Telemetry Data Contract

This document explains how contributors should use Paperclip's public telemetry contract. It intentionally does not list individual events or dimensions.

The canonical source for first-party event names, dimensions, optionality, allowed primitive value types, and enum descriptions is packages/shared/src/telemetry/generated/paperclip-telemetry.ts.

Shared enum constants live in packages/shared/src/constants.ts. Use those constants when code needs a reusable domain, but treat the generated telemetry types as the final authority for emitted first-party telemetry shapes.

Public Sources

Use these files when reviewing or changing telemetry code:

Contract item	Public source
First-party event names	`PaperclipEventName` in `generated/paperclip-telemetry.ts`
Per-event dimensions and optionality	`EventDimensionsMap` in `generated/paperclip-telemetry.ts`
Enum descriptions for telemetry dimensions	`PAPERCLIP_ENUM_DESCRIPTIONS` in `generated/paperclip-telemetry.ts`
Schema version and event envelope helpers	`SCHEMA_VERSION`, `makeEvent()`, and `makeBatch()` in `generated/paperclip-telemetry.ts`
Runtime-safe event names and dimensions	`TelemetryEventName` and `TelemetryEventDimensions` in `types.ts`
Allowed primitive dimension values	`TelemetryDimensionValue` in `types.ts`
Shared reusable enum domains	Named exports in `constants.ts`
First-party typed emit helpers	`events.ts`
Generic client behavior	`client.ts`
Retention windows and event class assignments	`RETENTION_DAYS` and `EVENT_RETENTION_CLASS` in `retention.ts`

Do not copy generated event lists or dimension tables into this README. They will drift as the generated contract changes.

Emission Boundary

Paperclip telemetry uses named events with explicit dimension fields. Treat open-ended string dimensions as public contract values, not as a place for user content or private operational data. Do not send PII, secrets, credentials, private paths, prompts, model output, or other sensitive values through telemetry dimensions.

Telemetry emitters send raw dimension values. They must not pre-normalize enum-like values into a reporting form just to match today's known domain.

The receiving layer owns canonicalization. Keeping canonicalization in one place means emitters can stay simple and accurate: emit what the product observed, use the generated contract for required and optional fields, and let the receiving layer decide how legacy spellings, aliases, unknown names, and future values map to a stable reporting shape.

Do not add client-side lowercasing, alias mapping, or fallback mapping unless the generated telemetry contract specifically requires that emitted value.

If a dimension is privacy-protected before emission, emit only the protected value and its matching public marker as defined by the typed helper or generated contract. Do not emit private source material in telemetry dimensions.

Dimension Values

Telemetry dimension values must be primitives. Use only the value types allowed by TelemetryDimensionValue:

string
number
boolean

Do not emit null, undefined, arrays, or objects as dimension values. Optional dimensions should be omitted when absent.

When a dimension is enum-like, use the shared constant from constants.ts when one exists. If no shared constant exists, use the generated telemetry type as the domain. In all cases, the generated telemetry type remains the source of truth for the emitted value.

Required, Optional, And Sentinel Values

Required and optional dimensions are defined by EventDimensionsMap.

Required dimensions must be present for every event of that name. Optional dimensions should be emitted only when the value is known and useful.

Sentinel values are only for required fields that have no observed raw value at the emitting layer. Do not use a sentinel to hide a concrete value that is new, custom, or not yet represented by a shared constant. Emit the concrete raw value and let the receiving layer canonicalize it.

Adding Or Changing Telemetry

Client code is responsible for emitting approved telemetry events at the right place in the product. Stable event names, dimensions, and enum domains must come from the generated telemetry contract before normal emitters use them.

For product work that needs to propose a new first-party event before schema registration, use the proposal marker workflow in doc/TELEMETRY_WORKFLOW.md. Those proposed calls stay on client.track(), carry an @ts-expect-error marker on the event-name argument, and are swallowed at runtime until the generated schema registers the event name.

For stable event work:

Start from generated/paperclip-telemetry.ts. The generated types are what reviewers use to verify event names, dimensions, optionality, value types, enum descriptions, and schema version.
Choose stable event and dimension names. Do not include user content, local machine details, secrets, credentials, private paths, or values that are not part of the public event contract.
Use only string, number, or boolean dimension values.
Reuse a shared constant from constants.ts for enum-like dimensions when one exists. If the generated telemetry domain has values beyond a shared constant, keep the emitter aligned with the generated telemetry type.
Keep emitters raw. Do not normalize, alias-map, or lowercase enum-like values in the client unless the generated contract explicitly calls for that emitted value.
Add or update a typed helper in events.ts when the event is first-party and should have a stable helper API.
Update tests for helper behavior, including raw pass-through for enum-like values when that is the intended boundary.
Update this README only when the contributor workflow, source-of-truth pointers, or durable invariants change. Do not add an event catalog here.

Before opening a pull request, verify that the emitted code, typed helpers, and generated telemetry contract agree. If they disagree, fix the contract or code rather than documenting around the mismatch in this README.

For new first-party events that are not in the generated contract yet, follow the public proposal and promotion workflow in doc/TELEMETRY_WORKFLOW.md.

Retention

Retention windows are documented in retention.ts. Each event is assigned a retention class; the class determines the window in days. This is a housekeeping and query-cost concern managed by data-infra, not a schema concern — updating a retention window does not require a schema version bump.

Current classes:

Class	Window	Description
`operational_enum_count`	90 days	Enum/boolean/count/bucket events. No token material, no PII.

When a new event carries only enums, booleans, counts, or coarse buckets and no token material or PII, assign it to operational_enum_count in EVENT_RETENTION_CLASS. If no existing class fits, define a new class in RETENTION_DAYS and document it here.