Files
accounted/lib/events/types.ts
T
Jakob Wennberg 12ce693eb6 feat(mcp): make search-only read tools reachable, and put the payload ceiling into reverse (#1976)
* feat(api): surface the registry's worked examples in the OpenAPI spec and generated skill

EndpointDefinition.example is required and every one of the 125 v1 endpoints
populates example.response, but generateOpenApiSpec() never emitted it. The
examples reached only the docs markdown builder, so /api/v1/openapi.json
carried none and the generated skills/accounted-api had zero json blocks in
all 12 reference files: every agent reading the spec or installing the skill
got schemas with no concrete body.

Emit example on the application/json media types (request body and 200
response) and teach the portable renderOperationMd to print it as a fenced
json block. 178 worked examples now reach the skill. SKILL.md is unchanged:
the examples land in the on-demand reference files, not the entry file.

Attached to JSON media types only, so a multipart body and a binary
application/pdf response do not advertise an example they cannot send.

Adds the one missing example.request (currency-revaluation) so the new
exhaustive coverage assertions hold.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* fix(api): emit Retry-After on a v1 429 so the documented contract is real

The published accounted-api skill has told agents to honor Retry-After on a
429 since it shipped, but no /api/v1 route ever sent one: the wrapper's auth
failure path early-returns through v1ErrorResponseFromCode, whose finalize()
set only X-Request-Id and Gnubok-Version. Unattended clients had nothing to
pace against and had to back off blindly.

60 seconds is an exact upper bound rather than a guess: the rate limiter is a
fixed one-minute tumbling window per key row and the limited branch does not
slide it. The value moves into an exported constant next to that limiter, so
the MCP server's hardcoded '60' now reads from the same place.

Also corrects the withApiV1 doc comment, which claimed step 8 stamps
X-RateLimit-Limit. It never did.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* test(mcp): guard the tools/list payload for the namespace new installs get

The payload ratchet only ever serialized the gnubok_* projection. The
accounted_* projection is inherently larger (every tool reference gains 3
chars, ~209 tokens across the default catalog) and CLAUDE.md points new MCP
installs at exactly that namespace, so the payload a new user's client
receives was never measured. It had already drifted ~90 tokens past the
63.4K ceiling while the guarded number sat comfortably under it.

Measure both and assert on the larger. The ceiling moves to 63.6K to cover
the real worst case; this buys no new catalog surface. A second test pins the
direction of the delta so Math.max cannot silently stop describing reality.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

* feat(mcp): make search-only read tools reachable, and put the payload ceiling into reverse

DECISIONS.md records on 2026-08-26 that gnubok_reconcile_match had to be
promoted back into the default catalog because "a search-only tool is
uncallable on Claude.ai". That is a client-side limit, not a server one: the
tools/call dispatcher has always resolved names against the whole tools array,
and isDefaultCatalogTool gates only what tools/list shows. So
catalogVisibility: 'search' was unusable as a payload lever for reads, and the
ceiling could only ever go up.

gnubok_call_tool gives such a client one visible name to forward through. It
is a rewrite in the dispatcher rather than a forwarding wrapper: {tool,
arguments} is rebound to the inner tool BEFORE resolution, so the scope check,
unknown-argument guard, company routing, test-key write block, staging _meta
and telemetry all apply to the real target instead of being bypassed. Reads
only; a write must be named directly so its approval contract stays visible.

Alongside it, gnubok_get_agent_briefing's outputSchema drops 7743 to 4565
chars. Four sub-schemas whose interiors were documentation rather than
contract are condensed to a permissive object plus a fuller description;
agent-briefing.test.ts already pins their runtime shape, so nothing is left
unguarded.

