refactor(ai): migrate AI services to structured output plugins

Convert all AI services to use plugin-based structured output:
- Create dedicated plugins for code intelligence, review, docs, issues, and workflows
- Replace JSON parsing with SendForStructuredOutputAsync
- Add PluginHelpers for consistent deserialization
- Remove inline prompt instructions in favor of plugin definitions
- Eliminate brittle JSON parsing and error handling
- Improve type safety and maintainability across all AI features

Affected services: CodeIntelligence, CodeReview, Documentation, Issue, Workflow inspection

src/GitCaddy.AI.Service/Controllers/AIController.cs

@@ -4,6 +4,7 @@
 using GitCaddy.AI.Service.Services;
 using GitCaddy.AI.Service.Configuration;
 using GitCaddy.AI.Service.Licensing;
+using GitCaddy.AI.Service.Plugins;
 using MarketAlly.AIPlugin.Conversation;
 using Microsoft.AspNetCore.Mvc;
 
@@ -429,15 +430,8 @@ public class AIController : ControllerBase
                     - Performance issues (unnecessary steps, missing caching)
                     - Compatibility issues with the available runner labels
                     - Best practice violations
-
-                    Respond with a JSON object containing:
-                    {
-                        "valid": true/false,
-                        "issues": [{"line": 0, "severity": "error|warning|info", "message": "...", "fix": "..."}],
-                        "suggestions": ["..."]
-                    }
-                    Only respond with the JSON object, no other text.
                     """)
+                .RegisterPlugin<InspectWorkflowPlugin>()
                 .Build();
 
             var prompt = $"Workflow file: {request.FilePath}\n\n```yaml\n{request.Content}\n```";
@@ -446,45 +440,26 @@ public class AIController : ControllerBase
                 prompt += $"\n\nAvailable runner labels: {string.Join(", ", request.RunnerLabels)}";
             }
 
-            var aiResponse = await conversation.SendAsync(prompt, cancellationToken);
-            var responseText = aiResponse.FinalMessage ?? "{}";
+            var aiResponse = await conversation.SendForStructuredOutputAsync<InspectWorkflowPluginResult>(
+                prompt, "InspectWorkflow", cancellationToken);
 
-            // Parse the AI response as JSON
-            try
-            {
-                var result = System.Text.Json.JsonSerializer.Deserialize<InspectWorkflowResult>(
-                    responseText,
-                    new System.Text.Json.JsonSerializerOptions { PropertyNameCaseInsensitive = true });
+            var result = PluginHelpers.DeserializeOutput<InspectWorkflowPluginResult>(aiResponse.StructuredOutput);
 
-                return Ok(new
-                {
-                    valid = result?.Valid ?? true,
-                    issues = result?.Issues?.Select(i => new
-                    {
-                        line = i.Line,
-                        severity = i.Severity,
-                        message = i.Message,
-                        fix = i.Fix
-                    }).ToList() ?? [],
-                    suggestions = result?.Suggestions ?? [],
-                    confidence = 0.8,
-                    input_tokens = 0,
-                    output_tokens = 0
-                });
-            }
-            catch (System.Text.Json.JsonException)
+            return Ok(new
             {
-                // If AI didn't return valid JSON, wrap the text response
-                return Ok(new
+                valid = result.Valid,
+                issues = result.Issues?.Select(i => new
                 {
-                    valid = true,
-                    issues = Array.Empty<object>(),
-                    suggestions = new[] { responseText },
-                    confidence = 0.5,
-                    input_tokens = 0,
-                    output_tokens = 0
-                });
-            }
+                    line = i.Line,
+                    severity = i.Severity,
+                    message = i.Message,
+                    fix = i.Fix
+                }).ToList() ?? [],
+                suggestions = result.Suggestions ?? [],
+                confidence = 0.8,
+                input_tokens = 0,
+                output_tokens = 0
+            });
         }
         catch (Exception ex)
         {
@@ -722,18 +697,3 @@ public class InspectWorkflowDto
     public List<string>? RunnerLabels { get; set; }
 }
 
-// Internal model for parsing AI response
-internal class InspectWorkflowResult
-{
-    public bool Valid { get; set; }
-    public List<InspectWorkflowIssue>? Issues { get; set; }
-    public List<string>? Suggestions { get; set; }
-}
-
-internal class InspectWorkflowIssue
-{
-    public int Line { get; set; }
-    public string? Severity { get; set; }
-    public string? Message { get; set; }
-    public string? Fix { get; set; }
-}

src/GitCaddy.AI.Service/Plugins/ABTestAnalyzePlugin.cs

@@ -0,0 +1,79 @@
+// Copyright 2026 MarketAlly. All rights reserved.
+// SPDX-License-Identifier: BSL-1.1
+
+using System.Text.Json.Serialization;
+using MarketAlly.AIPlugin;
+
+namespace GitCaddy.AI.Service.Plugins;
+
+/// <summary>
+/// Result DTO for A/B test analysis.
+/// </summary>
+public class ABTestAnalyzeResult
+{
+    [JsonPropertyName("status")]
+    public string Status { get; set; }
+
+    [JsonPropertyName("winner_variant_id")]
+    public long WinnerVariantId { get; set; }
+
+    [JsonPropertyName("confidence")]
+    public double Confidence { get; set; }
+
+    [JsonPropertyName("summary")]
+    public string Summary { get; set; }
+
+    [JsonPropertyName("recommendation")]
+    public string Recommendation { get; set; }
+}
+
+/// <summary>
+/// AI plugin that analyzes A/B test experiment results.
+/// Evaluates conversion rates, impression counts, and event distributions
+/// to determine if there is a statistically significant winner.
+/// </summary>
+[AIPlugin("AnalyzeABTestResults",
+    "Analyze A/B test experiment results and determine the outcome. " +
+    "Evaluate conversion rates, impression counts, and statistical significance. " +
+    "Require at least 100 impressions per variant before declaring a winner. " +
+    "Use a minimum 95% confidence threshold.")]
+public class ABTestAnalyzePlugin : IAIPlugin
+{
+    [AIParameter("Analysis status: must be exactly one of 'winner', 'needs_more_data', or 'no_difference'", required: true)]
+    public string Status { get; set; }
+
+    [AIParameter("ID of the winning variant (use 0 if no winner)", required: true)]
+    public long WinnerVariantId { get; set; }
+
+    [AIParameter("Statistical confidence level from 0.0 to 1.0", required: true)]
+    public double Confidence { get; set; }
+
+    [AIParameter("Brief human-readable summary of the results", required: true)]
+    public string Summary { get; set; }
+
+    [AIParameter("Actionable recommendation for what to do next", required: true)]
+    public string Recommendation { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["status"] = typeof(string),
+        ["winnervariantid"] = typeof(long),
+        ["confidence"] = typeof(double),
+        ["summary"] = typeof(string),
+        ["recommendation"] = typeof(string)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new ABTestAnalyzeResult
+        {
+            Status = Status,
+            WinnerVariantId = WinnerVariantId,
+            Confidence = Confidence,
+            Summary = Summary,
+            Recommendation = Recommendation
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "A/B test analysis complete"));
+    }
+}

src/GitCaddy.AI.Service/Plugins/ABTestGeneratePlugin.cs

@@ -0,0 +1,74 @@
+// Copyright 2026 MarketAlly. All rights reserved.
+// SPDX-License-Identifier: BSL-1.1
+
+using System.Text.Json.Serialization;
+using MarketAlly.AIPlugin;
+
+namespace GitCaddy.AI.Service.Plugins;
+
+/// <summary>
+/// A/B test variant generated by AI, with a partial config override.
+/// </summary>
+public class ABTestVariant
+{
+    [JsonPropertyName("name")]
+    public string Name { get; set; }
+
+    /// <summary>
+    /// Partial LandingConfig fields to override for this variant.
+    /// Stored as object to preserve arbitrary nested JSON structure.
+    /// </summary>
+    [JsonPropertyName("config_override")]
+    public object ConfigOverride { get; set; }
+
+    [JsonPropertyName("weight")]
+    public int Weight { get; set; }
+}
+
+/// <summary>
+/// Result DTO for A/B test experiment generation.
+/// </summary>
+public class ABTestGenerateResult
+{
+    [JsonPropertyName("name")]
+    public string Name { get; set; }
+
+    [JsonPropertyName("variants")]
+    public List<ABTestVariant> Variants { get; set; }
+}
+
+/// <summary>
+/// AI plugin that generates A/B test experiment variants for a landing page.
+/// The AI analyzes the current landing page config and produces meaningful
+/// variant overrides to test (headlines, CTAs, value props, etc.).
+/// </summary>
+[AIPlugin("GenerateABTestExperiment",
+    "Generate an A/B test experiment for a landing page. " +
+    "Analyze the current landing page config and create meaningful test variants " +
+    "that focus on high-impact changes like headlines, CTAs, and value propositions. " +
+    "Do NOT include a control variant — it is added automatically.")]
+public class ABTestGeneratePlugin : IAIPlugin
+{
+    [AIParameter("Short descriptive name for the experiment (e.g. 'Headline Impact Test')", required: true)]
+    public string ExperimentName { get; set; }
+
+    [AIParameter("Test variants to create. Each must have 'name' (string), 'config_override' (object with partial landing config fields to override), and 'weight' (integer traffic percentage, should sum to ~50 since control gets 50%). Generate 1-3 variants with meaningfully different but plausible changes.", required: true)]
+    public List<ABTestVariant> Variants { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["experimentname"] = typeof(string),
+        ["variants"] = typeof(List<ABTestVariant>)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new ABTestGenerateResult
+        {
+            Name = ExperimentName,
+            Variants = Variants ?? new List<ABTestVariant>()
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "A/B test experiment generated"));
+    }
+}

