feat: LLM + vector banking chatbot sample (Dozer + LangChain) for dozer#1690

README.md

@@ -47,6 +47,7 @@ Refer to the [Installation section](https://getdozer.io/docs/installation) for i
 |                  | [IMDB Analytics](./usecases/imdb-analytics)                              | Use Dozer to get interesting analytics using an IMDb dataset                 |
 |                  | Use Dozer to Instrument (Coming soon)                                    | Combine Log data to get real time insights                                   |
 |                  | Real Time Model Scoring (Coming soon)                                    | Deploy trained models to get real time insights as APIs                      |
+|                  | [LLM Vector Banking Chatbot](./usecases/llm-vector-banking-chatbot)      | Dozer + LangChain + vector retrieval for card personalization (#1690)     |
 |                  |                                                                          |                                                                              |
 | Client Libraries | [Dozer React Starter](./usecases/react/)                                 | Instantly start building real time views using Dozer and React               |
 |                  | [Ingest Polars/Pandas Dataframes](./client-samples/ingest-python-sample) | Instantly ingest Polars/Pandas dataframes using Arrow format and deploy APIs |

usecases/llm-vector-banking-chatbot/.gitignore

@@ -0,0 +1,9 @@
+.dozer/
+__pycache__/
+*.pyc
+.venv/
+venv/
+.env
+.chroma/
+*.egg-info/
+.pytest_cache/

usecases/llm-vector-banking-chatbot/README.md

@@ -0,0 +1,105 @@
+# Dozer + LLM + Vector DB + LangChain (Banking Chatbot)
+
+Sample for [getdozer/dozer#1690](https://github.com/getdozer/dozer/issues/1690) ($250 Algora).
+
+Inspired by the Dozer hyper-personalization banking chatbot write-up: unify customer
+profiles, accounts, and transactions in Dozer, then pass that context into a LangChain
+retrieval flow over credit-card products (vector store + optional LLM).
+
+## What this sample includes
+
+| Piece | Path | Role |
+| --- | --- | --- |
+| Dozer config | `dozer-config.yaml` | LocalStorage CSV sources + spend-profile SQL + REST endpoints |
+| Seed data | `data/*/*.csv` | customers, accounts, transactions, card products |
+| RAG stub | `app/rag_chatbot.py` | fixture mode (offline) + `--use-dozer` + optional `--llm` |
+| Unit tests | `tests/test_rag_chatbot.py` | fixture load, segment gate, keyword/rerank |
+| Deps | `app/requirements.txt` | LangChain / Chroma / OpenAI (optional) |
+| Demo log | `demo-log.txt` | text capture of live Dozer REST + chatbot (no video yet) |
+
+## Prerequisites
+
+- **Dozer 0.3.x** on `PATH` for the live path (API-era binary with `endpoints`).
+  Dozer **≥0.4.0** removed built-in `endpoints` / `dozer-api` — that binary will reject
+  this config. See [`SAMPLE_NOTES.md`](./SAMPLE_NOTES.md).
+- Python 3.10+
+- `protoc` (`protobuf-compiler`) for `dozer build` on 0.3.x
+- Optional: `OPENAI_API_KEY` for the ChatOpenAI answer path
+
+## Quick start (offline fixture — no Dozer binary)
+
+```bash
+cd usecases/llm-vector-banking-chatbot
+python3 app/rag_chatbot.py \
+  --customer C001 \
+  --question "Which card is best for travel and dining rewards?"
+```
+
+Expected shape: a recommendation for **Dozer Travel Signature** grounded in C001's
+travel/dining spend.
+
+Student example:
+
+```bash
+python3 app/rag_chatbot.py \
+  --customer C003 \
+  --question "I need a no-fee student card for education"
+```
+
+## Live Dozer path (verified on 0.3.0)
+
+```bash
+cd usecases/llm-vector-banking-chatbot
+rm -rf .dozer
+dozer --ignore-pipe build -c dozer-config.yaml
+dozer --ignore-pipe run -c dozer-config.yaml
+# elsewhere:
+python3 -m venv .venv && .venv/bin/pip install -r app/requirements.txt
+.venv/bin/python app/rag_chatbot.py --use-dozer --customer C001 \
+  --question "Which card is best for travel and dining rewards?"
+```
+
+Dozer REST listens at `http://localhost:8080` (override with `--dozer-base` or
+`DOZER_API_BASE`). Responses are bare JSON lists; the client filters by `customer_id`.
+
+Optional LLM polish:
+
+```bash
+export OPENAI_API_KEY=sk-...
+.venv/bin/python app/rag_chatbot.py --use-dozer --llm --customer C001 \
+  --question "Which card is best for travel and dining rewards?"
+```
+
+## Tests
+
+```bash
+cd usecases/llm-vector-banking-chatbot
+python3 -m venv .venv && .venv/bin/pip install pytest httpx
+.venv/bin/pytest -q tests/test_rag_chatbot.py
+```
+
+## APIs exposed (once Dozer 0.3.x is up)
+
+- `GET /customer_profiles`
+- `GET /accounts`
+- `GET /transactions`
+- `GET /card_products`
+- `GET /customer_spending_profile` — SQL aggregate used as chatbot context
+
+## Architecture (sample)
+
+```
+CSV seeds ──► Dozer LocalStorage ──► SQL spend profile ──► REST/gRPC APIs
+                                                                  │
+                     LangChain retriever (Chroma / FakeEmbeddings) │
+                     + customer-aware rerank ◄─────────────────────┘
+                                                                  │
+                     deterministic answer  or  ChatOpenAI (--llm)
+```
+
+## Status / honesty
+
+See [`SAMPLE_NOTES.md`](./SAMPLE_NOTES.md). Live `dozer run` (0.3.0) + `--use-dozer`
+chatbot verified; text demo log attached. **No payout claimed.** Demo *video* and
+maintainer confirmation of bounty eligibility remain open. Crowded claim field
+(`dozer-samples` #139–#145, etc.).

