Slab

Slab — connector documentation

• MCP endpoint: https://slab.connectorbay.com/mcp
• REST API: POST https://slab.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://slab.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://slab.connectorbay.com/health · Tool schemas: https://slab.connectorbay.com/tools.json
• Publisher: Unify Dynamics LLC · connectorbay.com/slab · agent@connectorbay.com

What Slab is for

"How many bags of concrete do I need?" "What mix ratio for a 3000 psi driveway?" "How long before I can drive on it?" The questions every DIY concrete or masonry project runs into, answered from real geometry math and widely published construction-industry reference figures — not a guess, and not a dozen contradictory forum threads.

What it does

Real cubic-foot/cubic-yard volume calculators for rectangular slabs (slab_volume_calculator) and for footings or square/rectangular columns and piers (footing_volume_calculator) — exact geometry from length, width, and thickness/depth, not an estimate. A bag-count estimator (bag_count_estimator) that converts a target volume into how many 40, 60, or 80 lb bags of pre-mixed concrete to buy, using each bag size's published cubic-foot yield plus a 10% waste allowance. Standard cement:sand:aggregate volumetric mix ratios across six nominal strength grades from lean fill up to higher-strength structural mixes (mix_ratio_guide). Curing-time guidance covering how long fresh concrete typically needs before it's safe to walk on, drive on, have formwork stripped, or reach its 28-day design strength (curing_time_guide). General, illustrative rebar/reinforcement spacing by application — slabs, footings, foundation walls, columns, sidewalks (rebar_spacing_guide), always paired with an explicit disclaimer that real spacing for load-bearing or permitted work requires a structural engineer and/or local building code. Hot- and cold-weather concrete-pouring considerations (weather_considerations_guide). A glossary of core concrete/masonry terms — rebar, formwork, aggregate, slump, curing, footing, and more (masonry_glossary). And a full-text search across all of the above (search).

What it is not

Not a substitute for a structural engineer, a licensed contractor, or your local building department. The volume and bag-count math is exact geometry and arithmetic — that part is simply correct. But mix ratios, cure times, and especially rebar spacing are general, commonly cited reference figures that vary with real materials, soil, climate, and code, and load-bearing or permitted work always needs an engineer's design and/or code compliance, never a rule of thumb from a calculator. Slab makes no live upstream calls of any kind — everything is either math computed from your inputs or a bundled, hand-curated reference file.

Tools

Calculators

slab_volume_calculator — Real geometry for a rectangular slab: area (length x width) times thickness, converted to cubic feet and cubic yards. Use for "how many cubic yards for a 10x10 slab at 4 inches thick", "volume of a 20 by 30 foot driveway at 5 inches". Args: length_ft, width_ft, thickness_in.

footing_volume_calculator — Real geometry for a strip or pad footing, or a square/rectangular column or pier: length x width x depth, converted to cubic feet and cubic yards (the same L x W x H math covers all three — a column is just a tall, narrow footing). For a round column or pier (e.g. a cylindrical Sonotube form), the volume formula is pi x radius^2 x height instead — see masonry_glossary's "Footing" entry. Use for "volume of a footing 30 feet long, 18 inches wide, 12 inches deep", "concrete for a 12 by 12 inch, 4 foot tall pier". Args: length_ft, width_ft, depth_in.

bag_count_estimator — How many pre-mixed concrete bags (40, 60, or 80 lb) are needed for a target cubic-yard volume, using each bag's published cubic-foot yield (0.30 / 0.45 / 0.60 cu ft respectively), plus a 10% waste allowance rounded up to a whole bag. Use for "how many 80 lb bags of concrete for 1 cubic yard", "bags of 60 lb concrete mix for 0.5 cubic yards". Args: cubic_yards, bag_size_lb.

