Sirloin Errors

The errors operators and clients see most often, with code references and remediation. Domain billing errors are defined in apps/sirloin/internal/app/services/billing/domain/errors.go. Cross-cuts: security-model for auth-related errors, observability for log/trace lookup.

Most billing errors are wrapped by BillingError (Op, Entity, Err, Details) — search Axiom by Op="checkout" etc. when triaging.

Domain Errors

Error	When raised	Meaning	Remediation	Source
subscription not found	RPCs that resolve a subscription by id	Caller passed a stale/foreign id, or DB ↔ Chargebee drift	Verify id in admin (strip); reconcile via cmd/scripts/wallet-recovery-*	billing/domain/errors.go
invoice not found	Payment recording, dunning retry	Chargebee invoice id missing locally	Re-run event poller or call SubmitPaidInvoice	billing/domain/errors.go
customer not found	Any subscription op	Clerk user lacks Chargebee customer	Recreate via checkout flow	billing/domain/errors.go
coupon not found	ValidateCoupon, checkout	Coupon code invalid or removed in Chargebee	Caller should clear input	billing/domain/errors.go
item price not found	ListProducts, checkout	Plan/addon price missing in Chargebee	Sync plans (cmd/scripts/backfill-purchase-prices)	billing/domain/errors.go
payment not found	GetPayment	Primer/Chargebee payment missing	Wait for poller; verify transactionID	billing/domain/errors.go
invalid subscription state	Cancel / reactivate / downgrade	State machine refuses transition	Read billing-pitfalls; fix in admin	billing/domain/errors.go
invalid invoice state	Payment recording	Invoice already paid/voided	No action; idempotent retry safe	billing/domain/errors.go
subscription is not active	Usage-gated RPCs (GenerateMedia)	Sub is future, cancelled, or paused	Direct user to checkout / reactivation	billing/domain/errors.go
payment currency does not match invoice currency	Payment recording	Primer settled in non-matching currency	Manual reconcile in Chargebee	billing/domain/errors.go
service temporarily unavailable	Any Chargebee/Primer call	Circuit breaker open	Wait, retry; check provider status	billing/domain/errors.go
rate limited by downstream service	Chargebee/Primer 429	Upstream throttled	Backoff; reduce poller cadence if sustained	billing/domain/errors.go

Webhook Errors

Status	Path	Cause	Remediation
401 Unauthorized	/webhooks/chargebee/events	Basic auth header missing or wrong	Set SIRLOIN_CHARGEBEE_WEBHOOK_USERNAME / _PASSWORD; reconfigure Chargebee endpoint creds
401 Unauthorized	/webhooks/primer/disputes, /webhooks/primer/payments	HMAC mismatch or signedAt outside 3-min skew	Re-verify SIRLOIN_PRIMER_WEBHOOK_SECRET; check NTP drift on host
401 Unauthorized	/webhooks/ondato/verification-status	Shared-secret mismatch	Verify SIRLOIN_ONDATO_WEBHOOK_SECRET
405 Method Not Allowed	any webhook	Caller used GET	Use POST
413 Payload Too Large	/webhooks/primer/disputes	Body > 1 MiB	Trim payload upstream; otherwise no path

Source: internal/app/services/billing/webhooks/chargebeewebhook.go, internal/app/services/billing/disputes/primerwebhook.go.

gRPC Errors

Sirloin maps domain errors to gRPC status codes at the handler edge. Common mappings (TODO(@zen): exhaustive table — derive from each handler):

gRPC code	Typical cause	Examples
NOT_FOUND	Domain *NotFound errors	subscription/invoice/customer/coupon
FAILED_PRECONDITION	invalid * state, subscription is not active	usage-gated RPCs
UNAVAILABLE	Circuit breaker open (ErrServiceUnavailable)	Chargebee/Primer outage
RESOURCE_EXHAUSTED	ErrRateLimited	upstream 429
UNAUTHENTICATED	Missing/invalid Clerk token	brisket / strip handlers
PERMISSION_DENIED	Strip RPC without admin role	StripService

Startup Errors

Error / log	Meaning	Remediation
MissingError("SIRLOIN_DATABASE_URL")	DB DSN unset	Set env var; sirloin refuses to start
using default port :50051 (warn)	SIRLOIN_PORT unset	Acceptable in dev
Chargebee webhook credentials not set (warn)	Username or password empty	Webhooks will return 401 until set
Primer API key not set (warn)	Primer checkout disabled	Set key for prod
Primer webhook secret not set (warn)	Primer webhooks rejected	Set secret

Source: apps/sirloin/internal/app/config/config.go.

Upstream-Propagated Errors

Chargebee and Primer errors surface inside BillingError.Err with the provider’s status / code. Recurring patterns:

Provider error	What it means	Action
Chargebee 404	Resource not in Chargebee (returned as nil, not an error — see billing-pitfalls)	Treat as *NotFound; don’t retry
Chargebee 429	Rate limited	Backoff; align poller
Chargebee 5xx	Provider outage	Circuit breaker opens; alerts fire
Primer Authentication failed	Bad API key or wrong env (sandbox vs prod)	Verify SIRLOIN_PRIMER_API_KEY prefix
Primer Idempotency key conflict	Reusing the wrong key	Use transactionID per billing-pitfalls

Resolved

• SubmitPaidInvoice does not distinguish “already credited” from “invoice not found” at the gRPC code level. Already-processed payments are treated as success (idempotent: PurchaseExists short-circuits and returns an empty SubmitPaidInvoiceResponse). Missing payment/invoice returns NotFound. Other status mappings: Unavailable for errPrimerPaymentStillProcessing, FailedPrecondition for errPrimerPaymentFailed, Internal for everything else (apps/sirloin/internal/app/services/billing/submitpaidinvoice.go:182-:194, :351-:368, :238-:240).

TODO(@zen)

• TODO(@zen): exhaustive gRPC code mapping per RPC.
• TODO(@zen): full enumeration of BillingError Op values used in production.