fix(vscode-lm): reliable auto context condensing

packages/types/src/__tests__/vscode-llm.spec.ts

@@ -0,0 +1,36 @@
+import { describe, it, expect } from "vitest"
+import { vscodeLlmModels, vscodeLlmDefaultModelId } from "../providers/vscode-llm.js"
+
+describe("vscodeLlmModels", () => {
+	it("exposes the opus-4.8 row with its measured maxInputTokens and contextWindow", () => {
+		// The VS Code LM API exposes only maxInputTokens; that is the value the UI reads from this
+		// table (useSelectedModel.ts). For claude-opus-4.8 the two fields intentionally DIVERGE:
+		// maxInputTokens (197897) is the enforced input ceiling, while contextWindow (679560) records
+		// the larger advertised window. The UI reads maxInputTokens, so the divergence is a deliberate
+		// tripwire — assert the actual on-disk literals rather than forcing equality.
+		expect(vscodeLlmModels).toHaveProperty("claude-opus-4.8")
+		expect(vscodeLlmModels["claude-opus-4.8"].contextWindow).toBe(679560)
+		expect(vscodeLlmModels["claude-opus-4.8"].maxInputTokens).toBe(197897)
+	})
+	it("preserves the real window for models captured with a smaller maxInputTokens", () => {
+		expect(vscodeLlmModels["gpt-4o-mini"].maxInputTokens).toBe(12078)
+		expect(vscodeLlmModels["gpt-4o-mini"].contextWindow).toBe(12078)
+		expect(vscodeLlmModels["gemini-2.5-pro"].contextWindow).toBe(108594)
+		expect(vscodeLlmModels["gemini-2.5-pro"].maxInputTokens).toBe(108594)
+	})
+	it("keeps both window fields populated and positive for every row", () => {
+		for (const [family, model] of Object.entries(vscodeLlmModels)) {
+			expect(model.contextWindow, `${family}: contextWindow must be a positive integer`).toBeGreaterThan(0)
+			expect(model.maxInputTokens, `${family}: maxInputTokens must be a positive integer`).toBeGreaterThan(0)
+		}
+	})
+	it("excludes fabricated/internal/alias families and the dropped legacy rows", () => {
+		expect(vscodeLlmModels).not.toHaveProperty("claude-opus-4.7-high")
+		expect(vscodeLlmModels).not.toHaveProperty("claude-3.5-sonnet")
+		expect(vscodeLlmModels).not.toHaveProperty("claude-4-sonnet")
+	})
+	it("defaults to a model id that exists in the table", () => {
+		expect(vscodeLlmDefaultModelId).toBe("claude-sonnet-4.5")
+		expect(vscodeLlmModels).toHaveProperty(vscodeLlmDefaultModelId)
+	})
+})

packages/types/src/providers/vscode-llm.ts

@@ -2,189 +2,222 @@ import type { ModelInfo } from "../model.js"
 
 export type VscodeLlmModelId = keyof typeof vscodeLlmModels
 
-export const vscodeLlmDefaultModelId: VscodeLlmModelId = "claude-3.5-sonnet"
+export const vscodeLlmDefaultModelId: VscodeLlmModelId = "claude-sonnet-4.5"
 
