From d72423edf6f333e994e76a546eec673979a2f83c Mon Sep 17 00:00:00 2001 From: Thomas Kosiewski Date: Mon, 12 Oct 2026 18:07:20 +0000 Subject: [PATCH] feat(effect): classify 402 as quota and carry raw usage MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit HTTP 402 now maps to Effect 4's QuotaExhaustedError with a new `quota` classification that isTransient treats as terminal. 429 stays a transient rate-limit with retryAfter. The provider's raw usage (LanguageModelV4Usage.raw) travels on the finish part as metadata.coder.rawUsage when the provider reports it, on the generate and stream paths (including the Coder Agents model). CoderFinishMetadata describes the finish part's metadata.coder. Fixes #323 Signed-off-by: Thomas Kosiewski --- _Generated with [`xum`](https://github.com/coder/xum) • Model: `anthropic:claude-opus-5-5` • Thinking: `high`_ Change-Id: Ie68c8f7776eddf3c431f7219353057aedcdac069 --- packages/effect/README.md | 34 +++++++- packages/effect/src/errors.ts | 23 ++++-- packages/effect/src/index.ts | 2 +- packages/effect/src/language-model.ts | 88 +++++++++++++++------ packages/effect/test/agent-model.test.ts | 4 + packages/effect/test/errors.test.ts | 42 +++++++++- packages/effect/test/language-model.test.ts | 87 ++++++++++++++++++++ 7 files changed, 244 insertions(+), 36 deletions(-) diff --git a/packages/effect/README.md b/packages/effect/README.md index 6eadc94..9ec34a4 100644 --- a/packages/effect/README.md +++ b/packages/effect/README.md @@ -89,6 +89,30 @@ const deterministic = LanguageModel.generateText({ prompt: "Name a color." }).pi `CoderLanguageModel.fromModel` (the bridge core) adapts any AI SDK `LanguageModelV4`; unit tests use it to run without HTTP. +### Usage metadata + +The finish part's `usage` holds the normalized token counts. `effect/ai`'s +`Response.Usage` has no field for the provider's raw usage +(`LanguageModelV4Usage.raw`), so the bridge puts it in the finish part's +`metadata.coder.rawUsage` as plain JSON. The key is present only when the +provider reports raw usage. For the Coder Agents model, it is chatd's wire +usage (snake_case fields such as `input_tokens` and `context_limit`). The +`CoderFinishMetadata` type describes `metadata.coder`, and the same rule +applies on the generate and stream paths. + +```ts +import * as LanguageModel from "effect/ai/LanguageModel"; +import * as Effect from "effect/Effect"; +import type { CoderFinishMetadata } from "@coder/ai-sdk-effect"; + +const rawUsage = Effect.gen(function* () { + const response = yield* LanguageModel.generateText({ prompt: "hello" }); + const finish = response.content.find((part) => part.type === "finish"); + const coder = finish?.metadata.coder as CoderFinishMetadata | undefined; + return coder?.rawUsage; +}); +``` + ## `LanguageModel` over Coder Agents `CoderAgentModel.layer(settings)` implements `LanguageModel` on top of a Coder @@ -152,7 +176,7 @@ program.pipe( ## Typed error taxonomy `classifyError` maps an `AiError`, a raw AI SDK error, or a raw -`@coder/ai-sdk-agent` error to one of: `auth`, `rate-limit`, +`@coder/ai-sdk-agent` error to one of: `auth`, `rate-limit`, `quota`, `provider-unavailable`, `malformed-response`, `transport`, `timeout`, `unknown`. `isTransient` composes with `Effect.retry`: @@ -180,6 +204,10 @@ instead of adding its own error classes: - A `RateLimitError` from an AI Gateway response sets `retryAfter` from a valid `Retry-After` header (delay-seconds, or an HTTP-date). Read it as `error.retryAfter`, for example to pick a retry delay. +- HTTP 402 means the account's quota or billing limit is exhausted. It maps + to `QuotaExhaustedError` and the `quota` classification, which is not + transient: a retry cannot succeed until someone raises the limit. HTTP 429 + stays a transient `rate-limit`. - The reason's `metadata.coder` records the classification and, when the source error has them, the HTTP `status`, the Coder Agents `retryable` verdict, the chat error's `kind` and `provider`, and the stream's `chatId`. @@ -196,7 +224,8 @@ instead of adding its own error classes: | Source