MCP serverAvailable tools
Read tax rules
List the approved tax parameters and read their values in force on a date, with evidence.
MCP tool
get_tax_rulesPurpose
- Use when
- You need a rate, ceiling, tariff or wage as the law sets it on a date.
- Do not use when
- You need the legal text itself; use get_tax_law with a rule’s lawReferences.
- Required permissions
- Side effects
- None
- Idempotency
- Idempotent
Input schema
JSON Schema{ "type": "object", "properties": { "input": { "oneOf": [ { "type": "object", "properties": { "operation": { "const": "list" }, "query": { "description": "Words of the rule’s key, label or legal basis", "allOf": [ { "type": "string", "minLength": 2, "maxLength": 100 } ] }, "law": { "description": "Only rules that rest on this law or regulation", "allOf": [ { "enum": [ "LIVA", "LISR", "CFF", "LIEPS", "LSS", "LFT", "LDVUMA", "RLIVA", "RLISR", "RCFF", "RLIEPS", "RMF" ], "description": "A law, regulation or the RMF: LIVA, LISR, CFF, LIEPS, LSS, LFT, LDVUMA, RLIVA, RLISR, RCFF, RLIEPS, RMF" } ] } }, "required": [ "operation" ], "additionalProperties": false, "description": "The rules that exist, without values" }, { "type": "object", "properties": { "operation": { "const": "get" }, "keys": { "minItems": 1, "maxItems": 20, "type": "array", "items": { "enum": [ "withholding.operationTypes", "iva.standardRate", "iva.borderStimulus.north", "iva.borderStimulus.south", "iva.withholding.personalServices", "iva.withholding.freight", "iva.withholding.waste", "isr.withholding.professionalServices", "isr.withholding.realEstateRent", "isr.withholding.resico", "isr.corporateRate", "isr.dividendRate", "isr.leaseOptionalDeduction", "isr.monthlyTariff", "isr.annualTariff", "isr.dailyTariffDivisor", "isr.resicoMonthlyRates", "isr.resicoIncomeLimit", "deductions.cashPaymentLimit", "cfdi.certificationWindowHours", "cfdi.payroll.subsidyCausedMonthlyCeiling", "cfdi.payroll.subsidyCausedDailyCeiling", "cfdi.payroll.subsidyCausedMonthlyMaxDays", "cfdi.payroll.extraordinaryPeriodicity", "calendar.bankClosures", "uma", "payroll.minimumWage", "payroll.northBorderMunicipalities", "payroll.employmentSubsidy", "payroll.minimumWageIsr", "payroll.minimumWageQuotaPayer", "payroll.registeredContractTypes", "payroll.registeredRegimeTypes", "imss.contributionCapUma", "imss.contributionFloorMinimumWage", "lss.integrationYearDays", "imss.excessThresholdUma", "imss.employee.sicknessExcessRate", "imss.employee.cashBenefitsRate", "imss.employee.pensionerMedicalRate", "imss.employee.invalidityLifeRate", "imss.employee.oldAgeRate", "lft.weeklySalaryDays", "lft.monthlySalaryDays", "lss.quincenaSalaryDays", "lft.aguinaldoDays", "lft.vacationPremiumRate", "lft.vacationDays", "agro.exemptionPerPartnerUma", "agro.exemptionCompanyMaxUma" ] }, "description": "Rule keys from the list operation" }, "asOf": { "description": "The date whose values are wanted (YYYY-MM-DD, Mexico City); defaults to today", "allOf": [ { "type": "string", "format": "date", "pattern": "^(?:(?:\\d\\d[2468][048]|\\d\\d[13579][26]|\\d\\d0[48]|[02468][048]00|[13579][26]00)-02-29|\\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\\d|30)|(?:02)-(?:0[1-9]|1\\d|2[0-8])))$" } ] } }, "required": [ "operation", "keys" ], "additionalProperties": false, "description": "The values in force on a date, with their evidence" } ] } }, "required": [ "input" ], "$schema": "http://json-schema.org/draft-07/schema#", "additionalProperties": false}Output schema
