{"id":"unit-convert","title":"Exact unit conversion with dimensional analysis (NIST SP 811)","description":"Converts up to 100 values between units for an agent that needs the exact factor and a refusal when the units do not match: SI and NIST SP 811 length, mass, time, volume, pressure, energy, power, temperature, with compound expressions like kg*m/s^2. Rejects incompatible dimensions, converts absolute temperatures affinely through kelvin and temperature differences linearly, and converts mass to volume (cups to grams) only with a caller-supplied density. It does NOT look up ingredient densities, guess which cup or gallon a bare symbol means (cup is 236.5882365 mL US customary, 240 mL US label, 250 mL metric or 200 mL Japanese: say which), or handle currencies and dates.","roi":"Wrong unit conversions fail silently in recipes, dosing and specs. 100 conversions per $0.005 call, each with its factor source.","audience":"business","package":"physical-ops-kit","channels":["x402","mcp"],"endpoint":{"method":"POST","url":"https://agents.writerslogic.com/api/v1/unit-convert","path":"/api/v1/unit-convert","contentType":"application/json"},"price":{"amount":"0.005","currency":"USDC","network":"base","perCall":true,"failedCallsCharged":false},"inputSchema":{"type":"object","additionalProperties":false,"required":["items"],"properties":{"items":{"type":"array","items":{"type":"object","additionalProperties":false,"required":["value","from","to"],"properties":{"value":{"anyOf":[{"type":"number"},{"type":"string","maxLength":50,"pattern":"^-?\\d{1,30}(\\.\\d{1,30})?([eE][+-]?\\d{1,3})?$"}],"description":"A finite number, or a decimal string when the digits must stay exact (\"236.5882365\"). Magnitude at most 1e15."},"from":{"type":"string","maxLength":80,"description":"Unit expression: symbols, SI prefixes, * / ^ and parentheses, e.g. m/s^2, kg*m/s2, degF, cup_us, lb/ft3. Bare cup/tbsp/tsp/gal/pt/qt/floz/cal/hp/ton are ambiguous and answer unknown with the candidates."},"to":{"type":"string","maxLength":80,"description":"Target unit expression."},"kind":{"type":"string","enum":["absolute","difference"],"description":"absolute (default): a temperature reading, converted affinely through kelvin. difference: a temperature interval, converted linearly."},"density":{"type":"object","additionalProperties":false,"required":["value","unit"],"properties":{"value":{"type":"number","minimum":1e-9,"maximum":1000000000,"description":"Caller-supplied mass per volume. Never looked up: no ingredient density table is shipped."},"unit":{"type":"string","maxLength":40,"description":"Mass per volume unit expression, e.g. g/mL, kg/m3, lb/ft3, oz/cup_us."}},"description":"Per-item density, overriding the top-level one. Required to cross mass and volume (cups to grams)."},"claimed":{"anyOf":[{"type":"number"},{"type":"string","maxLength":50,"pattern":"^-?\\d{1,30}(\\.\\d{1,30})?([eE][+-]?\\d{1,3})?$"}],"description":"Optional claimed result in the target unit; a mismatch beyond relTolerance fails with expected vs actual."},"relTolerance":{"type":"number","description":"Relative tolerance for claimed. Default 1e-9.","minimum":0,"maximum":1},"label":{"type":"string","maxLength":80,"description":"Free label echoed back."}}},"maxItems":100,"minItems":1,"description":"Conversions to run."},"density":{"type":"object","additionalProperties":false,"required":["value","unit"],"properties":{"value":{"type":"number","minimum":1e-9,"maximum":1000000000,"description":"Caller-supplied mass per volume. Never looked up: no ingredient density table is shipped."},"unit":{"type":"string","maxLength":40,"description":"Mass per volume unit expression, e.g. g/mL, kg/m3, lb/ft3, oz/cup_us."}},"description":"Default density for items that cross mass and volume."