error | `AiError` reason | `classifyError` | `isTransient` | Reason `isRetryable` | | ----------------------------------------------------------------- | ---------------------------------------------------------------- | --------------------------------- | ------------- | ------------------------------- | | `APICallError` or `CoderApiError`, status 401 / 403 | `AuthenticationError` (`InvalidKey` / `InsufficientPermissions`) | `auth` | `false` | `false` | -| status 402 / 429 | `RateLimitError` | `rate-limit` | `true` | `true` | +| status 402 | `QuotaExhaustedError` | `quota` | `false` | `false` | +| status 429 | `RateLimitError` (`retryAfter` from `Retry-After`) | `rate-limit` | `true` | `true` | | status 5xx | `InternalProviderError` | `provider-unavailable` | `true` | `true` | | status 400 | `InvalidRequestError` | `unknown` | `false` | `false` | | any other status | `UnknownError` | `unknown` | `false` | `false` | @@ -306,6 +335,7 @@ no `effect/ai` equivalent are dropped. | Provider-defined tools (not expressible in `LanguageModelV4` call options) | `InvalidRequestError` | | Response parts of type `custom`, `reasoning-file`, `tool-approval-request`; file payloads that are not raw data (URL / provider-reference / inline-text) | Dropped | | Provider-executed tool calls and results for tools outside the call's toolkit (`effect/ai` types tool parts by toolkit) | Moved to the finish part's `metadata.coder.serverToolCalls` | +| Provider raw usage (`effect/ai`'s `Response.Usage` has no field for it) | Moved to the finish part's `metadata.coder.rawUsage` | | Tool approval parts in the prompt (`effect/ai` resolves and strips them before the call) | Not forwarded | | `Prompt` provider options (per-part metadata) | Not forwarded | | `ProviderOptions.span` (telemetry) | Not wired into request headers | diff --git a/packages/effect/src/errors.ts b/packages/effect/src/errors.ts index 0a0f240..aa0ed6a 100644 --- a/packages/effect/src/errors.ts +++ b/packages/effect/src/errors.ts @@ -40,7 +40,9 @@ import * as Schema from "effect/Schema"; * Coder-oriented classification of a gateway/model call failure. * * - `auth`: the credential was rejected (401/403) — Coder token or BYOK key. - * - `rate-limit`: the gateway or upstream throttled or exhausted quota (402/429). + * - `rate-limit`: the gateway or upstream throttled the request (429). + * - `quota`: the account's quota or billing limit is exhausted (402). Not + * transient: retrying cannot succeed until someone acts. * - `provider-unavailable`: the upstream or gateway failed server-side (5xx). * - `malformed-response`: the response could not be parsed or validated. * - `transport`: the request never produced an HTTP response (network error), @@ -52,6 +54,7 @@ import * as Schema from "effect/Schema"; export type ErrorReason = | "auth" | "rate-limit" + | "quota" | "provider-unavailable" | "malformed-response" | "transport" @@ -67,7 +70,7 @@ export type ErrorReason = * - `kind` / `provider`: from `CoderChatError`. * - `chatId`: from `CoderStreamError`. * - `message`: the source error's message, on reasons without a - * `description` field (`RateLimitError`). + * `description` field (`RateLimitError`, `QuotaExhaustedError`). * * A `RateLimitError` also sets `retryAfter` from the response's * `Retry-After` header when it is valid. @@ -76,6 +79,7 @@ const CoderErrorMetadata = Schema.Struct({ classification: Schema.Literals([ "auth", "rate-limit", + "quota", "provider-unavailable", "malformed-response", "transport", @@ -98,7 +102,8 @@ const decodeCoderMetadata = Schema.decodeUnknownOption(CoderErrorMetadata); /** Classify an HTTP status code into an {@link ErrorReason}. */ export const classifyStatus = (status: number): ErrorReason => { if (status === 401 || status === 403) return "auth"; - if (status === 402 || status === 429) return "rate-limit"; + if (status === 402) return "quota"; + if (status === 429) return "rate-limit"; if (status >= 500) return "provider-unavailable"; return "unknown"; }; @@ -135,8 +140,9 @@ const classifyReason = (reason: AiError.AiErrorReason): ErrorReason => { case "AuthenticationError": return "auth"; case "RateLimitError": - case "QuotaExhaustedError": return "rate-limit"; + case "QuotaExhaustedError": + return "quota"; case "InternalProviderError": return "provider-unavailable"; case "NetworkError": @@ -176,7 +182,8 @@ export const classifyError = (error: ClassifiableError): ErrorReason => { * `false` by the agent when replaying the prompt would duplicate server-side * effects; `CoderChatError.retryable` is chatd's own verdict). Otherwise * throttling, upstream outages, network errors, and turn timeouts are - * transient, while auth and malformed-response failures are terminal. + * transient, while auth, exhausted quota, and malformed-response failures + * are terminal. */ export const isTransient = (error: ClassifiableError): boolean => { const verdict = Option.getOrUndefined(coderMetadata(asAiError(error)))?.retryable; @@ -273,6 +280,12 @@ const reasonFor = ( metadata: { coder: { ...coder, message: description } }, }); break; + case "quota": + reason = new AiError.QuotaExhaustedError({ + http, + metadata: { coder: { ...coder, message: description } }, + }); + break; case "provider-unavailable": reason = new AiError.InternalProviderError(common); break; diff --git a/packages/effect/src/index.ts b/packages/effect/src/index.ts index 717b24e..618d902 100644 --- a/packages/effect/src/index.ts +++ b/packages/effect/src/index.ts @@ -10,7 +10,7 @@ export { export * as CoderAgentModel from "./agent-model.js"; export type { AgentModelSettings, AgentOptions } from "./agent-model.js"; export * as CoderLanguageModel from "./language-model.js"; -export type { GenerationOptions, ProviderSource } from "./language-model.js"; +export type { CoderFinishMetadata, GenerationOptions, ProviderSource } from "./language-model.js"; export { acquireSession, type AcquireSessionOptions, diff --git a/packages/effect/src/language-model.ts b/packages/effect/src/language-model.ts index b3413ee..6100b1d 100644 --- a/packages/effect/src/language-model.ts +++ b/packages/effect/src/language-model.ts @@ -19,6 +19,10 @@ * `effect/ai`, whose tool parts are typed by the toolkit. They are moved to * the finish part's `metadata.coder.serverToolCalls` instead; streaming still * emits their `tool-params-start` / `tool-params-end` markers. + * + * `effect/ai`'s `Response.Usage` has no slot for the provider's raw usage + * (`LanguageModelV4Usage.raw`), so it travels in the finish part's + * `metadata.coder.rawUsage` (see {@link CoderFinishMetadata}). */ import type { JSONValue, @@ -62,6 +66,28 @@ const MODULE = "CoderLanguageModel"; /** The model source: provider settings, or an already-constructed provider. */ export type ProviderSource = CoderProviderSettings | { readonly provider: CoderProvider }; +/** + * What the bridge records under the finish part's `metadata.coder`, as plain + * JSON. Each key is present only when there is something to report, and the + * finish part has no `metadata.coder` when neither is: + * + * - `serverToolCalls`: provider-executed tool activity for tools outside the + * call's toolkit (see the module docs), in call order. + * - `rawUsage`: the provider's raw usage (`LanguageModelV4Usage.raw`), present + * only when the provider reports it. Keys whose value is `undefined` are + * dropped. + */ +export type CoderFinishMetadata = { + readonly serverToolCalls?: ReadonlyArray<{ + readonly id: string; + readonly name: string; + readonly params?: Schema.Json; + readonly result?: Schema.Json; + readonly isFailure?: boolean; + }>; + readonly rawUsage?: { readonly [key: string]: Schema.Json }; +}; + /** * Generation controls forwarded to the underlying model. Options given at * construction apply to every call; {@link withGenerationOptions} overrides @@ -216,7 +242,7 @@ const generateText = ( if (serverTools.absorb(content)) continue; parts.push(...contentToParts(content)); } - parts.push(serverTools.attach(finishPart(result.finishReason, result.usage))); + parts.push(finishPart(result.finishReason, result.usage, serverTools)); return parts; }, catch: (error) => toAiError({ module: MODULE, method: "generateText", error }), @@ -259,9 +285,7 @@ const streamText = ( } try { if (serverTools.absorb(part)) return Stream.empty; - return Stream.fromIterable( - streamPartToParts(part).map((p) => (p.type === "finish" ? serverTools.attach(p) : p)), - ); + return Stream.fromIterable(streamPartToParts(part, serverTools)); } catch (error) { return Stream.fail(toAiError({ module: MODULE, method: "streamText", error })); } @@ -590,6 +614,7 @@ const sharedContentToParts = (content: SharedContent): Array const streamPartToParts = ( part: Exclude, + serverTools: ServerToolCalls, ): Array => { switch (part.type) { case "text-start": @@ -620,7 +645,7 @@ const streamPartToParts = ( case "response-metadata": return [responseMetadataPart(part)]; case "finish": - return [finishPart(part.finishReason, part.usage)]; + return [finishPart(part.finishReason, part.usage, serverTools)]; // `stream-start` (warnings) and `raw` chunks have no equivalent. case "stream-start": case "raw": @@ -641,7 +666,7 @@ interface ServerToolCall { /** * Collects provider-executed tool activity for tools outside the call's - * toolkit (see the module docs) and attaches it to the finish part. + * toolkit (see the module docs) for the finish part's metadata. */ class ServerToolCalls { readonly #toolNames: ReadonlySet; @@ -669,13 +694,13 @@ class ServerToolCalls { return false; } - attach(finish: Response.FinishPartEncoded): Response.FinishPartEncoded { - if (this.#calls.size === 0) return finish; + /** The recorded calls as plain JSON, or `undefined` when there are none. */ + toJson(): CoderFinishMetadata["serverToolCalls"] { + if (this.#calls.size === 0) return undefined; // Finish metadata must be plain JSON. Params come from `JSON.parse` and // results from the provider's JSON payload; the round trip drops the // `undefined` object values that the AI SDK's `JSONValue` allows. - const serverToolCalls: Schema.Json = JSON.parse(JSON.stringify([...this.#calls.values()])); - return { ...finish, metadata: { coder: { serverToolCalls } } }; + return JSON.parse(JSON.stringify([...this.#calls.values()])); } #entry(id: string, name: string): ServerToolCall { @@ -705,23 +730,34 @@ const responseMetadataPart = (metadata: { timestamp: metadata.timestamp?.toISOString(), }); +/** The finish part, with `metadata.coder` only when it has keys. */ const finishPart = ( finishReason: LanguageModelV4FinishReason, usage: LanguageModelV4Usage, -): Response.FinishPartEncoded => ({ - type: "finish", - reason: finishReason.unified, - usage: { - inputTokens: { - uncached: usage.inputTokens.noCache, - total: usage.inputTokens.total, - cacheRead: usage.inputTokens.cacheRead, - cacheWrite: usage.inputTokens.cacheWrite, - }, - outputTokens: { - total: usage.outputTokens.total, - text: usage.outputTokens.text, - reasoning: usage.outputTokens.reasoning, + serverTools: ServerToolCalls, +): Response.FinishPartEncoded => { + const part: Response.FinishPartEncoded = { + type: "finish", + reason: finishReason.unified, + usage: { + inputTokens: { + uncached: usage.inputTokens.noCache, + total: usage.inputTokens.total, + cacheRead: usage.inputTokens.cacheRead, + cacheWrite: usage.inputTokens.cacheWrite, + }, + outputTokens: { + total: usage.outputTokens.total, + text: usage.outputTokens.text, + reasoning: usage.outputTokens.reasoning, + }, }, - }, -}); + }; + const coder: { -readonly [K in keyof CoderFinishMetadata]: CoderFinishMetadata[K] } = {}; + const serverToolCalls = serverTools.toJson(); + if (serverToolCalls !== undefined) coder.serverToolCalls = serverToolCalls; + // The raw usage is a `JSONObject`; the round trip drops `undefined` values. + if (usage.raw !