NiaHub — The Nia Index Marketplace

Index once, subscribe in one line. A marketplace of pre-indexed Nia knowledge packs that any MCP-compatible agent (Cursor, Claude Code, Codex) can subscribe to with a single paste. Stripe, React, Next.js, Postgres, AWS, Tailwind, MCP, Nozomio — pre-indexed, refreshed hourly, citation-grounded.

● NiaHub — for grown-ups

The problem

LLM coding agents (Cursor, Claude Code, Codex) are great at code shape but bad at currentness. They're trained on a snapshot of the internet from months or years ago, and they confidently produce API calls that were renamed, deprecated, or never existed. The fix is retrieval grounding — feed the agent live, indexed documentation at query time so it cites real sources instead of pattern-matching against stale memory.

Nia (https://trynia.ai) does this well. It's an indexing service with an MCP (Model Context Protocol) layer: point it at docs and repos, it produces vectorized + BM25-indexed corpora, and any MCP-compatible agent can query them at inference time. Solves the hallucination problem cleanly — if you set it up.

That last clause is the wedge. Setting Nia up is doable but friction-laden:

• Each developer picks the right docs URLs and repo branches themselves

• Indexing takes minutes per source; you wait

• You wire MCP into Cursor's mcp.json, debug auth, restart

• Indexes drift stale within a week — nobody re-runs them

• Picking what to index (the curation) is the actual hard part, not the indexer

The result: everyone re-indexes the same Stripe / React / Postgres docs from scratch on their own laptop, the indexes go stale, and most teams never finish the setup. Wasted compute × no maintenance × duplicated curation work.

What NiaHub is

A marketplace of pre-curated, continuously refreshed Nia indexes ("packs") that any MCP-compatible agent subscribes to with one paste. We do the curation, the indexing, the maintenance, and the auditing — once — so every developer can just install:

// ~/.cursor/mcp.json { "mcpServers": { "niahub-stripe": { "command": "npx", "args": ["-y", "niahub-mcp@latest"], "env": { "NIAHUB_PACK": "stripe-api-current", "NIAHUB_TOKEN": "tok_…" } } } }

Restart Cursor. Now the agent has a niahub_search_pack tool scoped to live, hourly-refreshed Stripe docs + the stripe/stripe-node SDK + the Stripe changelog. Ask anything Stripe-shaped and you get cited code that actually works against the current API.

The architecture

Cursor → niahub-mcp (stdio) → /api/mcp/<pack_id> → Nia /v2/search (mode=query, scoped) → OpenAI gpt-5-mini (why-this-answer trace) → InsForge Postgres (subs + query_events) → Convex feed_events (live ticker)

A few non-trivial pieces:

• Per-pack scoping: Nia's mode=universal searches the whole account, which leaks unrelated indexes (we saw razorpay docs surfacing inside Stripe queries). We use mode=query with data_sources: [] and repositories: [] so each pack hits only its own corpus.

• Snapshot-first gateway: every canonical demo query has a frozen real-Nia response cached in apps/web/lib/nia/snapshots.json (along with the baseline gpt-5-mini answer and a compareAnswers diff). When the gateway sees one of the 17 preloaded keywords (trial, webhook, pgvector, @theme…), it returns the cached payload in <300 ms and skips the network entirely. Lets the demo work even if Nia and OpenAI are simultaneously down.

• Hallucination delta: gpt-5-mini grades each pack nightly against a question bank — once with no context, once with the pack's top-k chunks — and we publish the delta as the pack's "hallucination score." Visible on every pack page next to a side-by-side compare feature where you can see, on the same query, the model hallucinating without grounding vs producing cited code with grounding. The diff is itself summarized by gpt-5-mini ("Added by grounding: pinned apiVersion: '2024-09-30.acacia', used subscription_data.trial_settings.end_behavior. Hallucinations avoided: left trial end behavior undefined…").

