fix(agent): harden model execution continuity

Apps/CLI/CHANGELOG.md

@@ -11,6 +11,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `peekaboo agent --model` now accepts GPT-5.6 Sol, Terra, and Luna (`gpt-5.6` selects Sol) plus Claude Sonnet 5.
 
 ### Fixed
+- Resuming an agent session without `--model` now preserves its credential-free provider-qualified model selection instead of silently switching to the current default; ambiguous legacy sessions fail closed and require an explicit override.
+- Multi-step Ollama agent runs now preserve native tool-call history and recursive schemas, surface streamed server errors, and fail with a resumable saved session when pending tool work exhausts the validated `1...100` step budget.
+- Custom-provider models marked `supportsTools: false` now get actionable agent guidance, and `config models-provider --save` preserves existing model capabilities, limits, and parameters in both human and JSON modes.
 - OpenRouter, Together, and OpenAI-compatible GPT-5.6 routes now preserve the 372K context/128K output capability profile, omit unsupported temperature, and recognize routing suffixes such as `:online`.
 - Adding a macOS application bundle to the Dock now places it with applications instead of mistaking its on-disk directory for a folder.
 - Bare `peekaboo paste` now pastes the current clipboard, while payload-only flags without a payload fail validation even when `--restore-delay-ms` explicitly uses its 150ms default; `list apps` also accepts the `app list` visibility flags and emits preferred snake_case keys alongside legacy keys.

Apps/CLI/Sources/PeekabooCLI/CLI/PeekabooEntryPoint.swift

@@ -42,7 +42,8 @@ func executePeekabooCLI(arguments: [String]) async -> Int32 {
 }
 
 private func containsJSONOutputFlag(_ arguments: [String]) -> Bool {
-    arguments.contains("--json") || arguments.contains("-j") || arguments.contains("--json-output")
+    arguments.contains("--json") || arguments.contains("-j") || arguments.contains("--json-output") ||
+        arguments.contains("--jsonOutput")
 }
 
 private func commanderErrorMessage(_ error: CommanderProgramError) -> String {

Apps/CLI/Sources/PeekabooCLI/Commands/AI/AgentChatEventDelegate.swift

@@ -5,6 +5,7 @@ import PeekabooAgentRuntime
 final class AgentChatEventDelegate: AgentEventDelegate {
     private weak var ui: AgentChatUI?
     private var lastToolArguments: [String: [String: Any]] = [:]
+    private(set) var hasReceivedError = false
 
     init(ui: AgentChatUI) {
         self.ui = ui
@@ -28,6 +29,7 @@ final class AgentChatEventDelegate: AgentEventDelegate {
         case .verificationCompleted, .desktopContextRefreshed:
             break
         case let .error(message):
+            self.hasReceivedError = true
             ui.showError(message)
         case .completed:
             ui.finishStreaming()

Apps/CLI/Sources/PeekabooCLI/Commands/AI/AgentChatLaunchPolicy.swift

@@ -17,6 +17,23 @@ struct AgentChatLaunchContext {
     let listSessions: Bool
     let normalizedTaskInput: String?
     let capabilities: TerminalCapabilities
+    let hasSessionResumption: Bool
+
+    init(
+        chatFlag: Bool,
+        hasTaskInput: Bool,
+        listSessions: Bool,
+        normalizedTaskInput: String?,
+        capabilities: TerminalCapabilities,
+        hasSessionResumption: Bool = false
+    ) {
+        self.chatFlag = chatFlag
+        self.hasTaskInput = hasTaskInput
+        self.listSessions = listSessions
+        self.normalizedTaskInput = normalizedTaskInput
+        self.capabilities = capabilities
+        self.hasSessionResumption = hasSessionResumption
+    }
 }
 
 /// Determines how the agent should launch chat mode based on flags and terminal context.
@@ -31,6 +48,10 @@ struct AgentChatLaunchPolicy {
             return .none
         }
 
+        if context.hasSessionResumption {
+            return .interactive(initialPrompt: nil)
+        }
+
         if context.capabilities.isInteractive && !context.capabilities.isPiped && !context.capabilities.isCI {
             return .interactive(initialPrompt: nil)
         }

Apps/CLI/Sources/PeekabooCLI/Commands/AI/AgentChatUI.swift

@@ -154,6 +154,12 @@ final class AgentChatUI {
         self.requestRender()
     }
 