JSON Schema{ "type": "object", "properties": { "data": { "anyOf": [ { "type": "object", "properties": { "rules": { "type": "array", "items": { "type": "object", "properties": { "key": { "$ref": "#/definitions/__schema0" }, "label": { "$ref": "#/definitions/__schema1" }, "legalBasis": { "$ref": "#/definitions/__schema2" }, "lawReferences": { "$ref": "#/definitions/__schema3" } }, "required": [ "key", "label", "legalBasis", "lawReferences" ], "additionalProperties": false } }, "notice": { "type": "string" } }, "required": [ "rules", "notice" ], "additionalProperties": false }, { "type": "object", "properties": { "rules": { "type": "array", "items": { "type": "object", "properties": { "key": { "$ref": "#/definitions/__schema0" }, "label": { "$ref": "#/definitions/__schema1" }, "legalBasis": { "$ref": "#/definitions/__schema2" }, "lawReferences": { "$ref": "#/definitions/__schema3" }, "status": { "enum": [ "in_force", "earliest_known", "not_in_force", "not_recorded" ] }, "value": {}, "validFrom": { "anyOf": [ { "$ref": "#/definitions/__schema4" }, { "type": "null" } ] }, "validTo": { "anyOf": [ { "$ref": "#/definitions/__schema4" }, { "type": "null" } ] }, "evidence": { "anyOf": [ { "type": "object", "properties": { "url": { "type": "string" }, "quote": { "anyOf": [ { "type": "string" }, { "type": "null" } ] } }, "required": [ "url", "quote" ], "additionalProperties": false }, { "type": "null" } ] } }, "required": [ "key", "label", "legalBasis", "lawReferences", "status", "value", "validFrom", "validTo", "evidence" ], "additionalProperties": false } }, "notice": { "type": "string" } }, "required": [ "rules", "notice" ], "additionalProperties": false } ] }, "error": { "$schema": "http://json-schema.org/draft-07/schema#", "type": "object", "properties": { "code": { "enum": [ "validation_error", "unauthenticated", "forbidden", "payment_required", "not_found", "method_not_allowed", "conflict", "idempotency_conflict", "operation_in_progress", "recovery_required", "migration_required", "rate_limited", "provider_unavailable", "internal" ] }, "message": { "type": "string" }, "details": { "type": "object", "properties": { "document": { "type": "object", "properties": { "documentRef": { "type": "string", "pattern": "^(invoice|withholding|sales_receipt|declaration|tax_compliance_opinion|sales_receipt_refund):.+$" }, "editable": { "type": "boolean" } }, "required": [ "documentRef", "editable" ], "additionalProperties": false }, "issues": { "type": "array", "items": { "type": "object", "properties": { "path": { "type": "array", "items": { "anyOf": [ { "type": "string" }, { "type": "number" } ] } }, "message": { "type": "string" }, "code": { "type": "string" } }, "required": [ "path", "message" ], "additionalProperties": false } }, "retryable": { "type": "boolean" }, "retryAfterSeconds": { "type": "integer", "exclusiveMinimum": 0, "maximum": 9007199254740991 }, "reason": { "type": "string" }, "balanceMinor": { "type": "integer", "minimum": 0, "maximum": 9007199254740991 }, "topUpUrl": { "type": "string" } }, "additionalProperties": false } }, "required": [ "code", "message" ], "additionalProperties": false } }, "$schema": "http://json-schema.org/draft-07/schema#", "additionalProperties": false, "definitions": { "__schema0": { "type": "string" }, "__schema1": { "type": "string" }, "__schema2": { "type": "string" }, "__schema3": { "type": "array", "items": { "type": "object", "properties": { "law": { "enum": [ "LIVA", "LISR", "CFF", "LIEPS", "LSS", "LFT", "LDVUMA", "RLIVA", "RLISR", "RCFF", "RLIEPS", "RMF" ] }, "article": { "type": "string" } }, "required": [ "law", "article" ], "additionalProperties": false } }, "__schema4": { "type": "string", "format": "date" } }, "oneOf": [ { "required": [ "data" ] }, { "required": [ "error" ] } ]}