},"precision":{"type":"integer","description":"Significant digits of the reported value. Default 12.","minimum":1,"maximum":30}}},"resultSchema":{"type":"object","properties":{"status":{"type":"string","enum":["pass","fail","unknown","unsupported"],"description":"pass: every rule held. fail: a rule was violated (see witnesses). unknown: the input lacks the evidence to decide. unsupported: outside what this engine covers. Missing evidence is never a pass."},"results":{"type":"array","items":{"type":"object","properties":{"index":{"type":"integer"},"label":{"type":"string"},"status":{"type":"string","enum":["pass","fail","unknown","unsupported"]},"from":{"type":"string"},"to":{"type":"string"},"kind":{"type":"string"},"value":{"type":"string","description":"Converted value rounded to `precision` significant digits, as a plain decimal string."},"valueNumber":{"type":"number","description":"Absent when the value exceeds the double range; use value."},"exact":{"type":"boolean","description":"True when the unrounded result terminates inside the 60-digit working precision and no inexact factor or density was used."},"path":{"type":"string"},"sources":{"type":"array","items":{"type":"string"}},"note":{"type":"string"},"reason":{"type":"string","description":"Rule id when the item did not pass."},"message":{"type":"string"},"candidates":{"type":"array","items":{"type":"string"}}}}},"precision":{"type":"integer"},"witnesses":{"type":"array","items":{"type":"object","properties":{"ruleId":{"type":"string"},"detail":{"type":"string"},"path":{"type":"string","description":"JSON pointer or dotted path into the input."},"offset":{"type":"integer"},"index":{"type":"integer"},"expected":{"description":"What the rule required."},"actual":{"description":"What the input had."}}}},"versions":{"type":"object","description":"Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile)."},"limits":{"type":"array","items":{"type":"string"}},"deterministic":{"type":"boolean","description":"Always true: pure code, no model."}}},"outputSchema":{"type":"object","properties":{"data":{"type":"object","properties":{"status":{"type":"string","enum":["pass","fail","unknown","unsupported"],"description":"pass: every rule held. fail: a rule was violated (see witnesses). unknown: the input lacks the evidence to decide. unsupported: outside what this engine covers. Missing evidence is never a pass."},"results":{"type":"array","items":{"type":"object","properties":{"index":{"type":"integer"},"label":{"type":"string"},"status":{"type":"string","enum":["pass","fail","unknown","unsupported"]},"from":{"type":"string"},"to":{"type":"string"},"kind":{"type":"string"},"value":{"type":"string","description":"Converted value rounded to `precision` significant digits, as a plain decimal string."},"valueNumber":{"type":"number","description":"Absent when the value exceeds the double range; use value."},"exact":{"type":"boolean","description":"True when the unrounded result terminates inside the 60-digit working precision and no inexact factor or density was used."},"path":{"type":"string"},"sources":{"type":"array","items":{"type":"string"}},"note":{"type":"string"},"reason":{"type":"string","description":"Rule id when the item did not pass."},"message":{"type":"string"},"candidates":{"type":"array","items":{"type":"string"}}}}},"precision":{"type":"integer"},"witnesses":{"type":"array","items":{"type":"object","properties":{"ruleId":{"type":"string"},"detail":{"type":"string"},"path":{"type":"string","description":"JSON pointer or dotted path into the input."},"offset":{"type":"integer"},"index":{"type":"integer"},"expected":{"description":"What the rule required."},"actual":{"description":"What the input had."}}}},"versions":{"type":"object","description":"Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile)."},"limits":{"type":"array","items":{"type":"string"}},"deterministic":{"type":"boolean","description":"Always true: pure code, no model."