503 Flatbush Avenue, Brooklyn, NY 11225
BBL 3011970004 (Borough 3, Block 1197, Lot 4) · BIN 3330674, 3330673 · Last updated: · Prospect Lefferts Gardens-Wingate · ZIP 11225
Also recorded in city data as: 1110 Washington Ave · 505 Flatbush Ave
Summary · as of November 8, 2026
503 Flatbush Avenue (Brooklyn, NY 11225; tax lot BBL 3011970004) is a garage or parking property (building class GW: garage, gas station or parking (subtype GW)), built around 1930, on a 7,618 sq ft lot zoned C8-2. City tax records list the owner as FLATBUSH AVENUE COMMONS, LLC; per ACRIS, a deed to this owner dated July 31, 2017 lists a price of $1,610,000. The Department of Finance's final market value for tax year 2027 is $1,286,000. As of November 8, 2026, NYC Open Data shows three active DOB violations, three active ECB violations and six OATH tickets with an unpaid balance. There were seven 311 requests in the past 12 months and no HPD complaints since 2019. (Source: NYC Open Data — DOB, HPD, OATH, DOF, DCP and ACRIS datasets — compiled by NYC Property Facts.)
- Owner of record
- FLATBUSH AVENUE COMMONS, LLC
- Building class
- GW · Garage, gas station or parking
- Year built · units
- 1930 · 0 res.
- Lot area · zoning
- 7,618 sq ft · C8-2
- Market value (DOF)
- $1,286,000 FY2027
- Last priced deed
- $1,610,000 · 2017-07-31
- BBL
- 3011970004
- BIN
- 3330674, 3330673
- 0Open DOB jobs (permit issued, no sign-off)
- 3Active DOB violations
- 3Active ECB violations
- 0Open HPD violations
- 6OATH tickets with unpaid balance
How to cite: NYC Property Facts, “503 Flatbush Avenue, Brooklyn, NY 11225 (BBL 3011970004)”, data as of 2026-11-08, https://nycpropertyfacts.com/ny/brooklyn/503-flatbush-avenue-3011970004. Source: NYC Open Data.
Lot & building
Basic facts about the tax lot and building from the city’s PLUTO database.
- Owner (as listed by the city)
- FLATBUSH AVENUE COMMONS, LLCThe owner name on the city’s tax records. It can lag behind recent sales and is often an LLC.
- Building class
- GW – Garage, gas station or parking (subtype GW)The Department of Finance’s category for what kind of building this is.
- Land use
- Commercial & officeCity Planning’s broad category of how the lot is used.
- Year built
- 1930Often an estimate for older buildings. Major alteration recorded: 2003.
- Floors
- 2
- Units
- 0 residential / 2 totalResidential units are apartments; total includes stores and offices.
- Buildings on lot
- 2
- Lot size
- 7,618 sq ft (50 ft × 141.67 ft)
- Building floor area
- 12,670 sq ft (incl. 12,670 sq ft commercial)
- Zoning
- C8-2The zoning district sets what can be built and used here. Commercial district.
- Built vs. allowed density (FAR)
- 1.66 built / 0.00 max residentialFloor Area Ratio = building floor area ÷ lot area. If built FAR is below the maximum, zoning may allow more floor area (other rules apply).
- Identifiers
- BBL 3011970004 (Borough 3, Block 1197, Lot 4) · BIN 3330674, 3330673BBL identifies the tax lot; BIN identifies each building (from DOB/HPD/footprint records).
Agency lookups: DOB BIS · ZoLa (zoning map) · ACRIS
Source: PLUTO (Dept. of City Planning) — city dataset updated 2026-08-24; last loaded 2026-11-08; Building Footprints — city dataset updated 2026-11-08; last loaded 2026-11-08
Tax assessment
How the Department of Finance values this lot for property tax.
- Market value (tax year 2027, final roll)
- $1,286,000The Department of Finance’s estimate of value for tax purposes. It is not an appraisal and is often far from the sale price.
- Assessed value
- $578,700The portion of market value that taxes are calculated on (capped by law for small homes).
- Taxable value (final)
- $492,750Assessed value minus any exemptions.