src/GitCaddy.AI.Service/Plugins/CodeIntelligencePlugin.cs

@@ -0,0 +1,162 @@
+// Copyright 2026 MarketAlly. All rights reserved.
+// SPDX-License-Identifier: BSL-1.1
+
+using System.Text.Json.Serialization;
+using MarketAlly.AIPlugin;
+
+namespace GitCaddy.AI.Service.Plugins;
+
+// ============================================================================
+// Result DTOs
+// ============================================================================
+
+public class SummarizeChangesResult
+{
+    [JsonPropertyName("summary")]
+    public string Summary { get; set; }
+
+    [JsonPropertyName("bullet_points")]
+    public List<string> BulletPoints { get; set; }
+
+    [JsonPropertyName("impact_assessment")]
+    public string ImpactAssessment { get; set; }
+}
+
+public class CodeReferenceItem
+{
+    [JsonPropertyName("description")]
+    public string Description { get; set; }
+
+    [JsonPropertyName("url")]
+    public string Url { get; set; }
+}
+
+public class ExplainCodeResult
+{
+    [JsonPropertyName("explanation")]
+    public string Explanation { get; set; }
+
+    [JsonPropertyName("key_concepts")]
+    public List<string> KeyConcepts { get; set; }
+
+    [JsonPropertyName("references")]
+    public List<CodeReferenceItem> References { get; set; }
+}
+
+public class SuggestFixResult
+{
+    [JsonPropertyName("explanation")]
+    public string Explanation { get; set; }
+
+    [JsonPropertyName("suggested_code")]
+    public string SuggestedCode { get; set; }
+
+    [JsonPropertyName("alternative_fixes")]
+    public List<string> AlternativeFixes { get; set; }
+}
+
+// ============================================================================
+// Plugins
+// ============================================================================
+
+[AIPlugin("SummarizeChanges",
+    "Summarize code changes with a brief paragraph, key bullet points, " +
+    "and an impact assessment.")]
+public class SummarizeChangesPlugin : IAIPlugin
+{
+    [AIParameter("Brief summary paragraph describing the overall changes", required: true)]
+    public string Summary { get; set; }
+
+    [AIParameter("Key changes as a list of concise bullet point strings", required: true)]
+    public List<string> BulletPoints { get; set; }
+
+    [AIParameter("Assessment of the potential impact of these changes", required: true)]
+    public string ImpactAssessment { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["summary"] = typeof(string),
+        ["bulletpoints"] = typeof(List<string>),
+        ["impactassessment"] = typeof(string)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new SummarizeChangesResult
+        {
+            Summary = Summary,
+            BulletPoints = BulletPoints ?? [],
+            ImpactAssessment = ImpactAssessment ?? ""
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Changes summarized"));
+    }
+}
+
+[AIPlugin("ExplainCode",
+    "Explain what code does, including key concepts, patterns used, " +
+    "and relevant documentation references.")]
+public class ExplainCodePlugin : IAIPlugin
+{
+    [AIParameter("Clear explanation of what the code does, how it works, and any notable patterns", required: true)]
+    public string Explanation { get; set; }
+
+    [AIParameter("Key programming concepts and patterns found in the code, as a list of strings", required: true)]
+    public List<string> KeyConcepts { get; set; }
+
+    [AIParameter("Relevant documentation references. Each item must have 'description' (string) and 'url' (string). Use empty array if no relevant references.", required: true)]
+    public List<CodeReferenceItem> References { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["explanation"] = typeof(string),
+        ["keyconcepts"] = typeof(List<string>),
+        ["references"] = typeof(List<CodeReferenceItem>)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new ExplainCodeResult
+        {
+            Explanation = Explanation,
+            KeyConcepts = KeyConcepts ?? [],
+            References = References ?? []
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Code explained"));
+    }
+}
+
+[AIPlugin("SuggestFix",
+    "Analyze code with an error and suggest a fix, including an explanation " +
+    "of the cause, corrected code, and alternative solutions.")]
+public class SuggestFixPlugin : IAIPlugin
+{
+    [AIParameter("Explanation of what is causing the error", required: true)]
+    public string Explanation { get; set; }
+
+    [AIParameter("The corrected code that fixes the error", required: true)]
+    public string SuggestedCode { get; set; }
+
+    [AIParameter("Alternative fix approaches as a list of description strings", required: true)]
+    public List<string> AlternativeFixes { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["explanation"] = typeof(string),
+        ["suggestedcode"] = typeof(string),
+        ["alternativefixes"] = typeof(List<string>)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new SuggestFixResult
+        {
+            Explanation = Explanation,
+            SuggestedCode = SuggestedCode ?? "",
+            AlternativeFixes = AlternativeFixes ?? []
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Fix suggested"));
+    }
+}

src/GitCaddy.AI.Service/Plugins/CodeReviewPlugin.cs

@@ -0,0 +1,192 @@
+// Copyright 2026 MarketAlly. All rights reserved.
+// SPDX-License-Identifier: BSL-1.1
+
+using System.Text.Json.Serialization;
+using MarketAlly.AIPlugin;
+
+namespace GitCaddy.AI.Service.Plugins;
+
+// ============================================================================
+// Result DTOs
+// ============================================================================
+
+public class ReviewCommentItem
+{
+    [JsonPropertyName("path")]
+    public string Path { get; set; }
+
+    [JsonPropertyName("line")]
+    public int Line { get; set; }
+
+    [JsonPropertyName("end_line")]
+    public int EndLine { get; set; }
+
+    [JsonPropertyName("body")]
+    public string Body { get; set; }
+
+    [JsonPropertyName("severity")]
+    public string Severity { get; set; }
+
+    [JsonPropertyName("category")]
+    public string Category { get; set; }
+
+    [JsonPropertyName("suggested_fix")]
+    public string SuggestedFix { get; set; }
+}
+
+public class SecurityIssueItem
+{
+    [JsonPropertyName("path")]
+    public string Path { get; set; }
+
+    [JsonPropertyName("line")]
+    public int Line { get; set; }
+
+    [JsonPropertyName("issue_type")]
+    public string IssueType { get; set; }
+
+    [JsonPropertyName("description")]
+    public string Description { get; set; }
+
+    [JsonPropertyName("severity")]
+    public string Severity { get; set; }
+
+    [JsonPropertyName("remediation")]
+    public string Remediation { get; set; }
+}
+
+public class ReviewPullRequestResult
+{
+    [JsonPropertyName("summary")]
+    public string Summary { get; set; }
+
+    [JsonPropertyName("verdict")]
+    public string Verdict { get; set; }
+
+    [JsonPropertyName("comments")]
+    public List<ReviewCommentItem> Comments { get; set; }
+
+    [JsonPropertyName("suggestions")]
+    public List<string> Suggestions { get; set; }
+
+    [JsonPropertyName("security_issues")]
+    public List<SecurityIssueItem> SecurityIssues { get; set; }
+
+    [JsonPropertyName("security_risk_score")]
+    public int SecurityRiskScore { get; set; }
+
+    [JsonPropertyName("security_summary")]
+    public string SecuritySummary { get; set; }
+
+    [JsonPropertyName("estimated_review_minutes")]
+    public int EstimatedReviewMinutes { get; set; }
+}
+
+public class ReviewCommitResult
+{
+    [JsonPropertyName("summary")]
+    public string Summary { get; set; }
+
+    [JsonPropertyName("comments")]
+    public List<ReviewCommentItem> Comments { get; set; }
+
+    [JsonPropertyName("suggestions")]
+    public List<string> Suggestions { get; set; }
+}
+
+// ============================================================================
+// Plugins
+// ============================================================================
+
+[AIPlugin("ReviewPullRequest",
+    "Review a pull request and provide structured feedback including a verdict, " +
+    "line-by-line comments with severity levels, security analysis, and improvement suggestions.")]
+public class ReviewPullRequestPlugin : IAIPlugin
+{
+    [AIParameter("Brief overview of the changes and overall assessment", required: true)]
+    public string Summary { get; set; }
+
+    [AIParameter("Review verdict: must be exactly 'approve', 'request_changes', or 'comment'", required: true)]
+    public string Verdict { get; set; }
+
+    [AIParameter("Line-by-line review comments. Each item must have 'path' (string, file path), 'line' (int), 'end_line' (int, 0 if single line), 'body' (string, the comment), 'severity' (string: 'info', 'warning', 'error', or 'critical'), 'category' (string: 'security', 'performance', 'style', 'bug', etc.), 'suggested_fix' (string, code fix or empty)", required: true)]
+    public List<ReviewCommentItem> Comments { get; set; }
+
+    [AIParameter("General improvement suggestions as a list of strings", required: true)]
+    public List<string> Suggestions { get; set; }
+
+    [AIParameter("Security issues found. Each item must have 'path' (string), 'line' (int), 'issue_type' (string: 'sql_injection', 'xss', 'hardcoded_secret', etc.), 'description' (string), 'severity' (string), 'remediation' (string). Use empty array if no issues.", required: true)]
+    public List<SecurityIssueItem> SecurityIssues { get; set; }
+
+    [AIParameter("Security risk score from 0 (no risk) to 100 (critical risk)", required: true)]
+    public int SecurityRiskScore { get; set; }
+
+    [AIParameter("Brief summary of security analysis findings", required: true)]
+    public string SecuritySummary { get; set; }
+
+    [AIParameter("Estimated time in minutes to review these changes", required: true)]
+    public int EstimatedReviewMinutes { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["summary"] = typeof(string),
+        ["verdict"] = typeof(string),
+        ["comments"] = typeof(List<ReviewCommentItem>),
+        ["suggestions"] = typeof(List<string>),
+        ["securityissues"] = typeof(List<SecurityIssueItem>),
+        ["securityriskscore"] = typeof(int),
+        ["securitysummary"] = typeof(string),
+        ["estimatedreviewminutes"] = typeof(int)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new ReviewPullRequestResult
+        {
+            Summary = Summary,
+            Verdict = Verdict,
+            Comments = Comments ?? [],
+            Suggestions = Suggestions ?? [],
+            SecurityIssues = SecurityIssues ?? [],
+            SecurityRiskScore = SecurityRiskScore,
+            SecuritySummary = SecuritySummary ?? "",
+            EstimatedReviewMinutes = EstimatedReviewMinutes
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Pull request review complete"));
+    }
+}
+
+[AIPlugin("ReviewCommit",
+    "Review a single commit and provide structured feedback including comments " +
+    "with severity levels and improvement suggestions.")]
+public class ReviewCommitPlugin : IAIPlugin
+{
+    [AIParameter("Brief overview of the commit and overall assessment", required: true)]
+    public string Summary { get; set; }
+
+    [AIParameter("Line-by-line review comments. Each item must have 'path' (string), 'line' (int), 'end_line' (int, 0 if single line), 'body' (string), 'severity' (string: 'info', 'warning', 'error', or 'critical'), 'category' (string), 'suggested_fix' (string or empty)", required: true)]
+    public List<ReviewCommentItem> Comments { get; set; }
+
+    [AIParameter("General improvement suggestions as a list of strings", required: true)]
+    public List<string> Suggestions { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["summary"] = typeof(string),
+        ["comments"] = typeof(List<ReviewCommentItem>),
+        ["suggestions"] = typeof(List<string>)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new ReviewCommitResult
+        {
+            Summary = Summary,
+            Comments = Comments ?? [],
+            Suggestions = Suggestions ?? []
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Commit review complete"));
+    }
+}