}}},"_provenance":{"type":"object","description":"C2PA-aligned manifest and W3C VC 2.0 (eddsa-jcs-2022) issued by the hub DID; verify at POST /api/v1/verify-provenance"}},"required":["data","_provenance"]},"example":{"items":[{"value":212,"from":"degF","to":"degC"},{"value":1,"from":"cup_us","to":"mL"},{"value":10,"from":"degC","to":"degF","kind":"difference"}]},"openapiOperation":{"operationId":"unit_convert","summary":"Exact unit conversion with dimensional analysis (NIST SP 811)","description":"Converts up to 100 values between units for an agent that needs the exact factor and a refusal when the units do not match: SI and NIST SP 811 length, mass, time, volume, pressure, energy, power, temperature, with compound expressions like kg*m/s^2. Rejects incompatible dimensions, converts absolute temperatures affinely through kelvin and temperature differences linearly, and converts mass to volume (cups to grams) only with a caller-supplied density. It does NOT look up ingredient densities, guess which cup or gallon a bare symbol means (cup is 236.5882365 mL US customary, 240 mL US label, 250 mL metric or 200 mL Japanese: say which), or handle currencies and dates.\n\nPrice: 0.005 USDC on Base (x402).","x-x402-price-usdc":"0.005","x-x402-amount":"5000","x-payment-info":{"protocols":["x402"],"price":{"mode":"fixed","currency":"USD","amount":"0.005"}},"x-audience":"business","x-sample-url":"https://agents.writerslogic.com/api/v1/samples/unit-convert","security":[{"x402":[]},{"apiKey":[]}],"requestBody":{"required":true,"content":{"application/json":{"schema":{"type":"object","additionalProperties":false,"required":["items"],"properties":{"items":{"type":"array","items":{"type":"object","additionalProperties":false,"required":["value","from","to"],"properties":{"value":{"anyOf":[{"type":"number"},{"type":"string","maxLength":50,"pattern":"^-?\\d{1,30}(\\.\\d{1,30})?([eE][+-]?\\d{1,3})?$"}],"description":"A finite number, or a decimal string when the digits must stay exact (\"236.5882365\"). Magnitude at most 1e15."},"from":{"type":"string","maxLength":80,"description":"Unit expression: symbols, SI prefixes, * / ^ and parentheses, e.g. m/s^2, kg*m/s2, degF, cup_us, lb/ft3. Bare cup/tbsp/tsp/gal/pt/qt/floz/cal/hp/ton are ambiguous and answer unknown with the candidates."},"to":{"type":"string","maxLength":80,"description":"Target unit expression."},"kind":{"type":"string","enum":["absolute","difference"],"description":"absolute (default): a temperature reading, converted affinely through kelvin. difference: a temperature interval, converted linearly."},"density":{"type":"object","additionalProperties":false,"required":["value","unit"],"properties":{"value":{"type":"number","minimum":1e-9,"maximum":1000000000,"description":"Caller-supplied mass per volume. Never looked up: no ingredient density table is shipped."},"unit":{"type":"string","maxLength":40,"description":"Mass per volume unit expression, e.g. g/mL, kg/m3, lb/ft3, oz/cup_us."}},"description":"Per-item density, overriding the top-level one. Required to cross mass and volume (cups to grams)."},"claimed":{"anyOf":[{"type":"number"},{"type":"string","maxLength":50,"pattern":"^-?\\d{1,30}(\\.\\d{1,30})?([eE][+-]?\\d{1,3})?$"}],"description":"Optional claimed result in the target unit; a mismatch beyond relTolerance fails with expected vs actual."},"relTolerance":{"type":"number","description":"Relative tolerance for claimed. Default 1e-9.","minimum":0,"maximum":1},"label":{"type":"string","maxLength":80,"description":"Free label echoed back."}}},"maxItems":100,"minItems":1,"description":"Conversions to run."},"density":{"type":"object","additionalProperties":false,"required":["value","unit"],"properties":{"value":{"type":"number","minimum":1e-9,"maximum":1000000000,"description":"Caller-supplied mass per volume. Never looked up: no ingredient density table is shipped."},"unit":{"type":"string","maxLength":40,"description":"Mass per volume unit expression, e.g. g/mL, kg/m3, lb/ft3, oz/cup_us."}},"description":"Default density for items that cross mass and volume."