- Tax class
- Tax class 4 – commercial / industrial
| Tax year | Roll | Market value | Assessed value | Tax class |
|---|---|---|---|---|
| 2027 | Final | $1,286,000 | $578,700 | 4 |
| 2026 | Final | $1,214,000 | $546,300 | 4 |
| 2025 | Final | $1,151,000 | $517,950 | 4 |
Source: DOF Property Valuation and Assessment Data — city dataset updated 2026-09-14; last loaded 2026-11-08
Sales & deed history 6
Deeds recorded with the City Register (ACRIS). A deed transfers ownership. A $0 or very low price usually means a transfer between related parties, an estate, or a refinance-related transfer, not a market sale. This is not a title search; mortgages, liens and other documents are not shown.
| Date | Type | Price | Seller (grantor) | Buyer (grantee) | Doc ID |
|---|---|---|---|---|---|
| 2017-07-31 | DEED | $1,610,000 | Marshall, Esq, Referee, Deborah | Flatbush Avenue Commons, Llc | 2017081601415001 |
| 2006-03-10 | DEED | $2,200,000 | 503-505 Flatbush Realty Corp. | Automotive Realty Partners, Llc | 2006031701533003 |
| 1989-08-22 | DEED | $0 / not stated | Winer, Moshe; Taub, Martin | 503-505 Flatbush Rlty Cp | FT_3050001481605 |
| 1989-02-06 | DEED | $0 / not stated | Holmes, Roger | Winer, Moshe; Taub, Martin | FT_3630001434163 |
| 1985-10-03 | DEED | $0 / not stated | Mayflower Oxygen& Am/Fka; 514 Flatbush Av Cp; M.B.O. Corp | Holmes, Roger W | FT_3370001117837 |
| 1977-10-05 | DEED | $0 / not stated | Rudin Louis; Kaplan Samuel | 514 Flatbush Ave Corp | BK_7730094900305 |
Source: ACRIS Real Property Master — city dataset updated 2026-10-08; last loaded 2026-11-08; ACRIS Real Property Legals — city dataset updated 2026-10-08; last loaded 2026-11-08; ACRIS Real Property Parties — city dataset updated 2026-10-08; last loaded 2026-11-08
DOB job filings 0 open of 4
A “job” is an application to the Department of Buildings to do construction work. A job marked Permitted, not signed off had a work permit issued but the city has no record of final sign-off (inspection/completion). Old jobs left in this state are common and appear in buyer and lender due diligence; the work may or may not have been done.
| Status | Job # | Type | Filed | Est. cost |
|---|---|---|---|---|
| Not open Objections · 2026-06-26 | B01363487-I1 DOB NOW | Alteration CO | 2026-03-05 | $10,000 |
| Not open SIGNED OFF · 2005-07-20 | 301573447 BIS | A2 – Alteration with multiple work types (no change to use/occupancy) | 2003-07-23 | $15,000 |
| Not open SIGNED OFF · 2006-01-24 | 301533927 BIS | A1 – Major alteration (changes use, egress or occupancy) | 2003-04-10 | $60,000 |
| Not open PLAN EXAM - APPROVED · 1993-06-03 | 300255612 BIS | A2 – Alteration with multiple work types (no change to use/occupancy) | 1993-06-03 | $140,000 |
Source: DOB NOW: Build – Job Application Filings — city dataset updated 2026-11-07; last loaded 2026-11-08; DOB Job Application Filings (BIS) — city dataset updated 2026-11-07; last loaded 2026-11-08
Work permits 6
Individual permits issued under DOB jobs (one job can have several permits, e.g. plumbing and construction). Permit expiration alone does not mean the job was completed or signed off.
| Issued | Expires | Job # | Work | Permit status |
|---|---|---|---|---|
| 2005-03-02 | 2006-03-02 | 301533927 BIS | Plumbing / Plumbing | ISSUED (renewal) |
| 2005-02-08 | 2006-02-08 | 301573447 BIS | Equipment work / Sprinkler | ISSUED (renewal) |
| 2004-02-23 | 2005-02-22 | 301573447 BIS | Equipment work / Sprinkler | ISSUED (initial) |
| 2004-02-23 | 2005-02-22 | 301533927 BIS | Plumbing / Plumbing | ISSUED (initial) |
| 2003-06-27 | 2004-03-21 | 301533927 BIS | Alteration | ISSUED (initial) |
| 2003-06-27 | 2003-12-31 | 301533927 BIS | Construction equipment (scaffold, fence, shed) / Construction equipment | ISSUED (initial) |
Source: DOB NOW: Build – Approved Permits — city dataset updated 2026-11-07; last loaded 2026-11-08; DOB Permit Issuance (BIS) — city dataset updated 2026-11-07; last loaded 2026-11-07
DOB violations 3 active of 19
Violations issued by the Department of Buildings for building-code or zoning conditions. Active means DOB has not recorded the violation as resolved or dismissed. Many active DOB violations are old (e.g. elevator or boiler inspection paperwork).
