollback
The refresh token is already a plain litellm virtual key, so rotation can
delegate to the same atomic DB update /key/regenerate uses instead of a
bespoke update_many + compensating-rollback dance. This makes silent CLI
refresh an Enterprise feature, same as regular key regeneration.
* refactor: replace CLI stateless JWT + refresh-key pair with one self-rotating virtual key
The CLI previously minted two credentials on login: a stateless self-signed
JWT for LLM calls, and a separate DB-backed refresh-only key (scoped away
from ever calling an LLM) just to authorize minting a new JWT. Collapse
this into a single real virtual key, used directly as the LLM bearer token
and re-presented to /sso/cli/refresh to rotate its own secret in place.
This also means the CLI session key now shows up in the Admin UI's Keys
page and can be revoked/regenerated like any other key, rather than being
an invisible, unmanageable stateless token.
* refactor: drop silent CLI refresh, key just expires and requires re-login
/sso/cli/refresh only ever benefited Enterprise deployments (regenerate_key_fn's
gate), while everyone else already fell through to "re-run lite login" on
failure. Cut the endpoint, the rotation logic, and the client-side refresh
path entirely; print-token now just prints the cached key until it hits its
LITELLM_CLI_JWT_EXPIRATION_HOURS duration, then fails fast telling the user
to log in again. Session key itself is unaffected: still a real, revocable
virtual key visible in the Keys UI, `lite logout` still revokes it directly.
* fix(ci): regenerate schema.d.ts after removing /sso/cli/refresh route
* revert: go back to stateless JWT, keep only lite auth print-token
The virtual-key redesign (revocable, Keys-UI-visible credential) wasn't
needed just to support print-token, and cost real server-side surface
(a mint path, a logout-revoke endpoint, migrated tests/docs) for a property
this repo doesn't need yet. Reverting cli_poll_key/_types.py/schema.d.ts
back to the original stateless-JWT design; the only durable addition from
this whole effort is `lite auth print-token` (reads the cached credential,
prints it while fresh, fails with a clear message once it's past
LITELLM_CLI_JWT_EXPIRATION_HOURS) plus the base_url_explicit plumbing it
needs. `lite logout` goes back to clearing the local file only, since a
stateless JWT can't be revoked server-side.
* refactor: move CLI token freshness check to cli_token_utils, drop unnecessary renames
Addresses review: the freshness check is a pure token-shape/timestamp
util, not command logic, so it belongs alongside the other SDK-level
CLI token helpers (load_cli_token, get_litellm_gateway_api_key) rather
than in commands/auth.py. Also reverted a few incidental jwt_token/
session_key variable and string renames that weren't load-bearing.
get_key_object's raw transport error propagated uncaught out of
_reload_admitted_key as an opaque 500; classify it via the shared
_raise_503_if_db_unavailable helper (also used by the live-policy gate) so a
database outage is a retryable 503, while a key-not-found ProxyException stays
the fail-closed 401.
Streaming requests return from common_request_processing before
async_post_call_success_hook runs, so response._hidden_params.additional_headers
never gets the v3 x-ratelimit-{descriptor_key}-{remaining|limit}-{rate_limit_type}
entries. Prometheus / logging callbacks that read those values from
standard_logging_object.hidden_params.additional_headers then see nothing;
combined with the pre-existing gap that Prometheus reads from that same slot
(LIT-2577 / PR #28816), per-key remaining RPM/TPM cannot be monitored for
streaming traffic at all.
Fix in three parts:
- Stash the pre-call RateLimitResponse in the metadata channels the async
success-logging callback inherits, alongside the existing top-level entry
the non-streaming path reads.
- Add async_logging_hook to the v3 handler. It fires in a distinct earlier
loop inside async_success_handler (all callbacks' async_logging_hook
complete before any async_log_success_event starts), so mirroring the
pre-call snapshot into standard_logging_object.hidden_params.additional_headers
and response._hidden_params.additional_headers here guarantees every
downstream success callback sees the values regardless of registration
order. Non-streaming keeps the existing async_post_call_success_hook write
and this hook re-populates the same values idempotently.
- Extract the shared `_merge_ratelimit_statuses_into_additional_headers`
helper the non-streaming path already had inlined so both callsites emit
the identical key shape.
Over-budget rendered 401 (should be 429), model-access and other typed
failures collapsed to 401, and a transient DB outage was masked as an auth
error. Mirror UserAPIKeyAuthExceptionHandler: budget maps to 429, a sub-check's
own HTTPException/ProxyException keeps its status, a DB outage is a retryable
503, and only a genuinely unresolvable failure stays the fail-closed 401.
Two follow-ups on the envelope admission arm flagged in review.
