fillin

Search engine for AI agents.

CommunityOnlineNo sign-inGlobalFreeCan modify data

What it can do

  • Fillin Query: Retrieve documents published after a training cutoff, ranked by similarity. Call this whenever the user asks about events, releases, papers, issues, or news that might post-date your tra
  • Fillin Answer: Synthesized post-cutoff answer with inline citations. Use this when your model is small / cheap / weaker at tool-result synthesis (Llama, Gemini Flash, Mistral, Nemotron, Qwen). Fillin
  • Fillin Stats: Get corpus stats — total docs, date range, freshness.

What data it sees

Do you need an account

No: the server works without sign-in

Search engine for AI agents. Closes the gap between an LLM's training cutoff and now, plus daily snapshots of high-signal slices agents care about: supply- chain CVEs, new research papers, and frontier AI lab releases. Corpus is ~22,800+ timestamped docs across 6 active sources — Hacker News, arXiv, curated developer RSS, GitHub Releases, NVD + GitHub Security Advisories + OSV (cves), HuggingFace daily papers + bioRxiv (papers), and frontier lab announcements (frontier). Refreshed continuously, with deeper daily slice snapshots fired at 1pm Mountain Time.

Seven tools, priced per call in USDC over x402: • fillin_query ($0.01) — generic post-cutoff vector search across all corpora • fillin_answer ($0.02) — synthesized answer with inline citations • query_cves ($0.02) — supply-chain vulnerabilities (NVD + GHSA + OSV) • query_papers ($0.03) — new research (HF daily + bioRxiv ∪ arXiv) • query_frontier ($0.05) — frontier lab announcements + trending models • fillin_stats / fillin_health — free

Try before you pay: GET https://fillin.glyphapi.dev/v1/probe gives every IP one free query per UTC day. Or hit https://fillin.glyphapi.dev/signup for a 20-query trial bearer key (no card, no wallet).

Pilot evidence (n=23, Anthropic Opus 4.7): ~3.4× fewer input tokens, ~2.25× cheaper than web search. Full thesis: https://fillin.glyphapi.dev/thesis

How to connect

How to connect fillin to Claude

The server address to paste into Claude settings:

https://fillin--mandalazenwave.run.tools

  1. Open Claude (claude.ai or the desktop app).
  2. Go to Settings → Connectors.
  3. Click Add custom connector.
  4. Paste the server address copied below into Remote MCP server URL and click Add.
  5. In a chat, click + → Connectors and switch the new connector on.

Custom connectors are available on Free, Pro, Max, Team and Enterprise plans (Free is limited to one). On Team and Enterprise an organization Owner adds the connector first under Organization settings → Connectors.

Authorization

After you click Add, a sign-in window for the service opens. Sign in with your own account and approve access. Claude never sees your password.

How to connect fillin to ChatGPT

The server address to paste into ChatGPT settings:

https://fillin--mandalazenwave.run.tools

  1. Open ChatGPT in a browser (chatgpt.com). A Plus, Pro, Business, Enterprise or Edu plan is required.
  2. Turn on developer mode once: Settings → Apps → Advanced settings → Developer mode.
  3. Open Settings → Connectors and click Create.
  4. Fill in the form: Name (anything), Description (one line about what the service does), MCP server URL (copy it below).
  5. Under Authentication choose OAuth if the service requires sign-in, otherwise None. Click Create.
  6. In a new chat open + → Apps/Connectors and enable the connector.

OpenAI has renamed this section before (Connectors → Apps/Plugins). If the label differs, search settings for "developer mode". On Business/Enterprise workspaces an admin must allow custom connectors first.

Authorization

On first use ChatGPT opens the service's sign-in window. Sign in and approve access.

How to connect fillin to Cursor

The server address to paste into Cursor settings:

https://fillin--mandalazenwave.run.tools

Fastest: click Open in Cursor below and confirm the prompt.

Manually:

  1. In Cursor open Settings → Cursor Settings → MCP and click Add new global MCP server.
  2. Paste the JSON copied below into ~/.cursor/mcp.json (per project: .cursor/mcp.json in the repo root).
  3. Save the file. The server appears in the MCP list; authorize it there if asked.

Authorization

If the service needs sign-in, an authorize button appears next to the server in the MCP list.