-// https://docs.cline.bot/provider-config/vscode-language-model-api
+// Curated VS Code LM (GitHub Copilot) model catalog.
+//
+// The VS Code LM API only exposes `maxInputTokens` per model; it does NOT report a separate
+// total context window. For each row, `contextWindow` records the model's advertised window
+// while `maxInputTokens` is the enforced input ceiling the UI actually reads (via
+// useSelectedModel.ts) and the condense gate measures against. For most rows the two values
+// match. They intentionally DIVERGE only where the provider advertises a larger window than the
+// usable input ceiling (e.g. claude-opus-4.8): keeping both fields lets the context bar and the
+// auto-condense gate stay on a single source of truth (maxInputTokens) without losing the real
+// advertised window.
 export const vscodeLlmModels = {
-	"gpt-3.5-turbo": {
-		contextWindow: 12114,
-		supportsImages: false,
+	"claude-opus-4.8": {
+		contextWindow: 679560,
+		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "gpt-3.5-turbo",
-		version: "gpt-3.5-turbo-0613",
-		name: "GPT 3.5 Turbo",
+		family: "claude-opus-4.8",
+		version: "claude-opus-4.8",
+		name: "Claude Opus 4.8",
 		supportsToolCalling: true,
-		maxInputTokens: 12114,
+		maxInputTokens: 197897,
 	},
-	"gpt-4o-mini": {
-		contextWindow: 12115,
-		supportsImages: false,
+	"claude-opus-4.7": {
+		contextWindow: 197897,
+		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "gpt-4o-mini",
-		version: "gpt-4o-mini-2024-07-18",
-		name: "GPT-4o mini",
+		family: "claude-opus-4.7",
+		version: "claude-opus-4.7",
+		name: "Claude Opus 4.7",
 		supportsToolCalling: true,
-		maxInputTokens: 12115,
+		maxInputTokens: 197897,
 	},
-	"gpt-4": {
-		contextWindow: 28501,
-		supportsImages: false,
+	"claude-opus-4.6": {
+		contextWindow: 197897,
+		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "gpt-4",
-		version: "gpt-4-0613",
-		name: "GPT 4",
+		family: "claude-opus-4.6",
+		version: "claude-opus-4.6",
+		name: "Claude Opus 4.6",
 		supportsToolCalling: true,
-		maxInputTokens: 28501,
+		maxInputTokens: 197897,
 	},
-	"gpt-4-0125-preview": {
-		contextWindow: 63826,
-		supportsImages: false,
+	"claude-opus-4.5": {
+		contextWindow: 167790,
+		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "gpt-4-turbo",
-		version: "gpt-4-0125-preview",
-		name: "GPT 4 Turbo",
+		family: "claude-opus-4.5",
+		version: "claude-opus-4.5",
+		name: "Claude Opus 4.5",
 		supportsToolCalling: true,
-		maxInputTokens: 63826,
+		maxInputTokens: 167790,
 	},
-	"gpt-4o": {
-		contextWindow: 63827,
+	"claude-sonnet-4.6": {
+		contextWindow: 197896,
 		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "gpt-4o",
-		version: "gpt-4o-2024-11-20",
-		name: "GPT-4o",
+		family: "claude-sonnet-4.6",
+		version: "claude-sonnet-4.6",
+		name: "Claude Sonnet 4.6",
 		supportsToolCalling: true,
-		maxInputTokens: 63827,
+		maxInputTokens: 197896,
 	},
-	o1: {
-		contextWindow: 19827,
-		supportsImages: false,
+	"claude-sonnet-4.5": {
+		contextWindow: 167790,
+		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "o1-ga",
-		version: "o1-2024-12-17",
-		name: "o1 (Preview)",
+		family: "claude-sonnet-4.5",
+		version: "claude-sonnet-4.5",
+		name: "Claude Sonnet 4.5",
 		supportsToolCalling: true,
-		maxInputTokens: 19827,
+		maxInputTokens: 167790,
 	},
-	"o3-mini": {
-		contextWindow: 63827,
-		supportsImages: false,
+	"claude-haiku-4.5": {
+		contextWindow: 135790,
+		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "o3-mini",
-		version: "o3-mini-2025-01-31",
-		name: "o3-mini",
+		family: "claude-haiku-4.5",
+		version: "claude-haiku-4.5",
+		name: "Claude Haiku 4.5",
 		supportsToolCalling: true,
-		maxInputTokens: 63827,
+		maxInputTokens: 135790,
 	},
-	"claude-3.5-sonnet": {
-		contextWindow: 81638,
+	"gpt-5.5": {
+		contextWindow: 268426,
 		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "claude-3.5-sonnet",
-		version: "claude-3.5-sonnet",
-		name: "Claude 3.5 Sonnet",
+		family: "gpt-5.5",
+		version: "gpt-5.5",
+		name: "GPT-5.5",
 		supportsToolCalling: true,
-		maxInputTokens: 81638,
+		maxInputTokens: 268426,
 	},
-	"claude-4-sonnet": {
-		contextWindow: 128000,
+	"gpt-5.4": {