src/GitCaddy.AI.Service/Plugins/DocumentationPlugin.cs

@@ -0,0 +1,100 @@
+// Copyright 2026 MarketAlly. All rights reserved.
+// SPDX-License-Identifier: BSL-1.1
+
+using System.Text.Json.Serialization;
+using MarketAlly.AIPlugin;
+
+namespace GitCaddy.AI.Service.Plugins;
+
+// ============================================================================
+// Result DTOs
+// ============================================================================
+
+public class DocumentationSectionItem
+{
+    [JsonPropertyName("title")]
+    public string Title { get; set; }
+
+    [JsonPropertyName("content")]
+    public string Content { get; set; }
+}
+
+public class GenerateDocumentationResult
+{
+    [JsonPropertyName("documentation")]
+    public string Documentation { get; set; }
+
+    [JsonPropertyName("sections")]
+    public List<DocumentationSectionItem> Sections { get; set; }
+}
+
+public class GenerateCommitMessageResult
+{
+    [JsonPropertyName("message")]
+    public string Message { get; set; }
+
+    [JsonPropertyName("alternatives")]
+    public List<string> Alternatives { get; set; }
+}
+
+// ============================================================================
+// Plugins
+// ============================================================================
+
+[AIPlugin("GenerateDocumentation",
+    "Generate comprehensive code documentation including a full documentation " +
+    "string and organized sections for different aspects of the code.")]
+public class GenerateDocumentationPlugin : IAIPlugin
+{
+    [AIParameter("The complete documentation text in the requested format (jsdoc, docstring, xml, or markdown)", required: true)]
+    public string Documentation { get; set; }
+
+    [AIParameter("Documentation broken into sections. Each item must have 'title' (string, section heading like 'Description', 'Parameters', 'Returns', 'Examples') and 'content' (string, section body)", required: true)]
+    public List<DocumentationSectionItem> Sections { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["documentation"] = typeof(string),
+        ["sections"] = typeof(List<DocumentationSectionItem>)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new GenerateDocumentationResult
+        {
+            Documentation = Documentation,
+            Sections = Sections ?? []
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Documentation generated"));
+    }
+}
+
+[AIPlugin("GenerateCommitMessage",
+    "Generate a commit message for code changes, including a primary message " +
+    "and 2-3 alternative options.")]
+public class GenerateCommitMessagePlugin : IAIPlugin
+{
+    [AIParameter("The primary commit message following the requested style", required: true)]
+    public string Message { get; set; }
+
+    [AIParameter("2-3 alternative commit message options", required: true)]
+    public List<string> Alternatives { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["message"] = typeof(string),
+        ["alternatives"] = typeof(List<string>)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new GenerateCommitMessageResult
+        {
+            Message = Message,
+            Alternatives = Alternatives ?? []
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Commit message generated"));
+    }
+}

src/GitCaddy.AI.Service/Plugins/IssuePlugin.cs

@@ -0,0 +1,173 @@
+// Copyright 2026 MarketAlly. All rights reserved.
+// SPDX-License-Identifier: BSL-1.1
+
+using System.Text.Json.Serialization;
+using MarketAlly.AIPlugin;
+
+namespace GitCaddy.AI.Service.Plugins;
+
+// ============================================================================
+// Result DTOs
+// ============================================================================
+
+public class TriageIssueResult
+{
+    [JsonPropertyName("priority")]
+    public string Priority { get; set; }
+
+    [JsonPropertyName("category")]
+    public string Category { get; set; }
+
+    [JsonPropertyName("suggested_labels")]
+    public List<string> SuggestedLabels { get; set; }
+
+    [JsonPropertyName("suggested_assignees")]
+    public List<string> SuggestedAssignees { get; set; }
+
+    [JsonPropertyName("summary")]
+    public string Summary { get; set; }
+
+    [JsonPropertyName("is_duplicate")]
+    public bool IsDuplicate { get; set; }
+
+    [JsonPropertyName("duplicate_of")]
+    public long DuplicateOf { get; set; }
+}
+
+public class LabelSuggestionItem
+{
+    [JsonPropertyName("label")]
+    public string Label { get; set; }
+
+    [JsonPropertyName("confidence")]
+    public float Confidence { get; set; }
+
+    [JsonPropertyName("reason")]
+    public string Reason { get; set; }
+}
+
+public class SuggestLabelsResult
+{
+    [JsonPropertyName("suggestions")]
+    public List<LabelSuggestionItem> Suggestions { get; set; }
+}
+
+public class GenerateIssueResponseResult
+{
+    [JsonPropertyName("response")]
+    public string Response { get; set; }
+
+    [JsonPropertyName("follow_up_questions")]
+    public List<string> FollowUpQuestions { get; set; }
+}
+
+// ============================================================================
+// Plugins
+// ============================================================================
+
+[AIPlugin("TriageIssue",
+    "Triage a software issue by determining its priority, category, " +
+    "suggested labels, and whether it is a duplicate.")]
+public class TriageIssuePlugin : IAIPlugin
+{
+    [AIParameter("Issue priority: must be exactly 'critical', 'high', 'medium', or 'low'", required: true)]
+    public string Priority { get; set; }
+
+    [AIParameter("Issue category: e.g. 'bug', 'feature', 'question', 'docs', 'enhancement'", required: true)]
+    public string Category { get; set; }
+
+    [AIParameter("Suggested labels from the available labels list", required: true)]
+    public List<string> SuggestedLabels { get; set; }
+
+    [AIParameter("Suggested assignees (usernames) who might be best to handle this. Use empty array if unknown.", required: true)]
+    public List<string> SuggestedAssignees { get; set; }
+
+    [AIParameter("Brief summary of the issue and recommended actions", required: true)]
+    public string Summary { get; set; }
+
+    [AIParameter("Whether this issue appears to be a duplicate of an existing issue", required: true)]
+    public bool IsDuplicate { get; set; }
+
+    [AIParameter("Issue ID of the original if this is a duplicate, or 0 if not a duplicate", required: true)]
+    public long DuplicateOf { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["priority"] = typeof(string),
+        ["category"] = typeof(string),
+        ["suggestedlabels"] = typeof(List<string>),
+        ["suggestedassignees"] = typeof(List<string>),
+        ["summary"] = typeof(string),
+        ["isduplicate"] = typeof(bool),
+        ["duplicateof"] = typeof(long)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new TriageIssueResult
+        {
+            Priority = Priority,
+            Category = Category,
+            SuggestedLabels = SuggestedLabels ?? [],
+            SuggestedAssignees = SuggestedAssignees ?? [],
+            Summary = Summary,
+            IsDuplicate = IsDuplicate,
+            DuplicateOf = DuplicateOf
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Issue triaged"));
+    }
+}
+
+[AIPlugin("SuggestLabels",
+    "Suggest appropriate labels for an issue from the available label options, " +
+    "with confidence scores and reasoning.")]
+public class SuggestLabelsPlugin : IAIPlugin
+{
+    [AIParameter("Label suggestions. Each item must have 'label' (string, from available labels), 'confidence' (float, 0.0-1.0), 'reason' (string, why this label applies)", required: true)]
+    public List<LabelSuggestionItem> Suggestions { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["suggestions"] = typeof(List<LabelSuggestionItem>)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new SuggestLabelsResult
+        {
+            Suggestions = Suggestions ?? []
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Labels suggested"));
+    }
+}
+
+[AIPlugin("GenerateIssueResponse",
+    "Generate a professional response to a software issue, " +
+    "including optional follow-up questions for clarification.")]
+public class GenerateIssueResponsePlugin : IAIPlugin
+{
+    [AIParameter("The response text to post as a comment on the issue", required: true)]
+    public string Response { get; set; }
+
+    [AIParameter("Follow-up questions to ask the reporter for clarification. Use empty array if none needed.", required: true)]
+    public List<string> FollowUpQuestions { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["response"] = typeof(string),
+        ["followupquestions"] = typeof(List<string>)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new GenerateIssueResponseResult
+        {
+            Response = Response,
+            FollowUpQuestions = FollowUpQuestions ?? []
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Issue response generated"));
+    }
+}

