Add GPT-6.1 Sol and make it the default Codex model

packages/fold-agent/src/Catalog/BakedCatalog.ts

@@ -845,6 +845,19 @@ export const bakedModelCatalog: ReadonlyArray<ModelCatalogEntry> = [
 		toolCall: true,
 		pricing: { inputPerMTokens: 2, outputPerMTokens: 10, cacheReadPerMTokens: 0.2, cacheWritePerMTokens: 2.5 },
 	},
+	{
+		providerId: 'openai',
+		modelId: 'gpt-6.1-sol',
+		name: 'GPT-6.1 Sol',
+		contextWindow: 1050000,
+		maxInputTokens: 922000,
+		maxOutputTokens: 128000,
+		reasoning: true,
+		reasoningEfforts: ['low', 'medium', 'high', 'xhigh', 'max'],
+		vision: true,
+		toolCall: true,
+		pricing: { inputPerMTokens: 2, outputPerMTokens: 10, cacheReadPerMTokens: 0.1, cacheWritePerMTokens: 2.5 },
+	},
 	{
 		providerId: 'openai',
 		modelId: 'gpt-image-1',

packages/fold-agent/src/Config/AgentModels.ts

@@ -6,7 +6,7 @@
  * which carries no key (it uses `~/.fold/auth.json`).
  *
  * `orchestrator` falls back to `smart` when unbound (D25). A binding without a model fills the provider
- * kind's default (codex → gpt-6-astra, anthropic → claude-opus-4-8); openai-compat has no default and
+ * kind's default (codex → gpt-6.1-sol, anthropic → claude-opus-4-8); openai-compat has no default and
  * requires an explicit model. Provider cross-references were validated at decode (ConfigSchema), so
  * remaining resolution failures are a missing credential env var, a model-less openai-compat binding,
  * or - when a model catalog is provided - a reasoning level the bound model does not support (D23:

packages/fold-agent/src/Config/ConfigSchema.ts

@@ -54,7 +54,7 @@ export const RoleBinding = Schema.Struct({
 	model: Schema.optionalKey(
 		Schema.String.annotate({
 			description:
-				'Provider model id; defaults: codex → gpt-6-astra, opencode → gpt-5.6-sol, xai → grok-4.6, anthropic → claude-opus-4-8; required for openai-compat',
+				'Provider model id; defaults: codex → gpt-6.1-sol, opencode → gpt-5.6-sol, xai → grok-4.6, anthropic → claude-opus-4-8; required for openai-compat',
 		}),
 	),
 	/** Reasoning level for this role's requests. Defaults to `off` when omitted. */

packages/fold-agent/src/Config/ConfigSchemaJson.ts

@@ -67,14 +67,14 @@ export const starterConfigJsonc = (): string =>
 
 	// Model roles bound to a provider (+ optional model). "smart" and "fast" are required;
 	// "orchestrator" is optional and falls back to "smart". Omitting "model" uses the provider
-	// defaults: codex → gpt-6-astra, opencode → gpt-5.6-sol, xai → grok-4.6,
+	// defaults: codex → gpt-6.1-sol, opencode → gpt-5.6-sol, xai → grok-4.6,
 	// anthropic → claude-opus-4-8.
 	"roles": {
 		// Default primary model for new sessions.
-		"smart": { "provider": "codex", "model": "gpt-6-astra", "reasoning": "medium" },
+		"smart": { "provider": "codex", "model": "gpt-6.1-sol", "reasoning": "medium" },
 		// An explicit model always wins over the provider default.
 		"fast": { "provider": "anthropic", "model": "claude-haiku-4-5-20251001" },
-		// No model: uses the codex default, gpt-6-astra.
+		// No model: uses the codex default, gpt-6.1-sol.
 		"orchestrator": { "provider": "codex", "reasoning": "high" }
 	},
 

packages/fold-agent/src/Config/FoldInfo.ts

@@ -73,14 +73,14 @@ is optional and falls back to \`smart\`.
 | \`orchestrator\` | the RLM mode's primary agent |
 
 Each binding is \`{ "provider": <key>, "model"?: <id>, "reasoning"?: <level> }\`. Omitting \`model\`
-uses the provider kind's default: codex → \`gpt-6-astra\`, opencode → \`gpt-5.6-sol\`, xai → \`grok-4.6\`, and
+uses the provider kind's default: codex → \`gpt-6.1-sol\`, opencode → \`gpt-5.6-sol\`, xai → \`grok-4.6\`, and
 anthropic → \`claude-opus-4-8\`
 (openai-compat requires an explicit model). \`reasoning\` is one of \`off · minimal · low · medium ·
 high · xhigh · max\` and is validated against the model catalog - a level the model does not support
 fails the launch naming the supported levels. All roles referenced by a launch resolve eagerly, so
 every binding needs working credentials.
 
