Bearing

Bearing — connector documentation

• MCP endpoint: https://bearing.connectorbay.com/mcp
• REST API: POST https://bearing.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://bearing.connectorbay.com/openapi.json
• Transport: Streamable HTTP, stateless, MCP specification 2025-06-18 or later
• Authentication: none required. An optional Authorization: Bearer <key> raises rate limits.
• Health: https://bearing.connectorbay.com/health · Tool schemas: https://bearing.connectorbay.com/tools.json
• Publisher: Unify Dynamics LLC · connectorbay.com/bearing · agent@connectorbay.com

What Bearing is for

The land-navigation and coordinate math that comes up whenever someone is planning a hike, sailing a course, reading a military or topographic map, or just trying to make sense of a GPS grid reference — done with real, citable formulas instead of a guess, entirely on the server, with no map tiles or geocoding API in the loop.

What it does

Converts a coordinate between Decimal Degrees, Degrees-Minutes-Seconds, Degrees-Decimal-Minutes, UTM and MGRS, implementing the actual ellipsoidal Transverse Mercator projection on the WGS84 datum rather than approximating it (convert_coordinates); parses a free-form DMS/DDM string in whatever punctuation someone typed it in (dms_parse); gives the initial compass bearing and great-circle distance between two points via the haversine formula (bearing_and_distance); computes the destination point reached from a start, a bearing and a distance (destination_point); finds the great-circle midpoint of two points (midpoint); reports how far off a great-circle course line a point is, and how far along it (cross_track_distance); names a numeric bearing's nearest 16-point compass direction (bearing_to_cardinal); runs a full dead-reckoning plot across a sequence of bearing/distance legs (plot_reckoning); estimates magnetic declination from a coarse bundled model (magnetic_declination); and defines about a dozen common land-navigation terms (land_nav_glossary).

What it is not

A reference and hobbyist/educational tool, not certified navigation equipment. The great-circle formulas (bearing, distance, destination point, midpoint, cross-track distance) use a spherical-Earth approximation, accurate to within a fraction of a percent for most terrestrial distances — fine for trip planning and understanding a course, not for precision surveying. The UTM/MGRS conversions use the full WGS84 ellipsoidal projection formulas and are accurate to well under a metre, but assume the WGS84 datum; a coordinate given on a different national datum can be off by tens to hundreds of metres on the ground. Magnetic declination is the weakest link: it comes from a small, hand-sampled table of values near a stated World Magnetic Model epoch, interpolated between points, rather than a full spherical-harmonic WMM evaluation — treat it as a rough few-degrees estimate, not a precision figure. None of this is certified for life-safety marine or aviation navigation. If you are actually navigating a vessel or aircraft where being wrong matters, use certified equipment, official charts, and an authoritative WMM calculator (NOAA/NCEI or the British Geological Survey both publish free ones) — not this connector.

Tools

Coordinates

convert_coordinates — Converts a coordinate between Decimal Degrees (DD), Degrees-Minutes-Seconds (DMS), Degrees-Decimal-Minutes (DDM), UTM and MGRS. UTM/MGRS math is the ellipsoidal Transverse Mercator projection on WGS84; DD/DMS/DDM are exact arithmetic. Use for "convert this lat/lon to UTM", "what's this MGRS grid ref in decimal degrees". Args: input, from_format, to_format.

dms_parse — Parses one free-form DMS/DDM/DD coordinate string (a single latitude or longitude value, not a full lat/lon pair) into decimal degrees, handling common formatting variants and hemisphere letters. Use for "what's 37 46 30 N in decimal degrees". Args: dms_string.

Great-circle

bearing_and_distance — The initial compass bearing (forward azimuth, degrees true) and great-circle distance between two points, via the haversine formula on a spherical Earth (accurate to within about 0.3%). Use for "bearing and distance from London to Paris", "how far is it from A to B and which way". Args: lat1, lon1, lat2, lon2, unit.

destination_point — Given a start point, an initial bearing and a distance, computes the destination point (the direct geodesic problem, spherical-Earth approximation). Use for "where do I end up 10 km on a bearing of 045 from here". Args: lat, lon, bearing_deg, distance, unit.

midpoint — The great-circle midpoint between two coordinates (spherical-Earth approximation) -- not the same as simply averaging the two lat/lon pairs, especially over long distances or near the poles. Use for "what's halfway between these two points". Args: lat1, lon1, lat2, lon2.

cross_track_distance — How far a point is off the great-circle course line between two other points ('am I on course'), and how far along that course line the point's projection falls. Positive cross-track = right of the course line heading from path_start to path_end; negative = left. Spherical-Earth approximation. Args: lat, lon, path_start, path_end, unit.

bearing_to_cardinal — Converts a numeric bearing to its nearest 16-point compass direction name (N, NNE, NE, ENE, E, ...). Use for "what compass direction is 070 degrees". Args: bearing_deg.

Navigation

plot_reckoning — Dead-reckoning: given a starting point and a sequence of (bearing, distance) legs, computes the position after each leg and the final position -- the manual navigation technique hikers and sailors use to track position without a fix. Also reports the direct (great-circle) distance from start to final position for comparison against total distance travelled. Use for "plot my course: 10 km on 045, then 5 km on 090". Args: start_lat, start_lon, legs, unit.

magnetic_declination — Estimates magnetic declination (the angle between true north and magnetic north at a location, positive = east) from a coarse, hand-sampled World Magnetic Model-epoch lookup table, inverse-distance interpolated. This is NOT a full spherical-harmonic WMM evaluation -- see the disclaimer field. Use for "what's the magnetic declination in Denver", "how much do I need to correct my compass for true north here". Args: lat, lon, date.

