Track per-provider and per-(provider,upstream-model) upstream-attempt
outcomes using the existing fixed-window counter machinery (limits.go),
following mcp_a2a.go's per-target counter pattern: kind-embedded keys
(kindProvider="prov", kindProviderModel="provmodel") keep a provider
scope collision-safe against a user/group/MCP-target/agent of the same
name.
limiter.recordProviderAttempt(provider, model, resp, err) increments an
"attempts" counter on every call, and a "failures" counter only for a
provider-fault outcome — reusing retry.go's own isTransient(resp, err)
classification exactly (transport/connection error, HTTP 429, or a 5xx),
not forking it. Both counters are written at minute and day granularity
only; provider health is a now-and-today question, not a billing one, so
there is no month window. limiter.providerUsage batches every scope's
read into one storeGetMulti round trip, mirroring targetUsage's own
single-batch discipline.
Wired at every chokepoint an upstream HTTP attempt resolves:
- providers.go's upstreamJSON/upstreamRawBytes path (chat, embeddings,
images, audio) via retry.go's retryPolicy.do, which now looks up an
optional attemptRecorder from ctx and invokes it once per retry
attempt (attempt-accounting: a request retried twice before
succeeding reports three attempts, not one).
- routes_unified.go's runUnified (chat/embeddings, streaming and
non-streaming alike — both funnel through the same upstreamJSON call).
- routes_media.go's three media handlers (images.generations,
audio.speech, audio.transcriptions).
- routes_passthrough.go's proxyUpstream (native provider passthrough) —
a single un-retried attempt, provider-level only: the upstream model
lives in the response body, read only after the attempt resolves.
The attemptRecorder is threaded via context (providers.go's
withAttemptRecorder/attemptRecorderFromContext), not a new function
parameter on every call site — proxyUpstream and retryPolicy.do are
both shared with paths that must NOT record provider accounting
(registry.go's discovery listModels calls, and the MCP/A2A target
proxy, mcp_a2a.go's handleTargetProxy), so scoping via context keeps
their signatures unchanged and those callers correctly opt out by
simply never wrapping their context.
Data layer for the upcoming Vue admin charts (v0.2 data-layer task).
Tokens-in/out split (limits.go): metricTok replaced by metricTokIn
("tokin") and metricTokOut ("tokout"). account() records usage.prompt
and usage.completion independently, skipping a direction only when its
own value is zero. A TokensPerDay/TokensPerMonth limit still enforces
one TOTAL budget: tokenBudgetViolation reads both counters in one
storeGetMulti batch and sums them; the violation message still says
"tokens". Estimated usage (the request-body-size fallback) lands
entirely in tokin, documented at its call site.
Hour window (limits.go): windowHour ("hour"), bucket format
"2006010215" UTC, hourWindowTTL (48h). checkAndCount/account both write
it on every metered route; no LimitsConfig field ever names it, so
evaluateScope never evaluates it. dayWindowTTL/monthWindowTTL bumped to
35d/400d so the usage-history API's largest span always finds a live
key.
Total scope (limits.go, routes_unified.go): a synthetic
{kind:"total", id:"all"} scope, limits always nil. withTotalScope
wraps buildLimitScopes' result at every metered route (unified,
media, passthrough, mcp/a2a) so none can forget it; handleAdminAPI's
own accounting stays on buildLimitScopes alone, so admin traffic never
contributes to it.
History API (admin.go): GET /admin/api/usage/history?scope=&metric=&
window=&span= — admin-gated like the other two JSON routes, but
skips checkAndCount ahead of that same change landing for every
/admin/api/* route in a later task. Validates scope kind/metric/window
(400), span bounds per window (400), and unknown user/group id (404).
Computes every bucket key up front and reads them in ONE storeGetMulti
batch; a storeDown read is 503, never a silently-zero series. Works
against memoryStore too.
Admin usage API (admin.go): scopeUsage/adminUsageEntryView now expose
tokensInPerDay/tokensOutPerDay and their per-month counterparts in
place of the combined tokensPerDay/tokensPerMonth pair; buildAdminUsage
adds a "total" row to the response, still one storeGetMulti round trip
overall. usageKeysPerScope names the per-scope key stride (was a bare
6, now 8), closing a deferred review follow-up while the count changed
anyway.
Tests: TDD throughout — bucket/window-key math incl. UTC and hour
boundaries, the month step-back day-31 AddDate trap, split accounting,
token budget summing both directions, total-scope counting-without-
evaluating on every metered route, and the full history API (shape,
oldest-first, span bounds, validation table, 404, 503, one-batch
assertion via a counting stub). Integration: TestAdminDashboard now
fetches an hour history series for user alice and for total and
asserts a non-zero current-hour bucket.
Migration: none — old "tok" counter keys simply expire on their
existing TTL; nothing is deployed yet.
Add GET /v1/mcp/servers and GET /v1/agents: group-filtered,
name-sorted registry listings of configured MCP servers and A2A
agents, with their gateway-relative proxy (and, for agents, card)
URLs.
Add handleTargetProxy for /mcp/{name}/{rest...} and
/a2a/{name}/{rest...}: reverse-proxies to the target's configured
URL. Checks run unknown name (404), group deny via allowsMCP/
allowsAgent (403), request-rate limits (429/503), then Upgrade
(501) and path traversal (400) around the proxy call itself. No
upstream credential is injected — MCP servers and A2A agents are
in-cluster targets, unlike native provider passthrough.
Extract proxyUpstream from routes_passthrough.go's handlePassthrough
into a shared reverse-proxy core (header stripping, SSE-safe
flushWriter streaming, dead-upstream 502, canceled-client log-only,
optional JSON usage teeing) used by both native passthrough and the
new target proxy. Behavior-preserving for Task 13: its tests pass
unmodified.
Validate every configured MCP-server and agent target URL at
construction (url.Parse, http/https scheme only) — a malformed or
non-HTTP target is a constructor error, not a per-request 502.
lukaszraczylo