Team revocation bypass: _reload_admitted_key checked only the key's own
blocked/expires, so blocking a key's team left every envelope minted under it
live until expiry. Reload the team and reject a blocked team, mirroring
common_checks, so a team block revokes its envelopes immediately.
Caller-overridable upstream token: egress resolves the per-server auth header
alias-first, but injection keyed under server_name, so for a server with a
distinct alias a caller-forwarded x-mcp-{alias}-authorization sat at the
higher-priority slot and paired the admitted identity with an attacker's
upstream credential. Inject under alias-first so the sealed token owns the slot
egress resolves.
The bridge envelope sealed only user_id/server_id, and admission fabricated a
UserAPIKeyAuth(user_id=...) with no object_permission, team_id, org_id, or key
identity. Downstream MCP permission checks read the missing restrictions as
unrestricted, so a caller holding a valid envelope for a restricted key could
reach tools and servers that key was never granted, and a revoked key kept
working until the envelope expired.
Bind the hashed authorizing key into the envelope identity and reload the live
UserAPIKeyAuth by it at admission via get_key_object, failing closed with a 401
when the key is missing, blocked, or expired. Authorization is resolved fresh
per request instead of frozen at mint time, so current key/team/org and tool
restrictions plus revocation are enforced.
- config: KeywordTierRule now strips and drops blank/whitespace keywords (a stray
"" makes _keyword_matches match every prompt, silently forcing that tier for all
traffic); still requires at least one real keyword to remain
- frontend build_complexity_router_config: trim keywords and drop rules left empty so
an unfilled "Add keyword rule" row no longer ships a rule the backend rejects with a
400 in the heuristic (non-semantic) flow, where the client-side semantic guard doesn't run
- proxy clear_cache / delete_model: the auto_router/ prefix also covers quality_router/
and adaptive_router/, so pop the model_name from all four router registries (no-op
where absent) instead of only auto/complexity; otherwise a DB quality_router's stale
entry made reload raise "already exists" and abort, and adaptive left a leak
- frontend ComplexityRouterConfig: only render the Keyword Tier Overrides and Semantic
keyword matching sections when their change handlers are provided, so the edit-auto-
router modal (which omits them) no longer shows interactive-but-dead controls
Replace the request.path_params read (and its defensive getattr guard) with
the route template. A real Starlette request always exposes path_params, but
common_checks runs on lightweight request doubles that don't, so reading it
directly forced a getattr workaround that only existed to tolerate those
doubles.
Instead, match the route template (/team/{team_id}) to identify the RESTful
update route and take the team id from the last path segment. This drops the
path_params dependency entirely, and because the template distinguishes the
PATCH route from its single-segment siblings (/team/new, /team/list, ...), it
also avoids a spurious team lookup those routes would otherwise trigger if we
matched the resolved path shape alone.
A dynamically registered (RFC 7591) OAuth client persisted onto the MCP server row is bound to the redirect_uri it was first registered with, but that binding was never recorded. After the proxy's public origin changed, every authorize paired the reused client with the new callback and the IdP rejected it permanently.
The DCR persist now records redirect_uris alongside the client identity. The admin register path treats a positive mismatch between the recording and the current callback as stale and re-registers a replacement client; rows without a recording (pre-existing installs and admin-configured clients) are grandfathered so upgrades never re-mint client_ids or orphan refresh tokens. The persist also writes client_secret and token_endpoint_auth_method explicitly as None when absent so the credential blob merge cannot pair a re-registered public client with the previous client's secret. Public register routes and non-admin callers keep existing behavior.
Closes#32473
apply_json_merge_patch recurses into nested objects, which the repo's recursive_detector code-quality check flags because unbounded recursion over caller-supplied JSON has caused CPU/stack issues before. Cap the recursion at a depth far above any realistic team-metadata shape and reject deeper patches with a ValueError so a pathologically nested body fails closed instead of overflowing the stack, then register the function in the detector's ignore list alongside the other depth-bounded JSON walkers
delete_model popped the auto_routers/complexity_routers registries by the deleted
deployment's model_name without checking it was actually an auto_router/* deployment.
Deleting a regular DB model that merely shares a name with a config-defined router
therefore evicted that router, which add_deployment never restores, leaving it
unroutable until a proxy restart. This is the same cross-tenant DoS clear_cache was
hardened against; mirror its auto_router/ prefix guard here.
Extracts _deployment_name_and_model to read model_name and litellm_params.model from
the deployment (delete_deployment returns the raw model_list dict at runtime despite
its Deployment annotation), and adds a regression test asserting a same-named config
router survives deletion of an unrelated regular model.