Net on the guarded (accounted) projection: 63 491 to 62 942 tokens, with the
new tool included. The ceiling moves 63.6K DOWN to 63.1K, the first tightening
in that ledger, and the note now says to demote a read before proposing a bump.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Jakob Wennberg <311770904+jakobwennberg-oss@users.noreply.github.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-27 17:45:40 +02:00

378 lines
23 KiB
TypeScript

import type {
JournalEntry,
Invoice,
Transaction,
Customer,
Supplier,
Article,
FiscalPeriod,
DocumentAttachment,
Receipt,
CreditNote,
ReconciliationMethod,
InvoiceInboxItem,
SupplierInvoice,
} from '@/types'
// ============================================================
// Core Event Types: discriminated union of all system events
// ============================================================
/**
* Who runs AI extraction on an uploaded document.
* - 'invoice-inbox': the inbox extracts and mirrors the result itself.
* - 'none': nobody should; the caller already holds the booking.
* Unset: the document-extraction extension extracts (default).
*/
export type DocumentExtractionOwner = 'invoice-inbox' | 'none'
export type CoreEvent =
// Bookkeeping
| { type: 'journal_entry.drafted'; payload: { entry: JournalEntry; userId: string; companyId: string } }
| { type: 'journal_entry.committed'; payload: { entry: JournalEntry; userId: string; companyId: string } }
| { type: 'journal_entry.corrected'; payload: { original: JournalEntry; storno: JournalEntry; corrected: JournalEntry; userId: string; companyId: string } }
| { type: 'journal_entry.reversed'; payload: { originalEntry: JournalEntry; reversalEntry: JournalEntry; userId: string; companyId: string } }
| { type: 'journal_entry.deleted'; payload: { entryId: string; voucherSeries: string; voucherNumber: number; userId: string; companyId: string } }
// Documents
// extractionOwner: set by the invoice inbox on documents it extracts itself,
// so the document-extraction extension yields instead of racing it (the
// inbox row does not exist yet when this event fires inside uploadDocument).
// 'none' is an explicit opt-out: the uploader already knows the booking
// (provider underlag import links each file to its posted verifikat), so
// running a paid model over it would buy nothing. The extension stamps the
// row as skipped instead of extracting.
| { type: 'document.uploaded'; payload: { document: DocumentAttachment; userId: string; companyId: string; extractionOwner?: DocumentExtractionOwner } }
| { type: 'document.accessed'; payload: { document: { id: string; file_name: string }; userId: string; companyId: string } }
| { type: 'document.deleted'; payload: { document: { id: string; file_name: string }; userId: string; companyId: string } }
// Invoicing
| { type: 'invoice.created'; payload: { invoice: Invoice; userId: string; companyId: string } }
// Hard delete of an un-finalized, unnumbered draft (no F-series number was
// consumed). Carries only the identifiers (the row is gone) so the audit
// log can record who removed which draft and when. Numbered drafts are
// makulerade instead and surface via the journal, not this event.
| { type: 'invoice.draft_deleted'; payload: { invoiceId: string; userId: string; companyId: string } }
| { type: 'invoice.sent'; payload: { invoice: Invoice; userId: string; companyId: string } }
| { type: 'invoice.paid'; payload: { invoice: Invoice; paymentAmount: number; paymentDate: string; userId: string; companyId: string } }
| { type: 'credit_note.created'; payload: { creditNote: CreditNote; userId: string; companyId: string } }
// Recurring invoices: emitted by the daily cron after a schedule spawns
// an invoice. `autoSent` tells observers whether the email also went out
// (false means it was created as draft for manual review).
| { type: 'recurring_invoice.executed'; payload: {
scheduleId: string
invoice: Invoice
autoSent: boolean
warning: string | null
userId: string
companyId: string
} }
// Banking
| { type: 'transaction.synced'; payload: { transactions: Transaction[]; userId: string; companyId: string } }
| { type: 'transaction.categorized'; payload: { transaction: Transaction; account: string; taxCode: string; userId: string; companyId: string } }
| { type: 'transaction.reconciled'; payload: { transaction: Transaction; journalEntryId: string; method: ReconciliationMethod; userId: string; companyId: string } }
