agent-aech-ir-architecture-conversation.md•10.7 kB
# Agent Aech: Modular IR Architecture and Reasoning Primer
This document is a comprehensive, detailed record of a technical conversation about designing a modular, future-proof Information Retrieval (IR) backend for Agent Aech—a domain-integrated agent operating via MCP (Model Context Protocol) with access to M365 (Teams, OneDrive, Email, etc.) and extensible to any business workflow. The goal is to provide a reasoning LLM with a rich, structured context for proposing novel architectures and solutions.
---
## 1. Problem Statement & Vision
- **Agent Aech** is an autonomous agent with its own mailbox, OneDrive, Teams, and more, operating as a first-class user in an M365 domain.
- The goal is to enable Agent Aech to automate any business workflow via MCP-enabled apps, with IR as a core capability.
- Data sources are varied (PDF, Word, Excel, email, chat, etc.), and the IR backend must be:
- **Flexible** (easy to add new sources, chunking strategies, search modes)
- **Powerful** (hybrid search, LLM reranking, RAG, etc.)
- **Low-maintenance** (easy to operate, update, and extend)
- **Composable** (MCP tools/resources for LLMs and agentic clients)
---
## 2. Modular MCP Server for FlockMTL & DuckDB: Architecture & Benefits
### 2.1. Motivation
- **Reusability**: Plug-and-play IR backend for any MCP-enabled app
- **Separation of Concerns**: Core IR logic decoupled from domain adapters (Teams, Email, etc.)
- **Scalability**: Dedicated resources, centralized optimization, resource pooling
- **LLM Integration**: Direct tool access, unified data interface, RAG pipeline standardization
### 2.2. Layered Architecture
```
┌─────────────────────────────────────────────────────────────────┐
│ FlockMTL-DuckDB MCP Server │
├─────────────────┬──────────────────────┬────────────────────────┤
│ Core Layer │ Extension Layer │ Adapter Layer │
├─────────────────┼──────────────────────┼────────────────────────┤
│ • DuckDB Engine │ • Schema Management │ • Application Adapters │
│ • FlockMTL │ • Search Extensions │ - Teams Adapter │
│ Extensions │ • Index Management │ - Email Adapter │
│ • Embedding │ • LLM Connectors │ - Document Adapter │
│ Generation │ • Resource Management│ • Schema Transformers │
└─────────────────┴──────────────────────┴────────────────────────┘
▲ ▲ ▲
│ │ │
▼ ▼ ▼
┌────────────────┐ ┌────────────────┐ ┌────────────────────────┐
│ LLM Agents │ │ Teams MCP App │ │ Other MCP Applications │
│ (Direct Access)│ │ │ │ │
└────────────────┘ └────────────────┘ └────────────────────────┘
```
- **Core Layer**: DuckDB, FlockMTL, vector/embedding, storage
- **Extension Layer**: Search, LLM connectors, resource management
- **Adapter Layer**: Teams, Email, Document adapters; schema transformers
### 2.3. MCP Interface
- **Resources**: tables, models, prompts, indexes
- **Tools**: execute_sql, create_table, search, hybrid_search, semantic_search, keyword_search, llm_rerank, llm_summarize, llm_generate
### 2.4. Handling Domain-Specific Logic
- **Adapter Pattern**: Map domain objects to generic schema
- **Schema Abstraction**: Use abstract tables with metadata for platform-specific fields
- **Plugin Architecture**: Register adapters/plugins for each domain
### 2.5. Code Management
- **Dedicated repo** with clear layering (core, extensions, adapters, mcp, tests, docs)
- **Integration**: Python package, Docker, Git submodule
- **Versioning**: Semantic versioning, Git tags
- **Adapter management**: Monorepo or separate repos
- **Dependency management**: Core vs. optional deps
- **Extending**: Documented process for new adapters
---
## 3. DuckDB vs. PostgreSQL for IR
### 3.1. DuckDB
- **Embedded, serverless, zero-config**
- **Columnar, analytics-optimized** (OLAP, vectorized execution)
- **Modern SQL, easy extension loading**
- **Tight Python/data science integration**
- **Single-file, portable, low-maintenance**
### 3.2. PostgreSQL
- **Enterprise-grade, multi-user, networked**
- **ACID, robust, scalable, secure**
- **Rich extension ecosystem** (pgvector, pg_trgm, PostGIS)
- **Advanced features** (materialized views, partitioning, triggers)
- **Best for production, multi-user, transactional workloads**
### 3.3. Summary Table
| Feature | DuckDB | PostgreSQL |
|-----------------|-----------------------|----------------------|
| Deployment | Embedded, serverless | Networked, multiuser |
| Analytics | Excellent | Good |
| OLTP | Not ideal | Excellent |
| Extensions | Growing | Mature |
| Maintenance | Low | Higher |
| Python/DS | Excellent | Good |
---
## 4. Chunking Strategies for Document IR
### 4.1. Why Chunk?
- LLMs and vector search have context limits; long docs must be split
- Goal: maximize IR quality by chunking at optimal boundaries
### 4.2. Strategies
- **Fixed-size** (tokens/words/characters, with/without overlap)
- **Semantic/paragraph-based** (split at natural boundaries)
- **Hybrid** (merge small paragraphs, split large ones)
- **Sliding window** (overlapping chunks)
- **Content-aware** (special handling for code, tables, etc.)