},"precision":{"type":"integer","description":"Significant digits of the reported value. Default 12.","minimum":1,"maximum":30}}},"example":{"items":[{"value":212,"from":"degF","to":"degC"},{"value":1,"from":"cup_us","to":"mL"},{"value":10,"from":"degC","to":"degF","kind":"difference"}]}}}},"responses":{"200":{"description":"Paid result with provenance","content":{"application/json":{"schema":{"type":"object","properties":{"data":{"type":"object","properties":{"status":{"type":"string","enum":["pass","fail","unknown","unsupported"],"description":"pass: every rule held. fail: a rule was violated (see witnesses). unknown: the input lacks the evidence to decide. unsupported: outside what this engine covers. Missing evidence is never a pass."},"results":{"type":"array","items":{"type":"object","properties":{"index":{"type":"integer"},"label":{"type":"string"},"status":{"type":"string","enum":["pass","fail","unknown","unsupported"]},"from":{"type":"string"},"to":{"type":"string"},"kind":{"type":"string"},"value":{"type":"string","description":"Converted value rounded to `precision` significant digits, as a plain decimal string."},"valueNumber":{"type":"number","description":"Absent when the value exceeds the double range; use value."},"exact":{"type":"boolean","description":"True when the unrounded result terminates inside the 60-digit working precision and no inexact factor or density was used."},"path":{"type":"string"},"sources":{"type":"array","items":{"type":"string"}},"note":{"type":"string"},"reason":{"type":"string","description":"Rule id when the item did not pass."},"message":{"type":"string"},"candidates":{"type":"array","items":{"type":"string"}}}}},"precision":{"type":"integer"},"witnesses":{"type":"array","items":{"type":"object","properties":{"ruleId":{"type":"string"},"detail":{"type":"string"},"path":{"type":"string","description":"JSON pointer or dotted path into the input."},"offset":{"type":"integer"},"index":{"type":"integer"},"expected":{"description":"What the rule required."},"actual":{"description":"What the input had."}}}},"versions":{"type":"object","description":"Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile)."},"limits":{"type":"array","items":{"type":"string"}},"deterministic":{"type":"boolean","description":"Always true: pure code, no model."}}},"_provenance":{"type":"object","description":"C2PA-aligned manifest and W3C VC 2.0 (eddsa-jcs-2022) issued by the hub DID; verify at POST /api/v1/verify-provenance"}},"required":["data","_provenance"]}}}},"400":{"description":"Invalid request (no payment consumed)","content":{"application/json":{"schema":{"type":"object","properties":{"error":{"type":"string"},"code":{"type":"string"}}}}}},"401":{"description":"Invalid X-API-KEY","content":{"application/json":{"schema":{"type":"object","properties":{"error":{"type":"string"},"code":{"type":"string"}}}}}},"402":{"description":"Payment required or invalid","content":{"application/json":{"schema":{"type":"object","description":"x402 v2 PaymentRequired (also base64 in the PAYMENT-REQUIRED header)","properties":{"x402Version":{"type":"integer"},"error":{"type":"string"},"code":{"type":"string"},"resource":{"type":"object"},"accepts":{"type":"array","items":{"type":"object"}},"extensions":{"type":"object"}}}}}},"502":{"description":"Upstream failure; the payment is released or not settled","content":{"application/json":{"schema":{"type":"object","properties":{"error":{"type":"string"},"code":{"type":"string"}}}}}}}},"links":{"docs":"https://agents.writerslogic.com/docs/unit-convert/","docsJson":"https://agents.writerslogic.com/docs/unit-convert.json","sample":"https://agents.writerslogic.com/api/v1/samples/unit-convert","openapi":"https://agents.writerslogic.com/openapi.json","catalog":"https://agents.writerslogic.com/api/v1/catalog","verifyProvenance":"https://agents.writerslogic.com/api/v1/verify-provenance","index":"https://agents.writerslogic.com/docs/index.json"}}