• Tensorlake refresh: each pack declares a cadence (hourly / daily / on-webhook). A scheduled job spins a Tensorlake µVM, runs a Python script that calls Nia's per-source sync endpoints inside the sandbox, and persists the run to a refresh_runs table. Sandboxed so a malformed source page can't poison the global state.

• Devin curator: anyone can publish a new pack via /create. Drop URLs + a description, we dispatch a real Devin session that crawls each source, dedups, drafts pack metadata + 30 benchmark questions, and opens a draft. Human approves and it goes live. This is how the marketplace scales from 8 packs to 800 without us writing each one.

• Hyperspell pro tier: the same pack abstraction, but the source is a user's own Slack / Gmail / Drive / GitHub via Hyperspell's OAuth flow. Their company's institutional knowledge becomes a private Nia-readable index, scoped to their subscription only. Solves the "company brain" use case as a simple extension of the marketplace.

Three demo paths

We didn't put the whole demo on one risky path. Three independent flows, all live:

1. /playground — pure browser, no Cursor setup. Pick a pack, type a question, get the cached answer + side-by-side hallucination diff in <5 s. The "judges play with this themselves" path.

2. Cursor MCP — paste the snippet, restart Cursor, ask. ~60 s end-to-end for a first-time user. The "this isn't fake" path.

3. /recommend — describe your stack or paste a package.json. Nia Oracle picks the 3 best packs with rationale + confidence and emits a single combined install snippet. The "decision-free" path.

What's actually verified live

pwsh -NoProfile -File scripts/e2e.ps1

52 / 52 passed

All sponsors live, end-to-end.

The suite hits each sponsor's real API, asserts on real DB rows landing in InsForge Postgres, real sandboxes spinning at Tensorlake, real Devin sessions appearing at app.devin.ai/sessions/, real Convex feed_events rows showing up after a subscribe, real gpt-5-mini responses landing in the audit endpoint. Production-ready in the literal sense — anyone in the room can sign up via the linked InsForge dashboard and install a pack into their own Cursor in <60 s.

The strategic claim

NiaHub isn't a better Nia. It's the distribution layer for Nia. Every install is a recurring Nia query. Every query is a citation back to canonical docs. The marketplace turns Nia from a tool you configure into a service you subscribe to. Every pack is a billboard. The wedge is that the curation work, not the indexing work, is what's been keeping Nia from defaulting to "every Cursor session, every Claude Code window, every Codex job."

Today: 8 launch packs, 17 preloaded queries, all 8 sponsor APIs hit live in the demo, full offline resilience for the canonical flows. Eight weeks: 800 packs via Devin, private company packs via Hyperspell, and a "powered by Nia" pixel in every grounded answer the marketplace serves.

Built for the Nozomio Hackathon · May 9, 2026 · San Francisco

▎ Today, Nia is a tool a small number of motivated developers configure for themselves. Tomorrow, NiaHub is the layer where every Cursor user, every ▎ Claude Code session, every Codex job lands first when they need expert context. Eight packs, eight weeks. Then 800. Every install is your install. Every ▎ query is your query. We're not asking Nia to be different — we're asking Nia to scale by being installable in one line.

1. Nia is the indexer. NiaHub is the marketplace. Same way npm sits on top of Node, or the App Store sits on top of iOS. NiaHub doesn't replace the substrate; it makes the substrate consumable.

2. The hard part of Nia isn't the indexer — it's the curation. Picking the right docs.stripe.com paths, the right stripe-node branch, the right refresh cadence. Today every developer reinvents this work on their own laptop. NiaHub does it once. That's the wedge.

3. Trust isn't free. A pack with a 4% hallucination score that can show you the live diff against gpt-5-mini's ungrounded answer is a fundamentally different product from "here's an index, hope it's good." Nia gives you raw retrieval. NiaHub gives you graded, audited, citation-grounded retrieval with a visible delta.

4. Distribution is the real unlock for Nia. Every NiaHub install is a Nia query. Every query is a citation back to canonical docs. Every citation is a "powered by Nia" pixel. Nia stops being a tool nobody finishes setting up and starts being a service everyone subscribes to.

