DonSeTch

The web, for AI agents.

Why · Demo · Sponsors · Install · Quickstart · The 4 tools · Fetch · Search · PDF · Stealth · Compare · Limits · CLI

DonSeTch gives any AI agent full web research from a single local process: fetch, search, crawl, screenshot. Four tools, zero API keys, zero accounts, Rust, one binary. The transport is built from scratch (no hyper, no Playwright, no Selenium), so the fetch tier is fast and stealthy, and the tool surface stays small enough to fit an agent's context.

Works with every MCP client (Claude Code, Cursor, OpenCode, Pi, Hermes) and as a standalone CLI.

🤝 Use Bright Data? Support DonSeTch. Their proxy, SERP and Web Unlocker products come through this partner link and part of it comes back to keep DonSeTch free. You pay nothing extra: https://get.brightdata.com/ivqwoicrrlbr Bright Data plugs into the tool itself: the bd SERP provider, the Web Unlocker tier-3 bypass and the unlocker key type.

✨ Why it's different

🎬 Demo

(30-second walkthrough: search, bot-wall bypass, crawl)

(Pi agent session: live research with DonSeTch as a native extension)

💛 Sponsors

DonSeTch is free and open source, and stays that way. Sponsorship pays for the time it takes to keep shipping.

Prepaid monthly, cancel anytime. One-time sponsorships are welcome at any amount.

Pricing goes up as the project grows. It is early now, so a Gold at $49/mo is near-zero investment for any company whose product touches agent web research. If your product is part of this space (proxy platforms, search infrastructure, BYO providers, anything a DonSeTch user would plug in), Gold goes one step further: fit natively inside DonSeTch and you get the placement plus an official integration shipped in the binary itself.

Email bhandaribishesh879@gmail.com to become a sponsor.

📦 Install

npm, any platform (recommended):

npm install -g donsetch

Downloads the prebuilt binary for your platform from GitHub Releases with SHA256 verification. No build tools needed.

Homebrew (macOS/Linux):

brew tap dondai44423/donsetch && brew install donsetch

Pi agent (native extension):

pi install npm:donsetch

Registers the tools as native pi tools, spawns the binary at session start, self-updates with pi update --extensions.

DeepSeek Harness (dsh, first-class plugin):

dsh plugin --profile web add github:dondai44423/donsetch-dsh

One line and every dsh agent gets fetch, search and crawl as native donsetch_* tools, no mcp__ names and no manual MCP config: the plugin downloads the verified binary for your platform, registers the tools in-process, auto-updates with DonSeTch releases, and picks up donsetch keys add changes live. See the donsetch-dsh repo for the config reference.

Homebrew and dsh auto-track published releases.

Verify the install:

donsetch doctor          # fast local sweep, ~1 second
donsetch doctor --deep   # adds live browser + egress probes
donsetch doctor --fix    # repairs mechanical problems automatically
donsetch doctor --json   # machine-readable, also prints MCP registration blocks for your client

git clone https://github.com/dondai44423/donsetch.git
cd donsetch
cargo build --release --features ocr,rerank,http

sudo apt-get install -y cmake build-essential pkg-config libclang-dev clang lld nasm golang-go
RUSTFLAGS="-C link-arg=-fuse-ld=lld" cargo build --release

DONSETCH_BROWSER_BACKEND=chromium donsetch doctor             # default backend
DONSETCH_BROWSER_BACKEND=headless donsetch doctor --deep      # forced headless
DONSETCH_BROWSER_BACKEND=cloakbrowser \
  CLOAKBROWSER_BINARY_PATH=/path/to/chrome donsetch doctor --deep

🚀 Quickstart

MCP server (for any agent). Register and go:

{
  "mcpServers": {
    "donsetch": {
      "command": "donsetch",
      "args": ["mcp", "--supervised"]
    }
  }
}

--supervised is the crash-only daemon: a panic is a blip, the daemon restarts itself, the session survives. Without a global install, use "command": "npx", "args": ["donsetch", "mcp"].

HTTP transport instead of stdio: donsetch mcp --http --port 8765, clients connect to http://localhost:8765/mcp. Sessions, cancellation, /health, token auth via DONSETCH_HTTP_TOKEN and per-request timeouts are documented in donsetch mcp --help.