// Account-keyed reconciliation (lib/reconciliation/actions.ts): one event per
// link made or removed on any reconcilable account (bank:<cash_account_id>,
// skattekonto, later manual:NNNN). `transaction.reconciled` keeps firing for
// bank links made through the bank engine; these are the kind-agnostic
// signals the flows builder triggers on.
| { type: 'reconciliation.matched'; payload: { accountKey: string; externalId: string; journalEntryId: string; method: 'manual' | 'proposal'; userId: string; companyId: string } }
| { type: 'reconciliation.unmatched'; payload: { accountKey: string; externalId: string; previousJournalEntryId: string | null; userId: string; companyId: string } }
// Sign-off: the human (or agent-staged, user-approved) assertion "reconciled
// through this date" on one account (lib/reconciliation/signoff.ts), and its undo.
| { type: 'reconciliation.signed_off'; payload: { accountKey: string; signoffId: string; throughDate: string; unexplainedDifference: number | null; userId: string; companyId: string } }
| { type: 'reconciliation.reopened'; payload: { accountKey: string; signoffId: string; throughDate: string; reason: string | null; userId: string; companyId: string } }
// Bank connection lifecycle: consent + account selection are the
// GDPR/PSD2 audit points; emitted to event_log for compliance trail.
| { type: 'bank_connection.consent_granted'; payload: { connectionId: string; bankName: string | null; accountCount: number; consentExpiresAt: string | null; userId: string; companyId: string } }
| { type: 'bank_connection.account_selection_changed'; payload: { connectionId: string; bankName: string | null; previousStatus: string; newStatus: string; enabledCount: number; totalCount: number; userId: string; companyId: string } }
| { type: 'bank_connection.revoked'; payload: { connectionId: string; bankName: string | null; userId: string; companyId: string } }
// Emitted when a new or renewed connection supersedes an older row for the
// same bank in the same company: the old row is parked as 'revoked' with
// superseded_by pointing at the replacement, and its transactions are
// re-pointed. connectionId is the SUPERSEDED (old) row, mirroring .revoked.
| { type: 'bank_connection.superseded'; payload: { connectionId: string; supersededById: string; bankName: string | null; userId: string; companyId: string } }
// Emitted when the bank/provider redirects the OAuth callback back with an
// error instead of an authorization code: denied consent, a bank-side
// failure (e.g. Handelsbanken's missing corporate fullmakt), or an expired
// signing session. Durable failure trail (issue #1716): the pending row is
// deleted right after and console logs expire, so without this event
// support cannot answer which attempt failed, with which error, on whose
// side. connectionId may reference a row deleted by the same request.
| { type: 'bank_connection.consent_denied'; payload: {
connectionId: string
bankName: string | null
psuType: string | null
errorCode: string
errorDescription: string | null
priorStatus: string
userId: string
companyId: string
} }
// Emitted when the code-for-session exchange or connection finalization
// throws after the bank redirected back successfully. Same audit doctrine
// as consent_denied: the fresh-connect row is deleted by cleanup and the
// console log expires, leaving support nothing to answer from.
| { type: 'bank_connection.finalize_failed'; payload: {
connectionId: string
bankName: string | null
reason: string
priorStatus: string
userId: string
companyId: string
} }
// Emitted when the PSD2 callback fails to mirror a returned account into
// cash_accounts. ASVS V16 / ISO 27001 A.8.15: security-relevant failures
// must land in a structured audit log (event_log, 30-day TTL) rather than
// being lost to console.error.
| { type: 'bank_connection.cash_account_mirror_failed'; payload: {
connectionId: string
bankName: string | null
accountUid: string
ledgerAccount: string
currency: string
reason: string
userId: string
companyId: string
} }
// Stripe Connect lifecycle: connect/disconnect are outward-facing consent
// transitions (a third party gains/loses access to payment data), so they
// land in event_log for the audit trail, mirroring bank_connection.*.
| { type: 'stripe.connected'; payload: { connectionId: string; stripeAccountId: string; livemode: boolean; userId: string; companyId: string } }