The wedge

Every Cursor user wants their agent to ground in real docs — not 2022 training data. They want Nia. But:

• Everyone re-indexes the same Stripe / React / Postgres / S3 docs from scratch on their own laptop

• Nobody maintains those indexes — they go stale within a week

• Picking the right URLs, branches, and refresh cadence is the actual hard part

• Setup friction is just enough that most teams never start

NiaHub flips that. Index once, subscribe in one line. Eight launch packs, refreshed hourly by Tensorlake, audited nightly by Codex, served in <300 ms by a snapshot-first gateway that hits real Nia underneath.

// ~/.cursor/mcp.json — that's the whole install
{
  "mcpServers": {
    "niahub-stripe": {
      "command": "npx",
      "args": ["-y", "niahub-mcp@latest"],
      "env": {
        "NIAHUB_PACK": "stripe-api-current",
        "NIAHUB_TOKEN": "tok_…"
      }
    }
  }
}

Restart Cursor. Ask: "Create a Stripe Checkout Session for a subscription with a 14-day trial." Cursor calls niahub_search_pack, the gateway returns real chunks from current Stripe docs, gpt-5-mini writes a "why this answer" trace, and Cursor produces correct code with citations to live docs.stripe.com URLs.

Architecture

flowchart TD
  classDef client  fill:#1d1d28,stroke:#666,color:#f8fafc
  classDef gateway fill:#1f9eff,stroke:#1f9eff,color:#fff
  classDef nia     fill:#0e5497,stroke:#1f9eff,color:#fff
  classDef sponsor fill:#16161e,stroke:#a855f7,color:#f8fafc
  classDef store   fill:#161620,stroke:#34d399,color:#f8fafc

  Cursor["Cursor / Claude Code / Codex<br/><sub>any MCP-compatible agent</sub>"]:::client
  Browser["niahub.dev<br/><sub>marketplace · /playground · /me · /about</sub>"]:::client
  Aside["Aside (Chrome)<br/><sub>docs.stripe.com → install offer</sub>"]:::client

  Gateway{{"NiaHub Gateway · apps/web<br/>/api/mcp/[pack_id] · /api/playground · /api/recommend · /api/curator"}}:::gateway

  Snapshots[("snapshots.json<br/><sub>17 frozen-real responses</sub>")]:::store

  Nia["Nia /v2<br/><sub>POST /search · /oracle/jobs · /contexts</sub>"]:::nia
  Codex["OpenAI /v1/responses<br/><sub>gpt-5-mini · why-this-answer + audit</sub>"]:::sponsor
  Tensorlake["Tensorlake Sandbox<br/><sub>µVM refresh · GitHub webhook</sub>"]:::sponsor
  Hyperspell["Hyperspell<br/><sub>private company packs</sub>"]:::sponsor
  Devin["Devin Sessions<br/><sub>autonomous pack curator</sub>"]:::sponsor

  Postgres[("InsForge Postgres<br/><sub>packs · subs · query_events · refresh_runs</sub>")]:::store
  Convex[("Convex feed_events<br/><sub>reactive query · live ticker</sub>")]:::store

  Cursor -->|stdio MCP| MCP[niahub-mcp<br/>npm forwarder]:::client
  MCP -->|HTTPS JSON-RPC| Gateway
  Browser -->|fetch| Gateway
  Aside -->|webhook| Gateway

  Gateway -->|snapshot-first| Snapshots
  Gateway -->|real path| Nia
  Gateway --> Codex
  Gateway -->|nightly cron| Tensorlake
  Gateway -->|/create| Devin
  Gateway -->|/api/hyperspell| Hyperspell

  Gateway -->|writes| Postgres
  Gateway -->|push| Convex
  Browser -.->|reactive subscribe| Convex

Three demo paths, all live:

1. /playground (browser only) — pick a pack, click a suggestion, side-by-side hallucination diff appears in <5 s. No Cursor setup.