CLI (for humans and scripts). Same engine, thin adapter:

donsetch fetch https://example.com --focus "pricing"
donsetch search "rust async patterns" --intent code
donsetch crawl https://docs.python.org --mode map --topic asyncio

DONSETCH_MCP_TEXT_ONLY=1 donsetch mcp   # force the fold for every client

🎯 The 4 tools

Tool schemas: donsetch tools (same JSON as MCP tools/list). Every failure is structured: a stable code (wall.challenge, guard.ssrf, deadline.hit, archive.stale, network.dns…), an errorKind (permanent, transient, walled), and a next_action line, so agents branch on codes instead of parsing prose. The model surface carries evidence and the state that changes the next action; transport telemetry (tier, quality, escalation trace, timings, engines) stays under _meta, for example _meta["com.donsetch/fetch-debug"].

🌐 Fetch

Plain HTTP first, ~100-300ms. Wall or JS shell detected, auto-escalate to the ghost browser, solve, bounce the cookies back, refetch at full speed.

DonSift extraction: HTML bytes in, agent-native markdown out. Typed blocks (heading, paragraph, list, table, code, quote, media) with heading breadcrumbs.

• focus: BM25-relevant blocks only, which cuts context by 80%+ on long pages. 12-language BM25: CJK unigrams and bigrams, stopword lists, stemming, accent folding.
• toc + section: see the outline first, then target one section. Two cheap calls instead of one expensive one.
• Token policy: links stripped by default (~30% off), link farms and wiki junk dropped, duplicates suppressed.
• Classification: Article / Listing / Forum / Docs / Table / Page, a 0-1 quality score, and inline trust signals (focus-miss, JS-shell warning, empty content).
• Page memory: every fetch is fingerprinted, so a re-fetch reports changed with section-level diffs, and since_last=true collapses a re-check to one line (~30 tokens).
• must_contain: verifies a claim against the full page but returns MATCH/NO-MATCH plus up to 3 excerpts (~60 tokens instead of 4k).
• archive=auto: a dead link serves the nearest Wayback snapshot, honestly labeled with its age.
• stitch=true: walks rel=next into one call with part markers.
• deadline_ms everywhere: real MCP cancellation, progress notifications, ms cost footer. Nothing can silently hang.
• Domain adapters: Reddit, npm/PyPI/crates.io/Go/RubyGems, GitHub, Stack Overflow, Wikipedia and docs sites get restructured from each site's own keyless surfaces. Labeled via=adapter:…, kill-switchable.
• Anti-cloak check: on decoy-prone domains, tier-1 responses are equivalence-checked against a headless render, so decoy suspected is stamped instead of silently passing as content.

Tier 3 bypass (opt-in). When the ghost itself hits a hard wall, fetch falls back to Bright Data Web Unlocker if a key is configured (donsetch keys add unlocker <key>[::zone]). The unlocker solves server-side, captchas included, and returns rendered HTML into the normal pipeline. Failures carry exact guidance (token rejected, zone not found, balance empty, rate limit, target still walled) on the escalation trace, and donsetch doctor --deep validates token and zone for free before the first paid call. Every successful unlock is cached locally (URL-hash keyed, sliding 6h TTL, 200 entries, parallel fetches share one paid call), so the same page inside the TTL costs nothing. All of it lives in the [bypass] config section: donsetch config show. DonSeTch works identically without it.

🕷️ Crawl

Same-domain, best-first. Two phases: sitemap discovery (cheap URL inventory), then a Governor-paced frontier walk with extraction per page.

• Modes: full (map + content), map (URL inventory only), content (BFS from the seed, no sitemap).
• Focus-ranked frontier: focus="query" ranks pages by BM25 relevance over link text and URL path, and crawls only matches. No semantic matching before fetch: a link sharing no token with the query is never enqueued.
• Adaptive pacing: the Governor paces per (host, lane). 429/503 back off on host signals, host-declared waits (Retry-After, robots Crawl-delay) are honored in full, and everything self-inferred caps at ~7s. Zero artificial dwell on the fetch path: stealth through truth, never time.
• Crawl-shape: frontier pops get a seeded reader-like jitter so repeated crawls never replay one identical, score-eager order into server logs. Ordering only, payloads untouched. Kill switch: DONSETCH_NO_CRAWL_SHAPE=1.
• Resume tokens: a stopped crawl resumes in one call, valid 30 minutes, survives restarts.
• Near-duplicate detection: title plus first 200 chars, hashed.
• Honest stop reasons: FrontierEmpty, MaxPages, CharBudget, DepthLimit, Deadline, ThrottledOut.
• Cross-process politeness: one host-pace store shared by every crawler on the box, so two runs against one site do not double the rate.

