Use complete FXMacroData responses through native valyala/fastjson values. This independent companion is not an upstream endorsement.
go get github.com/fxmacrodata/fastjson-fxmacrodata@v0.1.0import fxmd "github.com/fxmacrodata/fastjson-fxmacrodata"
// responseJSON comes from your own current FXMacroData SDK/client.
doc, err := fxmd.ParseJSON(responseJSON)
if err != nil { return err }
response, err := doc.Native()
if err != nil { return err }
selected, err := doc.NativeAt("/data/0") // choose your actual JSON Pointer
if err != nil { return err }
consumeNative(response, selected)Native() returns a new complete native tree; NativeAt() selects a complete value by RFC 6901 JSON Pointer. All fields, nested values, revisions, provenance, units, clocks, unknown-time flags, explicit nulls and pagination metadata remain available. No parser instance is reused: later calls and native edits cannot invalidate or change earlier views or the original document. Each native tree is independently mutable and follows the upstream library's normal concurrency rules.
Document.Raw() returns an independent copy of the exact original response bytes. JSONAt() retains every selected field and numeric spelling while normalizing whitespace, escaping and object order. NumberTextAt() exposes the exact numeric lexeme. Native Value.String()/MarshalTo() retain number text without implicit float64 conversion. Use numeric conversion methods only when you explicitly want their native range/precision behavior. Native edits are derived values and never rewrite original observations. No dates or missing values are guessed.
Parse accepts JSON-serializable SDK models; ParseJSON also preserves unknown fields and original bytes that typed models may omit. Values already rounded by the caller cannot be reconstructed. Empty values and explicit nulls are supported; absent pointers return errors rather than fabricated zeroes. Duplicate keys, malformed JSON, invalid UTF-8, excess depth/value count and oversized input/views are rejected with payload-free errors. Limits: 4 MiB response, 8 MiB view, 64 nested containers, 50,000 JSON values and 4,096 UTF-8 pointer bytes. Original JSON remains available if a selected native representation fails.
The local MIT-licensed adapter and MIT-licensed native library need no hosted plan, account, card or infrastructure. Customers supply their own client, credentials and entitlements outside this package; always-free USD catalogue, macro history and calendar can be obtained through that client. There is no key/environment access, HTTP transport, endpoint/parameter allowlist, automatic pagination, live fallback or data storage. Future JSON response families can use the same interface. Media/stream/MCP execution belongs to the caller's client or renderer.
FXMacroData · API documentation
See CAPABILITIES.md. Native fixture tests cover exact numbers, null/missing distinctions, every JSON root shape, complete response families, independent native mutations/lifetimes, pointers, Unicode and bounds. go run ./examples/inspect uses a fictional fixture only. Tests do not certify live endpoints/authentication, real data or customer installation.