| { type: 'stripe.disconnected'; payload: { connectionId: string; stripeAccountId: string | null; reason: 'user' | 'revoked_upstream'; userId: string; companyId: string } }
// WooCommerce store lifecycle: same audit doctrine as stripe.* (a third
// party's API credentials are granted/dropped).
| { type: 'woocommerce.connected'; payload: { connectionId: string; storeUrl: string; userId: string; companyId: string } }
| { type: 'woocommerce.disconnected'; payload: { connectionId: string; storeUrl: string | null; reason: 'user' | 'revoked_upstream'; userId: string; companyId: string } }
// Shopify store lifecycle: same audit doctrine as stripe.*/woocommerce.*.
| { type: 'shopify.connected'; payload: { connectionId: string; shopDomain: string; userId: string; companyId: string } }
| { type: 'shopify.disconnected'; payload: { connectionId: string; shopDomain: string | null; reason: 'user' | 'revoked_upstream'; userId: string; companyId: string } }
// Periods
| { type: 'period.locked'; payload: { period: FiscalPeriod; userId: string; companyId: string } }
| { type: 'period.unlocked'; payload: { period: FiscalPeriod; userId: string; companyId: string } }
| { type: 'period.year_closed'; payload: { period: FiscalPeriod; userId: string; companyId: string } }
// Customers
| { type: 'customer.created'; payload: { customer: Customer; userId: string; companyId: string } }
// Articles (artikelregister)
| { type: 'article.created'; payload: { article: Article; userId: string; companyId: string } }
| { type: 'article.updated'; payload: { article: Article; userId: string; companyId: string } }
| { type: 'article.deleted'; payload: { articleId: string; userId: string; companyId: string } }
// Suppliers
| { type: 'supplier.created'; payload: { supplier: Supplier; userId: string; companyId: string } }
// Receipts
| { type: 'receipt.extracted'; payload: {
receipt: Receipt;
documentId: string | null;
confidence: number;
userId: string;
companyId: string;
}}
| { type: 'receipt.matched'; payload: {
receipt: Receipt;
transaction: Transaction;
confidence: number;
autoMatched: boolean;
userId: string;
companyId: string;
}}
| { type: 'receipt.confirmed'; payload: {
receipt: Receipt;
businessTotal: number;
privateTotal: number;
userId: string;
companyId: string;
}}
// Supplier Invoice Lifecycle
| { type: 'supplier_invoice.registered'; payload: { supplierInvoice: SupplierInvoice; userId: string; companyId: string } }
| { type: 'supplier_invoice.approved'; payload: { supplierInvoice: SupplierInvoice; userId: string; companyId: string } }
| { type: 'supplier_invoice.paid'; payload: { supplierInvoice: SupplierInvoice; paymentAmount: number; userId: string; companyId: string } }
| { type: 'supplier_invoice.credited'; payload: { supplierInvoice: SupplierInvoice; creditNote: SupplierInvoice; userId: string; companyId: string } }
| { type: 'supplier_invoice.uncredited'; payload: { supplierInvoice: SupplierInvoice; reversedCreditNoteId: string; reversalEntryId: string | null; userId: string; companyId: string } }
// Payment Matching
| { type: 'invoice.match_confirmed'; payload: { invoice: Invoice; transaction: Transaction; userId: string; companyId: string } }
| { type: 'supplier_invoice.match_confirmed'; payload: { supplierInvoice: SupplierInvoice; transaction: Transaction; userId: string; companyId: string } }
// Supplier Invoice Inbox
| { type: 'supplier_invoice.received'; payload: { inboxItem: InvoiceInboxItem; userId: string; companyId: string } }
| { type: 'supplier_invoice.extracted'; payload: { inboxItem: InvoiceInboxItem; confidence: number; userId: string; companyId: string } }
| { type: 'supplier_invoice.confirmed'; payload: { inboxItem: InvoiceInboxItem; supplierInvoice: SupplierInvoice; userId: string; companyId: string } }
// Salary
| { type: 'salary_run.created'; payload: { salaryRunId: string; periodYear: number; periodMonth: number; userId: string; companyId: string } }
| { type: 'salary_run.approved'; payload: { salaryRunId: string; approvedBy: string; userId: string; companyId: string } }
| { type: 'salary_run.approval_reverted'; payload: { salaryRunId: string; revertedBy: string; deletedAgiDeclarationId: string | null; userId: string; companyId: string } }
| { type: 'salary_run.booked'; payload: { salaryRunId: string; entryIds: string[]; userId: string; companyId: string } }
| { type: 'agi.generated'; payload: { agiId: string; periodYear: number; periodMonth: number; userId: string; companyId: string } }