🔎 Keyless search

No API key, no account. Six keyless engines across four independent index families, plus eight official verticals, run in parallel on your machine, then merge, dedupe and rank.

• Backends: Bing family (Bing, DuckDuckGo, Yahoo), Brave, Mojeek, Google, plus keyless verticals (GitHub, Wikipedia, HN, Semantic Scholar, arXiv, StackExchange, MDN, Google News).
• Native Google, browser-free: HTTP through the legacy mobile endpoint on the existing Rust transport, with seven experimentally verified Nokia profiles (6230-03.15 by default). A profile that succeeds stays preferred per egress, CAPTCHA advances the cursor circularly, rate limits do not. Retry, pacing and quarantine use the same policy as every other engine. Availability depends on Google and your network; see configuration and limits.
• Ghost SERP cascade: if the fan-out and its retry wave leave the merge thin (under 3 lanes or under 15 hits) and native Google failed, one headless render can recover Google's desktop SERP. It costs nothing when healthy, only fires under underdelivery, and reports itself honestly as google_ghost.
• Semantic reranking: a local ONNX cross-encoder (ms-marco-MiniLM-L-6-v2, 23MB) reads query + title + snippet through full attention, blended 60/40 with RRF + BM25 + consensus. A post-enrichment top-up re-scores close calls using the destination page's real title and description instead of SERP fragments.
• Consensus: a URL several independent indexes return gets a boost. Every result carries score, consensus (independent index families) and engines, and the compact surface shows · N sources.
• Learned engine health: per-engine trust EWMAs and chronic-failure quarantine survive restarts, so dead engines get benched instead of burning fan-out slots on every query.
• Entity coverage: anchor entities (B-tree, version numbers, years) are checked against results. Wrong entity, 0.3x.
• Honest reporting: weak=true means low consensus, per-engine status is always visible, and there is no fake "no results".
• Warm handoff: search pre-fetches the top results, so the next fetch S1 serves from cache in ~3ms. It also pre-solves: if the top result's domain is a known wall, a bounded background solve starts while the agent reads.
• Query compiler: site:, filetype: and intitle: are sent only to engines that honor them, and SERP instant answers are extracted with their source URLs.

Keyless quality, 110 questions across 11 niches with no keys: 95.5% answer-in-snippet against Tavily's published 93.3% (LLM-graded). Reproduce with python3 bench/search_quality.py --verbose; methodology and per-niche numbers live in the script. Search-quality caching for the bench lives in ~/.cache/donsetch/bench-search/, delete it when comparing binaries.

BYOK, optional and never required

Paid providers add rate limits and premium sources on top of the keyless chain.

donsetch keys add tavily tvly-...       # Tavily
donsetch keys add exa sk-exa-...        # Exa (stackable)
donsetch keys add serper ...            # Serper.dev
donsetch keys add serpapi ...           # SerpApi
donsetch keys add serpbase sb-...       # SerpBase Google SERP (100 free searches)
donsetch keys add bravesearch ...       # Brave Search API
donsetch keys add tinyfish sk-...       # TinyFish (free tier)
donsetch keys add parallel nKil3...     # Parallel AI (fast mode)
donsetch keys add bd 576d013c...        # Bright Data SERP
donsetch keys add unlocker <key>[::zone]  # Bright Data Web Unlocker
donsetch keys default local             # dispatch order: keyless first

• Stack keys per provider: two Exa keys are one 3,000-credit pool. donsetch keys export/import moves the store.
• Automatic fallback to keyless when a provider errors or runs dry, per-key rate-limit cooldown and depletion tracking.
• The native adapter list is deliberately short, only the biggest services get one. Everything else belongs in the plugin system below, wired by you, running in the same chain.
• Bright Data SERP, Web Unlocker and the proxy/data products are available at get.brightdata.com (affiliate link).