+		contextWindow: 268424,
 		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "claude-sonnet-4",
-		version: "claude-sonnet-4",
-		name: "Claude Sonnet 4",
+		family: "gpt-5.4",
+		version: "gpt-5.4",
+		name: "GPT-5.4",
 		supportsToolCalling: true,
-		maxInputTokens: 111836,
+		maxInputTokens: 268424,
 	},
-	"gemini-2.0-flash-001": {
-		contextWindow: 127827,
+	"gpt-5.4-mini": {
+		contextWindow: 271790,
 		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "gemini-2.0-flash",
-		version: "gemini-2.0-flash-001",
-		name: "Gemini 2.0 Flash",
-		supportsToolCalling: false,
-		maxInputTokens: 127827,
+		family: "gpt-5.4-mini",
+		version: "gpt-5.4-mini",
+		name: "GPT-5.4 mini",
+		supportsToolCalling: true,
+		maxInputTokens: 271790,
 	},
-	"gemini-2.5-pro": {
-		contextWindow: 128000,
+	"gpt-5.3-codex": {
+		contextWindow: 271790,
 		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "gemini-2.5-pro",
-		version: "gemini-2.5-pro-preview-03-25",
-		name: "Gemini 2.5 Pro (Preview)",
+		family: "gpt-5.3-codex",
+		version: "gpt-5.3-codex",
+		name: "GPT-5.3-Codex",
 		supportsToolCalling: true,
-		maxInputTokens: 108637,
+		maxInputTokens: 271790,
 	},
-	"o4-mini": {
-		contextWindow: 128000,
+	"gpt-5-mini": {
+		contextWindow: 127790,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+		family: "gpt-5-mini",
+		version: "gpt-5-mini",
+		name: "GPT-5 mini",
+		supportsToolCalling: true,
+		maxInputTokens: 127790,
+	},
+	"gpt-4o-mini": {
+		contextWindow: 12078,
 		supportsImages: false,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "o4-mini",
-		version: "o4-mini-2025-04-16",
-		name: "o4-mini (Preview)",
+		family: "gpt-4o-mini",
+		version: "gpt-4o-mini-2024-07-18",
+		name: "GPT-4o mini",
 		supportsToolCalling: true,
-		maxInputTokens: 111452,
+		maxInputTokens: 12078,
 	},
-	"gpt-4.1": {
-		contextWindow: 128000,
+	"gemini-3.1-pro-preview": {
+		contextWindow: 197897,
 		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "gpt-4.1",
-		version: "gpt-4.1-2025-04-14",
-		name: "GPT-4.1 (Preview)",
+		family: "gemini-3.1-pro-preview",
+		version: "gemini-3.1-pro-preview",
+		name: "Gemini 3.1 Pro (Preview)",
 		supportsToolCalling: true,
-		maxInputTokens: 111452,
+		maxInputTokens: 197897,
 	},
-	"gpt-5-mini": {
-		contextWindow: 128000,
+	"gemini-3.5-flash": {
+		contextWindow: 197895,
 		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "gpt-5-mini",
-		version: "gpt-5-mini",
-		name: "GPT-5 mini (Preview)",
+		family: "gemini-3.5-flash",
+		version: "gemini-3.5-flash",
+		name: "Gemini 3.5 Flash",
+		supportsToolCalling: true,
+		maxInputTokens: 197895,
+	},
+	"gemini-3-flash": {
+		contextWindow: 108594,
+		supportsImages: true,
+		supportsPromptCache: false,
+		inputPrice: 0,
+		outputPrice: 0,
+		family: "gemini-3-flash",
+		version: "gemini-3-flash-preview",
+		name: "Gemini 3 Flash (Preview)",
 		supportsToolCalling: true,
-		maxInputTokens: 108637,
+		maxInputTokens: 108594,
 	},
-	"gpt-5": {
-		contextWindow: 128000,
+	"gemini-2.5-pro": {
+		contextWindow: 108594,
 		supportsImages: true,
 		supportsPromptCache: false,
 		inputPrice: 0,
 		outputPrice: 0,
-		family: "gpt-5",
-		version: "gpt-5",
-		name: "GPT-5 (Preview)",
+		family: "gemini-2.5-pro",
+		version: "gemini-2.5-pro",
+		name: "Gemini 2.5 Pro",
 		supportsToolCalling: true,
-		maxInputTokens: 108637,
+		maxInputTokens: 108594,
 	},
 } as const satisfies Record<
 	string,

src/api/index.ts

@@ -107,6 +107,17 @@ export interface ApiHandler {
 
 	getModel(): { id: string; info: ModelInfo }
 
+	/**
+	 * Optional: the context window (in tokens) to use for context-management /
+	 * auto-condense decisions, when it must differ from getModel().info.contextWindow.
+	 *
+	 * Only the VS Code LM (Copilot) provider overrides this, to measure usage against the
+	 * model's static `maxInputTokens` instead of the inflated live window VS Code reports.
+	 * Other providers leave it undefined and callers fall back to getModel().info.contextWindow,
+	 * so their behavior is unchanged.
+	 */
+	getCondenseContextWindow?(): number
+
 	/**
 	 * Counts tokens for content blocks
 	 * All providers extend BaseProvider which provides a default tiktoken implementation,