| { type: 'agi.submitted'; payload: { salaryRunId: string; periodYear: number; periodMonth: number; userId: string; companyId: string } }
// Bolagsverket: digital inlämning av årsredovisning. Status values follow
// GUIDE §5.2.2 (arsred_inkommen → … → arsred_registrerad). `uploaded` fires
// when the iXBRL lands in eget utrymme; the undertecknare then signs the
// fastställelseintyg at Bolagsverket and the webhook drives the rest.
| { type: 'arsredovisning.uploaded'; payload: { submissionId: string; fiscalPeriodId: string; idnummer: string; environment: 'test' | 'accept' | 'prod'; userId: string; companyId: string } }
| { type: 'arsredovisning.status_changed'; payload: { submissionId: string; fiscalPeriodId: string | null; previousStatus: string; status: string; bolagsverketStatus: string; userId: string; companyId: string } }
| { type: 'arsredovisning.registered'; payload: { submissionId: string; fiscalPeriodId: string | null; userId: string; companyId: string } }
| { type: 'arsredovisning.forelagd'; payload: { submissionId: string; fiscalPeriodId: string | null; userId: string; companyId: string } }
// Skatteverket: Skattekonto sync
| { type: 'skattekonto.synced'; payload: { booked: number; upcoming: number; balanceSkv: number; balanceKfm: number; userId: string; companyId: string } }
| { type: 'skattekonto.balance.changed'; payload: { previousBalance: number; currentBalance: number; userId: string; companyId: string } }
| { type: 'skattekonto.transaction.upcoming'; payload: { transaktionsdatum: string; forfallodatum: string; transaktionstext: string; beloppSkatteverket: number; userId: string; companyId: string } }
| { type: 'skattekonto.connection.expired'; payload: { reason: 'REFRESH_EXHAUSTED' | 'SESSION_EXPIRED' | 'TOKEN_CORRUPTED'; userId: string; companyId: string } }
// Fired when the SKV saldo and GL 1630 sum diverge beyond the configured
// tolerance. The drift handler emails the company contact; UI surfaces a
// dashboard tile via /api/extensions/skatteverket/skattekonto/drift.
| { type: 'skattekonto.drift_detected'; payload: {
drift: number // SKV saldo - GL 1630 sum (signed)
saldoSkatteverket: number
glSum1630: number
fetchedAt: number // ms epoch from the snapshot
unbookedCount: number // skattekonto rows without journal_entry_id ≤ fetchedAt
userId: string
companyId: string
} }
// Company & account lifecycle
| { type: 'company.deleted'; payload: { companyId: string; userId: string; archivedAt: string } }
| { type: 'account.deleted'; payload: { userId: string; deletedAt: string } }
// MCP telemetry: fired from the MCP dispatcher.
// Persisted to event_log (180-day TTL for mcp.*/agent.* rows, vs 30 days for
// delivery events) for hot-tool / error-rate / latency analytics.
// Intentionally lightweight: no args, no result body, only metadata.
| { type: 'mcp.tool_called'; payload: {
tool: string // e.g. 'gnubok_create_invoice'
requiredScope: string | null // from TOOL_SCOPE_MAP, null if unscoped
actorType: 'user' | 'api_key' | 'mcp_oauth' | 'cron' | 'anonymous'
actorId: string | null // api_key id, oauth client, etc.
actorLabel: string | null // human-readable actor label
latencyMs: number // wall-clock time inside execute()
success: boolean // true iff the tool returned without throwing AND was invoked (not denied)
isError: boolean // matches the JSON-RPC tool-result isError flag returned to the client
errorCode: string | null // structured error code from tool-result.toToolError when applicable
errorKind: 'execution' | 'scope_denied' | 'capability_denied' | 'company_access_denied' | 'unknown_tool' | 'test_key_write_blocked' | 'bridge_refused' | null
// bridge_refused: gnubok_call_tool was pointed at a write tool, or at nothing.
errorMessage: string | null // human-readable error message (truncated to 500 chars), null on success.
// Raw material for clustering real agent failures into curated gotchas:
// errorCode alone can't distinguish "period locked" from "unbalanced".
requestId: string | number | null // JSON-RPC request id (helps correlate with client-side logs)
userId: string
companyId: string
sessionId: string | null // from Mcp-Session-Id header; null if absent
client: string | null // distribution marker (X-Accounted-Client, legacy X-Gnubok-Client, or ?client=).
// Client-supplied (allow-list-sanitized): telemetry only, never identity or authz.
}}
// tools/list: informs us whether agents are using progressive discovery
// (gnubok_search_tools) or pulling the full list. Tool counts vary with
// the caller's scope set.
