diff --git a/packages/ai/src/protocols/anthropic-messages.ts b/packages/ai/src/protocols/anthropic-messages.ts
index 532c69d152e..1997faed55b 100644
--- a/packages/ai/src/protocols/anthropic-messages.ts
+++ b/packages/ai/src/protocols/anthropic-messages.ts
@@ -1300,7 +1300,7 @@ const onContentBlockStart = (
   return [{ ...state, lifecycle: Lifecycle.stepStart(state.lifecycle, events) }, [...events, result]]
 }
 
-const onContentBlockDelta = Effect.fn("AnthropicMessages.onContentBlockDelta")(function* (
+const onContentBlockDelta = Effect.fnUntraced(function* (
   state: ParserState,
   event: AnthropicEvent & { readonly delta: AnthropicStreamDelta },
 ) {
@@ -1368,7 +1368,7 @@ const onContentBlockDelta = Effect.fn("AnthropicMessages.onContentBlockDelta")(f
   return [state, NO_EVENTS] satisfies StepResult
 })
 
-const onContentBlockStop = Effect.fn("AnthropicMessages.onContentBlockStop")(function* (
+const onContentBlockStop = Effect.fnUntraced(function* (
   state: ParserState,
   event: AnthropicEvent,
 ) {
@@ -1439,7 +1439,7 @@ const onMessageDelta = (
   ]
 }
 
-const onMessageStop = Effect.fn("AnthropicMessages.onMessageStop")(function* (state: ParserState) {
+const onMessageStop = Effect.fnUntraced(function* (state: ParserState) {
   if (Object.keys(state.compactions).length)
     return yield* ProviderShared.eventError(ADAPTER, "Response ended with an incomplete compaction block")
   const result = yield* ToolStream.finishAll(ADAPTER, state.tools)
diff --git a/packages/ai/src/protocols/cartesia-speech.ts b/packages/ai/src/protocols/cartesia-speech.ts
index 4f2b02c8c64..09f5563285d 100644
--- a/packages/ai/src/protocols/cartesia-speech.ts
+++ b/packages/ai/src/protocols/cartesia-speech.ts
@@ -75,7 +75,7 @@ const usesSse = (request: MediaProtocol.Addressed<Request>) => request.mode ===
 
 const CONTAINERS: Readonly<Record<string, "raw" | "wav" | "mp3">> = { pcm: "raw", wav: "wav", mp3: "mp3" }
 
-const outputFormat = Effect.fn("CartesiaSpeech.outputFormat")(function* (request: MediaProtocol.Addressed<Request>) {
+const outputFormat = Effect.fnUntraced(function* (request: MediaProtocol.Addressed<Request>) {
   const sse = usesSse(request)
   const format = request.format ?? (sse ? "pcm" : "mp3")
   const container = CONTAINERS[format]
@@ -121,7 +121,7 @@ const fromRequest = Effect.fn("CartesiaSpeech.fromRequest")(function* (request:
 // 6. Stream parsing
 // ---------------------------------------------------------------------------
 
-const onEvent = Effect.fn("CartesiaSpeech.onEvent")(function* (state: State, frame: string) {
+const onEvent = Effect.fnUntraced(function* (state: State, frame: string) {
   const event = yield* decodeEvent(frame)
   if (event.type === "chunk" && event.data !== undefined) return SpeechStream.delta(state, event.data)
   if (event.type === "timestamps" && event.word_timestamps !== undefined) {
@@ -140,7 +140,7 @@ const onEvent = Effect.fn("CartesiaSpeech.onEvent")(function* (state: State, fra
   return [state, []] as const
 })
 
-const finish = Effect.fn("CartesiaSpeech.finish")(function* (
+const finish = Effect.fnUntraced(function* (
   state: State,
   context: MediaProtocol.ResponseContext<Request>,
 ) {
diff --git a/packages/ai/src/protocols/cohere-chat.ts b/packages/ai/src/protocols/cohere-chat.ts
index e5ca666a5f5..6daac8fb678 100644
--- a/packages/ai/src/protocols/cohere-chat.ts
+++ b/packages/ai/src/protocols/cohere-chat.ts
@@ -252,7 +252,7 @@ const mapUsage = (usage: typeof NativeUsage.Type) =>
   })
 