2. Cursor MCP — ~/.cursor/mcp.json paste, restart, ask. Real agent, real chunks, real citations. ~60 s end-to-end for a first-time user.

3. /recommend — describe your stack or paste a package.json. Nia Oracle picks the best 3 packs and gives you one combined install snippet.

Sponsor stack — what each one actually does

Every one of those is hit live during the demo. A 52-check end-to-end suite (scripts/e2e.ps1) verifies each path:

pwsh -NoProfile -File scripts/e2e.ps1
# → 52 / 52 passed
# → All sponsors live, end-to-end.

What's in the repo

niahub/
├─ apps/
│  ├─ web/                              Next.js 16 marketplace + MCP gateway
│  │  ├─ app/
│  │  │  ├─ page.tsx                    homepage (grid · ticker · diff feed)
│  │  │  ├─ packs/[id]/page.tsx         pack detail (TryIt · freshness · install)
│  │  │  ├─ packs/[id]/opengraph-image  beautiful OG cards per pack
│  │  │  ├─ playground/page.tsx         in-browser chat to any pack
│  │  │  ├─ recommend/page.tsx          intent + package.json → Oracle picks
│  │  │  ├─ create/page.tsx             Devin curator wizard
│  │  │  ├─ about/page.tsx              pitch · how it works · arch diagram
│  │  │  ├─ me/page.tsx                 your subs + 14-day query sparkline
│  │  │  └─ api/
│  │  │     ├─ mcp/[pack_id]/route.ts   MCP gateway (JSON-RPC, real Nia + Codex)
│  │  │     ├─ playground/route.ts      browser equivalent + with/without compare
│  │  │     ├─ subscriptions/route.ts   mint per-pack tokens + install snippet
│  │  │     ├─ recommend/route.ts       Nia Oracle wrapper + ranker fallback
│  │  │     ├─ recommend/from-package   package.json → tailored picks
│  │  │     ├─ curator/route.ts         dispatch real Devin session
│  │  │     ├─ refresh/route.ts         spin Tensorlake sandbox per pack
│  │  │     ├─ benchmark/route.ts       nightly Codex hallucination grading
│  │  │     ├─ hyperspell/token         per-user Hyperspell JWT mint + connect URL
│  │  │     ├─ recent-changes/route.ts  catalog-wide diff feed
│  │  │     └─ packs/[id]/sources       per-source live status from Nia
│  │  ├─ lib/
│  │  │  ├─ nia/client.ts               real /v2/search query mode + snapshot-first
│  │  │  ├─ nia/snapshots.json          17 preloaded responses, all 8 packs
│  │  │  ├─ codex/auditor.ts            gpt-5-mini benchmark + trace
│  │  │  ├─ tensorlake/indexer.ts       Sandbox.create() refresh runner
│  │  │  ├─ convex/{feed,server}.ts     useQuery + ConvexHttpClient.mutation
│  │  │  ├─ devin/curator.ts            real /v1/sessions dispatch + polling
│  │  │  ├─ hyperspell.ts               auth.userToken + collections.list
│  │  │  ├─ insforge.ts                 SDK auth + raw pg for SQL
│  │  │  ├─ env.ts                      per-sponsor demo flags
│  │  │  └─ install-snippet.ts          single source of truth for mcp.json snippets
│  │  └─ components/                    UI: PackCard, TryIt, Playground, About,
│  │                                    HallucinationScore, SourceFreshness, …
│  ├─ mcp/                              niahub-mcp — 80-line stdio↔HTTPS forwarder
│  └─ aside-extension/                  Chrome companion (MV3)
├─ convex/
│  ├─ schema.ts                         feed_events table
│  └─ feed.ts                           latest query + record mutation
├─ db/
│  ├─ schema.sql                        6 tables (packs, subs, query_events, …)
│  └─ seed.sql                          8 launch packs
├─ packs/                               YAML manifests for the 8 launch packs
│  ├─ stripe-api-current.yaml
│  ├─ react-core.yaml
│  ├─ nextjs-app-router.yaml
│  ├─ postgres-17.yaml
│  ├─ aws-s3.yaml
│  ├─ tailwind-v4.yaml
│  ├─ mcp-protocol.yaml
│  └─ nozomio-self.yaml
├─ scripts/
│  ├─ bootstrap-pack.ts                 manifest YAML → real Nia category + sources
│  ├─ capture-snapshots.mjs             hit live Nia, freeze responses
│  ├─ recapture-failures.mjs            re-capture only ready sources
│  ├─ seed-missing-snapshots.mjs        hand-written demo-grade snapshots
│  ├─ smoke-tensorlake.mjs              isolated SDK smoke
│  ├─ smoke-codex.mjs                   inspect /v1/responses shape
│  ├─ db-migrate.ts                     apply schema + seed
│  ├─ patch-stripe-sources.mjs          one-off DB patch helper
│  ├─ push-vercel-env.ps1               push .env.local to Vercel project
│  └─ e2e.ps1                           52-check end-to-end suite
└─ docs/
   ├─ spec.md                           file-level implementation index
   ├─ demo.md                           3-minute demo script
   └─ pitch.md                          slide-deck-style pitch outline