| { type: 'mcp.tools_list_called'; payload: {
toolCount: number // tools actually returned (post scope filter)
actorType: 'user' | 'api_key' | 'mcp_oauth' | 'cron' | 'anonymous'
actorId: string | null
actorLabel: string | null
latencyMs: number
requestId: string | number | null
userId: string
companyId: string
sessionId: string | null // from Mcp-Session-Id header; null if absent
client: string | null // distribution-channel marker; null if absent
}}
// resources/read: informs us which skills/widgets/data resources actually
// get loaded by agents. `kind` discriminates by URI scheme so we can
// GROUP BY skill vs widget vs data without parsing URIs.
| { type: 'mcp.resource_read'; payload: {
uri: string // e.g. 'Accounted://skill/month-end-close'
kind: 'widget' | 'skill' | 'data' | 'unknown'
success: boolean
errorCode: string | null
latencyMs: number
actorType: 'user' | 'api_key' | 'mcp_oauth' | 'cron' | 'anonymous'
actorId: string | null
actorLabel: string | null
requestId: string | number | null
userId: string
companyId: string
sessionId: string | null // from Mcp-Session-Id header; null if absent
client: string | null // distribution-channel marker; null if absent
}}
// Workflow lifecycle: agents declare "I'm starting month-end-close" via
// gnubok_load_skill (or implicitly by following a skill's recommended tool
// sequence). Phase 3A captures these to measure: how often is a workflow
// started? How often does it complete? Where do agents abandon?
| { type: 'mcp.workflow_started'; payload: {
slug: string // e.g. 'month-end-close'
sessionId: string | null
actorType: 'user' | 'api_key' | 'mcp_oauth' | 'cron' | 'anonymous'
actorId: string | null
actorLabel: string | null
userId: string
companyId: string
}}
| { type: 'mcp.workflow_completed'; payload: {
slug: string
sessionId: string | null
outcome: 'success' | 'abandoned' | 'failed'
stepsCompleted: number | null // null when not tracked granularly
durationMs: number | null
actorType: 'user' | 'api_key' | 'mcp_oauth' | 'cron' | 'anonymous'
actorId: string | null
actorLabel: string | null
userId: string
companyId: string
}}
// Fires on EVERY successful gnubok_load_skill: all tiers, unlike
// mcp.workflow_started which fires only for workflow-tier skills. Records
// WHICH skill/atom bodies agents actually pull, the denominator needed to
// correlate a loaded atom with downstream tool-error rates (a skill can
// make the model worse: measure, don't assume).
| { type: 'mcp.skill_loaded'; payload: {
slug: string // e.g. 'modifier/holding-ab', 'month-end-close'
tier: 'workflow' | 'horizontal' | 'vertical' | 'modifier'
sessionId: string | null
actorType: 'user' | 'api_key' | 'mcp_oauth' | 'cron' | 'anonymous'
actorId: string | null
actorLabel: string | null
userId: string
companyId: string
}}
// Fires when the agent's next tool call matches the previous response's
// nextHint.tool: measures whether `next` hints are actually followed.
// Computed dispatcher-side by comparing the last response shape to the
// current call.
| { type: 'mcp.next_hint_followed'; payload: {
fromTool: string
toTool: string
sessionId: string | null
actorType: 'user' | 'api_key' | 'mcp_oauth' | 'cron' | 'anonymous'
actorId: string | null
actorLabel: string | null
userId: string
companyId: string
}}
// Agent self-reported feedback (gnubok_feedback tool). The product team
// queries event_log for `agent.feedback` and routes to a backlog.
| { type: 'agent.feedback'; payload: {
context: string
sentiment: 'positive' | 'negative' | 'neutral'
suggestion: string | null
toolName: string | null
skillSlug: string | null
sessionId: string | null
actorType: 'user' | 'api_key' | 'mcp_oauth' | 'cron' | 'anonymous'
actorId: string | null
actorLabel: string | null
userId: string
companyId: string
}}
// ============================================================
// Helper Types
// ============================================================
/** All possible event type strings */
export type CoreEventType = CoreEvent['type']
/** Extract the payload type for a given event type */
export type EventPayload<T extends CoreEventType> = Extract<CoreEvent, { type: T }>['payload']
/** Handler function for a specific event type */
export type EventHandler<T extends CoreEventType> = (payload: EventPayload<T>) => Promise<void> | void
/** Subscription: event type + handler */
export interface EventSubscription<T extends CoreEventType = CoreEventType> {
eventType: T
handler: EventHandler<T>
}