Reference

land_nav_glossary — Plain-language definitions of common land-navigation terms: azimuth, true vs magnetic north, declination vs deviation, grid north, great-circle vs rhumb line, datum, UTM, MGRS, DMS/DDM/DD, dead reckoning, cross-track distance, and isogonic line. Use for "what's the difference between declination and deviation", "what does MGRS stand for". Args: term.

Conventions

• Read-only. Every tool reads public data or computes; nothing is written anywhere and nothing about the user is stored.
• Result envelope. ok: true with data, or ok: false with a structured error (bad_input, not_found, upstream_error). degraded lists optional sources that were unreachable.
• Rate limits. Free tier 60 tool calls/minute and 300/day per user (keyed on the user identifier supplied by the host agent, else client IP); Pro keys raise this. Over-limit calls return HTTP 429 with Retry-After. initialize and tools/list are never counted.

Support

agent@connectorbay.com · connectorbay.com/bearing/support

Bearing — Privacy Policy

Effective 24 September 2026. Unify Dynamics LLC ("we", "us"), Menlo Park, California.

What Bearing is. Bearing is a connector (an MCP server and REST API) that AI assistants and personal agents call on your behalf for local land-navigation and coordinate math: coordinate format conversion, great-circle bearing/distance/destination/midpoint/cross-track calculations, magnetic declination estimates, dead-reckoning plots, compass-cardinal conversion, and a navigation glossary. You interact with your assistant; the assistant sends us only the arguments needed for that one calculation.

What we receive. The arguments of each tool call — coordinates, bearings, distances, a coordinate string to parse or convert, or a glossary term — the technical headers needed to serve the request (an IP address or a client identifier supplied by the assistant, and a Pro API key if you have one), and standard server logs.

Everything is computed, on the fly, from the request's own arguments plus a small bundled reference table (for the coarse magnetic-declination estimate). There is no upstream call at all — not to a mapping service, a geocoder, or a live magnetic-model API — and no query is logged in request bodies, recorded, or used to train anything.

What we do not receive or store. We do not receive your conversation with the assistant or your name, and we do not build a profile from your queries, your coordinates, or your routes: each request is answered independently and nothing carries over between requests. Rate-limit counters (a client identifier and timestamps) are held in memory for at most 24 hours. Hosting-provider access logs, which contain IP addresses and request paths but not request bodies, are retained for up to 30 days for security and abuse prevention.

Sub-processors. None — every calculation runs locally in the connector's own process. Hosting: Vercel (United States regions).

Legal bases and your rights. Our processing is necessary to provide the service you request through your assistant. Because we store no personal data beyond short-lived logs, requests to access, correct or delete personal data are usually satisfied automatically; you can still contact agent@connectorbay.com and we will respond within 30 days. We do not sell or share personal information and do not use your data to train models.

Children. Bearing is a general-audience service operated by the adult using the assistant.

Changes. We will post changes here with a new effective date.

Bearing — Terms of Service

Effective 24 September 2026. These terms govern use of the Bearing connector ("the Service") operated by Unify Dynamics LLC ("we", "us").

1. The Service. Bearing returns computed land-navigation and coordinate math — coordinate format conversion (DD/DMS/DDM/UTM/MGRS), great-circle bearing, distance, destination point, midpoint and cross-track distance, an estimated magnetic declination, dead-reckoning plots, compass-cardinal conversion, and a glossary — from published, cited formulas computed on the arguments you provide. It is accessed through an AI assistant or directly over MCP or HTTP.
2. Reference and educational use only — not certified navigation equipment. Bearing is a hobbyist and reference tool. Great-circle calculations use a spherical-Earth approximation; magnetic declination is a coarse, hand-sampled estimate near a stated model epoch, not a precision figure. Nothing in the Service is certified for, or should be relied on for, life-safety marine or aviation navigation, surveying, or any other application where an inaccurate position, bearing, or declination could cause harm. Use certified equipment, official charts, and an authoritative source for anything safety-critical.
3. Datum and accuracy. UTM/MGRS conversions assume the WGS84 datum; coordinates on a different national datum will not match exactly. Every response states the formula and its documented accuracy level.
4. Acceptable use. Automated use within the published rate limits is welcome.
5. Availability. The Service is provided "as is" without warranty. We may change, limit or discontinue it at any time.
6. Data. Our Privacy Policy describes what we process. In short: your request is answered by local computation, and nothing is stored.
7. Pro keys. Optional Pro API keys are issued at our discretion, are personal to the holder and may be revoked for abuse.
8. Liability. To the fullest extent permitted by law, Unify Dynamics LLC is not liable for any loss arising from use of or reliance on the Service, including any loss arising from navigation decisions made using it. Our total liability is limited to US $100.
9. Governing law. California law; venue in San Mateo County, California.
10. Contact. Unify Dynamics LLC · agent@connectorbay.com · https://connectorbay.com/bearing

Bearing support

Email agent@connectorbay.com. We answer within two business days.

• MCP endpoint: https://bearing.connectorbay.com/mcp
• REST API: https://bearing.connectorbay.com/openapi.json
• Live status: https://bearing.connectorbay.com/health

When you report a problem, include the question you asked your agent, roughly when, and which agent you used (for example Claude, ChatGPT or Gemini). Never send us passwords, account numbers or ID numbers. Bearing never asks for them.