| Status | Issued | Type | Description | Number |
|---|---|---|---|---|
| Active V-DOB VIOLATION - ACTIVE | 2019-12-26 | AEUHAZ1-FAIL TO CERTIFY CLASS 1 NONE | FAILURE TO CERTIFY CORRECTION ON IMMEDIATELY HAZARDOUS (CLASS 1) ECB VIOLATION | V122619AEUHAZ100644 |
| Active V-DOB VIOLATION - ACTIVE | 2019-11-13 | AEUHAZ1-FAIL TO CERTIFY CLASS 1 NONE | FAILURE TO CERTIFY CORRECTION ON IMMEDIATELY HAZARDOUS (CLASS 1) ECB VIOLATION | V111319AEUHAZ100639 |
| Active V-DOB VIOLATION - ACTIVE | 1997-01-13 | LL1081-LOCAL LAW 10/81 - ELEVATOR ELEVATOROPTIONAL | V011397LL108102628 | |
| Resolved/dismissed V*-DOB VIOLATION - DISMISSED | 2020-09-02 | AEUHAZ1-FAIL TO CERTIFY CLASS 1 NONE | FAILURE TO CERTIFY CORRECTION ON IMMEDIATELY HAZARDOUS (CLASS 1) ECB VIOLATION | V*090220AEUHAZ105313 |
| Resolved/dismissed V*-DOB VIOLATION - DISMISSED | 2020-02-19 | AEUHAZ1-FAIL TO CERTIFY CLASS 1 NONE | FAILURE TO CERTIFY CORRECTION ON IMMEDIATELY HAZARDOUS (CLASS 1) ECB VIOLATION | V*021920AEUHAZ100569 |
| Resolved/dismissed V%*-DOB VIOLATION - DISMISSED | 2018-04-14 | UB-UNSAFE BUILDINGS NONE | V%*041418UB3410/18 | |
| Resolved/dismissed V*-DOB VIOLATION - Resolved | 2003-05-29 | E-ELEVATOR ELEVATORREQUIRED | V*052903E9444/375239 | |
| Resolved/dismissed V*-DOB VIOLATION - Resolved | 2002-08-26 | E-ELEVATOR ELEVATORREQUIRED | 3F5549 | V*082602E9013/359111 |
| Resolved/dismissed V*-DOB VIOLATION - DISMISSED | 2001-03-08 | LL1081-LOCAL LAW 10/81 - ELEVATOR ELEVATOROPTIONAL | V*030801LL108102128 | |
| Resolved/dismissed V*-DOB VIOLATION - DISMISSED | 1999-01-20 | LL1081-LOCAL LAW 10/81 - ELEVATOR ELEVATOROPTIONAL | V*012099LL108102190 | |
| Resolved/dismissed V*-DOB VIOLATION - DISMISSED | 1997-01-13 | LL1081-LOCAL LAW 10/81 - ELEVATOR ELEVATOROPTIONAL | V*011397LL108102646 | |
| Resolved/dismissed V*-DOB VIOLATION - DISMISSED | 1996-03-08 | LL1081-LOCAL LAW 10/81 - ELEVATOR ELEVATOROPTIONAL | V*030896LL108102197 | |
| Resolved/dismissed V*-DOB VIOLATION - DISMISSED | 1995-04-17 | LL1081-LOCAL LAW 10/81 - ELEVATOR ELEVATOROPTIONAL | V*041795LL108102792 | |
| Resolved/dismissed V*-DOB VIOLATION - DISMISSED | 1994-05-31 | LL1081-LOCAL LAW 10/81 - ELEVATOR ELEVATOROPTIONAL | V*053194LL108103554 | |
| Resolved/dismissed V*-DOB VIOLATION - DISMISSED | 1993-06-28 | LL1081-LOCAL LAW 10/81 - ELEVATOR ELEVATOROPTIONAL | 1 | V*062893LL108102917 |
Showing 15 of 19 records. The API and the source dataset have the full list.
