feat: add CHAINLOOP_AI_CODING_SESSION material type

app/controlplane/api/workflowcontract/v1/crafting_schema.proto

@@ -151,6 +151,8 @@ message CraftingSchema {
       GITLEAKS_JSON = 27;
       // AI agent configuration collected automatically during attestation
       CHAINLOOP_AI_AGENT_CONFIG = 28;
+      // AI coding session telemetry collected during attestation
+      CHAINLOOP_AI_CODING_SESSION = 29;
     }
   }
 }

app/controlplane/api/workflowcontract/v1/crafting_schema_validations.go

@@ -50,6 +50,7 @@ var CraftingMaterialInValidationOrder = []CraftingSchema_Material_MaterialType{
 	CraftingSchema_Material_SLSA_PROVENANCE,
 	CraftingSchema_Material_CHAINLOOP_RUNNER_CONTEXT,
 	CraftingSchema_Material_CHAINLOOP_AI_AGENT_CONFIG,
+	CraftingSchema_Material_CHAINLOOP_AI_CODING_SESSION,
 	CraftingSchema_Material_ATTESTATION,
 	CraftingSchema_Material_CONTAINER_IMAGE,
 	CraftingSchema_Material_ARTIFACT,

internal/aicodingsession/aicodingsession.go

@@ -0,0 +1,135 @@
+//
+// Copyright 2026 The Chainloop Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package aicodingsession
+
+import "encoding/json"
+
+const (
+	// EvidenceID is the identifier for the AI coding session material type
+	EvidenceID = "CHAINLOOP_AI_CODING_SESSION"
+	// EvidenceSchemaURL is the URL to the JSON schema for AI coding session
+	EvidenceSchemaURL = "https://schemas.chainloop.dev/aicodingsession/0.1/ai-coding-session.schema.json"
+)
+
+// Agent identifies the AI agent provider.
+type Agent struct {
+	Name    string `json:"name"`
+	Version string `json:"version,omitempty"`
+}
+
+// Session holds timing and identity information for the coding session.
+type Session struct {
+	ID              string `json:"id"`
+	Slug            string `json:"slug,omitempty"`
+	StartedAt       string `json:"started_at"`
+	EndedAt         string `json:"ended_at,omitempty"`
+	DurationSeconds int    `json:"duration_seconds"`
+}
+
+// GitContext holds repository and commit information at capture time.
+type GitContext struct {
+	Repository  string   `json:"repository,omitempty"`
+	Branch      string   `json:"branch,omitempty"`
+	WorkDir     string   `json:"work_dir,omitempty"`
+	CommitStart string   `json:"commit_start,omitempty"`
+	CommitEnd   string   `json:"commit_end,omitempty"`
+	Commits     []string `json:"commits,omitempty"`
+	CommitCount int      `json:"commit_count,omitempty"`
+}
+
+// FileChange represents a single file modification in the session.
+type FileChange struct {
+	Path   string `json:"path"`
+	Status string `json:"status"`
+}
+
+// CodeChanges summarizes code modifications made during the session.
+type CodeChanges struct {
+	FilesModified int          `json:"files_modified,omitempty"`
+	FilesCreated  int          `json:"files_created,omitempty"`
+	FilesDeleted  int          `json:"files_deleted,omitempty"`
+	LinesAdded    int          `json:"lines_added,omitempty"`
+	LinesRemoved  int          `json:"lines_removed,omitempty"`
+	Files         []FileChange `json:"files,omitempty"`
+}
+
+// Model holds information about the AI models used in the session.
+type Model struct {
+	Primary    string   `json:"primary,omitempty"`
+	Provider   string   `json:"provider,omitempty"`
+	ModelsUsed []string `json:"models_used,omitempty"`
+}
+
+// Usage holds token usage and cost information.
+type Usage struct {
+	InputTokens              int     `json:"input_tokens,omitempty"`
+	OutputTokens             int     `json:"output_tokens,omitempty"`
+	TotalTokens              int     `json:"total_tokens,omitempty"`
+	CacheReadInputTokens     int     `json:"cache_read_input_tokens,omitempty"`
+	CacheCreationInputTokens int     `json:"cache_creation_input_tokens,omitempty"`
+	EstimatedCostUSD         float64 `json:"estimated_cost_usd,omitempty"`
+}
+
+// ToolSummary represents usage statistics for a single tool.
+type ToolSummary struct {
+	ToolName        string `json:"tool_name"`
+	InvocationCount int    `json:"invocation_count"`
+}
+
+// ToolsUsed summarizes tool usage during the session.
+type ToolsUsed struct {
+	Summary          []ToolSummary `json:"summary,omitempty"`
+	TotalInvocations int           `json:"total_invocations,omitempty"`
+}
+
+// Conversation holds message count statistics.
+type Conversation struct {
+	TotalMessages     int `json:"total_messages,omitempty"`
+	UserMessages      int `json:"user_messages,omitempty"`
+	AssistantMessages int `json:"assistant_messages,omitempty"`
+}
+
+// Data is the AI coding session payload.
+type Data struct {
+	SchemaVersion string                       `json:"schema_version"`
+	Agent         Agent                        `json:"agent"`
+	Session       Session                      `json:"session"`
+	GitContext    *GitContext                  `json:"git_context,omitempty"`
+	CodeChanges   *CodeChanges                 `json:"code_changes,omitempty"`
+	Model         *Model                       `json:"model,omitempty"`
+	Usage         *Usage                       `json:"usage,omitempty"`
+	ToolsUsed     *ToolsUsed                   `json:"tools_used,omitempty"`
+	Conversation  *Conversation                `json:"conversation,omitempty"`
+	Subagents     []json.RawMessage            `json:"subagents,omitempty"`
+	RawSession    map[string][]json.RawMessage `json:"raw_session,omitempty"`
+	Warnings      []string                     `json:"warnings,omitempty"`
+}
+
+// Evidence represents the complete evidence structure for AI coding session.
+type Evidence struct {
+	ID     string `json:"chainloop.material.evidence.id"`
+	Schema string `json:"schema"`
+	Data   Data   `json:"data"`
+}
+
+// NewEvidence creates a new Evidence instance.
+func NewEvidence(data Data) *Evidence {
+	return &Evidence{
+		ID:     EvidenceID,
+		Schema: EvidenceSchemaURL,
+		Data:   data,
+	}
+}