-The starter config defaults \`smart\` to Codex \`gpt-6-astra\` with \`medium\` reasoning, so a new
+The starter config defaults \`smart\` to Codex \`gpt-6.1-sol\` with \`medium\` reasoning, so a new
 default-mode session uses that model unless the user selects a profile or direct model override.
 
 ## Profiles - named presets (roles + optional mode)
@@ -143,7 +143,7 @@ foldcode --prompt "..."              # one-shot run; exit codes 0/130/1
 foldcode --profile ultracodex        # profile's roles + its pinned mode (rlm)
 foldcode --mode rlm --rpi            # explicit mode + RPI roster
 foldcode --role fast --reasoning off # primary on the fast role, reasoning off
-foldcode --provider codex            # kind change drops the stale model -> gpt-6-astra default
+foldcode --provider codex            # kind change drops the stale model -> gpt-6.1-sol default
 foldcode --resume latest|sess_*      # resume (config re-resolves; drift writes a durable transition)
 foldcode sessions                    # list this project's session logs
 foldcode config init|validate        # starter config + schema | validate

packages/fold-agent/test/Catalog/BakedCatalog.vi.test.ts

@@ -104,6 +104,21 @@ it('ships the GPT-6 Sol and Luna public limits, efforts, pricing, and Codex prov
 	}
 })
 
+it('ships the GPT-6.1 Sol public limits, efforts, pricing, and Codex provider lookup', () => {
+	const entry = lookupCatalogEntry(bakedModelCatalog, codexModel('gpt-6.1-sol'))
+
+	expect(entry).toMatchObject({
+		providerId: 'openai',
+		modelId: 'gpt-6.1-sol',
+		contextWindow: 1_050_000,
+		maxInputTokens: 922_000,
+		maxOutputTokens: 128_000,
+		reasoning: true,
+		reasoningEfforts: ['low', 'medium', 'high', 'xhigh', 'max'],
+		pricing: { inputPerMTokens: 2, outputPerMTokens: 10, cacheReadPerMTokens: 0.1 },
+	})
+})
+
 it('resolves an openai-compatible gpt-5.6-terra to the baked openai entry', () => {
 	const entry = lookupCatalogEntry(bakedModelCatalog, openAiTerra)
 

packages/fold-agent/test/Config/AgentModels.vi.test.ts

@@ -284,6 +284,22 @@ it.effect("GPT-6 Sol and Luna bindings with reasoning 'max' resolve against the
 	}),
 )
 
+it.effect("a GPT-6.1 Sol binding with reasoning 'max' resolves against the baked catalog", () =>
+	Effect.gen(function* () {
+		const config = yield* parseFoldConfig(`{
+			"providers": { "codex": { "kind": "codex" } },
+			"roles": {
+				"smart": { "provider": "codex", "model": "gpt-6.1-sol", "reasoning": "max" },
+				"fast": { "provider": "codex", "model": "gpt-6-luna", "reasoning": "low" }
+			}
+		}`)
+		const models = agentModelsFromConfig(config, { env: env({}), catalog: bakedModelCatalog })
+
+		const smart = yield* models.resolve('smart')
+		expect(smart.activeModel).toMatchObject({ modelId: 'gpt-6.1-sol', requestedReasoningLevel: 'max' })
+	}),
+)
+
 it.effect("gpt-5.5 with reasoning 'max' fails RoleResolutionError naming its supported levels", () =>
 	Effect.gen(function* () {
 		const config = yield* parseFoldConfig(gpt56ConfigText('gpt-5.5'))
@@ -312,7 +328,7 @@ const defaultsConfigText = `{
 	}
 }`
 