 // Lifecycle deltas open blocks on demand and ends are no-ops for closed blocks, so content-start needs no handling.
-const step = Effect.fn("CohereChat.step")(function* (state: State, event: Event) {
+const step = Effect.fnUntraced(function* (state: State, event: Event) {
   const events: LLMEvent[] = []
   switch (event.type) {
     case "message-start":
diff --git a/packages/ai/src/protocols/elevenlabs-speech.ts b/packages/ai/src/protocols/elevenlabs-speech.ts
index de864f37e92..30a853ea391 100644
--- a/packages/ai/src/protocols/elevenlabs-speech.ts
+++ b/packages/ai/src/protocols/elevenlabs-speech.ts
@@ -95,7 +95,7 @@ const OUTPUT_FORMATS: Readonly<Record<string, string>> = {
 }
 
 /** WAV is served only by the non-streaming endpoints. */
-const outputFormat = Effect.fn("ElevenLabsSpeech.outputFormat")(function* (request: MediaProtocol.Addressed<Request>) {
+const outputFormat = Effect.fnUntraced(function* (request: MediaProtocol.Addressed<Request>) {
   const format = request.providerOptions?.outputFormat ?? OUTPUT_FORMATS[request.format ?? "mp3"]
   if (format === undefined)
     return yield* route.unsupported(
@@ -138,7 +138,7 @@ const path = (request: MediaProtocol.Addressed<Request>) =>
 // 6. Stream parsing
 // ---------------------------------------------------------------------------
 
-const onRecord = Effect.fn("ElevenLabsSpeech.onRecord")(function* (state: State, frame: string) {
+const onRecord = Effect.fnUntraced(function* (state: State, frame: string) {
   const record = yield* decodeRecord(frame)
   const [next, events] = SpeechStream.delta(state, record.audio_base64)
   const alignment = record.alignment
@@ -169,7 +169,7 @@ const describeOutput = (format: string) => {
   return encoding === undefined ? SpeechStream.container(codec, sampleRate) : SpeechStream.pcm(encoding, sampleRate)
 }
 
-const finish = Effect.fn("ElevenLabsSpeech.finish")(function* (
+const finish = Effect.fnUntraced(function* (
   state: State,
   context: MediaProtocol.ResponseContext<Request>,
 ) {
diff --git a/packages/ai/src/protocols/google-interactions.ts b/packages/ai/src/protocols/google-interactions.ts
index 6cc040defe4..51abf1bcea1 100644
--- a/packages/ai/src/protocols/google-interactions.ts
+++ b/packages/ai/src/protocols/google-interactions.ts
@@ -364,7 +364,7 @@ const mapUsage = (usage: RawUsage | undefined, key: string) => {
   })
 }
 
-const onStart = Effect.fn("GoogleInteractions.onStart")(function* (
+const onStart = Effect.fnUntraced(function* (
   state: ParserState,
   index: number,
   step: OutputStep,
@@ -402,7 +402,7 @@ const onStart = Effect.fn("GoogleInteractions.onStart")(function* (
   return [{ ...state, lifecycle, tools, steps: { ...state.steps, [index]: step } }, events] satisfies StepResult
 })
 
-const onDelta = Effect.fn("GoogleInteractions.onDelta")(function* (
+const onDelta = Effect.fnUntraced(function* (
   state: ParserState,
   index: number,
   delta: typeof Delta.Type,
@@ -447,7 +447,7 @@ const onDelta = Effect.fn("GoogleInteractions.onDelta")(function* (
   return yield* ProviderShared.eventError(ADAPTER, `Unsupported Interactions delta: ${delta.type}`, encodeJson(delta))
 })
 
