Observability · how it works

Follow one name all the way

A name is written once in the contract. obs turns it into a typed constant per language. Your code passes that constant to a port. The adapter sends it to Alloy, Alloy stores it, and Grafana queries, alerts and draws it.

Pick a signal and a language below; every box and code sample redraws. PROPOSED · this site
The code is the shape from the design record. None of it is built yet. DECIDED · A193 tab 3

Pick a signal and a language

Signal

Language

Log · Bun

1 · Contract

Written by hand, once per service. DECIDED · A193 tab 3

events:
  checkout.charge.failed: { level: error, description: A card charge did not succeed }

2 · Generated name

as const keeps the exact string type; one list cannot drift. DECIDED · A193 tab 3

// src/observability/signals.g.ts
export const Event = {
  CheckoutChargeFailed: 'checkout.charge.failed',
} as const;
export type Event = (typeof Event)[keyof typeof Event];

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

if (!r.ok) this.t.logger.error(
  { event: Event.CheckoutChargeFailed, 'error.type': r.error.code },
  'charge failed',
);

4 · Adapter
sdk-logs LoggerProvider + OTLP exporter. Adds durian.cloud/event and the OTLP EventName field, the trace and span ids, and the LPSM keys. pino stays for the console. DECIDED · A193 tab 4
5 · Transport
OTLP → Alloy → loki:3100/otlp TESTED · Q15
6 · Store
Loki. The event key is stored as durian_cloud_event="checkout.charge.failed". PROPOSED · A193 tab 1, jaeda call 10

7 · Query, alert, dashboard

LogQL. Alert query B in charge-errors/critical.yaml. DECIDED · A193 tab 2

sum(count_over_time({service_name="checkout"}
  | durian_cloud_event="checkout.charge.failed" [5m])) > 10

Log · Go

1 · Contract

Written by hand, once per service. DECIDED · A193 tab 3

events:
  checkout.charge.failed: { level: error, description: A card charge did not succeed }

2 · Generated name

A struct with a hidden field, so no other package can make one. TESTED · Q7

// internal/signals/signals_gen.go
type Event struct{ name string }   // hidden field: closed
func (e Event) EventName() string { return e.name }
var EventCheckoutChargeFailed = Event{"checkout.charge.failed"}

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

log.Error(ctx, signals.EventCheckoutChargeFailed, "charge failed",
  interfaces.Attr("error.type", code))   // ctx first: the trace rides along

4 · Adapter
sdk/log + otlploghttp, record built with ctx, so it carries the trace. DECIDED · A193 tab 4
5 · Transport
OTLP → Alloy → loki:3100/otlp TESTED · Q15
6 · Store
Loki. The event key is stored as durian_cloud_event="checkout.charge.failed". PROPOSED · A193 tab 1, jaeda call 10

7 · Query, alert, dashboard

LogQL. Alert query B in charge-errors/critical.yaml. DECIDED · A193 tab 2

sum(count_over_time({service_name="checkout"}
  | durian_cloud_event="checkout.charge.failed" [5m])) > 10

Log · .NET

1 · Contract

Written by hand, once per service. DECIDED · A193 tab 3

events:
  checkout.charge.failed: { level: error, description: A card charge did not succeed }

2 · Generated name

A sealed class with a private constructor; a C# enum is not closed. DECIDED · A193 tab 3

// Lib/Observability/Signals.g.cs
public sealed class Event : IEventName {
  private Event(string n) => Name = n;   // private: closed
  public string Name { get; }
  public static readonly Event CheckoutChargeFailed = new("checkout.charge.failed");
}

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

log.Error(Event.CheckoutChargeFailed, "charge failed", attrs);
// Error is an extension of
// Log(LogLevel level, TEvent evt, string message, Attributes? a = null, Exception? error = null)

4 · Adapter
ILogger + OpenTelemetry logging, as today; it already stamps the current span. DECIDED · A193 tab 4
5 · Transport
OTLP → Alloy → loki:3100/otlp TESTED · Q15
6 · Store
Loki. The event key is stored as durian_cloud_event="checkout.charge.failed". PROPOSED · A193 tab 1, jaeda call 10

7 · Query, alert, dashboard

LogQL. Alert query B in charge-errors/critical.yaml. DECIDED · A193 tab 2

sum(count_over_time({service_name="checkout"}
  | durian_cloud_event="checkout.charge.failed" [5m])) > 10