-it.effect('a codex binding without a model resolves to the gpt-6-astra default', () =>
+it.effect('a codex binding without a model resolves to the gpt-6.1-sol default', () =>
 	Effect.gen(function* () {
 		const config = yield* parseFoldConfig(defaultsConfigText)
 		const models = agentModelsFromConfig(config, {
@@ -322,8 +338,8 @@ it.effect('a codex binding without a model resolves to the gpt-6-astra default',
 
 		const model = yield* models.resolve('smart')
 		expect(model.activeModel.providerKind).toBe('codex')
-		expect(model.activeModel.modelId).toBe('gpt-6-astra')
-		// Catalog validation ran against the defaulted id: Astra supports 'max'.
+		expect(model.activeModel.modelId).toBe('gpt-6.1-sol')
+		// Catalog validation ran against the defaulted id: GPT-6.1 Sol supports 'max'.
 		expect(model.activeModel.requestedReasoningLevel).toBe('max')
 	}),
 )
@@ -354,7 +370,7 @@ it.effect('an openai-compat binding without a model fails with the required-mode
 		expect(error._tag).toBe('RoleResolutionError')
 		expect(error.role).toBe('orchestrator')
 		expect(error.message).toContain('without a model')
-		expect(error.message).toContain('codex → gpt-6-astra')
+		expect(error.message).toContain('codex → gpt-6.1-sol')
 		expect(error.message).toContain('anthropic → claude-opus-4-8')
 		expect(error.message).toContain('required for openai-compat')
 	}),

packages/fold-agent/test/Config/ConfigSchemaJson.vi.test.ts

@@ -44,7 +44,7 @@ it.effect('the starter config is valid against the schema (round-trips through t
 
 		expect(config.roles.smart).toMatchObject({
 			provider: 'codex',
-			model: 'gpt-6-astra',
+			model: 'gpt-6.1-sol',
 			reasoning: 'medium',
 		})
 		expect(config.providers.codex?.kind).toBe('codex')

packages/fold-agent/test/Config/ModelSelections.vi.test.ts

@@ -76,7 +76,7 @@ it.effect('applies provider-specific role defaults around the directly selected
 		expect(normal.root.activeModel.role).toBe('smart')
 		expect(normal.smart.activeModel.modelId).toBe('chosen')
 		expect(normal.fast.activeModel).toMatchObject({ providerId: 'codex', modelId: 'gpt-5.6-luna' })
-		expect(normal.orchestrator.activeModel).toMatchObject({ providerId: 'codex', modelId: 'gpt-6-astra' })
+		expect(normal.orchestrator.activeModel).toMatchObject({ providerId: 'codex', modelId: 'gpt-6.1-sol' })
 		expect(rlm.root.activeModel.modelId).toBe('chosen')
 		expect(rlm.root.activeModel.role).toBe('orchestrator')
 		expect(rlm.smart.activeModel).toMatchObject({ providerId: 'codex', modelId: 'gpt-5.6-terra' })
@@ -153,7 +153,7 @@ it.effect('describes profiles, credentials, and merged model candidates without
 		expect(description.providers.find(({ name }) => name === 'codex')?.models).toEqual([
 			'catalog-only',
 			'default-fast',
-			'gpt-6-astra',
+			'gpt-6.1-sol',
 			'profile-fast',
 			'profile-orchestrator',
 			'profile-smart',

packages/fold-agent/test/Config/ProviderConfig.vi.test.ts

@@ -155,7 +155,7 @@ it.effect('adds OAuth profiles without an API key and supplies their default mod
 			expect(updated.providers['work-codex']).toEqual({
 				kind: 'codex',
 				baseUrl: 'https://example.test',
-				configuredModels: ['gpt-6-astra'],
+				configuredModels: ['gpt-6.1-sol'],
 			})
 		}),
 	).pipe(Effect.provide(NodeFileSystem.layer)),

packages/fold-agent/test/Mode/Launch.vi.test.ts

@@ -519,7 +519,7 @@ it.effect('mergeModelSelection drops the stale model when the newly named provid
 		const config = yield* parseFoldConfig(mergeConfigText)
 