-const onStop = Effect.fn("GoogleInteractions.onStop")(function* (state: ParserState, index: number) {
+const onStop = Effect.fnUntraced(function* (state: ParserState, index: number) {
   const step = state.steps[index]
   if (!step) return yield* ProviderShared.eventError(ADAPTER, "Interactions step.stop without step.start")
   const events: LLMEvent[] = []
@@ -465,7 +465,7 @@ const onStop = Effect.fn("GoogleInteractions.onStop")(function* (state: ParserSt
   return [{ ...state, tools: result.tools }, result.events ?? []] satisfies StepResult
 })
 
-const step = Effect.fn("GoogleInteractions.step")(function* (state: ParserState, event: Event) {
+const step = Effect.fnUntraced(function* (state: ParserState, event: Event) {
   switch (event.event_type) {
     case "step.start":
       return yield* onStart(state, event.index, event.step)
diff --git a/packages/ai/src/protocols/google-speech.ts b/packages/ai/src/protocols/google-speech.ts
index 6a25890de47..2f9593060f4 100644
--- a/packages/ai/src/protocols/google-speech.ts
+++ b/packages/ai/src/protocols/google-speech.ts
@@ -94,7 +94,7 @@ const fromRequest = Effect.fn("GoogleSpeech.fromRequest")(function* (request: Me
 // 6. Stream parsing
 // ---------------------------------------------------------------------------
 
-const step = Effect.fn("GoogleSpeech.step")(function* (state: State, frame: string) {
+const step = Effect.fnUntraced(function* (state: State, frame: string) {
   const chunk = yield* decodeChunk(frame)
   const blocked = GeminiGenerateContent.blocked(route.name, chunk, frame)
   if (blocked !== undefined) return yield* blocked
diff --git a/packages/ai/src/protocols/google-transcription.ts b/packages/ai/src/protocols/google-transcription.ts
index 77a66ad3ec4..8eab87ccf5f 100644
--- a/packages/ai/src/protocols/google-transcription.ts
+++ b/packages/ai/src/protocols/google-transcription.ts
@@ -138,7 +138,7 @@ const turn = (part: Schema.Schema.Type<typeof AudioTranscription>) => {
   }
 }
 
-const step = Effect.fn("GoogleTranscription.step")(function* (state: State, frame: string) {
+const step = Effect.fnUntraced(function* (state: State, frame: string) {
   const chunk = yield* decodeChunk(frame)
   const blocked = GeminiGenerateContent.blocked(route.name, chunk, frame)
   if (blocked !== undefined) return yield* blocked
diff --git a/packages/ai/src/protocols/meta-responses.ts b/packages/ai/src/protocols/meta-responses.ts
index 3df616f8163..083a753e866 100644
--- a/packages/ai/src/protocols/meta-responses.ts
+++ b/packages/ai/src/protocols/meta-responses.ts
@@ -95,7 +95,7 @@ const HOSTED_TOOLS = {
   image_generation_call: {
     name: "image_generation",
     input: () => ({}),
-    result: Effect.fn("MetaResponses.imageResult")(function* (raw: ResponsesHostedTools.Item) {
+    result: Effect.fnUntraced(function* (raw: ResponsesHostedTools.Item) {
       const item = yield* Schema.decodeUnknownEffect(ImageItem)(raw).pipe(
         Effect.mapError((cause) =>
           ProviderShared.eventError(
@@ -136,7 +136,7 @@ const HOSTED_TOOLS = {
   },
 } satisfies ResponsesHostedTools.Definitions
 
-const onEvent = Effect.fn("MetaResponses.onEvent")(function* (
+const onEvent = Effect.fnUntraced(function* (
   state: OpenResponses.ParserState,
   input: OpenResponses.Event,
 ) {
@@ -173,7 +173,7 @@ const onEvent = Effect.fn("MetaResponses.onEvent")(function* (
   ] satisfies OpenResponses.StepResult
 })
 