Source: DOB Violations — city dataset updated 2026-11-07; last loaded 2026-11-08
ECB violations (DOB) 3 active of 9
DOB violations that go to a hearing at OATH (formerly the Environmental Control Board) and can carry fines. Active or Resolved follows the DOB violation status field. The hearing status is about the hearing and its penalty: written off means the city stopped collecting the fine, not that the condition was corrected. A balance due is a fine the city says is unpaid.
| Status | Issued | Severity | What it was for | Penalty / paid / balance | ECB # |
|---|---|---|---|---|---|
| Active Hearing: IN VIOLATION | 2019-11-26 | CLASS - 1 | FAILURE TO MAINTAIN BUILDING IN CODE COMPLIANT MANNER NOTED OBSERVED TA FRON OF BUILDIN GAT EXPOSURE #1 THE WALL TILES ARE MISSING EXPOSING TEH BRICKS AN THE H IRON REPAIR AND OR REPLACE | $3,125 / $0 / $3,125 | 35459176K |
| Resolved Hearing: DISMISSED · Certification: N/A - DISMISSED | 2020-02-14 | CLASS - 1 | FAILURE TO MAINTAIN BUILDING IN CODE COMPLIANT MANNER, AT TIME OF INSPECTION OBSERVED AT FRONT OF BUILDING AT EXPOSURE#1 THE WALL TILES ARE MISSING EXPOSING THE BRICK.RE-ISSUE#3549176K;ISSUED ON 11/26/19.REM:RE | $0 / $0 / $0 | 35467836R |
| Resolved Hearing: IN VIOLATION · Certification: CERTIFICATE ACCEPTED | 2003-09-02 | Hazardous | FAILURE TO PROVIDE ADEQAUTE PROTECTION FOR SIDEWALK AND WALKWAYS DURING CONSTRUCTION OPERAITON. NOTE: PERMIT #301533927 OBTAIN FOR DEMOLITION. AT TIME OF INSPECTION, DEMOLITION WORK IN PROGRESS WITH NO PROTECTI | $2,000 / $2,000 / $0 | 34413105N |
| Active Hearing: IN VIOLATION · Certification: NO COMPLIANCE RECORDED | 2019-08-22 | CLASS - 1 | FAILURE TO MAINTAIN BLDG IN CODE COMPLIANT MANNER. OBSERVED INDUSTRIAL LIGHT FIXTURE HANG ONLY ON ELECTRICAL CABLE AT EXP#1 AT FACADE WALL LEFT SIDE OF ENTRANCE DOOR THE TILES FALLING DOWN ON SIDEWALK. | $1,250 / $0 / $1,250 | 35415691K |
| Resolved Hearing: IN VIOLATION · Certification: CERTIFICATE ACCEPTED | 2003-09-02 | Non-Hazardous | FAILURE TO POST PERMIT FOR WORK AT PREMISES: PERMITS # 301533927 OBTAIN FOR DEMOLITION AT TIME OF INSPECTION WORK IN PROGRESS NO PERMIT POSTED. STOP ALL WORK. REMEDY: POST PERMIT. CALL 802-3685 FOR INSPECTION B | $130 / $130 / $0 | 34413104L |
| Active Hearing: IN VIOLATION · Certification: NO COMPLIANCE RECORDED | 2019-10-04 | CLASS - 1 | FAILURE TO MAINTAIN BLDG IN CODE COMPLIANT MANNER. NOTED: OBSERVED AT THE FRONT OF THE BLDG THE TILES HAVE FELL OFF THE WALL ONTO THE SIDEWALK. REMEDY: REPAIR &/OR REPLACE. | $3,125 / $0 / $3,125 | 35452197H |
| Resolved Hearing: DEFAULT · Certification: CERTIFICATE ACCEPTED | 1999-08-05 | Non-Hazardous | 73X. ELEVATOR OUT OF ORDER. RETORE TO SERVICE SO A COMPLETE INSPECTION CAN BE MADE. | $2,500 / $2,500 / $0 | 38088841K |
| Resolved Hearing: STIPULATION/IN-VIO · Certification: CERTIFICATE ACCEPTED | 1995-09-22 | Non-Hazardous | 03#,09H,73Y,75M. 03 RENEW CAR FLOOR + TILES REPLACE HND RAIL. 73 REPACK SCALS. | $200 / $200 / $0 | 38051377R |
| Resolved Hearing: DISMISSED · Certification: N/A - DISMISSED | 2020-10-20 | CLASS - 2 | FAILURE TO COMPLY WITH COMMISSIONER'S ORDER CONTAINED IN SUMMONS/VIOLATION#35467836R ISSUED ON 2/14/20 AND TO FILE A CERTIFICATE OF CORRECTION PURSUANT TO 28-201.1 AND 1RCNY102-01.REM:COMPLY WITH COMMISSIONER'S | $0 / $0 / $0 | 35522023Z |
Source: DOB ECB Violations — city dataset updated 2026-11-07; last loaded 2026-11-08
OATH tickets (all agencies) 6 unpaid of 59
Summonses heard at the Office of Administrative Trials and Hearings, from agencies like Sanitation, Buildings, Fire and Health, linked to this lot’s block and lot. Default means the respondent did not appear at the hearing, which typically results in the maximum penalty. Tickets may be issued to tenants or businesses at the address, not just the owner. DOB ECB tickets appear here too.