Wire the coarse route gate so PATCH /team/{team_id} is reachable by exactly the roles that can call POST /team/update: proxy admins, org admins of the team's own organization, and JWT admins. Regular internal users and view-only proxy admins stay blocked, matching the existing endpoint
Because the team id lives in the path rather than the body, the org-context resolver now also reads it from path_team_id for the bare /team/{team_id} route, so an org admin's organization is resolved and injected the same way it already is for POST /team/update. /team/{team_id} is added to management_routes rather than the role-agnostic self_managed_routes; the latter would have opened POST /team/new to any authenticated user through the shared /team/{team_id} path pattern
Add deterministic keyword-to-tier overrides and optional embedding-based
(semantic) keyword matching to the complexity router, and surface both in the
Add Auto Router UI behind a Router Type selector: "Auto-Router v2 [Recommended]"
(complexity tiers + keyword overrides + semantic matching, the default) and
"Semantic Router [to be deprecated]" (the existing utterance-based router,
unchanged). Keyword-to-tier overrides resolve to the highest tier matched
rather than the first keyword matched, so match order no longer affects the
routing decision.
Backend:
- config: KeywordTierRule model plus keyword_tier_rules, semantic_keyword_matching,
embedding_model, and match_threshold on ComplexityRouterConfig, with a validator
requiring an embedding model and rules when semantic matching is on
- complexity_router: evaluate keyword rules before scoring; lexical matches escalate
to the most-severe matched tier (order-independent), and semantic mode reuses
LiteLLMRouterEncoder + SemanticRouter to match paraphrases by cosine similarity,
falling back to the scorer when nothing matches
- model management: clear complexity_routers on cache reload so config edits take effect
Frontend:
- Add Auto Router tab restores the Router Type radio (Auto-Router v2 recommended
by default, Semantic Router still available) and sends keyword_tier_rules plus
the semantic settings on the recommended path, instead of flattening keywords
into custom_technical_keywords
- client-side guard blocks submit when semantic matching is enabled without an
embedding model or without any keyword tier rules, mirroring the backend validator
- moved the "How Classification Works" explainer below Custom Technical Keywords
and above Keyword Tier Overrides
- remove the Test Connection action from the recommended flow, which can't build a
valid pre-save payload for a router (leaves a TODO for a JSON preview / config
test follow-up)
Tests cover lexical escalation, semantic matching via the real library with injected
embeddings, the semantic config guard, config validation, the reload-clear
regression, and the frontend payload builder
Add a RESTful PATCH /team/{team_id} that partially updates a team using RFC 7386 JSON Merge Patch. team_id comes from the path, and metadata is merged with the team's stored metadata instead of being replaced wholesale the way POST /team/update does: an omitted key is preserved, key: null deletes it, and any other value overwrites, recursing into nested objects. Every other field behaves the same as POST /team/update
The handler delegates to the existing update path, so authorization, budget checks, system-managed-key stripping, metadata encryption, cache refresh, and audit logging are shared rather than reimplemented. POST /team/update is untouched, so the change is purely additive
A trailing slash on --base-url (or LITELLM_PROXY_URL) produced
double-slash URLs like https://host//sso/cli/start, which 404s. Normalize
once in the CLI's top-level group callback so every subcommand benefits.
The /guardrails/usage/{overview,detail,logs} endpoints resolved guardrails only
from the litellm_guardrailstable Prisma table, so guardrails defined in
config.yaml (which live only in IN_MEMORY_GUARDRAIL_HANDLER) were invisible:
detail 404'd, overview omitted them or rendered them as Custom/Guardrail
orphans, and logs missed their logical-name alias.
Add config-owned accessors (list_config_guardrails, get_config_guardrail_by_id)
to the in-memory handler and use them in the usage endpoints, mirroring the
union/fallback already used by list_guardrails_v2 and get_guardrail_info. Also
preserve guardrail_info when storing a config guardrail (type/description were
dropped at initialize time) and read the Prisma-row / dict / LitellmParams
shapes uniformly.
Resolves LIT-2529
* fix(proxy): match list/dict guardrail_mode in compliance mode checks
* test(compliance): cover ComplianceChecker guardrail_mode shapes (str/list/dict/None)
* fix(proxy): trust only Mode.default in compliance mode matching (ignore tag overrides)
* fix(proxy): match dict guardrail_mode only when every branch runs in mode (no false-compliant)
* fix(proxy): treat multi-mode guardrail_mode as unresolved (no false-compliant)
The list branch previously counted a guardrail configured with mode:
[pre_call, post_call] under every listed mode. But when the writer cannot
infer the concrete hook that fired (apply_guardrail invocations), the raw
list is logged, and an image-only request that only reaches the post-call
path still records both modes. That let a pre_call compliance check pass on
a request that only ran post_call.
Match the tightened dict semantics: a list now counts for mode only when
every listed mode equals mode. Same trade-off (under-report instead of
false-COMPLIANT). Speculative set support is dropped (spend logs are
JSON-serialized, sets do not cross the wire).