 		// `fold --provider codex` alone: the anthropic model id must NOT ride onto codex - the binding
-		// comes back model-less so the codex default (gpt-6-astra) applies at resolution.
+		// comes back model-less so the codex default (gpt-6.1-sol) applies at resolution.
 		const merged = mergeModelSelection(config, config.roles.smart, { provider: 'codex' })
 		expect(merged).toEqual({ provider: 'codex', reasoning: 'medium' })
 		expect(merged.model).toBeUndefined()

packages/fold-cli/src/tui/ModelSelectionState.ts

@@ -78,8 +78,8 @@ export const modelPickerChoices = (
 		case 'model':
 			return (configuration.providers.find(({ name }) => name === state.provider)?.models ?? [])
 				.toSorted((left, right) => {
-					if (left === 'gpt-5.6-sol') return -1
-					if (right === 'gpt-5.6-sol') return 1
+					if (left === 'gpt-6.1-sol') return -1
+					if (right === 'gpt-6.1-sol') return 1
 					return left.localeCompare(right)
 				})
 				.map((model) => ({

packages/fold-cli/src/tui/ProviderConfigState.ts

@@ -31,7 +31,7 @@ export const emptyProviderForm = (): ProviderForm => ({
 })
 
 const defaults = (kind: ProviderForm['kind']): Pick<ProviderForm, 'baseUrl' | 'model'> => {
-	if (kind === 'codex') return { baseUrl: 'https://chatgpt.com/backend-api/codex', model: 'gpt-5.6-sol' }
+	if (kind === 'codex') return { baseUrl: 'https://chatgpt.com/backend-api/codex', model: 'gpt-6.1-sol' }
 	if (kind === 'opencode') return { baseUrl: 'https://opencode.ai/zen/v1', model: 'gpt-5.6-sol' }
 	if (kind === 'xai') return { baseUrl: 'https://api.x.ai/v1', model: 'grok-4.6' }
 	if (kind === 'anthropic') return { baseUrl: 'https://api.anthropic.com', model: '' }

packages/fold-cli/test/ContextWindow.vi.test.ts

@@ -16,6 +16,10 @@ it('shows the Codex usable Astra window instead of the public API catalog window
 	expect(contextWindowLimitForDisplay(astra, 1_050_000)).toBe(258_400)
 })
 
+it('shows the same Codex usable window for GPT-6.1 Sol', () => {
+	expect(contextWindowLimitForDisplay({ ...astra, modelId: 'gpt-6.1-sol' }, 1_050_000)).toBe(258_400)
+})
+
 it('matches the Codex gauge percentage after excluding its baseline tokens', () => {
 	const limit = contextWindowLimitForDisplay(astra, 1_050_000)
 

packages/fold-cli/test/tui/ModelSelection.vi.test.ts

@@ -109,14 +109,14 @@ describe('model picker state machine', () => {
 					kind: 'codex' as const,
 					apiKeyEnv: null,
 					credentialPresent: true,
-					models: ['gpt-5.6-terra', 'gpt-5.6-sol'],
+					models: ['gpt-5.6-terra', 'gpt-6.1-sol'],
 				},
 			],
 		}
 
 		expect(modelPickerChoices(configured, initialModelPickerState())[0]?.id).toBe('direct')
 		expect(modelPickerChoices(configured, { _tag: 'provider' })[0]?.id).toBe('codex')
-		expect(modelPickerChoices(configured, { _tag: 'model', provider: 'codex' })[0]?.id).toBe('gpt-5.6-sol')
+		expect(modelPickerChoices(configured, { _tag: 'model', provider: 'codex' })[0]?.id).toBe('gpt-6.1-sol')
 	})
 
 	it('stages profile selection without a mode', () => {

packages/fold-cli/test/tui/ProviderConfigState.vi.test.ts

@@ -81,7 +81,7 @@ describe('provider config form state', () => {
 		expect(nextProviderKind('xai')).toBe('anthropic')
 		expect(withNextProviderKind({ ...emptyProviderForm(), kind: 'openai-compat' })).toMatchObject({
 			kind: 'codex',
-			model: 'gpt-5.6-sol',
+			model: 'gpt-6.1-sol',
 			baseUrl: 'https://chatgpt.com/backend-api/codex',
 			apiKey: '',
 		})

packages/fold-codex/src/CodexModel.ts

@@ -45,7 +45,7 @@ export const CODEX_API_URL = 'https://chatgpt.com/backend-api/codex'
 export const DEFAULT_REQUEST_RETRY_TIMES = 3
 
