> ## Documentation Index > Fetch the complete documentation index at: https://crushrewards.dev/docs/llms.txt > Use this file to discover all available pages before exploring further. # Price index for a specific retailer over time > Compute a normalized price index (retailer avg / category avg) for a specific retailer day-by-day versus its category baseline. Points report insufficient_sample below sample_threshold products plus stable_avg_price over the products priced every day — read trends from the stable series. ## OpenAPI ````yaml https://api.syntalic.com/openapi.json get /v1/analyst/retailer-index openapi: 3.1.0 info: title: 'Syntalic — Data Analytics for Agentic Commerce ' version: 1.0.0 contact: name: Syntalic email: support@syntalic.com url: https://syntalic.com description: >- Competitive pricing data across US and Canadian e-commerce retailers (Amazon, Walmart, Target, Best Buy, Home Depot, etc.). Serves price comparisons, deal alerts, brand tracking, promotional intelligence, and market analytics to AI agents via x402 and MPP micropayments. x-guidance: >- This API has three endpoint groups organized by use case: **Shopper endpoints** ($0.01/query): Use these for price comparisons and deal hunting. Start with /v1/shopper/best-price?q= to find the cheapest option across retailers. Use /v1/shopper/deal-finder?category= to find discounted products. Use /v1/shopper/price-drop-alert?q= to check for recent price drops. **Marketing endpoints** ($0.01/query): Use these for competitive analysis. /v1/marketing/competitive-landscape?category= shows all products in a category with pricing. /v1/marketing/brand-tracker?brand= tracks a brand's pricing over time. /v1/marketing/share-of-shelf?category= shows brand market share. **Analyst endpoints** ($0.02/query): Use these for market-level insights. /v1/analyst/inflation?category= shows price trends over time. /v1/analyst/price-dispersion?category= shows price spread across retailers. All endpoints accept an optional 'country' parameter (us or ca, defaults to us). Query parameters use 'q' for free-text search and 'category' for category-level queries. Marketing and analyst responses carry a `meta` block (served_from, freshness_seconds, schema_version) for staleness budgeting and a `resolved` block describing how the category input was matched against the taxonomy. Every response also sends an X-Data-Freshness-Hours header. **Free pre-payment rejection:** requests that cannot be served are rejected BEFORE any payment challenge — invalid params (400 INVALID_PARAMS), retailers that are not serving-eligible (404 RETAILER_NOT_SERVING_ELIGIBLE, with the catalog quality status and the serving_eligible_retailers list in error.details), and shopper queries that resolve to nothing in the catalog (404 NO_RESULTS). You only pay when the API can actually execute your query. Retailer values are case-insensitive (amazon == Amazon). servers: - url: https://api.syntalic.com security: [] paths: /v1/analyst/retailer-index: get: tags: - Analyst summary: Price index for a specific retailer over time description: >- Compute a normalized price index (retailer avg / category avg) for a specific retailer day-by-day versus its category baseline. Points report insufficient_sample below sample_threshold products plus stable_avg_price over the products priced every day — read trends from the stable series. operationId: getRetailerIndex parameters: - name: retailer in: query required: true schema: type: string description: Retailer platform key (e.g., amazon, walmart) example: amazon - name: country in: query required: false schema: type: string enum: - us - ca default: us description: Country (us or ca) example: us - name: category in: query required: false schema: type: string minLength: 1 description: >- Product category in the Shopify product taxonomy. Accepts a display path (e.g. 'Electronics > Computers > Laptops'), its slug form (e.g. 'electronics/computers/laptops'), a single path segment (e.g. 'laptops', 'headphones'), or an everyday shelf name (e.g. 'apparel', 'beauty', 'grocery'); matched against the catalog's category tree (exact node, subtree, or whole path segment). Also accepts a GS1 GPC code (exactly 8 digits, e.g. '10001159') to filter by PRODUCT TYPE instead of by shelf placement — the same product type is shelved under different categories by different retailers, so a category filter answers from a fraction of the data while a GPC code spans them. Coarser codes (class/family/segment) match every brick beneath them. Resolve a phrase to a code with /v1/reference/classify?q=... ; when a code is used, resolved.match_source is 'gpc'. For analyst endpoints, supply either `category` or `department`; both may be supplied to narrow the scope. example: electronics - name: department in: query required: false schema: type: string minLength: 1 description: >- Top-level department (root category), e.g. 'Electronics', 'Beauty', 'Home & Kitchen'. Case-insensitive; matched against the category tree's root segment. For analyst endpoints, supply either `category` or `department`; both may be supplied to narrow the scope. example: Electronics - name: time_window in: query required: false schema: type: string enum: - last_30_days - last_60_days - last_90_days - month_to_date - previous_month - month_over_month - quarter_to_date - custom description: >- Historical window preset. Explicit `from`/`to` takes precedence and is reported as `custom`; `time_window=custom` requires both `from` and `to`. Date-only ranges use UTC calendar boundaries with inclusive `from` and exclusive `to`. example: last_60_days - name: from in: query required: false schema: type: string format: date description: Start date (ISO 8601, defaults to 30 days ago) example: '2026-05-01' - name: to in: query required: false schema: type: string format: date description: End date (ISO 