src/GitCaddy.AI.Service/Plugins/LandingPageContentPlugin.cs

@@ -0,0 +1,115 @@
+// Copyright 2026 MarketAlly. All rights reserved.
+// SPDX-License-Identifier: BSL-1.1
+
+using MarketAlly.AIPlugin;
+
+namespace GitCaddy.AI.Service.Plugins;
+
+/// <summary>
+/// AI plugin that captures structured landing page content generated by the AI model.
+/// Used with SendForStructuredOutputAsync to force the AI to return data via tool_choice
+/// rather than free-form text that requires parsing.
+/// </summary>
+[AIPlugin("GenerateLandingPageContent",
+    "Generate compelling landing page content for a software repository. " +
+    "Analyze the repository metadata provided and fill in all fields with professional, " +
+    "benefit-focused marketing copy.")]
+public class LandingPageContentPlugin : IAIPlugin
+{
+    [AIParameter("Project/brand name", required: true)]
+    public string BrandName { get; set; }
+
+    [AIParameter("Short brand tagline (one line)", required: true)]
+    public string BrandTagline { get; set; }
+
+    [AIParameter("Compelling hero headline (max 10 words)", required: true)]
+    public string HeroHeadline { get; set; }
+
+    [AIParameter("Supporting hero subheadline explaining the value (1-2 sentences)", required: true)]
+    public string HeroSubheadline { get; set; }
+
+    [AIParameter("Primary call-to-action button label (e.g. 'Get Started')", required: true)]
+    public string PrimaryCtaLabel { get; set; }
+
+    [AIParameter("Secondary call-to-action button label (e.g. 'View Source')", required: true)]
+    public string SecondaryCtaLabel { get; set; }
+
+    [AIParameter("Statistics to display. Each must have 'value' and 'label' string properties. Generate 3-4 stats based on repo data or compelling metrics.", required: true)]
+    public List<LandingPageStat> Stats { get; set; }
+
+    [AIParameter("Key value propositions. Each must have 'title', 'description', and 'icon' properties. Icon must be one of: zap, shield, rocket, check, star, heart, lock, globe, clock, gear, code, terminal, package, database, cloud, cpu, graph, people, tools, light-bulb. Generate exactly 3.", required: true)]
+    public List<LandingPageValueProp> ValueProps { get; set; }
+
+    [AIParameter("Features to highlight. Each must have 'title', 'description', and 'icon' properties (same icon options as value props). Generate 3-6 based on what the README describes.", required: true)]
+    public List<LandingPageFeature> Features { get; set; }
+
+    [AIParameter("Bottom CTA section headline (e.g. 'Ready to get started?')", required: true)]
+    public string CtaHeadline { get; set; }
+
+    [AIParameter("Bottom CTA section subheadline", required: true)]
+    public string CtaSubheadline { get; set; }
+
+    [AIParameter("Bottom CTA section button label (e.g. 'Get Started Free')", required: true)]
+    public string CtaButtonLabel { get; set; }
+
+    [AIParameter("SEO page title (50-60 characters)", required: true)]
+    public string SeoTitle { get; set; }
+
+    [AIParameter("SEO meta description (150-160 characters)", required: true)]
+    public string SeoDescription { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["brandname"] = typeof(string),
+        ["brandtagline"] = typeof(string),
+        ["heroheadline"] = typeof(string),
+        ["herosubheadline"] = typeof(string),
+        ["primaryctalabel"] = typeof(string),
+        ["secondaryctalabel"] = typeof(string),
+        ["stats"] = typeof(List<LandingPageStat>),
+        ["valueprops"] = typeof(List<LandingPageValueProp>),
+        ["features"] = typeof(List<LandingPageFeature>),
+        ["ctaheadline"] = typeof(string),
+        ["ctasubheadline"] = typeof(string),
+        ["ctabuttonlabel"] = typeof(string),
+        ["seotitle"] = typeof(string),
+        ["seodescription"] = typeof(string)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        // Properties are auto-populated by the framework before this runs.
+        // Assemble the result DTO matching the Go server's expected JSON structure.
+        var result = new LandingPageContentResult
+        {
+            Brand = new LandingPageBrand
+            {
+                Name = BrandName,
+                Tagline = BrandTagline
+            },
+            Hero = new LandingPageHero
+            {
+                Headline = HeroHeadline,
+                Subheadline = HeroSubheadline,
+                PrimaryCta = new LandingPageCtaLabel { Label = PrimaryCtaLabel },
+                SecondaryCta = new LandingPageCtaLabel { Label = SecondaryCtaLabel }
+            },
+            Stats = Stats ?? new List<LandingPageStat>(),
+            ValueProps = ValueProps ?? new List<LandingPageValueProp>(),
+            Features = Features ?? new List<LandingPageFeature>(),
+            CtaSection = new LandingPageCtaSection
+            {
+                Headline = CtaHeadline,
+                Subheadline = CtaSubheadline,
+                ButtonLabel = CtaButtonLabel
+            },
+            Seo = new LandingPageSeo
+            {
+                Title = SeoTitle,
+                Description = SeoDescription
+            }
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Landing page content generated"));
+    }
+}

src/GitCaddy.AI.Service/Plugins/LandingPageModels.cs

@@ -0,0 +1,186 @@
+// Copyright 2026 MarketAlly. All rights reserved.
+// SPDX-License-Identifier: BSL-1.1
+
+using System.Text.Json.Serialization;
+
+namespace GitCaddy.AI.Service.Plugins;
+
+// --- Shared model classes for AI-generated landing page content ---
+
+/// <summary>
+/// A statistic/metric to display on the landing page (e.g., "100+ Stars").
+/// </summary>
+public class LandingPageStat
+{
+    [JsonPropertyName("value")]
+    public string Value { get; set; }
+
+    [JsonPropertyName("label")]
+    public string Label { get; set; }
+}
+
+/// <summary>
+/// A value proposition with icon for the landing page.
+/// </summary>
+public class LandingPageValueProp
+{
+    [JsonPropertyName("title")]
+    public string Title { get; set; }
+
+    [JsonPropertyName("description")]
+    public string Description { get; set; }
+
+    [JsonPropertyName("icon")]
+    public string Icon { get; set; }
+}
+
+/// <summary>
+/// A feature with icon for the landing page.
+/// </summary>
+public class LandingPageFeature
+{
+    [JsonPropertyName("title")]
+    public string Title { get; set; }
+
+    [JsonPropertyName("description")]
+    public string Description { get; set; }
+
+    [JsonPropertyName("icon")]
+    public string Icon { get; set; }
+}
+
+// --- Result DTOs for content generation (matches Go aiGeneratedConfig struct) ---
+
+public class LandingPageContentResult
+{
+    [JsonPropertyName("brand")]
+    public LandingPageBrand Brand { get; set; }
+
+    [JsonPropertyName("hero")]
+    public LandingPageHero Hero { get; set; }
+
+    [JsonPropertyName("stats")]
+    public List<LandingPageStat> Stats { get; set; }
+
+    [JsonPropertyName("value_props")]
+    public List<LandingPageValueProp> ValueProps { get; set; }
+
+    [JsonPropertyName("features")]
+    public List<LandingPageFeature> Features { get; set; }
+
+    [JsonPropertyName("cta_section")]
+    public LandingPageCtaSection CtaSection { get; set; }
+
+    [JsonPropertyName("seo")]
+    public LandingPageSeo Seo { get; set; }
+}
+
+public class LandingPageBrand
+{
+    [JsonPropertyName("name")]
+    public string Name { get; set; }
+
+    [JsonPropertyName("tagline")]
+    public string Tagline { get; set; }
+}
+
+public class LandingPageHero
+{
+    [JsonPropertyName("headline")]
+    public string Headline { get; set; }
+
+    [JsonPropertyName("subheadline")]
+    public string Subheadline { get; set; }
+
+    [JsonPropertyName("primary_cta")]
+    public LandingPageCtaLabel PrimaryCta { get; set; }
+
+    [JsonPropertyName("secondary_cta")]
+    public LandingPageCtaLabel SecondaryCta { get; set; }
+}
+
+public class LandingPageCtaLabel
+{
+    [JsonPropertyName("label")]
+    public string Label { get; set; }
+}
+
+public class LandingPageCtaSection
+{
+    [JsonPropertyName("headline")]
+    public string Headline { get; set; }
+
+    [JsonPropertyName("subheadline")]
+    public string Subheadline { get; set; }
+
+    [JsonPropertyName("button_label")]
+    public string ButtonLabel { get; set; }
+}
+
+public class LandingPageSeo
+{
+    [JsonPropertyName("title")]
+    public string Title { get; set; }
+
+    [JsonPropertyName("description")]
+    public string Description { get; set; }
+}
+
+// --- Result DTOs for translation overlay (deep-merged onto base config) ---
+
+public class LandingPageTranslationResult
+{
+    [JsonPropertyName("hero")]
+    public LandingPageTranslationHero Hero { get; set; }
+
+    [JsonPropertyName("stats")]
+    public List<LandingPageStat> Stats { get; set; }
+
+    [JsonPropertyName("value_props")]
+    public List<LandingPageTranslationSection> ValueProps { get; set; }
+
+    [JsonPropertyName("features")]
+    public List<LandingPageTranslationSection> Features { get; set; }
+
+    [JsonPropertyName("cta_section")]
+    public LandingPageTranslationCta CtaSection { get; set; }
+
+    [JsonPropertyName("seo")]
+    public LandingPageSeo Seo { get; set; }
+}
+
+public class LandingPageTranslationHero
+{
+    [JsonPropertyName("headline")]
+    public string Headline { get; set; }
+
+    [JsonPropertyName("subheadline")]
+    public string Subheadline { get; set; }
+
+    [JsonPropertyName("primary_cta")]
+    public LandingPageCtaLabel PrimaryCta { get; set; }
+
+    [JsonPropertyName("secondary_cta")]
+    public LandingPageCtaLabel SecondaryCta { get; set; }
+}
+
+public class LandingPageTranslationSection
+{
+    [JsonPropertyName("title")]
+    public string Title { get; set; }
+
+    [JsonPropertyName("description")]
+    public string Description { get; set; }
+}
+
+public class LandingPageTranslationCta
+{
+    [JsonPropertyName("headline")]
+    public string Headline { get; set; }
+
+    [JsonPropertyName("subheadline")]
+    public string Subheadline { get; set; }
+
+    [JsonPropertyName("button")]
+    public LandingPageCtaLabel Button { get; set; }
+}

