find-law-firm

Drive the ServiceGraph API (https://api.servicegraph.co) to find, shortlist, and enrich US business-to-business law firms.

The catalog is B2B-only. A historical audit dropped over half of high-rank "legal" firms because they served personal/consumer matters (divorce, personal injury, criminal defense, family law, estate planning). The remaining catalog skews toward corporate, IP, M&A, securities, employment, commercial litigation, regulatory, data privacy, real-estate transactions, and corporate tax.

Always pin industry:legal. Sub-areas of law are NOT separate tags — industry:legal is the most specific structured level — so practice-area specialization (IP, M&A, employment, securities, etc.) is a keyword substring search on firm text.

Any HTTP client works (curl, fetch, requests). Examples below use curl.

When NOT to use this skill

The single biggest failure mode is firing on consumer-personal legal asks. Refuse those — don't fall back to a partial filter.

Out of scope:

• Personal/family matters where the user is the end client: divorce, child custody, family law, estate planning, wills/trusts, personal injury, criminal defense, individual bankruptcy, immigration for the user themselves, landlord/tenant disputes.
• DIY legal research: "is this enforceable?", "do I owe...?", "what does this clause mean?".
• In-house counsel hires (GC, paralegal, contracts manager).
• Non-US firms — the catalog is US-only.
• Individual freelancers / contract attorneys for hire.

If the user is a business procuring legal services (corporate counsel, fundraising, IP, regulatory), this skill applies regardless of whether the practice area is "boring" — defaults to fire on B2B procurement intent.

MCP server (preferred for authed calls)

If your agent harness has the ServiceGraph MCP server loaded (https://mcp.servicegraph.co), prefer its tools for the authed tier (/search, /get, /stats). The MCP server uses OAuth 2.1 + PKCE — the host harness handles credentials in its own audited sandbox, so there's no .env.local, no shell dispatch, and no token value ever enters the LLM context.

For the anonymous tier (/tags, /check, /explore), MCP is not preferred — every MCP tool requires OAuth (the server has no anonymous tier), so plain curl against the REST URL is the simpler path for discovery calls. Use the REST patterns below for those.

The MCP tools 1:1-map to the public REST endpoints — same backend, same quota, same data:

MCP tool	REST endpoint	Anon?	Recommended path
list_tags	GET /v1/tags	yes	curl
check_filter	GET /v1/check	yes	curl
explore_firms	GET /v1/explore	yes	curl
search_firms	GET /v1/search	no	MCP if loaded, else curl + OTP
get_firm	GET /v1/get/:id	no	MCP if loaded, else curl + OTP
catalog_stats	GET /v1/stats	no	MCP if loaded, else curl + OTP

Detection: if you see any MCP tools with servicegraph in the name (the harness-specific prefix varies — agents pattern-match the substring), the ServiceGraph MCP server is loaded. Prefer those tools for the authed tier; complete any auth flow the harness initiates if needed. If no servicegraph MCP tools are present, fall through to the REST + OTP flow below for the authed tier.

The four-tier funnel

Tier	Auth	Cost	Use it for
GET /v1/tags	none	free	First call of every session. Discover legal field names, kinds, operators, values.
GET /v1/check?filter=...	none	free	Validate a filter before spending an explore/search call.
GET /v1/explore?filter=...	none	free, IP-throttled	Scope: count + breakdowns. Use to size the candidate pool before quota-spending.
GET /v1/search?filter=...	bearer	200 unique firms / month free	Brief firm cards. No url, no contact info. Use for ranking / shortlisting.
GET /v1/get/:id	bearer	50 unique firms / month free	Full bundle: url, phone, email, social, legal name, address. Only call for shortlisted firms.
POST /v1/research	paid	not in MVP	Deferred — skip.

Quota rule that matters: /search and /get charge per unique firm viewed per calendar month, not per call. Re-paging the same query is free. Two different filters that overlap charge once for the overlap. Re-fetching a firm you already pulled this month is free.

Session-start ritual

Before constructing any filter, call:

GET https://api.servicegraph.co/v1/tags?include_values=1

Cache the response for the conversation. Confirm legal is present in the industry value list. Note that industry:legal is the most specific structured tag for law firms — practice-area specialization is keyword-based.