-const step = Effect.fn("MetaResponses.step")(function* (state: ParserState, input: OpenResponses.Event) {
+const step = Effect.fnUntraced(function* (state: ParserState, input: OpenResponses.Event) {
   const completedItems = new Set(state.completedItems)
   const event = OpenResponses.normalize(state, input)
   if (event.type === "response.output_item.done" && event.item && completedItems.has(event.item.id))
diff --git a/packages/ai/src/protocols/mistral-chat.ts b/packages/ai/src/protocols/mistral-chat.ts
index 37a206beb87..44a86f64577 100644
--- a/packages/ai/src/protocols/mistral-chat.ts
+++ b/packages/ai/src/protocols/mistral-chat.ts
@@ -596,7 +596,7 @@ const toolText = (tool: MistralToolDelta) => {
   return value === null || value === undefined ? "" : ProviderShared.encodeJson(value)
 }
 
-const appendTools = Effect.fn("MistralChat.appendTools")(function* (
+const appendTools = Effect.fnUntraced(function* (
   initial: ParserState,
   events: LLMEvent[],
   deltas: ReadonlyArray<MistralToolDelta>,
@@ -662,7 +662,7 @@ const hasLateContent = (event: MistralEvent) => {
   )
 }
 
-const step = Effect.fn("MistralChat.step")(function* (state: ParserState, event: MistralEvent) {
+const step = Effect.fnUntraced(function* (state: ParserState, event: MistralEvent) {
   if (event.error) {
     const body = ProviderShared.encodeJson(event)
     return yield* new AIError({
@@ -726,7 +726,7 @@ const step = Effect.fn("MistralChat.step")(function* (state: ParserState, event:
   ] as const
 })
 
-const finishEvents = Effect.fn("MistralChat.finishEvents")(function* (state: ParserState) {
+const finishEvents = Effect.fnUntraced(function* (state: ParserState) {
   if (!state.finishReason)
     return yield* new AIError({
       reason: new InvalidProviderOutputError({
diff --git a/packages/ai/src/protocols/open-responses.ts b/packages/ai/src/protocols/open-responses.ts
index 5570b357082..0e3f1e60006 100644
--- a/packages/ai/src/protocols/open-responses.ts
+++ b/packages/ai/src/protocols/open-responses.ts
@@ -1143,7 +1143,7 @@ const onReasoningSummaryPartDone = (state: ParserState, event: Event): StepResul
   ]
 }
 
-const onFunctionCallArgumentsDelta = Effect.fn("OpenResponses.onFunctionCallArgumentsDelta")(function* (
+const onFunctionCallArgumentsDelta = Effect.fnUntraced(function* (
   state: ParserState,
   event: Event,
 ) {
@@ -1174,7 +1174,7 @@ const onFunctionCallArgumentsDelta = Effect.fn("OpenResponses.onFunctionCallArgu
   return [{ ...state, lifecycle, tools: result.tools }, events] satisfies StepResult
 })
 
-const onOutputItemDone = Effect.fn("OpenResponses.onOutputItemDone")(function* (
+const onOutputItemDone = Effect.fnUntraced(function* (
   state: ParserState,
   item: NormalizedEvent["item"],
 ) {
@@ -1310,7 +1310,7 @@ const onOutputItemDone = Effect.fn("OpenResponses.onOutputItemDone")(function* (
   return [state, NO_EVENTS] satisfies StepResult
 })
 
-const onResponseFinish = Effect.fn("OpenResponses.onResponseFinish")(function* (state: ParserState, event: Event) {
+const onResponseFinish = Effect.fnUntraced(function* (state: ParserState, event: Event) {
   let current = state
   const events: LLMEvent[] = []
   if (event.type === "response.completed") {
diff --git a/packages/ai/src/protocols/openai-chat.ts b/packages/ai/src/protocols/openai-chat.ts
index 5448ad0fa8d..db144e94cd4 100644
--- a/packages/ai/src/protocols/openai-chat.ts
+++ b/packages/ai/src/protocols/openai-chat.ts
@@ -855,7 +855,7 @@ export const fromRequest = Effect.fn("OpenAIChat.fromRequest")(function* (
 // Streaming parsers are small state machines: every event returns a new state
 // plus the common `LLMEvent`s produced by that event. Tool calls are accumulated
 // because OpenAI streams JSON arguments across multiple deltas.
-const mapFinishReason = Effect.fn("OpenAIChat.mapFinishReason")(function* (event: OpenAIChatEvent, reason: string) {
+const mapFinishReason = Effect.fnUntraced(function* (event: OpenAIChatEvent, reason: string) {
   switch (reason) {
     case "error":
       return yield* new AIError({
@@ -1214,7 +1214,7 @@ const step = (state: ParserState, event: OpenAIChatEvent) =>
     ] as const
   })
 
