511 80th Street, Brooklyn, NY 11209
BBL 3059810079 (Borough 3, Block 5981, Lot 79) · BIN 3151006 · Last updated:
Summary · as of October 31, 2026
511 80th Street (Brooklyn, NY 11209; tax lot BBL 3059810079) is a 3-unit walk-up apartment building (building class C0: three-family walk-up), built around 1920, on a 2,000 sq ft lot zoned R4-1. City tax records list the owner as CHEN, DE ZHU; per ACRIS, a deed to this owner dated December 10, 2015 lists a price of $1,160,000. The Department of Finance's final market value for tax year 2027 is $1,826,000. As of October 31, 2026, NYC Open Data shows no open DOB jobs, active DOB/ECB violations, open HPD violations or unpaid OATH tickets for this lot. (Source: NYC Open Data — DOB, HPD, OATH, DOF, DCP and ACRIS datasets — compiled by NYC Property Facts.)
- Owner of record
- CHEN, DE ZHU
- Building class
- C0 · Three-family walk-up
- Year built · units
- 1920 · 3 res.
- Lot area · zoning
- 2,000 sq ft · R4-1
- Market value (DOF)
- $1,826,000 FY2027
- Last priced deed
- $1,160,000 · 2015-12-10
- BBL
- 3059810079
- BIN
- 3151006
- 0Open DOB jobs (permit issued, no sign-off)
- 0Active DOB violations
- 0Active ECB violations
- 0Open HPD violations
- 0OATH tickets with unpaid balance
How to cite: NYC Property Facts, “511 80th Street, Brooklyn, NY 11209 (BBL 3059810079)”, data as of 2026-10-31, https://nycpropertyfacts.com/ny/brooklyn/511-80th-street-3059810079. 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)
- CHEN, DE ZHUThe owner name on the city’s tax records. It can lag behind recent sales and is often an LLC.
- Building class
- C0 – Three-family walk-upThe Department of Finance’s category for what kind of building this is.
- Land use
- Multi-family walk-up buildingsCity Planning’s broad category of how the lot is used.
- Year built
- 1920Often an estimate for older buildings. Major alteration recorded: 2016.
- Floors
- 3
- Units
- 3 residential / 3 totalResidential units are apartments; total includes stores and offices.
- Buildings on lot
- 1
- Lot size
- 2,000 sq ft (20 ft × 100 ft)
- Building floor area
- 3,030 sq ft
- Zoning
- R4-1, R6B, C1-3, BRThe zoning district sets what can be built and used here. Residential district; the overlay (C1/C2…) allows local retail on residential blocks.
- Built vs. allowed density (FAR)
- 1.52 built / 1.00 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 3059810079 (Borough 3, Block 5981, Lot 79) · BIN 3151006BBL 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; data as of 2026-11-02; Building Footprints — city dataset updated 2026-10-25; data as of 2026-11-01
Tax assessment
How the Department of Finance values this lot for property tax.
- Market value (tax year 2027, final roll)
- $1,826,000The 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
- $109,560The portion of market value that taxes are calculated on (capped by law for small homes).
- Taxable value (final)
- $74,792Assessed value minus any exemptions.