Log · Flutter

1 · Contract
Flutter uses its own names in the same contract shape. DECIDED · A193 tab 3
```
events:
  checkout.pay.tapped: { level: info }
```

2 · Generated name

Dart enums are closed and carry the wire name. DECIDED · A193 tab 3

// lib/src/observability/signals.g.dart
enum Event implements EventName {
  checkoutPayTapped('checkout.pay.tapped');
  const Event(this.wireName);
  @override final String wireName;
}

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

log.info(Event.checkoutPayTapped, 'pay tapped');
// with an error: log.error(event, message, error: e, stack: s)

4 · Adapter
Faro adapter: pushLog(msg, level, context: {durian.cloud/event: …}); with an error → pushError. Context values must be strings. DECIDED · A193 tab 3 TESTED · Q17, wire only
5 · Transport
Faro POST …/collect → Alloy faro.receiver → Loki TESTED · Q17
6 · Store
Loki. Faro fields arrive renamed (log context as context_*, identity as app_name); obs maps them. TESTED · Q17
7 · Query, alert, dashboard
LogQL (field name per spike). Exact field spelling is for obs to map. TESTED · Q17 OPEN · mapping
```
{app_name="…"} | context_durian_cloud_event="checkout.pay.tapped"
```

Metric · Bun

1 · Contract

Written by hand, once per service. DECIDED · A193 tab 3

metrics:
  checkout.charges: { kind: counter, unit: "{charge}", budget: 30 }

2 · Generated name

as const keeps the exact string type; one list cannot drift. DECIDED · A193 tab 3

export const Counter = {
  CheckoutCharges: 'checkout.charges',
} as const;
export type Counter = (typeof Counter)[keyof typeof Counter];

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

this.t.meter.increment(Counter.CheckoutCharges, 1, {
  'payment.provider': provider,
  outcome: r.outcome,            // free-form label
});

4 · Adapter
sdk-metrics; every instrument is made at start from the contract. A View caps label sets at budget × 4. DECIDED · A193 tab 4
5 · Transport
OTLP → Alloy → vm:8428/opentelemetry TESTED · Q15
6 · Store
VictoriaMetrics. checkout.charges is stored as checkout_charges_total. PROPOSED · A193 tab 1, jaeda call 10
7 · Query, alert, dashboard
PromQL. Alert query A in charge-errors/critical.yaml. DECIDED · A193 tab 2
```
sum(rate(checkout_charges_total{outcome="error"}[5m])) > 1
```

Metric · Go

1 · Contract

Written by hand, once per service. DECIDED · A193 tab 3

metrics:
  checkout.charges: { kind: counter, unit: "{charge}", budget: 30 }

2 · Generated name
A struct with a hidden field, so no other package can make one. TESTED · Q7
```
type Counter struct{ name string }
var CounterCheckoutCharges = Counter{"checkout.charges"}
```

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

meter.Increment(ctx, signals.CounterCheckoutCharges, 1,
  interfaces.Attr("payment.provider", provider),
  interfaces.Attr("outcome", outcome))

4 · Adapter
sdk/metric; instruments from signals.Contract; a View caps label sets. DECIDED · A193 tab 4
5 · Transport
OTLP → Alloy → vm:8428/opentelemetry TESTED · Q15
6 · Store
VictoriaMetrics. checkout.charges is stored as checkout_charges_total. PROPOSED · A193 tab 1, jaeda call 10
7 · Query, alert, dashboard
PromQL. Alert query A in charge-errors/critical.yaml. DECIDED · A193 tab 2
```
sum(rate(checkout_charges_total{outcome="error"}[5m])) > 1
```

Metric · .NET

1 · Contract

Written by hand, once per service. DECIDED · A193 tab 3

metrics:
  checkout.charges: { kind: counter, unit: "{charge}", budget: 30 }

2 · Generated name

A sealed class with a private constructor; a C# enum is not closed. DECIDED · A193 tab 3

public sealed class Counter : ICounterName {
  private Counter(string n) => Name = n;
  public string Name { get; }
  public static readonly Counter CheckoutCharges = new("checkout.charges");
}

