> ## Documentation Index > Fetch the complete documentation index at: https://docs.closient.com/llms.txt > Use this file to discover all available pages before exploring further. # Decode a GS1-compressed Digital Link path segment > Decode the compressed form of a Digital Link (the single opaque path segment produced by GS1's compression scheme) back into its Application Identifiers, plus the equivalent uncompressed path. An undecodable segment is a `200` with `is_valid: false` and the reason — the same triage contract as `/validate`. The inverse direction (compressing an uncompressed URI) is not yet implemented; the engine behind this endpoint is decode-only. **Keyless** — no API key, no signup. IP-throttled at 300 requests/minute and cached at the edge for 24h, so repeat calls for the same input do not reach origin. Over-rate callers get a `429` with a `Retry-After` header and a `retry_after` field — it never silently degrades or returns a wrong answer under load. ## OpenAPI ````yaml /openapi/openapi-resolver.json get /resolver/api/v1/public/gs1/decompress openapi: 3.1.0 info: title: Resolver API version: 1.0.0 description: > GS1 Digital Link resolution with content negotiation and linkset support. ## Authentication All endpoints require an API key passed via the `X-API-Key` HTTP header, unless otherwise noted. ``` X-API-Key: csb__ ``` Generate API keys in **Settings > API Keys** in your dashboard, or via the Account API. Session-based (cookie) authentication is also accepted for browser-based access. ## Rate Limits | Tier | Requests / minute | Requests / day | |-------------|-------------------|----------------| | Default | 300 | 10,000 | | Custom | Contact us | Contact us | Rate-limit headers are included on every response so callers can self-throttle without hitting our 429s ("informed governor"): - `RateLimit-Policy` — every active window, e.g. `300;w=60, 10000;w=86400` - `RateLimit-Limit` — quota for the **most-restrictive** currently-active window - `RateLimit-Remaining` — requests left in that window - `RateLimit-Reset` — seconds until that window resets (relative; clock-skew safe) Legacy `X-RateLimit-*` aliases are also emitted for back-compat. `X-RateLimit-Reset` keeps the absolute Unix-timestamp shape to avoid breaking existing consumers. When rate-limited, you receive `429 Too Many Requests` with a `retry_after_seconds` field in the error envelope and a `Retry-After` header. ## Pagination List endpoints return paginated results in this envelope: ```json { "data": [...], "pagination": { "page": 1, "page_size": 25, "total_count": 342, "total_pages": 14, "has_next": true, "has_previous": false } } ``` Use `?page=2&page_size=50` query parameters. Maximum page size is 100. ## Error Responses All errors conform to [RFC 9457 Problem Details](https://www.rfc-editor.org/rfc/rfc9457) with `Content-Type: application/problem+json`: ```json { "type": "https://closient.com/docs/errors/not_found", "title": "Not Found", "status": 404, "detail": "The requested resource was not found.", "error_code": "not_found", "retryable": false, "timestamp": "2026-03-31T12:00:00+00:00" } ``` Common error codes: `unauthorized` (401), `forbidden` (403), `not_found` (404), `validation_error` (422), `rate_limited` (429), `internal_error` (500). termsOfService: https://www.closient.com/terms/ servers: - url: https://www.closient.com security: [] tags: - name: Resolver description: GS1 Digital Link resolution with content negotiation and linkset support. - name: Custom URLs description: >- Reusable custom-URL catalog (C-3339) — create, list, edit, and delete the custom redirect destinations that resolution rules point at. - name: Verification description: >- Serial verification (`gs1:verificationService`) — tiered, rate-limited responses for serialized GTIN scans. Experimental v1; see the verification-service guide. - name: GS1 Primitives (Public) description: >- Keyless GS1 Digital Link primitives (C-4295) — parse, validate, build, decompress, and check-digit analysis. **No API key, no signup.** Pure functions over strings: no database, no network, no catalog data. IP-throttled and edge-cached so repeat calls cost nothing. This is the reference implementation the resolver itself runs on. - name: Resolver Custom Hostnames description: >- BYO domain (C-4058) — register a customer-owned hostname, publish the CNAME records, verify ownership, and serve an org's Digital Link QRs from its own DNS. externalDocs: description: Closient Documentation url: https://docs.closient.com paths: /resolver/api/v1/public/gs1/decompress: get: tags: - GS1 Primitives (Public) summary: Decode a GS1-compressed Digital Link path segment description: >- Decode the compressed form of a Digital Link (the single opaque path segment produced by GS1's compression scheme) back into its Application Identifiers, plus the equivalent uncompressed path. An undecodable segment is a `200` with `is_valid: false` and the reason — the same triage contract as `/validate`. The inverse direction (compressing an uncompressed URI) is not yet implemented; the engine behind this endpoint is decode-only. **Keyless** — no API key, no signup. IP-throttled at 300 requests/minute and cached at the edge for 24h, so repeat calls for the same input do not reach origin. Over-rate callers get a `429` with a `Retry-After` header and a `retry_after` field — it never silently degrades or returns a wrong answer under load. operationId: apps_resolver_api_public_gs1_decompress_digital_link_public parameters: - in: query name: value schema: description: >- The compressed Digital Link path segment (GS1 base64 alphabet), e.g. `CxFKk4awWMhZyepCypCI--g`. maxLength: 4096 minLength: 1 title: Value type: string required: true description: >- The compressed Digital Link path segment (GS1 base64 alphabet), e.g. `CxFKk4awWMhZyepCypCI--g`. responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/DigitalLinkDecompressOut' components: schemas: DigitalLinkDecompressOut: description: Decoded contents of a GS1-compressed Digital Link path segment. examples: - gs1_ais: '10': ABC123 '01': '09506000164908' is_valid: true other: {} uncompressed_path: /01/09506000164908/10/ABC123 value: CxFKk4awWI1XgkY properties: value: description: The input segment, echoed back unchanged. title: Value type: string is_valid: description: True when the segment decoded to a well-formed GS1 AI set. title: Is Valid type: boolean error: anyOf: - type: string - type: 'null' description: Why decoding failed, or `null` on success. title: Error gs1_ais: additionalProperties: type: string description: >- Decoded `{ai_code: value}` pairs in canonical GS1 order (identifier, qualifiers, then attributes). title: Gs1 Ais type: object other: additionalProperties: type: string description: >- Any decoded non-GS1 query-string parameters carried in the compressed payload. title: Other type: object uncompressed_path: anyOf: - type: string - type: 'null' description: >- The equivalent uncompressed, root-relative Digital Link path, or `null` when decoding failed. title: Uncompressed Path required: - value - is_valid title: DigitalLinkDecompressOut type: object ````