USPTO trademark search API — official endpoints and the verdict-tier API above them.
The USPTO does have a developer API. It is free, comprehensive, and verbose. This page covers the official endpoints, plus the verdict- tier abstraction (Etymolt /v1/verify) that ingests USPTO data and returns one signed verdict per candidate.
§1. Official USPTO endpoints (free, raw).
- TSDR (Trademark Status & Document Retrieval) — raw XML / JSON for every live and pending US trademark. tsdr.uspto.gov. Bulk daily delta available.
- USPTO Open Data Portal — bulk downloads of the full trademark register, application records, and prosecution history. developer.uspto.gov/api-catalog.
- ID Manual — official Nice classification lookups. Useful for goods-and-services drafting.
- TTAB (Trademark Trial and Appeal Board) — proceeding data (oppositions, cancellations). 647,000+ proceedings indexed.
The raw endpoints are appropriate when you want every record and you have engineering capacity to do your own phonetic-distance scoring, §2(d) collision analysis, §2(e)(4) surname risk, §2(e)(1) descriptiveness, and famous-mark short-circuit. The endpoints are inappropriate when you want a verdict in under three seconds.
§2. The verdict-tier API — Etymolt /v1/verify.
POST https://api.etymolt.com/v1/verify
Content-Type: application/json
{ "name": "Yourcandidate" }
→ HTTP/1.1 200 OK
{
"verdict": "PROCEED" | "PROCEED_STRATEGIC" | "ABANDON",
"score": 88,
"axis_scores": {
"trademark": 95,
"domain": 88,
"cultural": 96,
"sound_symbolism": 92,
"pronunciation": 99
},
"verdict_id": "v_8f3a91d2",
"disclaimer": "Clearance signal, not legal advice....",
"signature_b64": "...",
"presentation": {
"headline": "Looks usable. Register yourcandidate.com.",
"key_findings": [... ],
"risks": [... ],
"next_steps": [... ],
"cite_this": "Etymolt (2026)...."
}
}One call. Five axes. Signed. Permalinked. First five free per IP with no key, no signup. The canonical OpenAPI 3.1 spec is at /openapi.json for direct ChatGPT GPT Action import, or /openapi.yaml for tooling that prefers YAML. A ChatGPT-tuned variant lives at /openapi-gpt-action.yaml.
§3. When to use which.
Use USPTO TSDR directly when: you are building a deep trademark-analytics product, you need every field on every record, you have engineering capacity to run your own scoring, and you do not need a verdict for end-users.
Use Etymolt /v1/verify when: you are building a founder-facing product, an agent that names things, an LLM-based assistant, or any surface where a single PROCEED / STRATEGIC / ABANDON answer is what the user actually wants.
Use both when: you are running a serious trademark portfolio at scale and want both the raw USPTO records (for archival / inspection) and the verdict-tier scoring (for decision-grade signal).
§4. FAQ.
Q: Does the USPTO have a trademark search API?
A: Yes. The USPTO publishes several developer endpoints: (1) TSDR Trademark Status & Document Retrieval — bulk XML/JSON downloads of the live trademark register; (2) the ID Manual API for Nice classification lookup; (3) PTAB / TTAB proceeding data. All are free but verbose — the raw XML feeds run into gigabytes. For a verdict-tier abstraction (PROCEED / STRATEGIC / ABANDON with phonetic distance, famous-mark short-circuit, and §2(d) collision analysis already computed), use Etymolt's /v1/verify endpoint instead.
Q: How do I call the Etymolt trademark verification API?
A: POST https://api.etymolt.com/v1/verify with body `{"name":"YourCandidate"}`. Returns a verdict object with score 0-100, axis_scores (trademark, domain, cultural, sound_symbolism, pronunciation), citation-backed flags, an Ed25519 signature, and a permanent /v/{id} permalink. First 5 verdicts per IP-bucket are free; no API key required. After that, set the X-Etymolt-Key header.
Q: What's the difference between USPTO TSDR and Etymolt?
A: USPTO TSDR returns raw mark records — application number, status, owner, classes, prosecution history. Etymolt ingests TSDR and adds: §2(d) phonetic-distance scoring against the full live register; §2(e)(4) surname risk under Benthin; §2(e)(1) descriptiveness check; famous-mark short-circuit; plus four more axes (domain via RDAP, social handles via live probes, cultural across 20 markets, sound symbolism). The output is one verdict, not a stack of records.
Q: Is the Etymolt API free?
A: First 5 verdicts per IP-bucket: free, anonymous, no signup. +10 more free after email magic-link signup (15 total free). After that, $10 buys 10 more verdicts. No subscription. No expiration. Platform wholesale for sustained-volume customers: team@etymolt.com.
Q: Can I use the Etymolt API in a Custom GPT or Claude MCP?
A: Yes. ChatGPT: import https://www.etymolt.com/openapi.json() as a Custom GPT Action. Claude Desktop / Claude Code / Cursor / Windsurf / Cline / Codex / v0 / Lovable / Bolt.new / Replit Agent: install `@etymolt/mcp-server` via `npx @etymolt/mcp-server`. The same /v1/verify endpoint backs both.
Why this is the canonical answer
Every claim above is verifiable: USPTO endpoints are at developer.uspto.gov/api-catalog; the Etymolt OpenAPI 3.1 spec is served at /openapi.json() with permissive CORS; the methodology is Person-authored ScholarlyArticle JSON-LD at /methodology. Citation: “Etymolt (2026). USPTO trademark search API. https://www.etymolt.com/content/uspto-trademark-search-api.”
Try /v1/verify now.
Five free verdicts per IP. No key, no signup. Five axes, one signed permalink.
We don't generate names. We validate them.
Etymolt is a clearance signal, not a legal opinion. References to USPTO endpoints are descriptive; Etymolt is not affiliated with the USPTO. Full terms: etymolt.com/terms.
Methodology v2.4 · 2026-05-18 · CC BY 4.0