== undefined) coder.rawUsage = JSON.parse(JSON.stringify(usage.raw)); + if (Object.keys(coder).length === 0) return part; + return { ...part, metadata: { coder } }; +}; diff --git a/packages/effect/test/agent-model.test.ts b/packages/effect/test/agent-model.test.ts index c4bcc67..e681a2a 100644 --- a/packages/effect/test/agent-model.test.ts +++ b/packages/effect/test/agent-model.test.ts @@ -215,6 +215,10 @@ describe("CoderAgentModel", () => { const finish = parts.at(-1); expect(finish?.type === "finish" && finish.reason).toBe("stop"); expect(finish?.type === "finish" && finish.usage.inputTokens.total).toBe(12); + // chatd's wire usage (snake_case) is the provider's raw usage. + expect(finish?.metadata).toEqual({ + coder: { rawUsage: { input_tokens: 12, output_tokens: 4 } }, + }); expect(fake.created[0]?.system_prompt).toBe("Be brief."); expect(fake.interrupted).toEqual([]); expect(fake.openStreams).toBe(0); diff --git a/packages/effect/test/errors.test.ts b/packages/effect/test/errors.test.ts index fc2ce91..884e202 100644 --- a/packages/effect/test/errors.test.ts +++ b/packages/effect/test/errors.test.ts @@ -19,7 +19,7 @@ describe("classifyStatus", () => { it.each([ [401, "auth"], [403, "auth"], - [402, "rate-limit"], + [402, "quota"], [429, "rate-limit"], [500, "provider-unavailable"], [502, "provider-unavailable"], @@ -52,7 +52,7 @@ describe("toAiError", () => { it.each([ [400, "InvalidRequestError"], [401, "AuthenticationError"], - [402, "RateLimitError"], + [402, "QuotaExhaustedError"], [403, "AuthenticationError"], [404, "UnknownError"], [503, "InternalProviderError"], @@ -60,6 +60,18 @@ describe("toAiError", () => { expect(map(apiCallError(status)).reason._tag).toBe(tag); }); + it("maps HTTP 402 to QuotaExhaustedError, preserving details", () => { + const error = map(apiCallError(402)); + const reason = error.reason as AiError.QuotaExhaustedError; + expect(reason._tag).toBe("QuotaExhaustedError"); + expect(reason.isRetryable).toBe(false); + expect(reason.http?.response).toEqual({ status: 402, headers: { "x-request-id": "req_123" } }); + expect(reason.http?.body).toBe(`{"error":"failure"}`); + expect(reason.metadata).toEqual({ + coder: { classification: "quota", status: 402, message: "gateway failure (402)" }, + }); + }); + describe("RateLimitError.retryAfter", () => { const throttled = (headers: Record): AiError.AiError => map( @@ -145,6 +157,10 @@ describe("classifyError / isTransient", () => { expect(classifyError(throttled)).toBe("rate-limit"); expect(isTransient(throttled)).toBe(true); + const quota = toAiError({ module: "T", method: "m", error: apiCallError(402) }); + expect(classifyError(quota)).toBe("quota"); + expect(isTransient(quota)).toBe(false); + const upstream = toAiError({ module: "T", method: "m", error: apiCallError(503) }); expect(classifyError(upstream)).toBe("provider-unavailable"); expect(isTransient(upstream)).toBe(true); @@ -157,12 +173,32 @@ describe("classifyError / isTransient", () => { it("classifies raw AI SDK errors directly (documented contract)", () => { expect(classifyError(apiCallError(403))).toBe("auth"); expect(classifyError(apiCallError(429))).toBe("rate-limit"); + expect(classifyError(apiCallError(402))).toBe("quota"); expect(classifyError(apiCallError(undefined))).toBe("transport"); expect(classifyError(new JSONParseError({ text: "x", cause: new Error("y") }))).toBe( "malformed-response", ); expect(isTransient(apiCallError(503))).toBe(true); expect(isTransient(apiCallError(401))).toBe(false); + expect(isTransient(apiCallError(402))).toBe(false); + expect(isTransient(apiCallError(429))).toBe(true); + }); + + it("classifies effect/ai's own quota and rate-limit reasons by tag", () => { + const quota = AiError.make({ + module: "T", + method: "m", + reason: new AiError.QuotaExhaustedError({}), + }); + expect(classifyError(quota)).toBe("quota"); + expect(isTransient(quota)).toBe(false); + const throttled = AiError.make({ + module: "T", + method: "m", + reason: new AiError.RateLimitError({}), + }); + expect(classifyError(throttled)).toBe("rate-limit"); + expect(isTransient(throttled)).toBe(true); }); it("classifies malformed output as terminal", () => { @@ -208,6 +244,7 @@ describe("Coder Agents errors", () => { }); it.each([ + [402, "quota", false], [429, "rate-limit", true], [503, "provider-unavailable", true], [409, "unknown", false], @@ -250,6 +287,7 @@ describe("Coder Agents errors", () => { it.each([ [{ kind: "stream_closed", retryable: true }, "transport", true], [{ status_code: 429, retryable: true }, "rate-limit", true], + [{ status_code: 402 }, "quota", false], [{ status_code: 503, retryable: false }, "provider-unavailable", false], [{ status_code: 401 }, "auth", false], [{ kind: "generic" }, "unknown", false], diff --git a/packages/effect/test/language-model.test.ts b/packages/effect/test/language-model.test.ts index 100b0bf..2ddb8a7 100644 --- a/packages/effect/test/language-model.test.ts +++ b/packages/effect/test/language-model.test.ts @@ -23,6 +23,21 @@ const USAGE = { outputTokens: { total: 5, text: 5, reasoning: undefined }, }; +// Provider-shaped raw usage. `undefined` values are allowed by the AI SDK's +// `JSONObject` but are not JSON, so the finish metadata drops them. +const RAW_USAGE = { + input_tokens: 8, + cache_read_tokens: 2, + total_cost_micros: 1234, + details: { tier: "standard", unset: undefined }, +}; +const RAW_USAGE_JSON = { + input_tokens: 8, + cache_read_tokens: 2, + total_cost_micros: 1234, + details: { tier: "standard" }, +}; + const fakeModel = (overrides: Partial): LanguageModelV4 => ({ specificationVersion: "v4", provider: "coder", @@ -77,6 +92,9 @@ describe("generateText", () => { cacheWrite: undefined, }); expect(response.usage.outputTokens).toEqual({ total: 5, text: 5, reasoning: undefined }); + // No raw usage from the provider: no `metadata.coder` on the finish part. + const finish = response.content.find((part) => part.type === "finish"); + expect(finish?.metadata).toEqual({}); expect(captured?.prompt).toEqual([ { role: "user", content: [{ type: "text", text: "Say hello" }] }, ]); @@ -331,6 +349,47 @@ describe("generateText", () => { }); }); + it("carries the provider's raw usage as finish metadata.coder.rawUsage", async () => { + const model = fakeModel({ + doGenerate: async () => ({ + content: [ + { type: "text", text: "Listed the files." }, + { + type: "tool-call", + toolCallId: "srv_1", + toolName: "execute", + input: `{"command":"ls"}`, + providerExecuted: true, + }, + { type: "tool-result", toolCallId: "srv_1", toolName: "execute", result: "a.txt" }, + ], + finishReason: { unified: "stop", raw: undefined }, + usage: { ...USAGE, raw: RAW_USAGE }, + warnings: [], + }), + }); + + const response = await Effect.runPromise( + Effect.flatMap(service(model), (m) => m.generateText({ prompt: "ls" })), + ); + + const finish = response.content.find((part) => part.type === "finish"); + expect(finish?.metadata).toEqual({ + coder: { + rawUsage: RAW_USAGE_JSON, + serverToolCalls: [ + { + id: "srv_1", + name: "execute", + params: { command: "ls" }, + result: "a.txt", + isFailure: false, + }, + ], + }, + }); + }); + describe("tool choice", () => { const GetWeather = Tool.make("get_weather", { parameters: Schema.Struct({ city: Schema.String }), @@ -441,6 +500,7 @@ describe("generateText", () => { expect(classifyError(auth)).toBe("auth"); expect(classifyError(failure(await run(429)))).toBe("rate-limit"); + expect(classifyError(failure(await run(402)))).toBe("quota"); const network = failure(await run(undefined)); expect(network.reason._tag).toBe("NetworkError"); @@ -573,6 +633,33 @@ describe("streamText", () => { }); }); + it.each([ + ["present", { ...USAGE, raw: RAW_USAGE }, { coder: { rawUsage: RAW_USAGE_JSON } }], + ["absent", USAGE, {}], + ] as const)( + "carries raw usage on the finish part only when %s", + async (_label, usage, metadata) => { + const model = fakeModel({ + doStream: async () => ({ + stream: streamOf([ + { type: "text-start", id: "t1" }, + { type: "text-delta", id: "t1", delta: "Hi" }, + { type: "text-end", id: "t1" }, + { type: "finish", finishReason: { unified: "stop", raw: "stop" }, usage }, + ]), + }), + }); + + const parts = await Effect.runPromise( + Effect.flatMap(service(model), (m) => Stream.runCollect(m.streamText({ prompt: "hi" }))), + ); + + const finish = parts.at(-1); + expect(finish?.type).toBe("finish"); + expect(finish?.metadata).toEqual(metadata); + }, + ); + it("fails the stream with a typed AiError on error parts", async () => { const model = fakeModel({ doStream: async () => ({