8601, defaults to now) example: '2026-06-01' responses: '200': description: Retailer index data content: application/json: schema: type: object properties: retailer: type: string category: type: string department: type: string nullable: true country: type: string currency: type: string window: type: object properties: preset: type: string from: type: string format: date to: type: string format: date granularity: type: string nullable: true comparison_from: type: string format: date nullable: true comparison_to: type: string format: date nullable: true timezone: type: string example: UTC additionalProperties: true sample_threshold: type: integer insufficient_sample_points: type: integer insufficient_sample: type: boolean description: >- True when any series point has a basket below sample_threshold. stable_basket_size: type: integer nullable: true description: >- Products priced in every period of the series (the basis of stable_avg_price). Null for single-point series. time_series: type: array items: type: object properties: date: type: string format: date period: type: string avg_price: type: number nullable: true min_price: type: number nullable: true max_price: type: number nullable: true median_price: type: number nullable: true product_count: type: integer observation_count: type: integer change_pct: type: number nullable: true matched_basket_size: type: integer method: type: string nullable: true in_stock_count: type: integer promo_count: type: integer retailer_avg_price: type: number nullable: true category_avg_price: type: number nullable: true price_index: type: number nullable: true stable_avg_price: type: number nullable: true description: >- Average over only the stable basket (products priced in EVERY period of the series) — immune to basket-composition shifts. Null when no product spans the whole series. insufficient_sample: type: boolean description: >- True when product_count is below sample_threshold — treat the point as anecdote, not trend. sample_threshold: type: integer additionalProperties: true resolved: type: object properties: input: type: string category_path: type: string nullable: true department: type: string nullable: true match_source: type: string nullable: true match_confidence: type: number nullable: true alternates: type: array items: type: object additionalProperties: true additionalProperties: true meta: type: object properties: served_from: type: string freshness_seconds: type: number schema_version: type: string computed_at: type: string format: date-time price_observed_at_min: type: string format: date-time nullable: true price_observed_at_max: type: string format: date-time nullable: true additionalProperties: true '400': description: >- Invalid query parameters or unsupported enum values. Rejected by preflight BEFORE the payment challenge — no payment is requested or charged for malformed requests. content: application/problem+json: schema: type: object required: - type - title - status properties: type: type: string format: uri-reference title: type: string example: Bad Request status: type: integer const: 400 detail: type: string instance: type: string error: type: object properties: code: type: string message: type: string details: type: object additionalProperties: true additionalProperties: true additionalProperties: true '402': description: Payment challenge required before executing paid work content: application/problem+json: schema: type: object required: - type - title - status properties: type: type: string format: uri-reference title: type: string example: Payment Required status: type: integer const: 402 detail: type: string instance: type: string error: type: object properties: code: type: string message: type: string details: type: object additionalProperties: true additionalProperties: true additionalProperties: true '404': description: >- No matching result. error.code distinguishes the cases: NO_RESULTS (the query resolves to nothing in the catalog), RETAILER_NOT_SERVING_ELIGIBLE (the requested retailer exists but is not serving-eligible — error.details carries its catalog quality_status and the serving_eligible_retailers list to retry against), or NOT_PUBLISHED (a social rollup the current publish run does not compute yet — a gap in what we publish, not a finding about the category). Structurally-unservable requests are rejected by preflight before any payment challenge. content: application/problem+json: schema: type: object required: - type - title - status properties: type: type: string format: uri-reference title: type: string example: Not Found status: type: integer const: 404 detail: type: string instance: type: string error: type: object properties: code: type: string message: type: string details: type: object additionalProperties: true additionalProperties: true additionalProperties: true '429': description: Rate limit exceeded content: application/problem+json: schema: type: object required: - type - title - status properties: type: type: string format: uri-reference title: type: string example: Too Many Requests status: type: integer const: 429 detail: type: string instance: type: string error: type: object properties: code: type: string message: type: string details: type: object additionalProperties: true additionalProperties: true additionalProperties: true '500': description: Unexpected server error content: application/problem+json: schema: type: object required: - type - title - status properties: type: type: string format: uri-reference title: type: string example: Internal Server Error status: type: integer const: 500 detail: type: string instance: type: string error: type: object properties: code: type: string message: type: string details: type: object additionalProperties: true additionalProperties: true additionalProperties: true ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.