src/GitCaddy.AI.Service/Plugins/LandingPageTranslationPlugin.cs

@@ -0,0 +1,102 @@
+// Copyright 2026 MarketAlly. All rights reserved.
+// SPDX-License-Identifier: BSL-1.1
+
+using MarketAlly.AIPlugin;
+
+namespace GitCaddy.AI.Service.Plugins;
+
+/// <summary>
+/// AI plugin that captures translated landing page content.
+/// Used with SendForStructuredOutputAsync to force the AI to return a translation
+/// overlay that gets deep-merged onto the base landing page config.
+/// </summary>
+[AIPlugin("TranslateLandingPageContent",
+    "Translate landing page content to the target language. " +
+    "Provide natural, marketing-quality translations. Keep technical terms, " +
+    "brand names, and URLs untranslated. Maintain the same number of items in arrays.")]
+public class LandingPageTranslationPlugin : IAIPlugin
+{
+    [AIParameter("Translated hero headline", required: true)]
+    public string HeroHeadline { get; set; }
+
+    [AIParameter("Translated hero subheadline", required: true)]
+    public string HeroSubheadline { get; set; }
+
+    [AIParameter("Translated primary CTA button label", required: true)]
+    public string PrimaryCtaLabel { get; set; }
+
+    [AIParameter("Translated secondary CTA button label", required: true)]
+    public string SecondaryCtaLabel { get; set; }
+
+    [AIParameter("Translated stats. Each must have 'value' (keep original numbers/values) and 'label' (translated) string properties. Must have the same number of items as the source.", required: true)]
+    public List<LandingPageStat> Stats { get; set; }
+
+    [AIParameter("Translated value propositions. Each must have 'title' and 'description' string properties (translated). Must have the same number of items as the source.", required: true)]
+    public List<LandingPageTranslationSection> ValueProps { get; set; }
+
+    [AIParameter("Translated features. Each must have 'title' and 'description' string properties (translated). Must have the same number of items as the source.", required: true)]
+    public List<LandingPageTranslationSection> Features { get; set; }
+
+    [AIParameter("Translated bottom CTA section headline", required: true)]
+    public string CtaHeadline { get; set; }
+
+    [AIParameter("Translated bottom CTA section subheadline", required: true)]
+    public string CtaSubheadline { get; set; }
+
+    [AIParameter("Translated bottom CTA button label", required: true)]
+    public string CtaButtonLabel { get; set; }
+
+    [AIParameter("Translated SEO page title", required: true)]
+    public string SeoTitle { get; set; }
+
+    [AIParameter("Translated SEO meta description", required: true)]
+    public string SeoDescription { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["heroheadline"] = typeof(string),
+        ["herosubheadline"] = typeof(string),
+        ["primaryctalabel"] = typeof(string),
+        ["secondaryctalabel"] = typeof(string),
+        ["stats"] = typeof(List<LandingPageStat>),
+        ["valueprops"] = typeof(List<LandingPageTranslationSection>),
+        ["features"] = typeof(List<LandingPageTranslationSection>),
+        ["ctaheadline"] = typeof(string),
+        ["ctasubheadline"] = typeof(string),
+        ["ctabuttonlabel"] = typeof(string),
+        ["seotitle"] = typeof(string),
+        ["seodescription"] = typeof(string)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        // Properties are auto-populated by the framework.
+        // Assemble the translation overlay DTO matching the expected deep-merge structure.
+        var result = new LandingPageTranslationResult
+        {
+            Hero = new LandingPageTranslationHero
+            {
+                Headline = HeroHeadline,
+                Subheadline = HeroSubheadline,
+                PrimaryCta = new LandingPageCtaLabel { Label = PrimaryCtaLabel },
+                SecondaryCta = new LandingPageCtaLabel { Label = SecondaryCtaLabel }
+            },
+            Stats = Stats ?? new List<LandingPageStat>(),
+            ValueProps = ValueProps ?? new List<LandingPageTranslationSection>(),
+            Features = Features ?? new List<LandingPageTranslationSection>(),
+            CtaSection = new LandingPageTranslationCta
+            {
+                Headline = CtaHeadline,
+                Subheadline = CtaSubheadline,
+                Button = new LandingPageCtaLabel { Label = CtaButtonLabel }
+            },
+            Seo = new LandingPageSeo
+            {
+                Title = SeoTitle,
+                Description = SeoDescription
+            }
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Landing page content translated"));
+    }
+}

src/GitCaddy.AI.Service/Plugins/PluginHelpers.cs

@@ -0,0 +1,34 @@
+// Copyright 2026 MarketAlly. All rights reserved.
+// SPDX-License-Identifier: BSL-1.1
+
+using System.Text.Json;
+
+namespace GitCaddy.AI.Service.Plugins;
+
+/// <summary>
+/// Shared helpers for working with AIPlugin structured output.
+/// </summary>
+public static class PluginHelpers
+{
+    /// <summary>
+    /// Safely deserializes StructuredOutput to the target type, handling the various
+    /// runtime types that the framework may return (typed object, JsonElement, or string).
+    /// </summary>
+    public static T DeserializeOutput<T>(object? structuredOutput) where T : class, new()
+    {
+        if (structuredOutput is T typed)
+            return typed;
+
+        string json;
+        if (structuredOutput is string str)
+            json = str;
+        else if (structuredOutput is JsonElement jsonElement)
+            json = jsonElement.GetRawText();
+        else if (structuredOutput != null)
+            json = JsonSerializer.Serialize(structuredOutput, structuredOutput.GetType());
+        else
+            return new T();
+
+        return JsonSerializer.Deserialize<T>(json) ?? new T();
+    }
+}

src/GitCaddy.AI.Service/Plugins/WorkflowInspectPlugin.cs

@@ -0,0 +1,76 @@
+// Copyright 2026 MarketAlly. All rights reserved.
+// SPDX-License-Identifier: BSL-1.1
+
+using System.Text.Json.Serialization;
+using MarketAlly.AIPlugin;
+
+namespace GitCaddy.AI.Service.Plugins;
+
+// ============================================================================
+// Result DTOs
+// ============================================================================
+
+public class WorkflowIssueItem
+{
+    [JsonPropertyName("line")]
+    public int Line { get; set; }
+
+    [JsonPropertyName("severity")]
+    public string Severity { get; set; }
+
+    [JsonPropertyName("message")]
+    public string Message { get; set; }
+
+    [JsonPropertyName("fix")]
+    public string Fix { get; set; }
+}
+
+public class InspectWorkflowPluginResult
+{
+    [JsonPropertyName("valid")]
+    public bool Valid { get; set; }
+
+    [JsonPropertyName("issues")]
+    public List<WorkflowIssueItem> Issues { get; set; }
+
+    [JsonPropertyName("suggestions")]
+    public List<string> Suggestions { get; set; }
+}
+
+// ============================================================================
+// Plugin
+// ============================================================================
+
+[AIPlugin("InspectWorkflow",
+    "Inspect a CI/CD workflow YAML file for issues including syntax errors, " +
+    "missing fields, security problems, performance issues, and best practice violations.")]
+public class InspectWorkflowPlugin : IAIPlugin
+{
+    [AIParameter("Whether the workflow file is valid (no errors found)", required: true)]
+    public bool Valid { get; set; }
+
+    [AIParameter("Issues found in the workflow. Each item must have 'line' (int, line number or 0), 'severity' (string: 'error', 'warning', or 'info'), 'message' (string, description of the issue), 'fix' (string, suggested fix)", required: true)]
+    public List<WorkflowIssueItem> Issues { get; set; }
+
+    [AIParameter("General improvement suggestions as a list of strings", required: true)]
+    public List<string> Suggestions { get; set; }
+
+    public IReadOnlyDictionary<string, Type> SupportedParameters => new Dictionary<string, Type>
+    {
+        ["valid"] = typeof(bool),
+        ["issues"] = typeof(List<WorkflowIssueItem>),
+        ["suggestions"] = typeof(List<string>)
+    };
+
+    public Task<AIPluginResult> ExecuteAsync(IReadOnlyDictionary<string, object> parameters)
+    {
+        var result = new InspectWorkflowPluginResult
+        {
+            Valid = Valid,
+            Issues = Issues ?? [],
+            Suggestions = Suggestions ?? []
+        };
+
+        return Task.FromResult(new AIPluginResult(result, "Workflow inspection complete"));
+    }
+}

src/GitCaddy.AI.Service/Services/CodeIntelligenceService.cs

@@ -3,12 +3,13 @@
 
 using GitCaddy.AI.Proto;
 using GitCaddy.AI.Service.Configuration;
+using GitCaddy.AI.Service.Plugins;
 using Microsoft.Extensions.Options;
 
 namespace GitCaddy.AI.Service.Services;
 
 /// <summary>
-/// Implementation of AI-powered code intelligence.
+/// Implementation of AI-powered code intelligence using MarketAlly.AIPlugin structured output.
 /// </summary>
 public class CodeIntelligenceService : ICodeIntelligenceService
 {
@@ -33,16 +34,28 @@ public class CodeIntelligenceService : ICodeIntelligenceService
             .WithSystemPrompt("""
                 You are an expert at summarizing code changes.
                 Provide clear, concise summaries that help developers understand what changed and why.
-
-                Output a brief summary paragraph followed by bullet points of key changes.
                 Also assess the potential impact of these changes.
                 """)
+            .RegisterPlugin<SummarizeChangesPlugin>()
             .Build();
 
         var prompt = BuildSummarizePrompt(request);
-        var response = await conversation.SendAsync(prompt, cancellationToken);
 
-        return ParseSummarizeResponse(response.FinalMessage ?? "");
+        var response = await conversation.SendForStructuredOutputAsync<SummarizeChangesResult>(
+            prompt, "SummarizeChanges", cancellationToken);
+
+        var result = PluginHelpers.DeserializeOutput<SummarizeChangesResult>(response.StructuredOutput);
+
+        var protoResponse = new SummarizeChangesResponse
+        {
+            Summary = result.Summary ?? "",
+            ImpactAssessment = result.ImpactAssessment ?? ""
+        };
+
+        if (result.BulletPoints != null)
+            protoResponse.BulletPoints.AddRange(result.BulletPoints);
+
+        return protoResponse;
     }
 
     public async Task<ExplainCodeResponse> ExplainCodeAsync(
@@ -60,6 +73,7 @@ public class CodeIntelligenceService : ICodeIntelligenceService
 
                 Adjust your explanation depth based on the code complexity.
                 """)
+            .RegisterPlugin<ExplainCodePlugin>()
             .Build();
 
         var prompt = $"""
@@ -72,12 +86,32 @@ public class CodeIntelligenceService : ICodeIntelligenceService
             {(string.IsNullOrEmpty(request.Question) ? "" : $"Specific question: {request.Question}")}
             """;
 
-        var response = await conversation.SendAsync(prompt, cancellationToken);
+        var response = await conversation.SendForStructuredOutputAsync<ExplainCodeResult>(
+            prompt, "ExplainCode", cancellationToken);
 
-        return new ExplainCodeResponse
+        var result = PluginHelpers.DeserializeOutput<ExplainCodeResult>(response.StructuredOutput);
+
+        var protoResponse = new ExplainCodeResponse
         {
-            Explanation = response.FinalMessage ?? ""
+            Explanation = result.Explanation ?? ""
         };
+
+        if (result.KeyConcepts != null)
+            protoResponse.KeyConcepts.AddRange(result.KeyConcepts);
+
+        if (result.References != null)
+        {
+            foreach (var r in result.References)
+            {
+                protoResponse.References.Add(new CodeReference
+                {
+                    Description = r.Description ?? "",
+                    Url = r.Url ?? ""
+                });
+            }
+        }
+
+        return protoResponse;
     }
 
     public async Task<SuggestFixResponse> SuggestFixAsync(
@@ -94,6 +128,7 @@ public class CodeIntelligenceService : ICodeIntelligenceService
 