 /** The codex model used when {@link CodexModelOptions.model} is omitted. */
-export const DEFAULT_CODEX_MODEL_ID = 'gpt-6-astra'
+export const DEFAULT_CODEX_MODEL_ID = 'gpt-6.1-sol'
 
 type ResponsesPayload = Omit<typeof OpenAiSchema.CreateResponse.Encoded, 'stream'>
 type ResponseBody = typeof OpenAiSchema.Response.Type
@@ -216,7 +216,7 @@ export const decorateCodexClient = (inner: OpenAiClient.Service, options: CodexR
 
 /** Options for {@link codexModel}. */
 export type CodexModelOptions = {
-	/** Codex model id, for example `gpt-6-astra`. Defaults to {@link DEFAULT_CODEX_MODEL_ID}. */
+	/** Codex model id, for example `gpt-6.1-sol`. Defaults to {@link DEFAULT_CODEX_MODEL_ID}. */
 	readonly model?: string
 	/** Reasoning level for requests. Defaults to `off`, which leaves the backend default untouched. */
 	readonly reasoning?: ReasoningLevel

packages/fold-codex/test/CodexModel.vi.test.ts

@@ -270,7 +270,7 @@ describe('codexModel defaults', () => {
 	it('omitting the model binds the default codex model id', () => {
 		const model = codexModel({})
 
-		expect(DEFAULT_CODEX_MODEL_ID).toBe('gpt-6-astra')
+		expect(DEFAULT_CODEX_MODEL_ID).toBe('gpt-6.1-sol')
 		expect(model.activeModel.modelId).toBe(DEFAULT_CODEX_MODEL_ID)
 		expect(model.activeModel.providerKind).toBe('codex')
 	})
@@ -279,8 +279,8 @@ describe('codexModel defaults', () => {
 		expect(codexModel({ model: 'gpt-5.5' }).activeModel.modelId).toBe('gpt-5.5')
 	})
 
-	it('preserves the canonical GPT-6 Sol and Luna ids and max reasoning', () => {
-		for (const modelId of ['gpt-6-sol', 'gpt-6-luna']) {
+	it('preserves the canonical GPT-6.1 Sol, GPT-6 Sol, and Luna ids and max reasoning', () => {
+		for (const modelId of ['gpt-6.1-sol', 'gpt-6-sol', 'gpt-6-luna']) {
 			const model = codexModel({ model: modelId, reasoning: 'max' })
 
 			expect(model.activeModel.modelId).toBe(modelId)

packages/fold-core/src/Compaction/CompactionEngine.ts

@@ -37,7 +37,7 @@ const filePartEstimateChars = 4_800
  */
 export const defaultModelContextWindows: ReadonlyArray<readonly [RegExp, number]> = [
 	[/claude|fable|mythos/, 200_000],
-	[/gpt-6-(?:astra|sol|luna)/, 272_000],
+	[/gpt-6(?:\.\d+)?-(?:astra|sol|luna)/, 272_000],
 	[/gpt-5|codex/, 272_000],
 	[/gpt-4\.1/, 1_000_000],
 ]

packages/fold-core/test/Api/SwitchModel.vi.test.ts

@@ -281,6 +281,35 @@ it.effect('switchModel preserves exact GPT-6 Sol and Luna ids in the durable tra
 	}).pipe(Effect.scoped, Effect.provide(NodeFileSystem.layer)),
 )
 
+it.effect('switchModel preserves the exact GPT-6.1 Sol id in the durable transition and requests', () =>
+	Effect.gen(function* () {
+		const astra: ActiveModel = {
+			...gptActiveModel,
+			providerId: 'codex',
+			providerKind: 'codex',
+			modelId: 'gpt-6-astra',
+			requestedReasoningLevel: 'max',
+			reasoning: { _tag: 'effort', effort: 'max', summary: 'auto' },
+		}
+		const sol61: ActiveModel = { ...astra, modelId: 'gpt-6.1-sol' }
+		const first = yield* scriptedModel(astra, [textTurn('from astra')])
+		const second = yield* scriptedModel(sol61, [textTurn('from gpt-6.1-sol')])
+		const session = yield* startSession({ agent: defineAgent({ model: first.model }) })
+
+		yield* session.send('first turn')
+		yield* session.switchModel(second.model, { reason: 'switch to the new default' })
+		yield* session.send('second turn')
+
+		const entries = yield* session.entries
+		const modelChanges = entries.filter((entry): entry is ModelChangeLogEntry =>
+			Predicate.isTagged(entry, 'model-change'),
+		)
+		expect(modelChanges).toHaveLength(1)
+		expect(modelChanges[0]?.model.modelId).toBe('gpt-6.1-sol')
+		expect((yield* second.scripted.requests)[0]?.openAiConfig?.model).toBe('gpt-6.1-sol')
+	}).pipe(Effect.scoped, Effect.provide(NodeFileSystem.layer)),
+)
+
 it.effect('switchModel rejects duplicate tool names in the replacement toolset as a defect', () =>
 	Effect.gen(function* () {
 		const first = yield* scriptedModel(gptActiveModel, [textTurn('one')])

