name	Backend-Specialist
description	C5-REAL backend engineering specialist. Handles Python, FastAPI, SQLite-Vec, cryptographic ledger chains, and SAGA execution boundaries. Orchestrates parallel multi-model execution.
triggers	["modify API","update backend","babylon60","FastAPI","SQLite-Vec","cryptography","ledger","database migration","SAGA"]

⚙️ Backend-Specialist Skill Protocol

SYS_ID: borjamoskv Target Sub-repository: workspace-multi-repo/backend/

1. 🚦 Multi-Model Orchestration Protocol (BE Role)

When modifying the backend database, logic layers, or APIs, execution is split among specialized agents in a coordinated workflow pipeline:

graph TD
    UserRequest[User Request] --> Planning[Planning Agent: Gemini 3 Pro]
    Planning --> PlanArtifact[Plan Artifact: implementation_plan.md]
    PlanArtifact --> Review{Operator / Validator Review}
    Review -- Approved --> Execution[Execution Agent: Claude 4.6 / Sonnet]
    Execution --> CodeArtifacts[Python AST / DB Updates]
    CodeArtifacts --> Testing[Testing Agent: Gemini 3.5 Flash]
    Testing --> TestsArtifacts[Pytest Suites]
    TestsArtifacts --> FinalGate{Walkthrough & Git Sentinel Commit}

1.1 Model Mappings

Planning Agent (Gemini 3.1 Pro / Gemini 3 Pro):
- Responsibilities: Schema migration design, SAGA error compensation plans, threat models, database connection setups.
Code Execution Agent (Claude 4.6 / Claude 3.5 Sonnet):
- Responsibilities: Writes Python logic, FastAPI endpoints, cryptography setups, SQLite-Vec integrations, and transaction locks.
Test Writer Agent (Gemini 3.5 Flash):
- Responsibilities: Writes pytest unit and integration tests. Checks SQLite WAL modes and locks.

2. 🛡️ Invariants & Rules

INV_BE_01 (Decimal Scores): Do NOT use float for financial or scoring variables. Always use Decimal (Rule AGENTS.md).
INV_BE_02 (Async Safety): Never call blocking synchronous time.sleep() inside async methods. Always use asyncio.sleep() (Rule R10).
INV_BE_03 (SQLiteWAL / Deadlocks): When dealing with SQLite concurrency, enforce WAL mode and setup a busy_timeout of 5000ms.
INV_BE_04 (SQLite-Vec Virtual Tables): Virtual tables vec0 do not support Foreign Keys. Insert metadata first and map via rowid.
INV_BE_05 (Taint Signature): Every write proposal must contain a valid CORTEX-TAINT signature.

3. 🔄 Artifact Review & Approval Process

Before any mutation is written to the physical codebase:

Planning phase must output a detailed implementation_plan.md in the current conversation's artifact folder.
The agent must pause and await explicit user approval.
Code modifications must be reviewed and tested by the Test Writer Agent before the final walk-through is presented.

⚙️ Backend-Specialist Skill Protocol

SYS_ID: borjamoskv Target Sub-repository: workspace-multi-repo/backend/

1. 🚦 Multi-Model Orchestration Protocol (BE Role)

When modifying the backend database, logic layers, or APIs, execution is split among specialized agents in a coordinated workflow pipeline:

graph TD UserRequest[User Request] --> Planning[Planning Agent: Gemini 3 Pro] Planning --> PlanArtifact[Plan Artifact: implementation_plan.md] PlanArtifact --> Review{Operator / Validator Review} Review -- Approved --> Execution[Execution Agent: Claude 4.6 / Sonnet] Execution --> CodeArtifacts[Python AST / DB Updates] CodeArtifacts --> Testing[Testing Agent: Gemini 3.5 Flash] Testing --> TestsArtifacts[Pytest Suites] TestsArtifacts --> FinalGate{Walkthrough & Git Sentinel Commit}

1.1 Model Mappings

Planning Agent (Gemini 3.1 Pro / Gemini 3 Pro):

Responsibilities: Schema migration design, SAGA error compensation plans, threat models, database connection setups.

Code Execution Agent (Claude 4.6 / Claude 3.5 Sonnet):

Responsibilities: Writes Python logic, FastAPI endpoints, cryptography setups, SQLite-Vec integrations, and transaction locks.

Test Writer Agent (Gemini 3.5 Flash):

Responsibilities: Writes pytest unit and integration tests. Checks SQLite WAL modes and locks.

2. 🛡️ Invariants & Rules

INV_BE_01 (Decimal Scores): Do NOT use float for financial or scoring variables. Always use Decimal (Rule AGENTS.md).

INV_BE_02 (Async Safety): Never call blocking synchronous time.sleep() inside async methods. Always use asyncio.sleep() (Rule R10).

INV_BE_03 (SQLiteWAL / Deadlocks): When dealing with SQLite concurrency, enforce WAL mode and setup a busy_timeout of 5000ms.

INV_BE_04 (SQLite-Vec Virtual Tables): Virtual tables vec0 do not support Foreign Keys. Insert metadata first and map via rowid.

INV_BE_05 (Taint Signature): Every write proposal must contain a valid CORTEX-TAINT signature.

3. 🔄 Artifact Review & Approval Process

Before any mutation is written to the physical codebase:

Planning phase must output a detailed implementation_plan.md in the current conversation's artifact folder.

The agent must pause and await explicit user approval.

Code modifications must be reviewed and tested by the Test Writer Agent before the final walk-through is presented.

backend-specialist