- Tax class
- Tax class 1 – 1–3 family homes (and some small mixed-use / vacant lots)
| Tax year | Roll | Market value | Assessed value | Tax class |
|---|---|---|---|---|
| 2027 | Final | $1,826,000 | $109,560 | 1 |
| 2026 | Final | $1,702,000 | $102,120 | 1 |
| 2025 | Final | $1,493,000 | $89,580 | 1 |
Source: DOF Property Valuation and Assessment Data — city dataset updated 2026-09-14; data as of 2026-11-02
Sales & deed history 5
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 |
|---|---|---|---|---|---|
| 2021-03-05 | DEED | $0 / not stated | Chen, De Zhu; Ni, Wei Kang | Ni, Wei Kang; Chen, De Zhu; Ni, Wei Xia | 2021032600753001 |
| 2015-12-10 | DEED | $1,160,000 | Jiang , Qing Feng; Jiang , Qing Song | Ni, Wei Kang; Chen , De Zhu | 2015121600500001 |
| 2013-09-09 | DEED | $920,000 | Agrapides, Argie; Salavantis, Tessie | Jiang, Qing Feng; Jiang, Qing Song | 2013092301583001 |
| 2006-03-06 | DEED | $10 | Bourlotos, James; Bourlotos, Theodora | Agrapides, Argie; Salavantis, Tessie | 2006030600691001 |
| 1968-01-12 | DEED | $0 / not stated | Nahra Alfred J; Nahra Julia | Burlotos Theodora; Burlotos James | BK_6830062700029 |
Source: ACRIS Real Property Master — city dataset updated 2026-10-08; data as of 2026-11-02; ACRIS Real Property Legals — city dataset updated 2026-10-08; data as of 2026-11-02; ACRIS Real Property Parties — city dataset updated 2026-10-08; data as of 2026-11-02
DOB job filings 0 open of 2
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 SIGNED OFF · 2016-12-22 | 321319596 BIS | A2 – Alteration with multiple work types (no change to use/occupancy) | 2016-03-18 | $290,000 |
| Not open PLAN EXAM - DISAPPROVED · 2016-03-02 | 340349625 BIS | A2 – Alteration with multiple work types (no change to use/occupancy) | 2016-02-03 | $94,500 |
Source: DOB NOW: Build – Job Application Filings — city dataset updated 2026-11-01; data as of 2026-11-02; DOB Job Application Filings (BIS) — city dataset updated 2026-10-30; data as of 2026-10-31
Work permits 4
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 |
|---|---|---|---|---|
| 2016-04-11 | 2017-04-11 | 321319596 BIS | Plumbing / Plumbing | ISSUED (initial) |
| 2016-04-07 | 2017-02-01 | 321319596 BIS | Equipment work / Mechanical/HVAC | ISSUED (initial) |
| 2016-04-07 | 2017-02-01 | 321319596 BIS | Equipment work / Other / general construction | ISSUED (initial) |
| 2016-04-07 | 2017-04-07 | 321319596 BIS | Construction equipment (scaffold, fence, shed) / Construction equipment | ISSUED (initial) |
Source: DOB NOW: Build – Approved Permits — city dataset updated 2026-11-02; data as of 2026-11-02; DOB Permit Issuance (BIS) — city dataset updated 2026-10-31; data as of 2026-10-31
DOB violations 0 active of 1
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 |
|---|---|---|---|---|
| Resolved/dismissed V*-DOB VIOLATION - DISMISSED | 2016-09-07 | AEUHAZ1-FAIL TO CERTIFY CLASS 1 NONE | FAILURE TO CERTIFY CORRECTION ON IMMEDIATELY HAZARDOUS (CLASS 1) ECB VIOLATION | V*090716AEUHAZ100376 |
Source: DOB Violations — city dataset updated 2026-11-02; data as of 2026-11-02
ECB violations (DOB) 0 active of 3
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 # |
|---|---|---|---|---|---|
| Resolved Hearing: IN VIOLATION · Certification: CERTIFICATE ACCEPTED | 2008-03-12 | Non-Hazardous | OCCUPANCY CONTRARY TO C OF O DEPT RECORDS NOTED BUILDING IS A LEGAL 3 FAMILY AS PER PERMIT 4103122 AT 12/14/22 WITH ONE FAMILY ON THE 3RD FL 2ND FL 1ST FL HOWEVER AT TIME OF INSPECTION BASEMENT FOUND WITH THE | $400 / $400 / $0 | 34640708M |