Server tool list (11)

Raw names from tools/list. Only developers need these.

fillin_queryRetrieve documents published after a training cutoff, ranked by similarity. Call this whenever the user asks about events, releases, papers, issues, or news that might post-date your training data. Fillin only returns documents published AFTER `cutoff`, so nothing returned is redundant with what the model already knows. Args: query: Natural-language search query (e.g. "rust async runtimes"). Max 512 characters. cutoff: ISO-8601 date representing the agent's training cutoff (e.g. "2026-01-01"). Documents on or before this date are excluded from results. k: Number of documents to retrieve, 1-20. Defaults to 5. Returns: A dict with: - cutoff: echoed cutoff (ISO timestamp) - query: echoed query - gap_days: days between cutoff and now - results: list of {id, source, url, published_at, title, text, score}
fillin_answerSynthesized post-cutoff answer with inline citations. Use this when your model is small / cheap / weaker at tool-result synthesis (Llama, Gemini Flash, Mistral, Nemotron, Qwen). Fillin runs a server-side LLM pass over the retrieved post-cutoff documents and returns a 150-250 word answer with [title](url) citations already embedded — you can quote it directly. Premium models (Opus, Sonnet, GPT-4o) usually get better results from `fillin_query` and synthesizing themselves, but this tool works for any caller. Costs more than fillin_query because of the synthesis pass. Returns: A dict with: - answer: the synthesized paragraph (str | None) - citations: list of {title, url} extracted from the answer - corpus_match: "strong" | "weak" | "none" — quality of retrieval - top_score: float — top reranked similarity score - model: the synthesizer model used (e.g. claude-haiku-4-5) - reason: set when answer is None (e.g. "no_relevant_docs") - results: raw post-cutoff documents (same shape as fillin_query) - cutoff, query, gap_days: echoes for context
fillin_statsGet corpus stats — total docs, date range, freshness.
fillin_healthLiveness + freshness — host, total docs, earliest, latest. No auth required.
query_cvesDaily snapshot of CVE / supply-chain advisories from NVD, GitHub Security Advisories, and OSV. Use before merging dependency updates, when triaging an alert, or when a user asks "is package X compromised". Each result row carries a structured `affected` list (one entry per affected package: ecosystem, name, vulnerable_range, patched_range) and a numeric `severity_score` (CVSS baseScore, nullable on OSV-only rows). A buyer can act on the returned row — pin to `patched_range` — without a second hop to NVD or GHSA.
query_papersDaily snapshot of new research relevant to AI/ML/agents. Union of arXiv (cs.AI/cs.LG/cs.CL/cs.CR/cs.DC), HuggingFace daily papers (with upvote signal in title), and bioRxiv. Use when a user asks about a new technique, paper, or benchmark.
query_frontierDaily snapshot of frontier AI lab announcements + HuggingFace trending model releases. Sources: OpenAI / DeepMind / Meta / Mistral blog RSS, Anthropic + HF blogs (via shared rss corpus), and the HF trending models API. Use when a user asks "what model dropped" or "did <lab> announce X".
query_marketsActive prediction markets across Polymarket, Kalshi, Manifold, and Metaculus. Use when a user asks "is there a market on X", "what odds is the market giving Y", or before any agent action that should be informed by a market price. Each result row carries the question, venue, close date, volume, and a first-sight price snapshot embedded in `text`. Prices in the corpus are point-in-time at first ingestion — for live pre-trade pricing, follow the `url` to the venue and read the current quote there.
fillin_market_searchSearch the Fillin marketplace for minted (data + reasoning) assets matching your fingerprint. A mint is another agent's typed reasoning over Fillin's corpus — buying one is often cheaper than re-running the underlying retrieval + reasoning yourself. Returns {fingerprint, mints[]}. Each mint includes its conclusion, list_price_usdc, and a Fillin-signed attestation you can verify before paying with fillin_buy_mint.
fillin_mintMint a (data + reasoning) asset on the Fillin marketplace. Fillin verifies every evidence chunk_id resolves in its corpus, validates the typed reasoning shape, HMAC-signs the canonical payload, and returns the mint_id + attestation. Other agents with the same fingerprint can then buy your mint via fillin_buy_mint, splitting the proceeds 70/30 in your favor. Requires FILLIN_API_KEY (a Fillin bearer token).
fillin_buy_mintBuy a listed mint. Debits your bearer balance, credits the seller (minus Fillin's rake), records the transaction, and returns the full mint payload including the previously-paywalled reasoning_graph. Requires FILLIN_API_KEY with sufficient balance for the mint's list price.