Tests updated to reflect the tightened list semantics, deduplicated (single
TestModeMatching class), and shortened. The invariant is now expressed as
a computed check: True implies every branch runs in the matched mode.
---------
Co-authored-by: Marton Schneider <marton@schneider.co.nl>
* fix(proxy): build redis usage cache from REDIS_* env when cache backend is not Redis
Selecting a semantic (or any non-Redis-KV) response cache left
redis_usage_cache unset, silently downgrading cross-pod rate limits,
parallel-request limits, spend coordination, and the pod lock manager
to per-pod in-memory state. Fall back to a standalone RedisCache built
from REDIS_* environment variables, mirroring the existing
use_redis_transaction_buffer escape hatch, which now shares the same
helper.
Resolves LIT-3861
* feat(proxy): configure the coordination redis independently of the response cache
Adds general_settings.coordination_redis, an explicit block for the Redis
the proxy uses for cross-pod rate limits, parallel-request limits, spend
tracking, the pod lock manager, and shared health checks. Resolution order
is the explicit block, then a plain-Redis response-cache backend, then the
REDIS_* environment. Cluster and sentinel targets are supported, and a
cluster target now builds a RedisClusterCache so cluster-aware consumers
take the cluster path.
Admins can configure it from the Caching page of the dashboard via
/coordination_redis/settings, which reports which source is in effect,
redacts credentials on read, and offers a connection test. Settings saved
there are read back at startup so they take effect on restart.
Also fixes redis client construction so an explicitly configured host
outranks REDIS_URL in the environment. Previously the url branch stripped
the caller's host and port, so an explicit block, or a connection test
typed into the dashboard, silently targeted whatever REDIS_URL named
* fix(ui): move coordination_redis_settings into renamed _components directory
---------
Co-authored-by: Yucheng Zhu <yucheng@berri.ai>
Selecting a semantic (or any non-Redis-KV) response cache left
redis_usage_cache unset, silently downgrading cross-pod rate limits,
parallel-request limits, spend coordination, and the pod lock manager
to per-pod in-memory state. Fall back to a standalone RedisCache built
from REDIS_* environment variables, mirroring the existing
use_redis_transaction_buffer escape hatch, which now shares the same
helper.
Resolves LIT-3861
A correctly signed JWT whose user_id or server_id claim was an empty string
passed claims validation but raised ValidationError from the EnvelopeIdentity
constructor inside open_envelope, breaking its never-raises guarantee. The
claims model now mirrors the identity's min_length constraints, so any claim
set that validates also constructs, and the empty-identity case maps to
MalformedPayload like every other bad claim shape.
Pure, unwired module: mints and opens the single client-held bearer that
carries both a litellm identity and the encrypted upstream OAuth grant with
zero server-side storage. HS256 JWT signing (same approach as the BYOK
session bearer) plus the existing encrypt_value/decrypt_value symmetric
helpers, with all key material and the clock injected as parameters. Opening
returns typed frozen error values (not_an_envelope, bad_signature, expired,
malformed_payload, decrypt_failed); minting rejects envelopes over
MAX_ENVELOPE_BYTES with a typed error instead of truncating. Error values
and reprs never carry token material.
For MCP servers with auth_type=oauth2 + delegate_auth_to_upstream=true, a
client-supplied upstream token that the upstream rejects was masked: the
upstream 401 raised during tools/list is absorbed by the list handler, so on a
single-server route a rejected token became HTTP 200 with an empty tool list.
Clients showed "0 tools" instead of re-authenticating, and monitoring never saw
an unauthorized signal.
Extend the connect-time preflight _check_passthrough_upstream_auth to probe
delegate-auth servers with the caller's bare Authorization bearer, reusing the
existing _probe_upstream_auth and the RFC 6750 challenge builder, so a rejected
token fails the connect with 401 + WWW-Authenticate error="invalid_token" and a
compliant client re-runs the upstream OAuth flow.
The bare Authorization header is a valid upstream token only when admission took
the delegate bypass, so the delegate target is resolved through
get_mcp_server_by_name (the same resolver admission uses) rather than the wider
allowed-server prefix/access-group matching. A name that reaches a delegate
server only via server_id or an access group is admitted as a real LiteLLM key,
so probing it would leak that key upstream; requiring the admission-resolver
match closes that gap. The probe is gated to single-server routes (matching the
OBO preflight), keyed to the caller's authorized set by server_id, and the
challenge echoes the requested name so aliased routes get the same
resource_metadata URL as the tokenless preemptive challenge. Tokenless requests
keep flowing to the preemptive discovery challenge unchanged.
Resolves LIT-4194