Search plugins: any provider, no release needed

Not natively supported is not the same as unsupported. Register any executable that answers a small stdin/stdout JSON contract and DonSeTch treats it like any other provider: default chain, fallback, attribution. Any language works.

donsetch keys add plugin searxng --cmd 'python3 ~/searxng-adapter.py' --test

Request on stdin, response on stdout:

{"format":1,"query":"rust async","max_results":8,"intent":"web","deadline_ms":30000}
{"format":1,"results":[{"title":"...","url":"https://...","snippet":"...","score":0.9}]}

Errors: exit non-zero with a message on stderr, or answer {"format":1,"error":"...","retryable":true,"error_kind":"rate_limited"}. error_kind is optional and says what actually went wrong: invalid_key, credit_depleted, rate_limited, server_error, network_error. Report one of the first three and the plugin is parked the way a native key in that state is parked, rate-limited for a 60s cooldown then retried, invalid or depleted until you re-register it with keys add plugin, and keys list shows which. Leave the field out and nothing changes: retryable alone still only picks between retrying this search elsewhere and reporting the failure. Constraints that keep it reliable: hard timeout (default 30s, --timeout to change), 8 MiB stdout cap, direct exec with no shell, killed on cancellation, and a malformed response degrades gracefully down the fallback chain. Keys belong in the adapter's own environment, never in DonSeTch config.

📄 PDF + OCR

PDFs are detected by Content-Type or %PDF magic and parsed through a custom PDFium FFI. No external PDF library, no Python subprocess.

Glyphs and rendered pixels come from the same content stream, so they are already aligned. Pixels tell the truth about structure, glyphs tell the truth about text, and the fusion is deterministic: no hallucination.

Tier B, lazy: OCR through the PP-OCR cascade (En → Zh → Deva) for scans and broken ToUnicode pages.

🖱️ Browser actions: page control inside one fetch

web_fetch takes an actions array, executed in the real browser before extraction:

{
  "url": "https://duckduckgo.com",
  "actions": [
    { "do": "type", "selector": "input[name=q]", "text": "rust async tokio" },
    { "do": "press", "key": "Enter" },
    { "do": "wait_text", "text": "tokio" }
  ],
  "focus": "tokio"
}

Steps: wait, wait_selector, wait_text, click, hover, type (human cadence), press, scroll. Up to 16 steps, deterministic waits, per-step results in structuredContent.actions. Search flows, form submits, load-more buttons: one call, no separate browser tool.

🛡️ Stealth: Chrome TLS, not Chrome-like

Everyone else patches a foreign TLS stack to resemble Chrome and ships hardcoded fingerprint tables that rot. DonSeTch drives Chrome's own BoringSSL with Chrome's native behaviors on: GREASE, extension permutation, ECH-GREASE, ALPS, SCT, OCSP, cert compression. The ClientHello comes out of the same machinery Chrome uses.

Own HTTP/2 stack. Off-the-shelf h2 does not expose pseudo-header order, the exact SETTINGS set, WINDOW_UPDATE values or HPACK indexing strategy, all of which are fingerprintable. So DonSeTch has its own: full HPACK (257 Huffman symbols, 61 static entries), frame engine (SETTINGS, DATA, WINDOW_UPDATE, PING, GOAWAY, RST_STREAM, CONTINUATION, PRIORITY), request HEADERS carrying Chromium's priority flag and block, flow control with replenishment, TLS 1.3 session resumption, connection pool. The h2 preface is asserted byte-identical to Chromium in CI, so a detectability regression is a build failure.

Temporal stealth. The part that is not in the bytes:

One identity per fetch. Per-domain personas drive Accept-Language, the ghost viewport and navigator.languages, so tier 1 and the browser claim the same person. The profile is derived from the browser actually installed, and donsetch --version tells you which one it detected.

👻 Solve-and-bounce

The browser almost never fetches content. It exists for the two things HTTP cannot do: pass a JS challenge and execute a JS-rendered page. Its output is cookies (handed to tier 1, which then fetches at full speed) or rendered HTML (handed to the extraction engine).