usecases/llm-vector-banking-chatbot/SAMPLE_NOTES.md

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+# SAMPLE_NOTES — getdozer/dozer#1690
+
+**Branch:** `bounty/1690-llm-vector-banking-scaffold`  
+**PR:** https://github.com/getdozer/dozer-samples/pull/144  
+**Issue:** https://github.com/getdozer/dozer/issues/1690  
+**Bounty:** $250 Algora — Dozer + LLM + Vector DB + LangChain sample  
+
+## Do NOT invent payout success
+
+No maintainer acceptance, no Algora payout confirmation. Multiple competing open PRs
+(`dozer-samples` #139–#145 and others). Algora may already show claims/completed —
+treat reward eligibility as **uncertain**.
+
+## What works now (verified locally)
+
+| Check | Result |
+| --- | --- |
+| Offline fixture chatbot | OK (C001→Travel Signature, C003→Campus Starter) |
+| `dozer build/run` **0.3.0** against `dozer-config.yaml` | OK (`--ignore-pipe`; needs `protoc` + OpenSSL 1.1) |
+| REST `GET /customer_profiles`, `/customer_spending_profile`, `/card_products` | 200, bare JSON lists |
+| `rag_chatbot.py --use-dozer` | OK after client-side customer filter fix |
+| Unit tests `tests/test_rag_chatbot.py` | 7 passed |
+| Text demo log | `demo-log.txt` |
+| Demo **video** | **Still missing** |
+
+### Commands that succeeded
+
+```text
+dozer --ignore-pipe build -c dozer-config.yaml   # dozer 0.3.0
+dozer --ignore-pipe run -c dozer-config.yaml
+python3 app/rag_chatbot.py --use-dozer --customer C001 --question "Which card is best for travel and dining rewards?"
+python3 app/rag_chatbot.py --use-dozer --customer C003 --question "I need a no-fee student card for education"
+pytest -q tests/test_rag_chatbot.py               # 7 passed
+```
+
+## Config / client fixes in this follow-up
+
+1. Explicit `api.rest` / `api.grpc` host+port (8080 / 50051).
+2. Composite PK on `customer_spending_profile`: `customer_id` + `top_category`
+   (matches `GROUP BY customer_id, category`).
+3. `--use-dozer` no longer trusts `?customer_id=` (0.3 ignores it and would always
+   pick the first profile); always filter client-side on bare lists.
+4. Document that **Dozer ≥0.4.0 rejects `endpoints`** (`unknown field endpoints`;
+   sinks-only era). This sample targets the API-era 0.3.x binary that matches the
+   historical LocalStorage samples in this repo.
+
+## Remaining gaps
+
+1. **No demo video** (Algora often wants ≤30s screen capture).
+2. **Architecture drift:** issue comments note current main may prefer
+   Dozer→sink→app API. This PR intentionally stays on 0.3-style REST endpoints to
+   match existing `dozer-samples` patterns; maintainers may ask for a sink rewrite.
+3. **Blog URL** `https://getdozer.io/blog/llm-chatbot` still 404 when last checked.
+4. **Crowded claims** — many open PRs; confirm with maintainers before banking on $250.
+5. Optional Chroma/LangChain path needs `pip install -r app/requirements.txt`; tests
+   and live demo use keyword retrieve + fixture/Dozer context without Chroma.
+
+## Confidence
+
+**~0.70** that this is a credible, runnable sample PR after live verify + tests.  
+**~0.20** that it wins $250 given competition + possible architecture preference for
+sinks — **do not bank on payout**.

usecases/llm-vector-banking-chatbot/app/__init__.py

@@ -0,0 +1 @@
+"""LangChain RAG stub for the Dozer banking chatbot sample."""