| Status | Date | Agency | Charge | Respondent | Imposed / paid / balance | Ticket # |
|---|---|---|---|---|---|---|
| Unpaid balance Default DOCKETED · DEFAULTED | 2022-01-19 | Fire Department Of Nyc | LABELS MARKINGS | FLATBUSH AVE COMMONS LLC | $2,000 / $0 / $2,000 | 011804271M |
| Unpaid balance Default DOCKETED · DEFAULTED | 2022-01-19 | Fire Department Of Nyc | RECORDKEEPING | FLATBUSH AVE COMMONS LLC | $2,000 / $0 / $2,000 | 011804266H |
| Unpaid balance Default DOCKETED · DEFAULTED | 2021-10-21 | Fire Department Of Nyc | INSPECTION AND TESTING | FLATBUSH AVE COMMONS LLC | $1,000 / $0 / $1,000 | 011802403X |
| Unpaid balance DOCKETED · IN VIOLATION | 2019-11-26 | Dept. Of Buildings | FAILURE TO MAINTAIN BUILDING IN CODE-COMPLIANT MANNER | FLTASHBUCH AVENUE COMMONS LLC | $3,125 / $0 / $3,125 | 035459176K |
| Unpaid balance DOCKETED · IN VIOLATION | 2019-10-04 | Dept. Of Buildings | FAILURE TO MAINTAIN BUILDING IN CODE-COMPLIANT MANNER | FLATBUSH AVE COMMONS LLC | $3,125 / $0 / $3,125 | 035452197H |
| Unpaid balance DOCKETED · IN VIOLATION | 2019-08-22 | Dept. Of Buildings | FAILURE TO MAINTAIN BUILDING IN CODE-COMPLIANT MANNER | FLATBUSH AVE COMMONS,LLC | $1,250 / $0 / $1,250 | 035415691K |
| No balance due PAID IN FULL | 2024-10-21 | Sanitation Others | IMPROPER RECEPTACLE ALL BUSINESSES 1ST | M M CARWASH LUBE | $50 / $50 / $0 | 048687208M |
| No balance due Default DEFAULTED · DEFAULTED | 2023-08-29 | Fire Department Of Nyc | PORTABLE FIRE EXTINGUISHERS AND FIRE HOSES | $1,000 / $1,000 / $0 | 014078581N | |
| No balance due PAID IN FULL · ADMIT IN-VIO | 2023-08-17 | Dep - Bureau Of Env. Complianc | IDLING OF MOTOR VEHICLE ENGINE MORE THAN THREE MINUTES 1ST OFF | MANHATTAN BEER DISTRIBUTORS | $350 / $350 / $0 | 000829990K |
| No balance due HEARING COMPLETED · DISMISSED | 2020-10-20 | Dept. Of Buildings | FAIL TO COMPLY W COMMISSIONER ORDER TO FILE CERT OF CORRECTION W DOB | FLATBUSH AVE COMMONS LLC | $0 / $0 / $0 | 035522023Z |
| No balance due HEARING COMPLETED · DISMISSED | 2020-02-14 | Dept. Of Buildings | FAILURE TO MAINTAIN BUILDING IN CODE-COMPLIANT MANNER | FLATBUSH AVENUE COMMONS LLC | $0 / $0 / $0 | 035467836R |
| No balance due PAID IN FULL · IN VIOLATION | 2019-04-17 | Vector - Dohmh | FAIL TO ELIMINATE STANDING WATER MOSQUITO CONDITIONS;MINOR | FLATBUSH AVE COMMONS LLC | $300 / $300 / $0 | 0801601067 |
Showing 12 of 59 records. The API and the source dataset have the full list.