+    func updateSessionId(_ sessionId: String) {
+        self.sessionId = sessionId
+        self.sessionLine.text = AgentChatUI.sessionDescription(for: sessionId, queueMode: self.queueMode)
+        self.requestRender()
+    }
+
     func showToolStart(name: String, summary: String?, icon: String?, displayName: String?) {
         let label = displayName ?? name
         let detail = summary.flatMap { $0.isEmpty ? nil : $0 }

Apps/CLI/Sources/PeekabooCLI/Commands/AI/AgentCommand+Chat.swift

@@ -3,6 +3,7 @@
 //  PeekabooCLI
 //
 
+import Commander
 import Foundation
 import PeekabooAgentRuntime
 import PeekabooCore
@@ -55,7 +56,9 @@ extension AgentCommand {
         capabilities: TerminalCapabilities,
         queueMode: QueueMode
     ) async throws {
-        guard self.ensureChatModePreconditions() else { return }
+        guard self.ensureChatModePreconditions() else {
+            throw ExitCode.failure
+        }
 
         if capabilities.isInteractive && !capabilities.isPiped {
             do {
@@ -67,6 +70,8 @@ extension AgentCommand {
                     queueMode: queueMode
                 )
                 return
+            } catch is ExitCode {
+                throw ExitCode.failure
             } catch {
                 self.printAgentExecutionError(
                     "Failed to launch TauTUI chat: \(error.localizedDescription). Falling back to basic chat."
@@ -101,7 +106,7 @@ extension AgentCommand {
             turnContext.sessionId = try await self.initialChatSessionId(agentService)
         } catch {
             self.printAgentExecutionError(error.localizedDescription)
-            return
+            throw ExitCode.failure
         }
 
         self.printChatWelcome(
@@ -157,7 +162,7 @@ extension AgentCommand {
             activeSessionId = try await self.initialChatSessionId(agentService)
         } catch {
             self.printAgentExecutionError(error.localizedDescription)
-            return
+            throw ExitCode.failure
         }
 
         let chatUI = AgentChatUI(
@@ -236,7 +241,13 @@ extension AgentCommand {
             } catch is CancellationError {
                 chatUI.showCancelled()
             } catch {
-                chatUI.showError(error.localizedDescription)
+                if let sessionId = self.stepLimitSessionId(from: error) {
+                    activeSessionId = sessionId
+                    chatUI.updateSessionId(sessionId)
+                }
+                if !tuiDelegate.hasReceivedError {
+                    chatUI.showError(error.localizedDescription)
+                }
             }
 
             currentRun = nil
@@ -359,7 +370,8 @@ extension AgentCommand {
                     task: batchedInput,
                     requestedModel: requestedModel,
                     maxSteps: self.resolvedMaxSteps,
-                    queueMode: queueMode
+                    queueMode: queueMode,
+                    preserveStepLimitError: true
                 )
             }
         }
@@ -381,6 +393,13 @@ extension AgentCommand {
         } catch is CancellationError {
             cancelMonitor.stop()
             return
+        } catch {
+            cancelMonitor.stop()
+            if let sessionId = self.stepLimitSessionId(from: error) {
+                context.sessionId = sessionId
+                return
+            }
+            throw error
         }
 
         if let updatedSessionId = result.sessionId {
@@ -390,6 +409,10 @@ extension AgentCommand {
         self.printChatTurnSummary(result)
     }
 
+    func stepLimitSessionId(from error: any Error) -> String? {
+        (error as? PeekabooAgentService.AgentStepLimitExceededError)?.sessionId
+    }
+
     private func printChatTurnSummary(_ result: AgentExecutionResult) {
         guard !self.quiet else { return }
         let duration = String(format: "%.1fs", result.metadata.executionTime)

Apps/CLI/Sources/PeekabooCLI/Commands/AI/AgentCommand+Execution.swift

@@ -112,7 +112,8 @@ extension AgentCommand {
         task: String,
         requestedModel: LanguageModel?,
         maxSteps: Int,
-        queueMode: QueueMode
+        queueMode: QueueMode,
+        preserveStepLimitError: Bool = false
     ) async throws -> AgentExecutionResult {
         let outputDelegate = self.makeDisplayDelegate(for: task)
         let streamingDelegate = self.makeStreamingDelegate(using: outputDelegate)
@@ -139,8 +140,15 @@ extension AgentCommand {
                     + "session=\(sessionId) tokens=\(finalTokens)"
             )
             return result
+        } catch let error as PeekabooAgentService.AgentStepLimitExceededError where preserveStepLimitError {
+            if outputDelegate?.hasReceivedError != true {
+                self.printAgentExecutionError("Agent execution failed: \(error.localizedDescription)")
+            }
+            throw error
         } catch {
-            self.printAgentExecutionError("Agent execution failed: \(error.localizedDescription)")
+            if outputDelegate?.hasReceivedError != true {
+                self.printAgentExecutionError("Agent execution failed: \(error.localizedDescription)")
+            }
             throw ExitCode.failure
         }
     }
@@ -159,6 +167,10 @@ extension AgentCommand {
         self.maxSteps ?? 100
     }
 