### 4.3. Workflow
1. Extract text (PDF, Word, etc.)
2. Chunk using best-fit strategy
3. Store each chunk as a row in DuckDB/Postgres (with metadata)
4. Embed and index (BM25, vector, hybrid)
5. Retrieve and rerank at query time
### 4.4. Optimization
- Tune chunk size/overlap for best recall/precision
- Store rich metadata for filtering/context expansion
- Experiment and compare strategies in SQL
---
## 5. Automation & State of the Art
- **Most chunking/embedding/indexing is still semi-manual** (Python scripts, pipelines)
- **TimescaleDB**: [Auto chunk size recommendations](https://medium.com/timescale/boost-your-postgresql-performance-with-auto-chunk-size-recommendations-f407406174e0) (infra-level, not semantic)
- **Frameworks**: LlamaIndex, LangChain, Haystack automate pipelines, often using Postgres as backend
- **No end-to-end semantic chunking automation in Postgres yet**
- **Emerging trend**: Managed platforms and cloud DBs are starting to automate more of the IR pipeline
---
## 6. Ideal IR Backend for Agent Aech
- **Modular, pluggable IR backend** (Postgres or DuckDB + FlockMTL)
- **Automated ingestion/chunking layer** (detects type, applies best strategy, embeds, stores, indexes)
- **MCP-enabled API layer** (all IR/search as MCP tools/resources)
- **Continuous improvement** (monitor, re-chunk, re-embed as models/strategies improve)
- **Abstract IR layer** (don't tie business logic to a specific DB or chunker)
- **Composable pipelines** (modular, swappable components)
- **Open standards** (for embeddings, metadata, chunk storage)
- **Monitor ecosystem** (swap in new models/chunkers as they emerge)
---
## 7. Review & Feedback
### 7.1. Strengths
- Clear motivation, benefits, and architecture
- Practical repo/code management plan
- Concrete handling of domain-specific logic
- Realistic chunking/IR workflow and best practices
- Cites relevant external work
### 7.2. Minor Gaps / Suggestions
- Note DuckDB's concurrency/networking limitations
- Add security/auth model (MCP auth, role separation)
- Mention observability (logging, tracing, metrics)
- Outline test strategy (unit/integration/contract)
- Suggest CI/CD pipeline (GitHub Actions, etc.)
- Data migration/versioning (Alembic, SQL scripts)
- LLM-provider abstraction (pluggable registry)
### 7.3. Optional Additions
- Roadmap/phased implementation
- Cost considerations (embedded vs. managed)
- Reference benchmarks
- Example MCP schema (YAML/JSON)
---
## 8. References & Further Reading
- [Building RAG with Postgres (anyblockers.com)](https://anyblockers.com/posts/building-rag-with-postgres)
- [Which RAG Chunking and Formatting Strategy Is Best for Your App With Pgvector (Timescale)](https://www.timescale.com/blog/which-rag-chunking-and-formatting-strategy-is-best/)
- [Boost Your PostgreSQL Performance With Auto Chunk Size Recommendations (Timescale)](https://medium.com/timescale/boost-your-postgresql-performance-with-auto-chunk-size-recommendations-f407406174e0)
---
## 9. Open Questions for Reasoning LLM
- How can chunking and embedding be made fully adaptive and content-aware, with minimal human tuning?
- What is the best way to automate the ingestion and IR pipeline for new data sources (e.g., OneDrive, SharePoint, email) in a modular MCP architecture?
- How can the IR backend be made "self-improving" (e.g., feedback loops, auto-rechunking, auto-reembedding)?
- What is the optimal way to expose IR/search capabilities to LLMs and agentic clients via MCP?
- How can we future-proof the architecture to quickly adopt new LLMs, chunkers, and search paradigms as they emerge?
- What are the best practices for observability, security, and cost management in such a modular, multi-adapter IR backend?
---
## 10. Call to Action
**Reasoning LLM:**
- Use this document as a starting point to propose novel architectures, automation strategies, and IR innovations for Agent Aech and MCP-enabled business automation.
- Suggest new approaches for chunking, indexing, retrieval, and LLM integration that maximize flexibility, performance, and maintainability.
- Identify gaps, risks, and opportunities for improvement in the current design.
---
*End of conversation summary. Ready for reasoning and innovation.*