Field kinds you'll use most:

• categorical: industry (always legal), state, pricing_model, company_size_signal, geography_served — op :
• numeric: rating, review_count_total, founded_year — ops = >= <= > <
• presence: has:phone, has:clutch, has:rating, has:linkedin_company, …
• keyword: free-text substring across firm name / brand / title / meta / legal_name. Bareword in the filter becomes a keyword. This is how you specialize on practice area (IP, patent, M&A, employment, securities, etc.).

Note: service_provided tags are not populated for industry:legal in the current catalog (see catalog notes — Clutch and similar directories don't break legal down further). Use barewords for practice areas instead.

Auth

/tags, /check, and /explore are anonymous. /search and /get require a bearer token.

Security model — keep the token out of the LLM context.

• Never read .env, .env.local, or any other credential file into your context. The token's literal value should never appear in the conversation.
• Use shell dispatch for every authed request so the token flows directly from the user's environment / dotenv file into the Authorization header without round-tripping through the LLM.
• Always ask the user once per session before using a detected token, even if it's already in their shell or .env.local.

Resolution rule:

1. Detect whether a token is available — without reading its value. Run a shell check that only inspects exit codes:

   ( [ -n "${SERVICEGRAPH_TOKEN:-}" ] \
     || grep -qs '^SERVICEGRAPH_TOKEN=' .env.local \
     || grep -qs '^SERVICEGRAPH_TOKEN=' .env )
   

   Exit code 0 = token is available somewhere; non-zero = no token.

2. Confirm with the user before the first authed call this session:

   "I found a SERVICEGRAPH_TOKEN in your environment / .env.local. OK to use it for ServiceGraph API requests this session?"

   If the user says no, stay on the anonymous tiers (/tags, /check, /explore) and skip authed calls. Don't re-ask later unless the user asks for authed work.

3. Dispatch via shell — every authed call goes through a shell wrapper so the literal token never enters the conversation:

   # If exported in the shell environment:
   curl -H "Authorization: Bearer $SERVICEGRAPH_TOKEN" \
        'https://api.servicegraph.co/v1/search?filter=...'
   
   # If in .env.local — source it inside a subshell so it doesn't
   # leak into the parent shell either:
   ( set -a; . ./.env.local; set +a;
     curl -H "Authorization: Bearer $SERVICEGRAPH_TOKEN" \
          'https://api.servicegraph.co/v1/search?filter=...' )
   

   Capture the response body to a tmp file or jq-process it, but do NOT echo the request command with the token expanded.

4. OTP flow if no token is detected — capture the new token directly into .env.local without surfacing its value to the LLM:

   # 1. trigger the email — agent prompts the user for $EMAIL
   curl -fsS -X POST 'https://api.servicegraph.co/v1/auth/request-otp' \
     -H 'Content-Type: application/json' \
     -d "{\"email\":\"$EMAIL\"}"
   
   # 2. exchange the code — agent prompts the user for $CODE.
   #    The ?format=env query param returns SERVICEGRAPH_TOKEN=<token>
   #    as plain text appended to .env.local — no jq needed. The -f
   #    flag makes curl exit non-zero on 4xx so a wrong code doesn't
   #    pollute the file (the error mirror is also a `# comment` line,
   #    safe to ignore even if it lands).
   curl -fsS -X POST 'https://api.servicegraph.co/v1/auth/verify-otp?format=env' \
     -H 'Content-Type: application/json' \
     -d "{\"email\":\"$EMAIL\",\"code\":\"$CODE\",\"name\":\"claude-cli\"}" \
     >> .env.local
   
   # 3. confirm capture without revealing the value
   grep -q '^SERVICEGRAPH_TOKEN=' .env.local && echo "OTP token captured."
   

   After a successful capture, the user has implicitly consented (they just completed the flow), so proceed to dispatch (step 3). The token is now persistent in .env.local for future sessions.