+    func validatedMaxStepCount() throws -> Int {
+        try AgentStepBudget.validate(self.resolvedMaxSteps)
+    }
+
     func resolvedQueueMode() throws -> QueueMode {
         guard let raw = self.queueMode?.trimmingCharacters(in: .whitespacesAndNewlines), !raw.isEmpty else {
             return .oneAtATime

Apps/CLI/Sources/PeekabooCLI/Commands/AI/AgentCommand+ModelParsing.swift

@@ -5,6 +5,10 @@ import Tachikoma
 
 @available(macOS 14.0, *)
 extension AgentCommand {
+    func shouldUsePersistedSessionModel(requestedModel: LanguageModel?) -> Bool {
+        (self.resume || self.resumeSession != nil) && requestedModel == nil
+    }
+
     @MainActor
     func parseModelString(
         _ modelString: String,
@@ -124,6 +128,15 @@ extension AgentCommand {
     @MainActor
     func validatedModelSelection(configuration: PeekabooCore.ConfigurationManager? = nil) throws -> LanguageModel? {
         guard let modelString = self.model else { return nil }
+
+        if let configuration,
+           let configuredModel = PeekabooAIService(configuration: configuration)
+               .resolveConfiguredModel(modelString),
+               case .custom = configuredModel,
+               !configuredModel.supportsTools {
+            throw Self.configuredCustomModelToolCapabilityError(modelString)
+        }
+
         guard let parsed = self.parseModelString(modelString, configuration: configuration) else {
             // A model that parses but lacks tool support is a real, installed model —
             // saying "unsupported" and listing an allowlist implies the name is wrong.
@@ -141,6 +154,46 @@ extension AgentCommand {
         return parsed
     }
 
+    @MainActor
+    func unavailableImplicitCustomModelToolCapabilityError(
+        from service: PeekabooAIService,
+        configuration: PeekabooCore.ConfigurationManager
+    ) -> PeekabooError? {
+        let selections: [String]
+        if configuration.hasExplicitAIProviderList() {
+            selections = configuration.getAIProviders()
+                .split(separator: ",")
+                .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
+                .filter { !$0.isEmpty }
+        } else if let defaultModel = configuration.getAgentModel()?
+            .trimmingCharacters(in: .whitespacesAndNewlines),
+            !defaultModel.isEmpty {
+            selections = [defaultModel]
+        } else {
+            return nil
+        }
+
+        for selection in selections {
+            guard let model = service.resolveConfiguredModel(selection),
+                  case .custom = model,
+                  !model.supportsTools
+            else {
+                continue
+            }
+            return Self.configuredCustomModelToolCapabilityError(selection)
+        }
+
+        return nil
+    }
+
+    private static func configuredCustomModelToolCapabilityError(_ modelString: String) -> PeekabooError {
+        PeekabooError.invalidInput(
+            "Model '\(modelString)' is configured with supportsTools: false, but `peekaboo agent` " +
+                "requires tool calling. Choose a tool-capable model, or set this model's supportsTools " +
+                "setting to true only if the endpoint actually supports tool calls."
+        )
+    }
+
     private static let supportedOpenAIInputs: Set<LanguageModel.OpenAI> = [
         .gpt56Sol,
         .gpt56Terra,

Apps/CLI/Sources/PeekabooCLI/Commands/AI/AgentCommand+Sessions.swift

@@ -1,3 +1,4 @@
+import Commander
 import Foundation
 import PeekabooAgentRuntime
 import PeekabooCore
@@ -233,8 +234,10 @@ extension AgentCommand {
             )
             self.displayResult(result, delegate: outputDelegate)
         } catch {
-            self.printAgentExecutionError("Failed to resume session: \(error.localizedDescription)")
-            throw error
+            if outputDelegate?.hasReceivedError != true {
+                self.printAgentExecutionError("Failed to resume session: \(error.localizedDescription)")
+            }
+            throw ExitCode.failure
         }
     }
 }