                 Be specific and provide working code.
                 """)
+            .RegisterPlugin<SuggestFixPlugin>()
             .Build();
 
         var prompt = $"""
@@ -111,12 +146,21 @@ public class CodeIntelligenceService : ICodeIntelligenceService
             Please suggest a fix.
             """;
 
-        var response = await conversation.SendAsync(prompt, cancellationToken);
+        var response = await conversation.SendForStructuredOutputAsync<SuggestFixResult>(
+            prompt, "SuggestFix", cancellationToken);
 
-        return new SuggestFixResponse
+        var result = PluginHelpers.DeserializeOutput<SuggestFixResult>(response.StructuredOutput);
+
+        var protoResponse = new SuggestFixResponse
         {
-            Explanation = response.FinalMessage ?? ""
+            Explanation = result.Explanation ?? "",
+            SuggestedCode = result.SuggestedCode ?? ""
         };
+
+        if (result.AlternativeFixes != null)
+            protoResponse.AlternativeFixes.AddRange(result.AlternativeFixes);
+
+        return protoResponse;
     }
 
     private static string BuildSummarizePrompt(SummarizeChangesRequest request)
@@ -149,25 +193,4 @@ public class CodeIntelligenceService : ICodeIntelligenceService
 
         return sb.ToString();
     }
-
-    private static SummarizeChangesResponse ParseSummarizeResponse(string response)
-    {
-        var result = new SummarizeChangesResponse
-        {
-            Summary = response
-        };
-
-        // Extract bullet points (lines starting with - or *)
-        var lines = response.Split('\n');
-        foreach (var line in lines)
-        {
-            var trimmed = line.Trim();
-            if (trimmed.StartsWith("- ") || trimmed.StartsWith("* "))
-            {
-                result.BulletPoints.Add(trimmed[2..]);
-            }
-        }
-
-        return result;
-    }
 }

src/GitCaddy.AI.Service/Services/CodeReviewService.cs

@@ -3,14 +3,13 @@
 
 using GitCaddy.AI.Proto;
 using GitCaddy.AI.Service.Configuration;
-using MarketAlly.AIPlugin;
-using MarketAlly.AIPlugin.Conversation;
+using GitCaddy.AI.Service.Plugins;
 using Microsoft.Extensions.Options;
 
 namespace GitCaddy.AI.Service.Services;
 
 /// <summary>
-/// Implementation of AI-powered code review using MarketAlly.AIPlugin.
+/// Implementation of AI-powered code review using MarketAlly.AIPlugin structured output.
 /// </summary>
 public class CodeReviewService : ICodeReviewService
 {
@@ -33,16 +32,16 @@ public class CodeReviewService : ICodeReviewService
     {
         var conversation = _providerFactory.CreateConversation()
             .WithSystemPrompt(GetCodeReviewSystemPrompt(request.Options))
+            .RegisterPlugin<ReviewPullRequestPlugin>()
             .Build();
 
-        // Build the review prompt
         var prompt = BuildPullRequestReviewPrompt(request);
 
-        // Get AI response
-        var response = await conversation.SendAsync(prompt, cancellationToken);
+        var response = await conversation.SendForStructuredOutputAsync<ReviewPullRequestResult>(
+            prompt, "ReviewPullRequest", cancellationToken);
 
-        // Parse and return structured response
-        return ParsePullRequestReviewResponse(response.FinalMessage ?? "");
+        var result = PluginHelpers.DeserializeOutput<ReviewPullRequestResult>(response.StructuredOutput);
+        return MapPullRequestResult(result);
     }
 
     public async Task<ReviewCommitResponse> ReviewCommitAsync(
@@ -50,12 +49,16 @@ public class CodeReviewService : ICodeReviewService
     {
         var conversation = _providerFactory.CreateConversation()
             .WithSystemPrompt(GetCodeReviewSystemPrompt(request.Options))
+            .RegisterPlugin<ReviewCommitPlugin>()
             .Build();
 
         var prompt = BuildCommitReviewPrompt(request);
-        var response = await conversation.SendAsync(prompt, cancellationToken);
 
-        return ParseCommitReviewResponse(response.FinalMessage ?? "");
+        var response = await conversation.SendForStructuredOutputAsync<ReviewCommitResult>(
+            prompt, "ReviewCommit", cancellationToken);
+
+        var result = PluginHelpers.DeserializeOutput<ReviewCommitResult>(response.StructuredOutput);
+        return MapCommitResult(result);
     }
 
     private static string GetCodeReviewSystemPrompt(ReviewOptions? options)
@@ -92,14 +95,6 @@ public class CodeReviewService : ICodeReviewService
             5. Consider the broader context and impact of changes
 
             {focusText}
-
-            Output Format:
-            Provide your review in a structured format:
-            - SUMMARY: A brief overview of the changes and overall assessment
-            - VERDICT: APPROVE, REQUEST_CHANGES, or COMMENT
-            - COMMENTS: Specific line-by-line feedback with severity levels
-            - SECURITY: Any security concerns found
-            - SUGGESTIONS: General improvement suggestions
             """;
     }
 
@@ -154,36 +149,105 @@ public class CodeReviewService : ICodeReviewService
         return sb.ToString();
     }
 
-    private static ReviewPullRequestResponse ParsePullRequestReviewResponse(string response)
+    private static ReviewPullRequestResponse MapPullRequestResult(ReviewPullRequestResult result)
     {
-        // TODO: Implement structured parsing using JSON mode or regex extraction
-        // For now, return a basic response
-        var result = new ReviewPullRequestResponse
+        var response = new ReviewPullRequestResponse
         {
-            Summary = response,
-            Verdict = ReviewVerdict.Comment,
-            EstimatedReviewMinutes = 5
+            Summary = result.Summary ?? "",
+            Verdict = ParseVerdict(result.Verdict),
+            EstimatedReviewMinutes = result.EstimatedReviewMinutes
         };
 
-        // Parse verdict from response
-        if (response.Contains("APPROVE", StringComparison.OrdinalIgnoreCase) &&
-            !response.Contains("REQUEST_CHANGES", StringComparison.OrdinalIgnoreCase))
+        if (result.Comments != null)
         {
-            result.Verdict = ReviewVerdict.Approve;
-        }
-        else if (response.Contains("REQUEST_CHANGES", StringComparison.OrdinalIgnoreCase))
-        {
-            result.Verdict = ReviewVerdict.RequestChanges;
+            foreach (var c in result.Comments)
+            {
+                response.Comments.Add(new ReviewComment
+                {
+                    Path = c.Path ?? "",
+                    Line = c.Line,
+                    EndLine = c.EndLine,
+                    Body = c.Body ?? "",
+                    Severity = ParseSeverity(c.Severity),
+                    Category = c.Category ?? "",
+                    SuggestedFix = c.SuggestedFix ?? ""
+                });
+            }
         }
 
-        return result;
+        if (result.Suggestions != null)
+            response.Suggestions.AddRange(result.Suggestions);
+
+        if (result.SecurityIssues is { Count: > 0 })
+        {
+            response.Security = new SecurityAnalysis
+            {
+                RiskScore = result.SecurityRiskScore,
+                Summary = result.SecuritySummary ?? ""
+            };
+            foreach (var si in result.SecurityIssues)
+            {
+                response.Security.Issues.Add(new SecurityIssue
+                {
+                    Path = si.Path ?? "",
+                    Line = si.Line,
+                    IssueType = si.IssueType ?? "",
+                    Description = si.Description ?? "",
+                    Severity = si.Severity ?? "",
+                    Remediation = si.Remediation ?? ""
+                });
+            }
+        }
+
+        return response;
     }
 
-    private static ReviewCommitResponse ParseCommitReviewResponse(string response)
+    private static ReviewCommitResponse MapCommitResult(ReviewCommitResult result)
     {
-        return new ReviewCommitResponse
+        var response = new ReviewCommitResponse
         {
-            Summary = response
+            Summary = result.Summary ?? ""
         };
+
+        if (result.Comments != null)
+        {
+            foreach (var c in result.Comments)
+            {
+                response.Comments.Add(new ReviewComment
+                {
+                    Path = c.Path ?? "",
+                    Line = c.Line,
+                    EndLine = c.EndLine,
+                    Body = c.Body ?? "",
+                    Severity = ParseSeverity(c.Severity),
+                    Category = c.Category ?? "",
+                    SuggestedFix = c.SuggestedFix ?? ""
+                });
+            }
+        }
+
+        if (result.Suggestions != null)
+            response.Suggestions.AddRange(result.Suggestions);
+
+        return response;
     }
+
+    private static ReviewVerdict ParseVerdict(string? verdict) =>
+        verdict?.ToLowerInvariant() switch
+        {
+            "approve" => ReviewVerdict.Approve,
+            "request_changes" => ReviewVerdict.RequestChanges,
+            "comment" => ReviewVerdict.Comment,
+            _ => ReviewVerdict.Comment
+        };
+
+    private static CommentSeverity ParseSeverity(string? severity) =>
+        severity?.ToLowerInvariant() switch
+        {
+            "critical" => CommentSeverity.Critical,
+            "error" => CommentSeverity.Error,
+            "warning" => CommentSeverity.Warning,
+            "info" => CommentSeverity.Info,
+            _ => CommentSeverity.Info
+        };
 }

src/GitCaddy.AI.Service/Services/DocumentationService.cs

@@ -3,12 +3,13 @@
 
 using GitCaddy.AI.Proto;
 using GitCaddy.AI.Service.Configuration;
+using GitCaddy.AI.Service.Plugins;
 using Microsoft.Extensions.Options;
 
 namespace GitCaddy.AI.Service.Services;
 
 /// <summary>
-/// Implementation of AI-powered documentation generation.
+/// Implementation of AI-powered documentation generation using MarketAlly.AIPlugin structured output.
 /// </summary>
 public class DocumentationService : IDocumentationService
 {
@@ -61,6 +62,7 @@ public class DocumentationService : IDocumentationService
 
                 Be concise but thorough.
                 """)
+            .RegisterPlugin<GenerateDocumentationPlugin>()
             .Build();
 
         var prompt = $"""
@@ -71,12 +73,29 @@ public class DocumentationService : IDocumentationService
             ```
             """;
 