| Resolved Hearing: DISMISSED · Certification: N/A - DISMISSED | 2008-03-12 | Hazardous | WORK W/O A PERMIT ILLEGAL WORK NOTED: ERECTED PLUMBING GAS LINE AND INSTALL GAS RANGE AT BASEMENT TO CREATE KITCHEN IN AN OPEN BOILER ROOM. REMEDY: OBTAIN PROPER PERMIT IF FEASIBLE OR RESTORE PREMISES TO PRIOR | $0 / $0 / $0 | 34640711N |
| Resolved Hearing: IN VIOLATION · Certification: CERTIFICATE ACCEPTED | 2016-06-08 | CLASS - 1 | WORK DOES NOT CONFORM TO APPROVED CONSTRUCTION DOCUMENTS &/OR APPROVEDAMENDMENTS. NOTED: CONTRACTOR IS WORKING ON ALT2 APP#321319596 & IT WAS OBSERVED THAT A NEW LEAD COATED COPPER LIGHT WAS INSTALLED IN THE | $500 / $500 / $0 | 35125311Y |
Source: DOB ECB Violations — city dataset updated 2026-10-31; data as of 2026-11-02
OATH tickets (all agencies) 0 unpaid of 7
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 # |
|---|---|---|---|---|---|---|
| No balance due PAID IN FULL | 2026-09-25 | Sanitation Others | FAIL TO RECYCLE ORGANIC WASTE 1-8 DWELLING UNITS 1ST | CHEN DE ZHU | $25 / $25 / $0 | 080127945R |
| No balance due PAID IN FULL · IN VIOLATION | 2016-06-08 | Dept. Of Buildings | WORK DOES NOT CONFORM TO APPROVED CONSTRUCTION DOCUMENTS AMENDMENTS | SK ONE CONSTRUCTION INC | $500 / $500 / $0 | 035125311Y |
| No balance due HEARING COMPLETED · DISMISSED | 2014-07-25 | Fire Department Of Nyc | GENERAL MAINTENANCE | QING SONG JIANG | — / — / — | 011410801Z |
| No balance due Default PAID IN FULL · DEFAULT | 2014-05-06 | IMPROPER DISPOSAL BEDDING 1ST OFFENSE | JIANG | $130 / $130 / — | 0178062684 | |
| No balance due PAID IN FULL | 2008-04-18 | Dos - Enforcement Agents | NON-RECYCLABLES LEFT IN RECYCLING CONTAINER FOR COLLECTION | AGRAPIDES | $25 / $25 / — | 041861161K |
| No balance due PAID IN FULL · IN VIOLATION | 2008-03-12 | Dept. Of Buildings | OCCUPANCY CONTRARY TO THAT ALLOWED BY C. OF O. OR DOB RECORDS. | ARGIE AGRAPIDES | $400 / $400 / — | 034640708M |
| No balance due HEARING COMPLETED · DISMISSED | 2008-03-12 | Dept. Of Buildings | WORK WITHOUT A PERMIT. | AGRAPIDES | — / — / — | 034640711N |
Source: OATH Hearings Division Case Status — city dataset updated 2026-11-02; data as of 2026-11-02
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.
- HPD building ID
- 176177
- Last registered
- 2025-07-01
- Registration valid until
- 2026-09-01 ExpiredRegistrations must be renewed every year.
| Role | Name | Company | Business city |
|---|---|---|---|
| Agent | Jessie Ni | Brooklyn, Ny | |
| Sitemanager | Jessie Ni | ||
| Jointowner | Weikang Ni | Brooklyn, Ny | |
| Jointowner | De Zhu Chen | Brooklyn, Ny |
Source: HPD Multiple Dwelling Registrations — city dataset updated 2026-10-28; data as of 2026-11-02; HPD Registration Contacts — city dataset updated 2026-10-28; data as of 2026-11-02
HPD housing-code violations 0 open of 127
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.
| Status | Class | Issued | Apt | Condition |
|---|---|---|---|---|
| Closed Violation Dismissed · 2026-05-08 | A | 2026-05-01 | (A) § HMC:FILE ANNUAL BEDBUG REPORT IN ACCORDANCE WITH HPD RULE AS DESCRIBED ON THE BACK OF THIS NOTICE OF VIOLATION OR AS DESCRIBED ON HPDS WEBSITE, WWW.NYC.GOV\HPD, SEARCH BED BUGS. | |