3 · Your code calls the port
Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7
```
meter.Increment(Counter.CheckoutCharges, 1, attrs);   // method name: shape, not final
```
4 · Adapter
System.Diagnostics.Metrics.Meter; instruments from SignalContract.Data; a View caps label sets. DECIDED · A193 tab 4
5 · Transport
OTLP → Alloy → vm:8428/opentelemetry TESTED · Q15
6 · Store
VictoriaMetrics. checkout.charges is stored as checkout_charges_total. PROPOSED · A193 tab 1, jaeda call 10
7 · Query, alert, dashboard
PromQL. Alert query A in charge-errors/critical.yaml. DECIDED · A193 tab 2
```
sum(rate(checkout_charges_total{outcome="error"}[5m])) > 1
```

Metric · Flutter

1 · Contract
Flutter uses its own names in the same contract shape. DECIDED · A193 tab 3
```
metrics:
  checkout.screen.load.duration: { kind: histogram, unit: s }
```

2 · Generated name

Dart enums are closed and carry the wire name. DECIDED · A193 tab 3

enum Histogram implements HistogramName {
  checkoutScreenLoadDuration('checkout.screen.load.duration');
  const Histogram(this.wireName);
  @override final String wireName;
}

3 · Your code calls the port
Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7
```
meter.record(Histogram.checkoutScreenLoadDuration, 0.42);
```
4 · Adapter
Faro adapter: pushMeasurement({'value': v}, name). It becomes a Loki line, not a metric. No gauges. DECIDED · A193 tab 3
5 · Transport
Faro POST …/collect → Alloy faro.receiver → Loki (as a log line) TESTED · Q17
6 · Store
Loki, as measurement lines. Dashboards read them with LogQL unwrap, not PromQL. DECIDED · A193 tab 3
7 · Query, alert, dashboard
LogQL. Flutter has no PromQL metrics. DECIDED · A193 tab 3
```
a LogQL query that `unwrap`s the measurement value
```

Span · Bun

1 · Contract
Written by hand, once per service. DECIDED · A193 tab 3
```
spans:
  checkout.charge: { kind: internal }
```

2 · Generated name

as const keeps the exact string type; one list cannot drift. DECIDED · A193 tab 3

export const Span = {
  CheckoutCharge: 'checkout.charge',
} as const;
export type Span = (typeof Span)[keyof typeof Span];

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

return this.t.tracer.run(Span.CheckoutCharge, { 'payment.provider': provider }, async () => {
  const r = await this.gateway.charge(order, provider); // auto http.client span nests here
  return r;                                             // Err → span status Error
});

4 · Adapter
tracer.startActiveSpan(name, {kind, attributes}, fn). On Err, recordProblem sets status Error and a problem event. DECIDED · A193 tab 4 TESTED · Q5
5 · Transport
OTLP → Alloy → tempo:4318 TESTED · Q15
6 · Store
Tempo. Tempo's metrics generator also writes traces_spanmetrics_calls_total to VictoriaMetrics. DECIDED · A193 tab 5 NOT TESTED · generator not in the spike config
7 · Query, alert, dashboard
PromQL on span metrics. Alerts on traces use span metrics, not TraceQL (experimental for alerts). DECIDED · A193 tab 2
```
traces_spanmetrics_calls_total{
  service_name="checkout", status_code="STATUS_CODE_ERROR"}
```

Span · Go

1 · Contract
Written by hand, once per service. DECIDED · A193 tab 3
```
spans:
  checkout.charge: { kind: internal }
```
2 · Generated name
A struct with a hidden field, so no other package can make one. TESTED · Q7
```
type Span struct{ name string }
var SpanCheckoutCharge = Span{"checkout.charge"}
```

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

err := tracer.Run(ctx, signals.SpanCheckoutCharge, attrs,
  func(ctx context.Context, span interfaces.Span[signals.Event]) error {
    return gateway.Charge(ctx, order, provider)   // error → span status Error
  })

4 · Adapter
tracer.Start(ctx, name) + defer span.End() inside Run; an error sets status Error. DECIDED · A193 tab 4 TESTED · Q11
5 · Transport
OTLP → Alloy → tempo:4318 TESTED · Q15
6 · Store
Tempo. Tempo's metrics generator also writes traces_spanmetrics_calls_total to VictoriaMetrics. DECIDED · A193 tab 5 NOT TESTED · generator not in the spike config
7 · Query, alert, dashboard
PromQL on span metrics. Alerts on traces use span metrics, not TraceQL (experimental for alerts). DECIDED · A193 tab 2
```
traces_spanmetrics_calls_total{
  service_name="checkout", status_code="STATUS_CODE_ERROR"}
```