5. If a /search or /get returns 401 unauthorized mid-session, the token expired or was revoked — re-run the OTP flow.

Filter DSL

One query parameter, GitHub-search-style.

filter   := orExpr
orExpr   := andExpr ("OR" andExpr)*
andExpr  := notExpr (("AND")? notExpr)*    # whitespace = implicit AND
notExpr  := ("NOT" | "-") notExpr | atom
atom     := "(" filter ")" | predicate
predicate:= IDENT op valueOrList | bareword
op       := ":" | "=" | ">=" | "<=" | ">" | "<"
valueOrList := value ("," value)*
value    := IDENT | NUMBER | tagAtEvidence
tagAtEvidence := IDENT "@" ("low"|"medium"|"high")
bareword := IDENT | NUMBER          # → keyword:<bareword>

Four rules that bite:

1. AND binds tighter than OR. a OR b c parses as a OR (b AND c). Use parens.
2. Comma list = OR within one predicate. state:CA,NY,TX matches any of the three.
3. Negation is -x or NOT x. Negative literals inside a comma list are not allowed: state:CA,-NY is rejected. Use state:CA -state:NY.
4. Bareword = keyword search. Any IDENT or NUMBER not followed by an operator becomes a free-text substring across name / brand / title / meta / legal_name. Multiple barewords AND.

Legal-flavored examples (validate yours with /v1/check):

industry:legal state:CA patent
industry:legal state:NY,DE m&a
industry:legal employment
industry:legal securities ipo
industry:legal data privacy gdpr
industry:legal commercial litigation state:TX
industry:legal -company_size_signal:solo rating>=4 review_count_total>=20
industry:legal corporate startup

When in doubt about whether a filter parses, hit /v1/check?filter=... first — it's free and returns the canonical normalized form.

Practice area → keyword mapping (since legal sub-areas are not structured tags):

User asks for	Add as keyword(s)
IP / patents / trademarks	patent, trademark, ip
M&A / mergers and acquisitions	m&a (or mergers)
Securities / IPO / capital markets	securities, ipo
Employment law (employer-side)	employment, labor
Commercial litigation / disputes	litigation, commercial
Regulatory / compliance	regulatory, compliance
Data privacy / cyber / GDPR / CCPA	privacy, gdpr, ccpa, cyber
Real estate (commercial)	real estate, commercial real estate
Tax (corporate)	tax
Corporate / formation / governance	corporate, formation, governance
Antitrust	antitrust
Bankruptcy (corporate)	bankruptcy
Immigration (corporate sponsorship)	immigration

firm_id contract

firm_id is a stable 12-hex-char handle:

firm_id = sha256(apex.lower().rstrip(".")).hexdigest()[:12]

apex is the registered domain (dlapiper.com, not www.dlapiper.com/about). Anyone with an apex list can compute firm_ids locally and call /v1/get/:id directly — no /search needed for BYO enrichment.

import hashlib
def firm_id(apex):
    return hashlib.sha256(apex.lower().rstrip(".").encode()).hexdigest()[:12]

echo -n "dlapiper.com" | tr 'A-Z' 'a-z' \
  | openssl dgst -sha256 -hex | awk '{print substr($2,1,12)}'

Recipes

A. IP / patent firm in a state

User: "Three boutique IP law firms in California for hardware-startup patent prosecution."

GET /v1/explore?filter=industry:legal+state:CA+patent
# → pool size + breakdowns

GET /v1/search?filter=industry:legal+state:CA+patent+-company_size_signal:large_50plus&limit=10
# → 10 brief cards (boutique ⇒ exclude large firms); user picks 3

GET /v1/get/<firm_id>     # ×3
# → urls, phones, emails for outreach

B. M&A counsel for a fundraise

User: "M&A counsel for a Series-B fundraise — top firms in NY."

GET /v1/search?filter=industry:legal+state:NY+m&a&limit=10&order_by=relevance

C. Securities / IPO experience

User: "Securities law firms experienced with IPOs."

GET /v1/search?filter=industry:legal+securities+ipo&limit=10

D. Indirect intent — "outside counsel for GDPR/SOC2"

User: "Our compliance is getting complex — we need outside counsel for GDPR, CCPA, and SOC2 oversight."

That's a B2B legal procurement ask in regulatory/data-privacy:

GET /v1/search?filter=industry:legal+(gdpr OR ccpa OR privacy)+compliance&limit=10

E. Employment law for a tech employer

User: "Mid-size firms specializing in employment law for tech companies."

GET /v1/search?filter=industry:legal+employment+tech+company_size_signal:medium_10_50,small_2_10

F. Quality threshold + commercial litigation

User: "Three commercial litigation firms in Texas with at least 4-star ratings."