| Closed Violation Dismissed · 2023-02-28 | I | 2022-11-07 | §27-2107 ADM CODE OWNER FAILED TO FILE A VALID REGISTRATION STATEMENT WITH THE DEPARTMENT AS REQUIRED BY ADM CODE §27-2097 AND IS THEREFORE SUBJECT TO CIVIL PENALTIES, PROHIBITED FROM CERTIFYING VIOLATIONS, AND DENIED THE RIGHT TO RECOVER POSSESSION OF PREMISE | |
| Closed Violation Dismissed · 2022-03-23 | I | 2022-02-22 | §27-2107 ADM CODE OWNER FAILED TO FILE A VALID REGISTRATION STATEMENT WITH THE DEPARTMENT AS REQUIRED BY ADM CODE §27-2097 AND IS THEREFORE SUBJECT TO CIVIL PENALTIES, PROHIBITED FROM CERTIFYING VIOLATIONS, AND DENIED THE RIGHT TO RECOVER POSSESSION OF PREMISE | |
| Closed Violation Dismissed · 2022-03-25 | A | 2022-02-22 | (A) § HMC:FILE ANNUAL BEDBUG REPORT IN ACCORDANCE WITH HPD RULE AS DESCRIBED ON THE BACK OF THIS NOTICE OF VIOLATION OR AS DESCRIBED ON HPDS WEBSITE, WWW.NYC.GOV\HPD, SEARCH BED BUGS. | |
| Closed Violation Dismissed · 2021-04-22 | A | 2021-04-07 | (A) § HMC:FILE ANNUAL BEDBUG REPORT IN ACCORDANCE WITH HPD RULE AS DESCRIBED ON THE BACK OF THIS NOTICE OF VIOLATION OR AS DESCRIBED ON HPDS WEBSITE, WWW.NYC.GOV\HPD, SEARCH BED BUGS. | |
| Closed Violation Dismissed · 2019-11-29 | I | 2019-10-29 | §27-2107 ADM CODE OWNER FAILED TO FILE A VALID REGISTRATION STATEMENT WITH THE DEPARTMENT AS REQUIRED BY ADM CODE §27-2097 AND IS THEREFORE SUBJECT TO CIVIL PENALTIES, PROHIBITED FROM CERTIFYING VIOLATIONS, AND DENIED THE RIGHT TO RECOVER POSSESSION OF PREMISE | |
| Closed Violation Dismissed · 2017-08-16 | I | 2016-11-03 | §27-2107 ADM CODE OWNER FAILED TO FILE A VALID REGISTRATION STATEMENT WITH THE DEPARTMENT AS REQUIRED BY ADM CODE §27-2097 AND IS THEREFORE SUBJECT TO CIVIL PENALTIES, PROHIBITED FROM CERTIFYING VIOLATIONS, AND DENIED THE RIGHT TO RECOVER POSSESSION OF PREMISE | |
| Closed Violation Dismissed · 2015-11-30 | I | 2015-10-07 | SECTION27-2107 ADM CODE OWNER FAILED TO FILE A VALID REGISTRATION STATEMENT WITH THE DEPARTMENT AS REQUIRED BY ADM CODE ?27-2097 AND IS THEREFORE SUBJECT TO CIVIL PENALTIES, PROHIBITED FROM CERTIFYING VIOLATIONS, AND DENIED THE RIGHT TO RECOVER POSSESSION OF P | |
| Closed Violation Closed · 2015-06-17 | A | 2015-04-24 | 3 | SECTION 27-2013 ADM CODE PAINT WITH LIGHT COLORED PAINT TO THE SATISFACTION OF THIS DEPARTMENT ALL PEELING PAINT SURFACES IN THE BATHROOM , THE KITCHEN , THE 1st ROOM FROM NORTH AT WEST LOCATED AT APT 3, 3rd STORY, 1st APARTMENT FROM WEST AT NORTH |
| Closed Violation Closed · 2015-06-17 | A | 2015-04-24 | 3 | SECTION 27-2013 ADM CODE PAINT WITH LIGHT COLORED PAINT TO THE SATISFACTION OF THIS DEPARTMENT THE SOUTH WALL IN THE 4th ROOM FROM NORTH LOCATED AT APT 3, 3rd STORY, 1st APARTMENT FROM WEST AT NORTH |
| Closed Violation Closed · 2015-06-29 | C | 2015-04-24 | 3 | SECTION 27-2056.6 ADM CODE - CORRECT THE LEAD-BASED PAINT HAZARD - PAINT THAT TESTED POSITIVE FOR LEAD CONTENT AND THAT IS PEELING OR ON A DETERIORATED SUBSURFACE - USING WORK PRACTICES SET FORTH IN 28 RCNY ?11-06(B)(2) 1st WINDOW FRAME FROM EAST AT SOUTH WALL |
| Closed Violation Closed · 2015-06-29 | C | 2015-04-24 | 3 | SECTION 27-2056.6 ADM CODE - CORRECT THE LEAD-BASED PAINT HAZARD - PAINT THAT TESTED POSITIVE FOR LEAD CONTENT AND THAT IS PEELING OR ON A DETERIORATED SUBSURFACE - USING WORK PRACTICES SET FORTH IN 28 RCNY ?11-06(B)(2) BASEBOARD AT SOUTH WALL, BASEBOARD AT EA |
| Closed Violation Closed · 2015-06-29 | C | 2015-04-24 | 3 | SECTION 27-2056.6 ADM CODE - CORRECT THE LEAD-BASED PAINT HAZARD - PAINT THAT TESTED POSITIVE FOR LEAD CONTENT AND THAT IS PEELING OR ON A DETERIORATED SUBSURFACE - USING WORK PRACTICES SET FORTH IN 28 RCNY ?11-06(B)(2) BASEBOARD AT NORTH WALL, BASEBOARD AT SO |