Span · .NET

1 · Contract
Written by hand, once per service. DECIDED · A193 tab 3
```
spans:
  checkout.charge: { kind: internal }
```

2 · Generated name

A sealed class with a private constructor; a C# enum is not closed. DECIDED · A193 tab 3

public sealed class Span : ISpanName {
  private Span(string n) => Name = n;
  public string Name { get; }
  public static readonly Span CheckoutCharge = new("checkout.charge");
}

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

return await tracer.Run(Span.CheckoutCharge, attrs,
  async span => await gateway.Charge(order, provider));  // Err → span status Error

4 · Adapter
ActivitySource.StartActivity(name, kind); Err → status Error + problem event. DECIDED · A193 tab 4 TESTED · Q11
5 · Transport
OTLP → Alloy → tempo:4318 TESTED · Q15
6 · Store
Tempo. Tempo's metrics generator also writes traces_spanmetrics_calls_total to VictoriaMetrics. DECIDED · A193 tab 5 NOT TESTED · generator not in the spike config
7 · Query, alert, dashboard
PromQL on span metrics. Alerts on traces use span metrics, not TraceQL (experimental for alerts). DECIDED · A193 tab 2
```
traces_spanmetrics_calls_total{
  service_name="checkout", status_code="STATUS_CODE_ERROR"}
```

Span · Flutter

1 · Contract

Flutter uses its own names in the same contract shape. DECIDED · A193 tab 3

spans:
  checkout.pay: { kind: client }     # example name: the record names no Flutter span

2 · Generated name

Dart enums are closed and carry the wire name. DECIDED · A193 tab 3

enum Span implements SpanName {
  checkoutPay('checkout.pay');      // example name
  const Span(this.wireName);
  @override final String wireName;
}

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

await tracer.run(Span.checkoutPay, attrs, () => api.pay(order));
// outgoing HTTP carries traceparent to the backend

4 · Adapter
Faro adapter: startSpan(name, fn, attributes). DECIDED · A193 tab 3 TESTED · Q17, wire only
5 · Transport
Faro POST …/collect → Alloy faro.receiver → Tempo TESTED · Q17
6 · Store
Tempo, linked to the backend span by traceparent. TESTED · Q17
7 · Query, alert, dashboard
Tempo. One trace across phone and server. TESTED · Q17, wire
```
the app span, then the backend span under it
```

Profile · Bun

1 · Contract

Written by hand, once per service. DECIDED · A193 tab 3

profiles:
  types:  [cpu, alloc, inuse]
  scopes: [checkout.fraud.score]

2 · Generated name

as const keeps the exact string type; one list cannot drift. DECIDED · A193 tab 3

export const ProfileScope = {
  CheckoutFraudScore: 'checkout.fraud.score',
} as const;
export type ProfileScope = (typeof ProfileScope)[keyof typeof ProfileScope];

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

const score = await this.t.profiler.scope(
  ProfileScope.CheckoutFraudScore, { 'payment.provider': provider },
  () => this.fraud.score(order),
);

4 · Adapter
node:inspector CPU profile → our ~80-line pprof converter. CPU only, no span link: samples are matched by time window. TESTED · Q3; Q4
5 · Transport
pprof → Alloy pyroscope.receive_http → pyroscope.write → Pyroscope DECIDED · A193 tab 1 #21 TESTED · Q14
6 · Store
Pyroscope. Samples carry service_name and the label durian.cloud/profile.scope=checkout.fraud.score. DECIDED · A193 tab 4
7 · Query, alert, dashboard
Pyroscope. No alerts on profiles. You open a flame graph from a dashboard panel or from a span. DECIDED · A193 tab 5
```
flame graph: service_name="checkout"
  label durian.cloud/profile.scope="checkout.fraud.score"
```

Profile · Go

1 · Contract

Written by hand, once per service. DECIDED · A193 tab 3

profiles:
  types:  [cpu, alloc, inuse]
  scopes: [checkout.fraud.score]