Source: OATH Hearings Division Case Status — city dataset updated 2026-11-08; last loaded 2026-11-08
HPD registration & contacts
Owners of most rental buildings must register with the Department of Housing Preservation and Development each year and list an owner and managing agent.
No HPD registration found. Registration is required for buildings with 3 or more apartments (and for 1–2 family homes where neither the owner nor family lives there).
Source: HPD Multiple Dwelling Registrations — city dataset updated 2026-11-04; last loaded 2026-11-08; HPD Registration Contacts — city dataset updated 2026-11-04; last loaded 2026-11-08
HPD housing-code violations 0 open of 0
Violations HPD inspectors issued for conditions in residential buildings (heat, leaks, mold, pests, lead paint, etc.). Class letters show how serious: Class A – non-hazardous (HPD gives 90 days to correct); Class B – hazardous (30 days to correct); Class C – immediately hazardous (24 hours to correct for most conditions); Class I – information / order (e.g. orders to register, lead or other administrative orders). Open means HPD has not recorded the condition as corrected.
No records found in this dataset for this lot.
Source: HPD Housing Maintenance Code Violations — city dataset updated 2026-11-08; last loaded 2026-11-08
HPD complaints 0
Complaints tenants or others made to HPD (usually via 311) about housing conditions, from 2019 onward. A complaint is not a violation; HPD may inspect and issue one.
No records found in this dataset for this lot.
Source: HPD Housing Maintenance Code Complaints and Problems — city dataset updated 2026-11-08; last loaded 2026-11-08
311 requests (last 12 months) 7
Recent 311 service requests the city geocoded to this lot: noise, illegal parking, heat, sanitation and more. Anyone can file them, so they describe activity at or near the address, not necessarily the building itself.
| Opened | Agency | Complaint | Status | Closed |
|---|---|---|---|---|
| 2026-08-10 | NYPD | Illegal Parking – Posted Parking Sign Violation | Closed | 2026-08-10 |
| 2026-06-08 | NYPD | Illegal Parking – Posted Parking Sign Violation | Closed | 2026-06-08 |
| 2026-05-08 | NYPD | Illegal Parking – Posted Parking Sign Violation | Closed | 2026-05-08 |
| 2026-04-18 | DSNY | Dirty Condition – Trash | Closed | 2026-04-20 |
| 2026-04-01 | DEP | Hazardous Materials – Chemical Spill/Release (HA1) | Closed | 2026-04-01 |
| 2026-04-01 | NYPD | Illegal Parking – Blocked Sidewalk | Closed | 2026-04-01 |
| 2026-03-31 | DEP | Hazardous Materials – Chemical Spill/Release (HA1) | Closed | 2026-03-31 |
Source: 311 Service Requests from 2020 to Present — city dataset updated 2026-11-07; last loaded 2026-11-07; a later sync attempt failed on 2026-11-08; showing the last successful load
Nearby properties
Ordered by map distance among lots on this street within 40 house numbers and on this tax block within 15 lot numbers.
More in Prospect Lefferts Gardens-Wingate: Open HPD violations · Active DOB violations · Active ECB violations · Open DOB jobs · Unpaid OATH tickets
Closest on Flatbush Ave
- 507 Flatbush Avenue (68 ft) (28 open items)
- 479 Flatbush Avenue (143 ft) (13 open items)
- 498 Flatbush Avenue (222 ft) (four open items)
- 496 Flatbush Avenue (222 ft) (20 open items)
- 500 Flatbush Avenue (223 ft) (65 open items)
- 494 Flatbush Avenue (224 ft) (four open items)
Open-item counts as of November 8, 2026; each section lists its own dataset date. Machine-readable: JSON API · Markdown · Plain text · API & MCP docs