Raw CDP launch without automation flags, so navigator.webdriver is natively false. Nothing is injected before page scripts: a real window, real GPU, real locale, a real PluginArray, and the window.chrome object Chrome actually ships. Where a stealth plugin patches a property so it looks less automated, this leaves the real one alone, because a patched property is a fingerprint of its own.

🧠 Self-improving fetch

Every fetch is an action and an observation. Pure deterministic state, no ML, and the loop converges: the more you use it, the less it escalates.

Cookie lifetime converges: observed_lifetime = min(previous, now - last_solved). Only clearance cookies persist (cf_clearance, datadome, _abck); tracking cookies are filtered out.

A wall that survives two real-browser solves is remembered, so future fetches answer honestly in milliseconds until the backoff lapses. A single failure never gates a domain, and any real solve or tier-1 cold success clears the memory. The daemon learns what its own environment cannot do.

Per-intent engine trust, egress-class domain profiles (cookies never cross exits), domain quality priors and crawl governor ladders all feed the same loop, all local, with receipts in donsetch status and donsetch doctor --improve. Disable disk state with DONSEEK_NO_DISK_STATE=1.

🏗️ Built from scratch

Every layer in Rust, no dependency on existing OSS web tooling.

1,300+ tests. Zero clippy warnings: cargo clippy --all-targets --features ocr,rerank -- -Dwarnings is the law, and CI runs the full matrix on Linux, macOS and Windows.

⚙️ Configuration

Every runtime knob lives in one typed config (src/config.rs), layered, later wins:

1. Compiled defaults. A bare donsetch mcp stays the law: zero config needed.
2. Legacy env vars (the pre-v4 names, DONSETCH_NO_CRAWL_SHAPE say). Honored exactly as before, reported as deprecated by doctor.
3. donsetch.toml at <config-dir>/donsetch/donsetch.toml, or anywhere via DONSETCH_CONFIG=/path/file.toml. Unknown keys and bad values are hard errors naming the file. DONSETCH_NO_CONFIG_FILE=1 skips the file layer (setting both is an error).
4. New env names: DONSETCH_<SECTION>__<KEY>, so DONSETCH_FETCH__PDF_MAX_MB=25.

Sections: transport, mcp, paths, state, proxy, tls, persona, cli, fetch, bypass, search, browser, debug.

[fetch]
h3 = true               # opt into the h3 lane
shadow_fetch = "never"  # or "auto" / "always"
pdf_max_mb = 100
dns_cache_ttl_secs = 30 # seconds a resolved name is reused in-process, 0 disables

[bypass]
max_daily = 100

Booleans take true/false, enums take their listed spellings.

• donsetch config show prints every knob with its value and its origin (default, legacy, file, env).
• donsetch config show --markdown prints the full reference table, one row per knob.
• donsetch config show --legacy maps every old env name to its config key.
• donsetch doctor warns about the legacy vars active in your shell, mapped to their keys.

💻 CLI

Thin adapter over the same engine the MCP server uses.

🔀 Proxies

Fetch dials direct by default, which keeps the stealth guarantee intact: a proxy you configured is a proxy that sees your traffic. But it follows the curl/openssl convention when the environment asks for it:

• HTTPS_PROXY / HTTP_PROXY / ALL_PROXY (any case) route fetches through that proxy, and NO_PROXY exempts.
• DONSETCH_NO_ENV_PROXY=1 disables the convention entirely.
• HTTP CONNECT proxies get an interception-safe handshake (no GREASE/ALPS/ECH/compress-cert), because TLS-terminating middleboxes re-sign with their own stack and some reset on exotic ClientHellos. SOCKS5 keeps the Chrome-true handshake, TLS rides end-to-end.
• SSL_CERT_FILE / SSL_CERT_DIR load into the trust store, which is the only way re-signed certificates verify in an intercepting network, exactly like curl.
• donsetch doctor reports the whole posture: resolved env proxy, kill-switch state, system and environment trust stores, plus a live check that names the interception fix when it fails.