| Closed Violation Closed · 2015-06-17 | A | 2015-04-24 | 3 | SECTION 27-2013 ADM CODE PAINT WITH LIGHT COLORED PAINT TO THE SATISFACTION OF THIS DEPARTMENT THE CEILING IN THE 5th ROOM FROM NORTH AT WEST LOCATED AT APT 3, 3rd STORY, 1st APARTMENT FROM WEST AT NORTH |
| Closed Violation Closed · 2015-06-17 | C | 2015-04-24 | 3 | SECTION 27-2005 ADM CODE REPLACE WITH NEW THE MISSING TRIP LEVER DRAIN STOPPER AT BATHTUB IN THE BATHROOM LOCATED AT APT 3, 3rd STORY, 1st APARTMENT FROM WEST AT NORTH |
| Closed Violation Closed · 2015-06-05 | B | 2015-04-10 | 3 | SECTION 27-2005 ADM CODE PROPERLY REPAIR WITH SIMILAR MATERIAL THE BROKEN OR DEFECTIVE WOOD FLOOR PARKAY PIECES IN THE 5th ROOM FROM NORTH AT WEST LOCATED AT APT 3, 3rd STORY, 1st APARTMENT FROM WEST AT NORTH |
| Closed Violation Closed · 2015-06-05 | B | 2015-04-10 | 3 | SECTION 27-2005 ADM CODE PROPERLY REPAIR WITH SIMILAR MATERIAL THE BROKEN OR DEFECTIVE WOOD FLOOR PARKAY PIECES IN THE 5th ROOM FROM NORTH AT EAST LOCATED AT APT 3, 3rd STORY, 1st APARTMENT FROM WEST AT NORTH |
| Closed Violation Closed · 2015-06-05 | C | 2015-04-10 | 3 | SECTION 27-2026 ADM CODE REMOVE ALL OBSTRUCTIONS FROM WATER CLOSET , OVER FLOWING IN THE BATHROOM LOCATED AT APT 3, 3rd STORY, 1st APARTMENT FROM WEST AT NORTH |
| Closed Violation Closed · 2015-06-29 | C | 2015-04-09 | 3 | SECTION 27-2056.6 ADM CODE - CORRECT THE LEAD-BASED PAINT HAZARD - PAINT THAT TESTED POSITIVE FOR LEAD CONTENT AND THAT IS PEELING OR ON A DETERIORATED SUBSURFACE - USING WORK PRACTICES SET FORTH IN 28 RCNY ?11-06(B)(2) BASEBOARD AT NORTH WALL, BASEBOARD AT SO |
| Closed Violation Closed · 2015-07-02 | A | 2015-02-24 | SECTION 62 M/D LAW REARRANGE TELEVISION AND/OR RADIO ANTENNA TO BE AT LEAST 10 FEET ABOVE ROOF AND NOT ATTACHED TO ANY FIRE ESCAPE OR SOIL OR VENT LINE .. |
Showing 20 of 127 records — open violations are listed first; the API lists every one. The API and the source dataset have the full list.
Source: HPD Housing Maintenance Code Violations — city dataset updated 2026-11-02; data as of 2026-11-02
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 2026-11-02; data as of 2026-11-02
311 requests (last 12 months) 0
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.
No records found in this dataset for this lot.
Source: 311 Service Requests from 2020 to Present — city dataset updated 2026-11-02; data as of 2026-11-02
Nearby properties
On 80 St
- 513 80th Street (one open item)
- 509 80th Street (eight open items)
- 515 80th Street (five open items)
- 517 80th Street (seven open items)
- 518 80th Street (one open item)
- 519 80th Street (14 open items)
- 520 80th Street
- 521 80th Street (eight open items)
- 524 80th Street
- 525 80th Street (four open items)
Same tax block (5981)
- 7923 5th Avenue (seven open items)
- 7921 5th Avenue (four open items)
- 7919 5th Avenue (six open items)
- 7917 5th Avenue (one open item)
- 7915 5th Avenue
- 7913 5th Avenue (12 open items)
- 7911 5th Avenue (one open item)
- 7909 5th Avenue (nine open items)
- 7907 5th Avenue (two open items)
- 7905 5th Avenue (six open items)
All properties on 80 St, Brooklyn · All of Brooklyn 11209 (Bay Ridge)
Open-item counts as of October 31, 2026; each section lists its own dataset date. Machine-readable: JSON API · Markdown · Plain text · API & MCP docs