llm-multiverse/implementation-plans/issue-020.md

Implementation Plan — Issue #20: Implement Append gRPC endpoint

Metadata

Field	Value
Issue	#20
Title	Implement Append gRPC endpoint
Milestone	Phase 2: Audit Service
Labels	type:feature, priority:critical, lang:rust, service:audit
Status	COMPLETED
Language	Rust
Related Plans	issue-019.md
Blocked by	#19 (completed)

Acceptance Criteria

• Append RPC validates required fields (session_id, agent_id, action)
• Append RPC validates session context when provided
• Append RPC returns success/error_message response
• Input validation unit tests for all error paths
• Session context validation (empty context.session_id rejected)

Architecture Analysis

Extended the existing AuditServiceImpl::append() handler (implemented in #19) with proper input validation:

• Validates session_id is non-empty
• Validates agent_id is non-empty
• Validates action is not UNSPECIFIED (0)
• Validates context.session_id is non-empty when context is provided
• Returns InvalidArgument status with descriptive messages on failure

Files to Create/Modify

File	Action	Purpose
services/audit/src/service.rs	Modify	Add input validation to Append handler
services/audit/src/lib.rs	Create	Re-export modules for integration test access
services/audit/src/main.rs	Modify	Use library crate instead of inline mod declarations

Deviation Log

Deviation	Reason
Created lib.rs to expose modules	Required for integration tests (#21) to access service types