Kaustubh Tripathi

One case file for cybercrime victims in India: ten deadline-tracked steps, 22 languages, voice or text. Built with Ashutosh Kumar at the Build What Moves India hackathon.

voice · text ──► transcribe
                     │
      regex ─────────┼───────── llm
  UTRs, UPI IDs      ▼     everything else
                   facts
                     │
     draft ──► guard: does it contradict
       ▲       a fact the citizen confirmed?
       └─ yes ─┘     │ no
                     ▼
     case file · 10 steps on legal clocks

stack GPT-5, GPT-5-mini, GPT-4o-transcribe · Next.js, TypeScript, Supabase, IndexedDB

• Strict JSON-schema outputs on every route, through a provider-agnostic client with no SDK lock-in.
• Hybrid regex and LLM extraction of transaction IDs (UTRs), phone numbers and UPI IDs.
• A guardrail throws out any draft that contradicts facts the citizen has confirmed.

visit ↗ source ↗ essay

Answers questions from a document corpus with verified citations, running locally with no paid APIs.

question
   ├──► pgvector ──┐
   └──► bm25 ──────┴──► rank fusion
                            │
                cross-encoder rerank
                            │
            draft answer + citations
                            │
    verify each claim against its evidence
                            │
     answer · or "the evidence isn't there"

stack Python, FastAPI, PostgreSQL + pgvector, Ollama · Next.js, React, TypeScript

• Hybrid retrieval: pgvector and BM25 fused by rank, then reranked by a local cross-encoder.
• Every cited claim is checked against the evidence it cites before the answer is shown.
• Says when evidence is missing or conflicting, instead of inventing an answer.

source ↗ essay

Notices when Claude Code is stuck repeating itself, using deterministic checks and no model calls.

tool call ──► record
               action · target
               failure · tests
                    │
   7 signals ──► score since the
                 last real progress
                    │
     normal ── suspicious ── loop
                               │
               warn once, then you pick:
               [inspect] [rethink]
               [pause]   [continue]

stack TypeScript · a Claude Code plugin of function hooks

• Turns every tool call into a record: its action, target, failure fingerprint and test results.
• Seven deterministic signals score the work since the last real progress: same history, same verdict.
• Never stops Claude on its own: Inspect, Rethink, Pause and Continue are buttons you press.

source ↗ essay

Interview prep run by three agents: a planner, a Socratic tutor and a code reviewer.

you ──► planner
          │  4 read-only tools
          │  at most 8 turns
          ├──► tutor     asks, never tells
          └──► reviewer  reads your code
                 │
   every call ──► log
                  tool calls · reasoning
                  trace · latency

stack Google Gemini function calling · React, Express, MongoDB

• The planner acts only through four read-only tools, for at most eight turns.
• Leitner-style spaced repetition, topic heatmaps and company-readiness analytics.
• Every call is logged with its tool calls, reasoning trace and latency.

source ↗ essay

An OpenAI-compatible LLM gateway in Go with payments-grade spend control. Point any OpenAI SDK at it: it checks a virtual key, enforces its rate limits and budget, routes the call with retries and fallback, streams the answer and records what it cost.

client · any OpenAI SDK
   │  POST /v1/chat/completions
   ▼
virtual key ─► rate limits ─► idempotency
                                  │
   ┌──────────────────────────────┘
   ▼
hold the worst case, in micro-USD
   │
   ▼
router ─► OpenAI-compatible · Anthropic
   │      retries, fallback, breakers
   ▼
settle the actual cost, store, respond

stack Go, PostgreSQL (pgx, sqlc), Prometheus, Docker · OpenAI-compatible and Anthropic APIs on raw net/http

• Done: OpenAI-compatible and Anthropic adapters, with retries, fallback and a circuit breaker per target, and streaming with a commit point.
• Done: hold-and-settle budgets in integer micro-USD, idempotency keys and reconciliation. 200 concurrent requests against a budget that fits exactly 37 holds: exactly 37 succeed.
• Benchmarked against a mock upstream: about 1.5 ms of overhead at the median. Next: a run with a live provider key, then a hosted demo.

source ↗ essay

A live map for groups riding together, with battery, SOS and lost-signal handling.

rider ──ws · jwt at handshake──┐
  battery · sos · position     ▼
                          trip room
                               │
                          group map
                               │
  signal lost? ──► stays at last known
                   position, marked offline
  trail: capped at 1,000 points a rider

stack Socket.io, React Leaflet, OpenStreetMap · Express, MongoDB

• A rider who loses signal stays on the map at their last known position, marked offline.
• JWT is checked at the socket handshake, and every event stays inside its trip's room.
• Trails are capped at 1,000 points per rider, so history stays a constant size.

visit ↗ source ↗ essay

Trade skills without money. Matches are found both ways, your own city first, and both sides must agree.

you: teach A, want B
              ▲ mutual match
              ▼ your city first
them: teach B, want A
              │
         real-time chat
              │
       trade proposed ──► both agree?
                            │ yes
                            ▼
                        trade on

stack MongoDB, Socket.io, JWT · React, Express

• Finds mutual matches and one-way interest, with people in your own city first.
• Real-time chat, and a trade lifecycle that needs consent from both sides.
• Dual-token JWT with silent renewal, OTP email verification, rate limiting and CORS whitelisting.

visit ↗ source ↗ essay