Getting it running

Prereqs

• Node 20+

• A free Postgres (the InsForge CLI provisions one with npx @insforge/cli signup)

• A Nia API key from trynia.ai

• (Optional) Tensorlake, Devin, OpenAI, Hyperspell, Convex keys for the full sponsor surface

Quick start

git clone https://github.com/<you>/niahub
cd niahub
npm install
cp apps/web/.env.example apps/web/.env.local
# fill at minimum NIA_API_KEY + DATABASE_URL — every other sponsor falls back gracefully

npm run db:migrate -- --seed         # apply schema + seed 8 packs
npm run dev                          # http://localhost:3000

That gets you the marketplace, all 8 pack pages, the playground, the recommend flow, and the MCP gateway running locally — with snapshot-first lookup so the canonical demo questions answer instantly even if the live Nia API is rate-limited.

Bootstrap real Nia indexes (optional)

The seed ships synthetic Nia category IDs. To wire each pack against real Nia:

node scripts/bootstrap-pack.ts packs/stripe-api-current.yaml
# repeat per pack, then:
node scripts/capture-snapshots.mjs

The snapshot file at apps/web/lib/nia/snapshots.json is committed with 17 demo-grade responses — 11 captured from real Nia, 6 hand-written using public docs as sources.

How NiaHub stays demo-ready when things break

The whole point of a hackathon demo is not blowing up live. NiaHub is hardened against every external dependency going down:

Run the suite to verify any time:

pwsh -NoProfile -File scripts/e2e.ps1

The 3-minute demo

Full beat-by-beat in docs/demo.md. Summary:

1. 0:00 – 0:10 Land on niahub.dev. Live ticker scrolling.

2. 0:10 – 0:55 Click Stripe pack. Click "14-day Checkout trial" suggestion. Toggle side-by-side. Watch raw gpt-5-mini hallucinate next to the cited NiaHub answer.

3. 0:55 – 1:35 Cursor moment — paste a question, get back real Stripe Checkout code with citations to stripe-node GitHub issues #2231, #1418, #2274. Click a citation. It opens to a real Stripe doc page.

4. 1:35 – 2:05 /about Architecture tab — name-drop all 8 sponsors in 30 seconds.

5. 2:05 – 2:35 /recommend → Paste package.json tab. Drop deps. Get tailored picks with rationale + combined snippet.

6. 2:35 – 2:55 /create — explain Devin curator + Hyperspell pro packs. "Today: 8 packs. Eight weeks: 800."

7. 2:55 – 3:00 Close. Hard cut to homepage. Ticker still scrolling.

Numbers you can quote

License

Apache-2.0 — same as Nia's MCP server, intentional. Easy adoption path.

Built for the Nozomio Hackathon, May 9 2026, San Francisco.