Mix & Cure

mix_ratio_guide — Standard cement:sand:aggregate volumetric mix ratios by nominal strength grade, from lean fill (~725 psi, 1:5:10) up to higher-strength structural mixes (~3625 psi, 1:1:2). Pass a target PSI to get the closest standard grade, or omit it to see the whole table. Use for "what's a 3000 psi concrete mix ratio", "cement sand gravel ratio for a driveway". Args: psi_target.

curing_time_guide — How long fresh concrete typically needs before it's safe to walk on (24-48 hours), drive on (~7 days), have non-load-bearing formwork stripped (24-48 hours), or reach its 28-day design strength. Use for "how long before I can walk on new concrete", "when can I drive on a new driveway", "how long until concrete is fully cured". Args: application.

weather_considerations_guide — Hot-weather (fast evaporation, plastic shrinkage cracking, shortened working time) and cold-weather (freeze damage before ~500 psi, hydration slowing below ~50°F) concrete-pouring considerations and precautions. Use for "can I pour concrete when it's freezing", "how do I keep concrete from cracking in hot weather".

Reference

rebar_spacing_guide — General, illustrative rebar/reinforcement spacing by application (slabs, footings, foundation walls, columns, sidewalks) — reference only. Every response carries an explicit disclaimer that real spacing for load-bearing or permitted work must come from a structural engineer and/or local building code, not this rule-of-thumb data. Use for "how far apart should rebar be in a slab", "rebar spacing for a footing" — always pair the answer with the engineer/code disclaimer. Args: application.

masonry_glossary — Definitions of common concrete/masonry terms: rebar, formwork, aggregate, slump, curing, PSI, Portland cement, mortar, footing, control joint, vapor barrier, efflorescence, air entrainment. Use for "what does slump mean", "what's the difference between cement and concrete". Args: term.

Search

search — Full-text search across Slab's own bundled reference content — mix ratios, curing stages, rebar spacing entries, weather guidance, and glossary terms — for a keyword or phrase. Purely local, not a web search. Use for "search slab for slump", "find anything about driveways". Args: query.

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/slab/support

Slab — Privacy Policy

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

What Slab is. Slab is a connector (an MCP server and REST API) that AI assistants and personal agents call on your behalf for DIY concrete and masonry calculators and reference information: slab/footing/column volume, bag counts, mix ratios, curing time, rebar spacing basics, weather considerations, and a glossary. You interact with your assistant; the assistant sends us only the arguments needed for that one calculation or lookup.

What we receive. The arguments of each tool call — dimensions (length, width, thickness/depth), a bag size, a target PSI, an application or search keyword — 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 answered from real math and a bundled reference file, and nothing is stored. No request is forwarded to any third party — there is no upstream call at all, live or otherwise — 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, your name, or any information about a specific property, project, or job, and we do not build a profile from your queries: 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 and lookup happens locally, with reference data bundled with the server. 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. Slab is a general-audience service operated by the adult using the assistant.

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

Slab — Terms of Service

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

1. The Service. Slab returns DIY concrete/masonry volume and bag-count calculations, computed directly from the dimensions you provide, plus a hand-curated reference guide (mix ratios, curing time, rebar spacing basics, weather considerations, and a glossary) bundled with the server. It is accessed through an AI assistant or directly over MCP or HTTP.
2. General information, not professional advice. Slab provides general DIY reference information and arithmetic for reference only. It is not engineering, architectural, or contracting advice, and in particular its rebar/reinforcement spacing guidance is illustrative only — not a code-compliance determination or a structural design for any real project. Any load-bearing, structural, or permitted work must be designed and/or reviewed by a licensed structural engineer and must comply with your local building code; do not rely on this Service for that purpose.
3. Real math, general guidance. Volume and bag-count results are exact geometry and arithmetic applied to the numbers you supply. Mix ratios, cure times, and weather guidance are commonly cited general figures that vary with real materials, climate, soil, and local code — treat them as a starting point, not a guarantee of a particular strength, schedule, or outcome.
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 from real math and a bundled reference file, 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 — including harm to a structure, a project, or a person — arising from use of or reliance on the Service, and in particular from load-bearing or structural work undertaken without a licensed structural engineer and applicable code compliance. 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/slab

Slab support

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

• MCP endpoint: https://slab.connectorbay.com/mcp
• REST API: https://slab.connectorbay.com/openapi.json
• Live status: https://slab.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. Slab never asks for them.