-const finishEvents = Effect.fn("OpenAIChat.finishEvents")(function* (state: ParserState) {
+const finishEvents = Effect.fnUntraced(function* (state: ParserState) {
   if (state.finishReason === undefined && state.requireFinishReason)
     return yield* new AIError({
       reason: new InvalidProviderOutputError({
diff --git a/packages/ai/src/protocols/openai-images.ts b/packages/ai/src/protocols/openai-images.ts
index f7a96de9e5b..ff938dd3544 100644
--- a/packages/ai/src/protocols/openai-images.ts
+++ b/packages/ai/src/protocols/openai-images.ts
@@ -208,7 +208,7 @@ const eventImage = (frame: string, label: string, data: string, format: string,
     info: info(format, size),
   })
 
-const onEvent = Effect.fn("OpenAIImages.onEvent")(function* (state: State, frame: string) {
+const onEvent = Effect.fnUntraced(function* (state: State, frame: string) {
   const event = yield* decodeEvent(frame)
   const format = event.output_format
   if ("partial_image_index" in event) {
@@ -229,7 +229,7 @@ const onEvent = Effect.fn("OpenAIImages.onEvent")(function* (state: State, frame
   ] as const
 })
 
-const onDocument = Effect.fn("OpenAIImages.onDocument")(function* (frame: Exclude<Frame, string>) {
+const onDocument = Effect.fnUntraced(function* (frame: Exclude<Frame, string>) {
   const invalid = (message: string, cause?: unknown) => route.frameError(message, frame.document, cause)
   const decoded = yield* decodeDocument(frame.document).pipe(
     Effect.mapError((cause) => invalid(`${route.name} returned an invalid response`, cause)),
diff --git a/packages/ai/src/protocols/openai-responses.ts b/packages/ai/src/protocols/openai-responses.ts
index 41436c8aa9d..b711db7805b 100644
--- a/packages/ai/src/protocols/openai-responses.ts
+++ b/packages/ai/src/protocols/openai-responses.ts
@@ -237,7 +237,7 @@ const checkpointBody = {
   }),
 }
 
-const hostedToolResult = Effect.fn("OpenAIResponses.hostedToolResult")(function* (item: ResponsesHostedTools.Item) {
+const hostedToolResult = Effect.fnUntraced(function* (item: ResponsesHostedTools.Item) {
   const isError = item.error !== undefined && item.error !== null
   if (item.type === "image_generation_call" && item.result) {
     yield* Effect.fromResult(Encoding.decodeBase64(item.result)).pipe(
diff --git a/packages/ai/src/protocols/openai-speech.ts b/packages/ai/src/protocols/openai-speech.ts
index 45e88af604a..a53584ca320 100644
--- a/packages/ai/src/protocols/openai-speech.ts
+++ b/packages/ai/src/protocols/openai-speech.ts
@@ -94,7 +94,7 @@ const fromRequest = Effect.fn("OpenAISpeech.fromRequest")(function* (request: Me
 
 const isSse = (body: MediaProtocol.Body) => body.type === "json" && body.value.stream_format === "sse"
 