-        var response = await conversation.SendAsync(prompt, cancellationToken);
+        var response = await conversation.SendForStructuredOutputAsync<GenerateDocumentationResult>(
+            prompt, "GenerateDocumentation", cancellationToken);
 
-        return new GenerateDocumentationResponse
+        var result = PluginHelpers.DeserializeOutput<GenerateDocumentationResult>(response.StructuredOutput);
+
+        var protoResponse = new GenerateDocumentationResponse
         {
-            Documentation = response.FinalMessage ?? ""
+            Documentation = result.Documentation ?? ""
         };
+
+        if (result.Sections != null)
+        {
+            foreach (var s in result.Sections)
+            {
+                protoResponse.Sections.Add(new DocumentationSection
+                {
+                    Title = s.Title ?? "",
+                    Content = s.Content ?? ""
+                });
+            }
+        }
+
+        return protoResponse;
     }
 
     public async Task<GenerateCommitMessageResponse> GenerateCommitMessageAsync(
@@ -110,9 +129,8 @@ public class DocumentationService : IDocumentationService
 
                 Analyze the changes and write an appropriate commit message.
                 Focus on WHAT changed and WHY, not HOW.
-
-                Also provide 2-3 alternative messages.
                 """)
+            .RegisterPlugin<GenerateCommitMessagePlugin>()
             .Build();
 
         var sb = new System.Text.StringBuilder();
@@ -128,26 +146,19 @@ public class DocumentationService : IDocumentationService
             sb.AppendLine();
         }
 
-        var response = await conversation.SendAsync(sb.ToString(), cancellationToken);
-        var responseContent = response.FinalMessage ?? "";
+        var response = await conversation.SendForStructuredOutputAsync<GenerateCommitMessageResult>(
+            sb.ToString(), "GenerateCommitMessage", cancellationToken);
 
-        // Parse response - first line is primary, rest are alternatives
-        var lines = responseContent.Split('\n', StringSplitOptions.RemoveEmptyEntries);
-        var result = new GenerateCommitMessageResponse
+        var result = PluginHelpers.DeserializeOutput<GenerateCommitMessageResult>(response.StructuredOutput);
+
+        var protoResponse = new GenerateCommitMessageResponse
         {
-            Message = lines.Length > 0 ? lines[0].Trim() : responseContent.Trim()
+            Message = result.Message ?? ""
         };
 
-        // Extract alternatives if present
-        for (var i = 1; i < lines.Length && result.Alternatives.Count < 3; i++)
-        {
-            var line = lines[i].Trim();
-            if (!string.IsNullOrEmpty(line) && !line.StartsWith('#') && !line.StartsWith('-'))
-            {
-                result.Alternatives.Add(line);
-            }
-        }
+        if (result.Alternatives != null)
+            protoResponse.Alternatives.AddRange(result.Alternatives);
 
-        return result;
+        return protoResponse;
     }
 }

src/GitCaddy.AI.Service/Services/IssueService.cs

@@ -3,12 +3,13 @@
 
 using GitCaddy.AI.Proto;
 using GitCaddy.AI.Service.Configuration;
+using GitCaddy.AI.Service.Plugins;
 using Microsoft.Extensions.Options;
 
 namespace GitCaddy.AI.Service.Services;
 
 /// <summary>
-/// Implementation of AI-powered issue management.
+/// Implementation of AI-powered issue management using MarketAlly.AIPlugin structured output.
 /// </summary>
 public class IssueService : IIssueService
 {
@@ -40,15 +41,9 @@ public class IssueService : IIssueService
                 2. Category: bug, feature, question, docs, enhancement, etc.
                 3. Suggested labels from the available labels: {{availableLabels}}
                 4. A brief summary of the issue
-
-                Respond in JSON format:
-                {
-                    "priority": "...",
-                    "category": "...",
-                    "suggested_labels": ["..."],
-                    "summary": "..."
-                }
+                5. Whether this is a duplicate of an existing issue
                 """)
+            .RegisterPlugin<TriageIssuePlugin>()
             .Build();
 
         var prompt = $"""
@@ -61,10 +56,27 @@ public class IssueService : IIssueService
             Existing labels: {string.Join(", ", request.ExistingLabels)}
             """;
 
-        var response = await conversation.SendAsync(prompt, cancellationToken);
+        var response = await conversation.SendForStructuredOutputAsync<TriageIssueResult>(
+            prompt, "TriageIssue", cancellationToken);
 
-        // Parse JSON response
-        return ParseTriageResponse(response.FinalMessage ?? "");
+        var result = PluginHelpers.DeserializeOutput<TriageIssueResult>(response.StructuredOutput);
+
+        var protoResponse = new TriageIssueResponse
+        {
+            Priority = result.Priority ?? "medium",
+            Category = result.Category ?? "bug",
+            Summary = result.Summary ?? "",
+            IsDuplicate = result.IsDuplicate,
+            DuplicateOf = result.DuplicateOf
+        };
+
+        if (result.SuggestedLabels != null)
+            protoResponse.SuggestedLabels.AddRange(result.SuggestedLabels);
+
+        if (result.SuggestedAssignees != null)
+            protoResponse.SuggestedAssignees.AddRange(result.SuggestedAssignees);
+
+        return protoResponse;
     }
 
     public async Task<SuggestLabelsResponse> SuggestLabelsAsync(
@@ -78,14 +90,8 @@ public class IssueService : IIssueService
                 Available labels: {{string.Join(", ", request.AvailableLabels)}}
 
                 For each suggested label, provide a confidence score (0.0-1.0) and reason.
-
-                Respond in JSON format:
-                {
-                    "suggestions": [
-                        {"label": "...", "confidence": 0.9, "reason": "..."}
-                    ]
-                }
                 """)
+            .RegisterPlugin<SuggestLabelsPlugin>()
             .Build();
 
         var prompt = $"""
@@ -95,9 +101,27 @@ public class IssueService : IIssueService
             {request.Body}
             """;
 
-        var response = await conversation.SendAsync(prompt, cancellationToken);
+        var response = await conversation.SendForStructuredOutputAsync<SuggestLabelsResult>(
+            prompt, "SuggestLabels", cancellationToken);
 
-        return ParseSuggestLabelsResponse(response.FinalMessage ?? "", request.AvailableLabels);
+        var result = PluginHelpers.DeserializeOutput<SuggestLabelsResult>(response.StructuredOutput);
+
+        var protoResponse = new SuggestLabelsResponse();
+
+        if (result.Suggestions != null)
+        {
+            foreach (var s in result.Suggestions)
+            {
+                protoResponse.Suggestions.Add(new LabelSuggestion
+                {
+                    Label = s.Label ?? "",
+                    Confidence = s.Confidence,
+                    Reason = s.Reason ?? ""
+                });
+            }
+        }
+
+        return protoResponse;
     }
 
     public async Task<GenerateIssueResponseResponse> GenerateResponseAsync(
@@ -120,6 +144,7 @@ public class IssueService : IIssueService
 
                 If you need more information, include follow-up questions.
                 """)
+            .RegisterPlugin<GenerateIssueResponsePlugin>()
             .Build();
 
         var sb = new System.Text.StringBuilder();
@@ -140,56 +165,19 @@ public class IssueService : IIssueService
         sb.AppendLine();
         sb.AppendLine("Please generate an appropriate response.");
 
-        var response = await conversation.SendAsync(sb.ToString(), cancellationToken);
+        var response = await conversation.SendForStructuredOutputAsync<GenerateIssueResponseResult>(
+            sb.ToString(), "GenerateIssueResponse", cancellationToken);
 
-        return new GenerateIssueResponseResponse
-        {
-            Response = response.FinalMessage ?? ""
-        };
-    }
+        var result = PluginHelpers.DeserializeOutput<GenerateIssueResponseResult>(response.StructuredOutput);
 
-    private static TriageIssueResponse ParseTriageResponse(string response)
-    {
-        // TODO: Implement proper JSON parsing
-        var result = new TriageIssueResponse
+        var protoResponse = new GenerateIssueResponseResponse
         {
-            Priority = "medium",
-            Category = "bug",
-            Summary = response
+            Response = result.Response ?? ""
         };
 
-        // Simple extraction (improve with JSON parsing)
-        if (response.Contains("\"priority\":", StringComparison.OrdinalIgnoreCase))
-        {
-            if (response.Contains("critical", StringComparison.OrdinalIgnoreCase))
-                result.Priority = "critical";
-            else if (response.Contains("high", StringComparison.OrdinalIgnoreCase))
-                result.Priority = "high";
-            else if (response.Contains("low", StringComparison.OrdinalIgnoreCase))
-                result.Priority = "low";
-        }
+        if (result.FollowUpQuestions != null)
+            protoResponse.FollowUpQuestions.AddRange(result.FollowUpQuestions);
 
-        return result;
-    }
-
-    private static SuggestLabelsResponse ParseSuggestLabelsResponse(string response, IEnumerable<string> availableLabels)
-    {
-        var result = new SuggestLabelsResponse();
-
-        // Simple heuristic: check which available labels appear in response
-        foreach (var label in availableLabels)
-        {
-            if (response.Contains(label, StringComparison.OrdinalIgnoreCase))
-            {
-                result.Suggestions.Add(new LabelSuggestion
-                {
-                    Label = label,
-                    Confidence = 0.8f,
-                    Reason = "Label mentioned in AI analysis"
-                });
-            }
-        }
-
-        return result;
+        return protoResponse;
     }
 }

src/GitCaddy.AI.Service/Services/WorkflowService.cs

@@ -1,8 +1,10 @@
 // Copyright 2026 MarketAlly. All rights reserved.
 // SPDX-License-Identifier: BSL-1.1
 
+using System.Text.Json;
 using GitCaddy.AI.Proto;
 using GitCaddy.AI.Service.Configuration;
+using GitCaddy.AI.Service.Plugins;
 using Grpc.Core;
 using Microsoft.Extensions.Options;
 