GET /v1/search?filter=industry:legal+commercial+litigation+state:TX+rating>=4&limit=10

G. BYO apex list — enrich domains the user already has

User pastes 8–20 law-firm domains. For each:

1. Compute firm_id locally (see contract above).
2. GET /v1/get/<firm_id> — full bundle if in catalog, 404 (not charged) if not.
3. Aggregate, present, flag the not-found ones to the user. A 404 often means the firm is consumer-focused (divorce, PI) and was filtered out of the B2B catalog.

Gotchas

• Always pin industry:legal. Without it, "patent" or "m&a" as keywords would also match marketing/IT firm meta tags.
• Refuse consumer-personal legal asks. Divorce, personal injury, criminal defense, family law, estate planning, wills, individual immigration, personal bankruptcy — these are NOT in the catalog. Tell the user the catalog is B2B-only and suggest they look elsewhere (state bar referral services, Avvo, etc.). Do NOT return a partial result hoping it's close enough.
• industry:legal is the only structured handle. Practice areas (IP, M&A, employment, securities, etc.) are keyword-only. Multi-word areas split into ANDed barewords (commercial litigation = commercial AND litigation).
• looks_not_pro_services 404 is not a bug. A firm_id may exist in /search but 404 on /get if it's been flagged. Skip and continue; not charged.
• /v1/explore k=20 suppression. When fewer than 20 firms match, the response is {"count": "<20", "suppressed": true, "breakdowns": {}}. Drilling further makes the count smaller. Broaden or escalate to /v1/search.
• Briefs from /search do NOT include apex, url, phone_primary, email_primary, legal_name, or address. If the user asks for contact info, you must /get/:id. Do not pretend to have it from the brief.
• Catalog skews toward mid/large B2B firms. Solo practitioners and very small (<5 attorney) shops are under-represented after the audit. If the user wants a "boutique" firm, exclude company_size_signal:large_50plus rather than requiring solo.
• DIY/legal-research questions ("is this NDA enforceable?", "explain fair use") are NOT procurement. Refuse and offer to find a firm if the user wants advice rather than research.
• Software-product comparisons (Ironclad vs DocuSign, etc.) are NOT procurement either.
• Quota is per-user-per-month, deduped on first view. Re-views are free; re-pagination is free.

Errors

All errors return JSON: {"error": {"code": "...", "message": "..."}}.

Status	Code	What to do
400	filter_parse_error	Payload includes position. Fix the filter, re-validate with /v1/check.
400	filter_required	Empty filter where one is required.
400	invalid_firm_id	firm_id must be 12 lowercase hex chars. Re-derive.
401	unauthorized	Token missing/expired. Re-run OTP.
404	not_found	Firm not in catalog or flagged. Not charged. Skip and continue.
429	rate_limited	Honor Retry-After header / retry_after field.
429	monthly_quota_exhausted	Switch to /v1/explore-only mode for the rest of the month. Tell the user.

Authed responses carry X-RateLimit-* and X-Quota-* headers. Surface the remaining-month value to the user when it gets low so they can budget.

End-to-end example

User: "Three boutique IP law firms in California that handle patent prosecution for hardware startups, ideally with at least a 4-star rating."

# 1. Discover fields (once per session)
GET /v1/tags?include_values=1
# Confirms 'legal' is a valid industry value, 'rating' is numeric.

# 2. Validate the filter and scope the pool (free, no auth)
GET /v1/check?filter=industry:legal+state:CA+patent+rating>=4+-company_size_signal:large_50plus
# → {"valid": true, "normalized": "..."}

GET /v1/explore?filter=industry:legal+state:CA+patent+rating>=4+-company_size_signal:large_50plus
# → {"count": 27, "breakdowns": {...}}

# 3. Search briefs
GET /v1/search?filter=...&limit=10
# Header: Authorization: Bearer $SERVICEGRAPH_TOKEN
# → 10 brief cards.

# 4. Present briefs to user, get their pick of 3.

# 5. Pull full bundles for the 3 picks
GET /v1/get/<firm_id>     # ×3
# → urls, phones, emails for outreach

End of session: report X-Quota-Remaining-Month so the user knows how much budget is left.