Search and crawl rotate proxies across lanes, each with durable health: sticky per-host lanes, persona-exclusive exits, RTT-aware pacing, burned lanes remembered across restarts. A direct dial that fails is not a dead link, and a lane that dies does not silently take a domain with it.

donsetch proxy add <url>            # rotate-able proxy entry
DONSEEK_PROXIES="url1,url2"         # env form, comma separated
donsetch proxy list                 # list, credentials masked
donsetch proxy check                # live connectivity test
donsetch proxy remove <n> && donsetch proxy clear

🔐 Logged-in sessions

Pages behind a login (x.com, gated docs, internal tools) need a real session. donsetch login gives you one without ever seeing your credentials:

donsetch login x.com          # opens YOUR browser, you sign in, press Enter
donsetch login --list         # stored sessions (names and counts only)
donsetch login --status x.com # one domain, in detail
donsetch login --logout x.com # forget a domain
donsetch login --import cookies.txt x.com   # servers and CI, Netscape format

• Credentials never enter DonSeTch. It opens a real Chromium on your display in a dedicated profile, never the automation one. You type into the browser. No keystroke capture, no screenshots, no CDP attach until you press Enter.
• Afterwards the cookies are harvested, filtered to session-worthy ones, and stored in the same 0600 vault the fetch engine already replays, so tier-1 fetches and tier-2 renders of that domain carry your login immediately, with no daemon restart. A post-login probe verifies wall detection (redirect to /login, 401/403) and surfaces it in --list.
• The registry (auth-state.json) stores metadata only: names, counts, expiries, probe verdicts. Never values.
• Multi-site: run bare donsetch login, sign into as many tabs as you like, press Enter once.

🐳 Docker

docker build -t donsetch-mcp .
docker compose up -d                 # loopback-only by default

Multi-stage build, non-root user, optional Chrome, resource limits in the compose file. An opt-in http profile serves the HTTP transport with a healthcheck, and docker compose stop gives in-flight tier-2 fetches a 45s grace period.

🧭 Pick the right tool

DonSeTch is a rapid-fire research tool: search, read, verify. A search, a fetch or two, a docs page, one PDF. Its speed is the point, and that speed is its stealth for one-shot reads.

It is NOT built for tasks where an agent "works through" a defended site the way a person would:

• Bulk document harvesting: discovering and downloading many PDFs from one repository in a single run.
• Long sessions against one site: page after page, at machine speed, same IP, no human pauses.
• Mass extraction: mirroring a file library, collecting a dataset, systematic downloads.

DonSeTch will probably work on those, and nothing stops it. But every request fires hundreds of times faster than a human, and a defended site reads that pattern itself as a bot, not just the fingerprint. The realistic risk is an IP-level block, sometimes on your whole network mid-run. When that happens it is the task shape, not a fetch-layer failure: the same page fetched once, as a research read, is fine.

For that other shape of work, use Bladebro: a real browser doing what a human does, page by page, download by download, at a human's pace. Slower than DonSeTch by design, because over a long session against a defended site, looking human beats being fast.

Rule of thumb: one-shot research = DonSeTch. Working a defended site like a person to collect things = Bladebro.

⚠️ Gotchas & honest limits

🆚 How it compares

The honest summary: nothing else in this space combines a real Chrome TLS stack, browser-free keyless search, PDF pixel-fusion and local-only operation in one binary.

Against Firecrawl, head to head, same tasks, live. Firecrawl is a paid cloud API, DonSeTch is free, local and keyless:

• Fetch: Wikipedia comes back 16x smaller (16KB against 267KB). An arXiv PDF is 22x faster and 4.4x smaller (1.4s/16KB against 32.6s/71KB). Reddit: Firecrawl refuses the site, DonSeTch returns the real feed.
• Crawl: 2.5x faster on the same docs target (18.7s against 47.6s), with --topic ranking the frontier instead of firehosing, and an honest small failure when the topic has no match instead of verbose unrelated content.
• Search: Firecrawl is genuinely faster (1-2s against 5-7s) and leans mainstream authority. DonSeTch leans technical specificity, matched or beat it on exact GitHub issues, and costs far fewer tokens per query.

🤝 Contributing

PRs welcome, see CONTRIBUTING.md. Before submitting: just check, just t <scope> for the area you touched, and just lint (clippy with -Dwarnings). CI runs the full matrix on three platforms. AGPL v3: all contributions land under the same license.

📄 License

Copyright (c) 2026 Bishesh Bhandari. AGPL-3.0, see LICENSE.