packages/fold-core/test/Compaction/AutoCompactSession.vi.test.ts

@@ -605,9 +605,9 @@ it.effect('a Codex model uses the app context window instead of the public API c
 	}).pipe(Effect.scoped, Effect.provide(NodeFileSystem.layer)),
 )
 
-it.effect('GPT-6 Sol and Luna compact against the 272k Codex window instead of the public catalog', () =>
+it.effect('GPT-6.1 Sol, GPT-6 Sol, and Luna compact against the 272k Codex window instead of the public catalog', () =>
 	Effect.gen(function* () {
-		for (const modelId of ['gpt-6-sol', 'gpt-6-luna']) {
+		for (const modelId of ['gpt-6.1-sol', 'gpt-6-sol', 'gpt-6-luna']) {
 			const activeModel = { ...codexActiveModel, modelId }
 			const { model, scripted } = yield* scriptedModel(activeModel, [
 				textTurn(`noted ${'a'.repeat(120)}`, { inputTokens: 224_000 }),

packages/fold-core/test/Compaction/CompactionEngine.vi.test.ts

@@ -150,6 +150,7 @@ it('defaultContextWindowFor uses the interim table with a conservative fallback'
 	expect(defaultContextWindowFor('gpt-6-astra')).toBe(272_000)
 	expect(defaultContextWindowFor('gpt-6-sol')).toBe(272_000)
 	expect(defaultContextWindowFor('gpt-6-luna')).toBe(272_000)
+	expect(defaultContextWindowFor('gpt-6.1-sol')).toBe(272_000)
 	expect(defaultContextWindowFor('some-unknown-model')).toBe(128_000)
 	expect(defaultContextWindowFor(null)).toBe(128_000)
 })
@@ -159,7 +160,7 @@ it('compactionUsableTokens applies the D11 formula, clamped for tiny windows', (
 	expect(compactionUsableTokens({ contextWindow: 200_000, reserveTokens: 16_384 })).toBe(151_616)
 	// Tiny windows clamp the output budget to window/4 and the reserve to window/8, staying positive.
 	expect(compactionUsableTokens({ contextWindow: 2_000, reserveTokens: 16_384 })).toBe(1_250)
-	// Fold's raw 272k Codex window compacts at 223,616 for Sol and Luna.
+	// Fold's raw 272k Codex window compacts at 223,616 for GPT-6.1 Sol, Sol, and Luna.
 	expect(compactionUsableTokens({ contextWindow: 272_000, reserveTokens: 16_384 })).toBe(223_616)
 })
 

packages/fold-core/test/Model/ModelFamily.vi.test.ts

@@ -39,6 +39,7 @@ it('classifies openai-compatible models by model id patterns', () => {
 	expect(modelFamilyFor(openAiCompatible('o3-mini'))).toBe('gpt')
 	expect(modelFamilyFor(openAiCompatible('gpt-5.1-codex-max'))).toBe('codex')
 	expect(modelFamilyFor(openAiCompatible('gpt-6-sol'))).toBe('gpt')
+	expect(modelFamilyFor(openAiCompatible('gpt-6.1-sol'))).toBe('gpt')
 	expect(modelFamilyFor(openAiCompatible('gpt-6-luna'))).toBe('gpt')
 	expect(modelFamilyFor(openAiCompatible('anthropic/claude-opus-4-8'))).toBe('claude')
 	expect(modelFamilyFor(openAiCompatible('llama-3.3-70b'))).toBe('unknown')