@@ -118,37 +120,18 @@ public class WorkflowService : IWorkflowService
 
         try
         {
-            var conversation = _providerFactory.CreateConversation()
-                .WithSystemPrompt("""
-                    You are a helpful assistant executing tasks for a software development workflow.
-                    Complete the requested task and provide clear results.
-                    If you cannot complete the task, explain why.
-                    """)
-                .Build();
-
-            var context = string.Join("\n", request.Context.Select(c => $"{c.Key}: {c.Value}"));
-            var prompt = $"""
-                Task: {request.Task}
-
-                Context:
-                {context}
-
-                Allowed tools: {string.Join(", ", request.AllowedTools)}
-
-                Please complete this task.
-                """;
-
-            var aiResponse = await conversation.SendAsync(prompt, cancellationToken);
-
-            return new ExecuteTaskResponse
+            return request.Task switch
             {
-                Success = true,
-                Result = aiResponse.FinalMessage ?? ""
+                "landing_page_generate" => await ExecuteLandingPageGenerateAsync(request, cancellationToken),
+                "landing_page_translate" => await ExecuteLandingPageTranslateAsync(request, cancellationToken),
+                "ab_test_generate" => await ExecuteABTestGenerateAsync(request, cancellationToken),
+                "ab_test_analyze" => await ExecuteABTestAnalyzeAsync(request, cancellationToken),
+                _ => await ExecuteGenericTaskAsync(request, cancellationToken)
             };
         }
         catch (Exception ex)
         {
-            _logger.LogError(ex, "Task execution failed");
+            _logger.LogError(ex, "Task execution failed: {Task}", request.Task);
 
             return new ExecuteTaskResponse
             {
@@ -158,6 +141,250 @@ public class WorkflowService : IWorkflowService
         }
     }
 
+    /// <summary>
+    /// Generates landing page content using structured output via the LandingPageContentPlugin.
+    /// The AI is forced (via tool_choice) to call the plugin, ensuring clean structured data
+    /// instead of free-form text that requires parsing.
+    /// </summary>
+    private async Task<ExecuteTaskResponse> ExecuteLandingPageGenerateAsync(
+        ExecuteTaskRequest request, CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("Generating landing page content via structured output plugin");
+
+        var conversation = _providerFactory.CreateConversation()
+            .WithSystemPrompt("""
+                You are a landing page copywriter for open-source software projects.
+                Analyze the repository metadata and generate compelling, professional landing page content.
+                Use action-oriented, benefit-focused copy. Keep it professional but engaging.
+                """)
+            .RegisterPlugin<LandingPageContentPlugin>()
+            .Build();
+
+        var ctx = request.Context;
+        var prompt = $"""
+            Generate landing page content for this repository:
+
+            Name: {GetContextValue(ctx, "repo_name")}
+            Description: {GetContextValue(ctx, "repo_description")}
+            Topics: {GetContextValue(ctx, "topics")}
+            Primary Language: {GetContextValue(ctx, "primary_language")}
+            Stars: {GetContextValue(ctx, "stars", "0")}
+            Forks: {GetContextValue(ctx, "forks", "0")}
+
+            README:
+            {GetContextValue(ctx, "readme")}
+            """;
+
+        var response = await conversation.SendForStructuredOutputAsync<LandingPageContentResult>(
+            prompt, "GenerateLandingPageContent", cancellationToken);
+
+        var json = SerializeStructuredOutput(response.StructuredOutput);
+
+        return new ExecuteTaskResponse
+        {
+            Success = true,
+            Result = json
+        };
+    }
+
+    /// <summary>
+    /// Translates landing page content using structured output via the LandingPageTranslationPlugin.
+    /// The AI is forced (via tool_choice) to call the plugin, ensuring clean structured data.
+    /// </summary>
+    private async Task<ExecuteTaskResponse> ExecuteLandingPageTranslateAsync(
+        ExecuteTaskRequest request, CancellationToken cancellationToken)
+    {
+        var ctx = request.Context;
+        var targetLanguage = GetContextValue(ctx, "target_language");
+        var targetCode = GetContextValue(ctx, "target_code");
+
+        _logger.LogInformation("Translating landing page content to {Language} ({Code}) via structured output plugin",
+            targetLanguage, targetCode);
+
+        var conversation = _providerFactory.CreateConversation()
+            .WithSystemPrompt($"""
+                You are a professional translator specializing in marketing copy.
+                Translate landing page content to {targetLanguage} ({targetCode}) with natural,
+                culturally-adapted phrasing. Do NOT translate brand names, technical terms, or URLs.
+                Use marketing-quality translations, not literal/robotic ones.
+                """)
+            .RegisterPlugin<LandingPageTranslationPlugin>()
+            .Build();
+
+        var prompt = $"""
+            Translate the following landing page content to {targetLanguage} ({targetCode}).
+
+            Maintain the exact same number of items in arrays (stats, value_props, features).
+            Adapt idioms and expressions for the target culture.
+
+            Source content:
+            {GetContextValue(ctx, "source_content")}
+            """;
+
+        var response = await conversation.SendForStructuredOutputAsync<LandingPageTranslationResult>(
+            prompt, "TranslateLandingPageContent", cancellationToken);
+
+        var json = SerializeStructuredOutput(response.StructuredOutput);
+
+        return new ExecuteTaskResponse
+        {
+            Success = true,
+            Result = json
+        };
+    }
+
+    /// <summary>
+    /// Generates A/B test experiment variants using structured output via the ABTestGeneratePlugin.
+    /// </summary>
+    private async Task<ExecuteTaskResponse> ExecuteABTestGenerateAsync(
+        ExecuteTaskRequest request, CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("Generating A/B test experiment via structured output plugin");
+
+        var conversation = _providerFactory.CreateConversation()
+            .WithSystemPrompt("""
+                You are a conversion rate optimization expert. Analyze landing page configurations
+                and create meaningful A/B test experiments that focus on high-impact changes.
+                Generate variants that test different headlines, CTAs, value propositions, or layouts.
+                Each variant should be meaningfully different but plausible.
+                The control variant (original config) is added automatically — do NOT include it.
+                """)
+            .RegisterPlugin<ABTestGeneratePlugin>()
+            .Build();
+
+        var ctx = request.Context;
+        var prompt = $"""
+            Analyze this landing page config and create an A/B test experiment.
+            Focus on high-impact changes: headlines, CTAs, value propositions.
+            Generate 1-3 test variants. Each variant's config_override should be a partial
+            LandingConfig with only the fields that differ from the control.
+
+            Repository: {GetContextValue(ctx, "repo_name")}
+            Description: {GetContextValue(ctx, "repo_description")}
+
+            Current landing page config:
+            {GetContextValue(ctx, "landing_config")}
+            """;
+
+        var response = await conversation.SendForStructuredOutputAsync<ABTestGenerateResult>(
+            prompt, "GenerateABTestExperiment", cancellationToken);
+
+        var json = SerializeStructuredOutput(response.StructuredOutput);
+
+        return new ExecuteTaskResponse
+        {
+            Success = true,
+            Result = json
+        };
+    }
+
+    /// <summary>
+    /// Analyzes A/B test experiment results using structured output via the ABTestAnalyzePlugin.
+    /// </summary>
+    private async Task<ExecuteTaskResponse> ExecuteABTestAnalyzeAsync(
+        ExecuteTaskRequest request, CancellationToken cancellationToken)
+    {
+        _logger.LogInformation("Analyzing A/B test results via structured output plugin");
+
+        var conversation = _providerFactory.CreateConversation()
+            .WithSystemPrompt("""
+                You are a data analyst specializing in A/B test evaluation.
+                Analyze experiment results using statistical methods to determine significance.
+                Require at least 100 impressions per variant before declaring a winner.
+                Use a minimum 95% confidence threshold for statistical significance.
+                Be conservative — only declare a winner when the data clearly supports it.
+                """)
+            .RegisterPlugin<ABTestAnalyzePlugin>()
+            .Build();
+
+        var ctx = request.Context;
+        var prompt = $"""
+            Analyze these A/B test results. Look at conversion rates, impression counts,
+            and event distributions across variants. Determine if there is a statistically
+            significant winner.
+
+            Experiment:
+            {GetContextValue(ctx, "experiment")}
+
+            Variants with metrics:
+            {GetContextValue(ctx, "variants")}
+            """;
+
+        var response = await conversation.SendForStructuredOutputAsync<ABTestAnalyzeResult>(
+            prompt, "AnalyzeABTestResults", cancellationToken);
+
+        var json = SerializeStructuredOutput(response.StructuredOutput);
+
+        return new ExecuteTaskResponse
+        {
+            Success = true,
+            Result = json
+        };
+    }
+
+    /// <summary>
+    /// Fallback for tasks that don't have a dedicated plugin.
+    /// Uses generic SendAsync with free-form text response.
+    /// </summary>
+    private async Task<ExecuteTaskResponse> ExecuteGenericTaskAsync(
+        ExecuteTaskRequest request, CancellationToken cancellationToken)
+    {
+        var conversation = _providerFactory.CreateConversation()
+            .WithSystemPrompt("""
+                You are a helpful assistant executing tasks for a software development workflow.
+                Complete the requested task and provide clear results.
+                If you cannot complete the task, explain why.
+                """)
+            .Build();
+
+        var context = string.Join("\n", request.Context.Select(c => $"{c.Key}: {c.Value}"));
+        var prompt = $"""
+            Task: {request.Task}
+
+            Context:
+            {context}
+
+            Allowed tools: {string.Join(", ", request.AllowedTools)}
+
+            Please complete this task.
+            """;
+
+        var aiResponse = await conversation.SendAsync(prompt, cancellationToken);
+
+        return new ExecuteTaskResponse
+        {
+            Success = true,
+            Result = aiResponse.FinalMessage ?? ""
+        };
+    }
+
+    /// <summary>
+    /// Safely serializes StructuredOutput to JSON regardless of its runtime type.
+    /// </summary>
+    private static string SerializeStructuredOutput(object structuredOutput)
+    {
+        if (structuredOutput == null)
+            return "{}";
+
+        if (structuredOutput is string str)
+            return str;
+
+        if (structuredOutput is JsonElement jsonElement)
+            return jsonElement.GetRawText();
+
+        return JsonSerializer.Serialize(structuredOutput, structuredOutput.GetType());
+    }
+
+    /// <summary>
+    /// Gets a value from the request context map with a default fallback.
+    /// </summary>
+    private static string GetContextValue(
+        Google.Protobuf.Collections.MapField<string, string> context,
+        string key, string defaultValue = "")
+    {
+        return context.TryGetValue(key, out var value) ? value : defaultValue;
+    }
+
     private static string GetWorkflowSystemPrompt(string workflowType)
     {
         return workflowType switch