2 · Generated name

A struct with a hidden field, so no other package can make one. TESTED · Q7

type ProfileScope struct{ name string }
var ProfileScopeCheckoutFraudScore = ProfileScope{"checkout.fraud.score"}

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

profiler.Scope(ctx, signals.ProfileScopeCheckoutFraudScore, attrs,
  func(ctx context.Context) { score = fraud.Score(ctx, order) })
// inside: pprof.Do(ctx, pprof.Labels(…))

4 · Adapter
pyroscope-go + otel-profiling-go: each sample carries the span id, so a span gets its own flame graph. TESTED · Q8
5 · Transport
pprof → Alloy pyroscope.receive_http → pyroscope.write → Pyroscope DECIDED · A193 tab 1 #21 TESTED · Q14
6 · Store
Pyroscope. Samples carry service_name and the label durian.cloud/profile.scope=checkout.fraud.score. DECIDED · A193 tab 4
7 · Query, alert, dashboard
Pyroscope. No alerts on profiles. You open a flame graph from a dashboard panel or from a span. DECIDED · A193 tab 5
```
flame graph: service_name="checkout"
  label durian.cloud/profile.scope="checkout.fraud.score"
```

Profile · .NET

1 · Contract

Written by hand, once per service. DECIDED · A193 tab 3

profiles:
  types:  [cpu, alloc, inuse]
  scopes: [checkout.fraud.score]

2 · Generated name

A sealed class with a private constructor; a C# enum is not closed. DECIDED · A193 tab 3

public sealed class ProfileScope : IProfileScopeName {
  private ProfileScope(string n) => Name = n;
  public string Name { get; }
  public static readonly ProfileScope CheckoutFraudScore = new("checkout.fraud.score");
}

3 · Your code calls the port

Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7

var score = profiler.Scope(ProfileScope.CheckoutFraudScore, attrs,
  () => fraud.Score(order));   // Pyroscope label API (name to check)

4 · Adapter
Pyroscope .NET profiler + span processor: span-filtered flame graphs. Needs the profiler files in the image. TESTED · Q9
5 · Transport
pprof → Alloy pyroscope.receive_http → pyroscope.write → Pyroscope DECIDED · A193 tab 1 #21 TESTED · Q14
6 · Store
Pyroscope. Samples carry service_name and the label durian.cloud/profile.scope=checkout.fraud.score. DECIDED · A193 tab 4
7 · Query, alert, dashboard
Pyroscope. No alerts on profiles. You open a flame graph from a dashboard panel or from a span. DECIDED · A193 tab 5
```
flame graph: service_name="checkout"
  label durian.cloud/profile.scope="checkout.fraud.score"
```

Profile · Flutter

1 · Contract
Flutter uses its own names in the same contract shape. DECIDED · A193 tab 3
```
# profiles: refused for Dart
# obs: "Faro has no profiling"
```
2 · Generated name
Dart enums are closed and carry the wire name. DECIDED · A193 tab 3
```
// nothing generated: obs refuses profiles for Dart
```
3 · Your code calls the port
Only typed names are accepted; labels are free-form. DECIDED · A193 tab 1 #5; #7
```
// The Profiler port is a no-op in Flutter: it just runs fn()
```
4 · Adapter
No adapter: Faro has no profiling. DECIDED · A193 tab 3
5 · Transport
— nothing is sent
6 · Store
—
7 · Query, alert, dashboard
No profiles from Flutter. DECIDED · A193 tab 5

The 7 stops, in words

Contract. You write the name once, by hand. Names are lowercase and dotted, and unique across kinds. Example: checkout.charges cannot be both a counter and an event. DECIDED · A193 tab 3 PROPOSED · A193 tab 1, jaeda call 1
Generated names. obs gen writes one file of constants per service. Same contract → same bytes. Constants only, never functions. DECIDED · A193 tab 1 #7
Port call. Your code calls a port with the constant. Labels are free-form. The trace context travels by itself. DECIDED · A193 tab 3
Adapter. The *-otel library turns the call into OpenTelemetry. It adds the event key, the 4 LPSM keys (where the signal came from: landscape, platform, service, module) and the error details. DECIDED · A193 tab 4
Transport. Logs, metrics and spans go as OTLP to Alloy. Profiles go as pprof to Alloy. Flutter goes through Faro to Alloy. DECIDED · A193 tab 5; A193 tab 1 #21
Store. Loki, VictoriaMetrics, Tempo or Pyroscope. Each store spells names its own way. Example: checkout.charges is stored as checkout_charges_total. PROPOSED · A193 tab 1, jaeda call 10
Query, alert, dashboard. Grafana reads the store. Alerts and dashboards live in observability/ and obs checks them. DECIDED · A193 tab 2