-const onEvent = Effect.fn("OpenAISpeech.onEvent")(function* (state: State, frame: string) {
+const onEvent = Effect.fnUntraced(function* (state: State, frame: string) {
   const event = yield* decodeEvent(frame)
   if (event.type === "speech.audio.delta") return SpeechStream.delta(state, event.audio)
   const usage = event.usage
diff --git a/packages/ai/src/protocols/openai-transcription.ts b/packages/ai/src/protocols/openai-transcription.ts
index 0890ce836dd..8530ce35eae 100644
--- a/packages/ai/src/protocols/openai-transcription.ts
+++ b/packages/ai/src/protocols/openai-transcription.ts
@@ -210,7 +210,7 @@ const segment = (value: Schema.Schema.Type<typeof Segment>): TranscriptionSegmen
   speaker: value.speaker,
 })
 
-const onEvent = Effect.fn("OpenAITranscription.onEvent")(function* (state: State, frame: string) {
+const onEvent = Effect.fnUntraced(function* (state: State, frame: string) {
   if (!EVENT_TYPES.has((yield* decodeEventType(frame)).type)) return [state, []] as const
   const event = yield* decodeEvent(frame)
   if (event.type === "error")
diff --git a/packages/ai/src/protocols/stability-images.ts b/packages/ai/src/protocols/stability-images.ts
index 2dcc538df8d..ed52c502a37 100644
--- a/packages/ai/src/protocols/stability-images.ts
+++ b/packages/ai/src/protocols/stability-images.ts
@@ -82,7 +82,7 @@ const endpoint = (model: string) => (model.startsWith("sd3") ? "sd3" : model)
 
 const RESERVED_FORM_FIELDS = new Set(["image", "prompt", "mode", "model"])
 
-const form = Effect.fn("StabilityImages.form")(function* (
+const form = Effect.fnUntraced(function* (
   identity: MediaProtocol.Identity,
   fields: Record<string, unknown>,
   native: Record<string, unknown> | undefined,
diff --git a/packages/ai/src/protocols/utils/responses-checkpoint.ts b/packages/ai/src/protocols/utils/responses-checkpoint.ts
index 7d4cf1ab14a..2557f6c61ba 100644
--- a/packages/ai/src/protocols/utils/responses-checkpoint.ts
+++ b/packages/ai/src/protocols/utils/responses-checkpoint.ts
@@ -11,7 +11,7 @@ interface State {
   readonly responseID?: string
 }
 
-const onOutputItem = Effect.fn("ResponsesCheckpoint.onOutputItem")(function* (
+const onOutputItem = Effect.fnUntraced(function* (
   state: State,
   input: OpenResponses.Event,
 ) {
@@ -63,7 +63,7 @@ export const make = <Body>(body: RouteBody<Body>): TriggerCompactOperation =>
           checkpoints: {},
         }),
         terminal: OpenResponses.terminal,
-        step: Effect.fn("ResponsesCheckpoint.step")(function* (state: State, event: OpenResponses.Event) {
+        step: Effect.fnUntraced(function* (state: State, event: OpenResponses.Event) {
           if (event.response?.id && state.responseID && event.response.id !== state.responseID)
             return yield* ProviderShared.eventError(source.id, "Compaction response ID changed during execution")
           if (event.type === "response.created") return [{ ...state, responseID: event.response?.id }, []] as const
diff --git a/packages/ai/src/protocols/utils/responses-hosted-tools.ts b/packages/ai/src/protocols/utils/responses-hosted-tools.ts
index 465ff23ed85..11d3e9708bc 100644
--- a/packages/ai/src/protocols/utils/responses-hosted-tools.ts
+++ b/packages/ai/src/protocols/utils/responses-hosted-tools.ts
@@ -33,7 +33,7 @@ export const onDone: (
   state: OpenResponses.ParserState,
   item: Item,
   tools: Definitions,
-) => Effect.Effect<OpenResponses.StepResult, AIError> = Effect.fn("ResponsesHostedTools.onDone")(
+) => Effect.Effect<OpenResponses.StepResult, AIError> = Effect.fnUntraced(
   function* (state, item, tools) {
     const tool = tools[item.type]
     if (!tool) return [state, []] satisfies OpenResponses.StepResult