How a wrong name fails

Bun: a log without an event → TS2345: Property 'event' is missing. DECIDED · A193 tab 3
Bun: a counter passed where a histogram is needed → TS2345: '"checkout.charges"' is not assignable to parameter of type 'Histogram'. DECIDED · A193 tab 3
Go: building a name outside the generated file → implicit assignment to unexported field name in struct literal. TESTED · Q7, evidence.txt
Go: a plain string → cannot use "…" (untyped string constant) as signals.Event value. DECIDED · A193 tab 3 NOT TESTED · not in the spike evidence
Go's one hole: an empty signals.Event{} compiles. A forbidigo lint rule or a short analyzer catches it; the port also errors on an empty name. TESTED · Q7
Only Go's closed names were spiked. The Bun, .NET and Dart error texts come from the design record, not a run. DECIDED · A193 tab 3 NOT TESTED · not run
.NET: new Event("x") → CS0122: inaccessible. DECIDED · A193 tab 3
Dart: a histogram passed as an event → The argument type 'Histogram' can't be assigned to the parameter type 'Event'. DECIDED · A193 tab 3

Errors in a Result mark the span

When your function returns Err(problem), tracer.run marks the span. No exception needed. DECIDED · A193 tab 1 #15 TESTED · Q5; Q11
It sets span status Error, adds a problem event with the RFC 9457 fields, and sets error.type. TESTED · Q5; Q11
Example: fetchUser(42) returns Err({ type: "…/suspended", status: 403 }) → span Error 403, a problem event, error.type=…/suspended. TESTED · Q5
The helper is small in each of Bun, Go and .NET (19 lines in Bun, 12 in Go). TESTED · Q5; Q11
A telemetry failure never changes your result. PROPOSED · A193 tab 1, jaeda call 5

Spans you get for free (auto spans)

The contract opts in with a list. Example: auto: [http.server, http.client, db.postgres, db.redis, runtime]. DECIDED · A193 tab 1 #18

Auto span	Bun	Go	.NET
HTTP in	our `instrumentServe` wrapper	`otelhttp.NewHandler`	ASP.NET Core instrumentation
HTTP out	our `instrumentedFetch`	`otelhttp.NewTransport`	HttpClient instrumentation
Postgres	`instrumentation-pg` ✓	`otelpgx` ✓ (2 spans per query)	Npgsql built in ✓
Redis	our wrapper (pick 5, decided)	`redisotel` ✓ (old attribute names)	contrib package ✓, errors not marked: we fix

Bun's Redis client and Bun SQL make no spans at all, so lib/bun/otel gets thin wrappers. Example: redis.get("cart:42") → span redis GET. TESTED · Q6 DECIDED · A193 tab 1 #20
Example trace: GET /checkout (auto) → checkout.charge (yours) → POST api.stripe.com (auto). The log checkout.charge.failed sits under checkout.charge. DECIDED · A193 tab 4

What changes in each library

New major of each *-interfaces (Bun, Go, .NET, Dart): the 4 ports, name interfaces, in-memory test doubles, the banned-label policy. DECIDED · A193 tab 6 round 1a
The tracer moves from *-otel into *-interfaces. Today it is TraceEmitter. DECIDED · A193 tab 1 #6
New major of each *-otel (Bun, Go, .NET): Result helper, DB spans, profiling, LPSM keys. DECIDED · A193 tab 6 round 2a
New lib/dart/faro behind the Dart ports. DECIDED · A193 tab 1 #12
Go ports take ctx first. Today's Emit(record) uses context.Background() and loses the trace. PROPOSED · A193 tab 1, jaeda call 3
C# ports are named ISignal*, so they do not clash with ILogger. PROPOSED · A193 tab 1, jaeda call 4
Bun: NodeSDK 0.301 sent 0 spans under Bun, so the adapter builds the providers by hand. TESTED · A193 tab 4, spike js
.NET: the template must first move to Host.CreateApplicationBuilder. DECIDED · A193 tab 4