> ## Documentation Index > Fetch the complete documentation index at: https://docs.fireweave.ai/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Official FireWeave SDK documentation. > Product noun is control point. OpenFeature and the wire protocol use flagKey — do not invent controlPointKey. > Do not invent APIs, packages, env vars, or endpoints. Guardrails are a typed stub (UnsupportedCapability). OpenFeature Tracking (spec section 6) is not implemented. > registerTarget and identify exist on Node, Python, and Web only. Go and Java have no target-registration API on master. > sendExposure defaults to false. Java close() does not flush exposures. # Errors > FireWeave’s 15-kind error taxonomy, OpenFeature errorCode map, and how to read a default-valued decision. The client evaluation API **never throws**. Abnormal execution returns the caller-supplied **default** with `reason: ERROR` and an `errorCode` (OpenFeature spec §1.4.10). If a typed getter raised, that is a bug. First diagnostic step: read **details**, not just the value. ```ts theme={null} const d = await client.getBooleanDetails('new-checkout', false, ctx); // d.reason, d.errorCode, d.errorMessage, d.flagMetadata['fireweave.errorKind'] ``` `flagMetadata["fireweave.errorKind"]` is the FireWeave kind. Use it to tell `NotReady` from `AlreadyClosed` — both map to OpenFeature `PROVIDER_NOT_READY`. ## 15 kinds Canonical kinds from `contracts/errors.md`. Messages are secret-redacted (no API keys, bearer tokens, or `FW_PROJECT_API_KEY` values). | Kind | OpenFeature `errorCode` | Retryable | When | | ----------------------- | --------------------------------------------- | --------- | -------------------------------------------------------------------------------------- | | `NotReady` | `PROVIDER_NOT_READY` | yes | Evaluation before successful init | | `FlagNotFound` | `FLAG_NOT_FOUND` | no | Key absent (includes quota-empty snapshots → default + `fireweave.quotaLimited: true`) | | `TypeMismatch` | `TYPE_MISMATCH` | no | Stored type ≠ requested getter | | `InvalidContext` | `INVALID_CONTEXT` or `TARGETING_KEY_MISSING` | no | Bad/oversized context; missing targeting key when required | | `Authentication` | `GENERAL` | no | HTTP 401 / invalid key | | `Authorization` | `GENERAL` | no | HTTP 403 / key lacks permission | | `RateLimited` | `GENERAL` | yes | HTTP 429 (still serve defaults) | | `Timeout` | `GENERAL` | yes | Request or init deadline exceeded | | `Network` | `GENERAL` | yes | DNS / connect / reset / TLS | | `BackendUnavailable` | `GENERAL` | yes | 5xx / upstream unavailable | | `MalformedResponse` | `PARSE_ERROR` | no | Non-JSON or schema-invalid body | | `UnsupportedCapability` | `GENERAL` | no | Extension not in this build (guardrails stub; Java `PostHogAdapter.create(config)`) | | `Configuration` | `PROVIDER_FATAL` (init) / `GENERAL` (runtime) | no | Invalid host, missing required key, bad options | | `AlreadyClosed` | `PROVIDER_NOT_READY` | no | Call after shutdown | | `Internal` | `GENERAL` | no | Unexpected invariant | \* `MalformedResponse` is permanent for a given response; a later request may succeed. Adapters must not invent flag values. `InvalidContext` subtype: missing required `targetingKey` → `TARGETING_KEY_MISSING`. All other context violations (type, reserved keys, size/depth/count bounds) → `INVALID_CONTEXT`. ## OpenFeature codes All eight OpenFeature codes are reachable: | OF `errorCode` | FireWeave kind(s) | | ----------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ | | `PROVIDER_NOT_READY` | `NotReady`, `AlreadyClosed` | | `PROVIDER_FATAL` | `Configuration` (init-fatal) | | `FLAG_NOT_FOUND` | `FlagNotFound` | | `PARSE_ERROR` | `MalformedResponse` | | `TYPE_MISMATCH` | `TypeMismatch` | | `TARGETING_KEY_MISSING` | `InvalidContext` (missing targeting key) | | `INVALID_CONTEXT` | `InvalidContext` | | `GENERAL` | `Authentication`, `Authorization`, `RateLimited`, `Timeout`, `Network`, `BackendUnavailable`, `UnsupportedCapability`, `Internal`, non-fatal `Configuration` | ## Language surfaces | Language | Type | | ---------- | --------------------------------------------------------------------------------------------------------------------------------------- | | Node / Web | Single class `FireweaveError` with `kind`, `openFeatureErrorCode`, `retryable` | | Python | `ErrorKind` plus subclasses (`NotReadyError`, `FlagNotFoundError`, `TimeoutError_`, `TargetingKeyMissingError`, …) | | Go | `fireweave.Error` with `ErrorKind` constants; implements `error` | | Java | `ErrorKind` enum + `FireweaveException` / `FireweaveError` value type. Evaluation returns defaults; extensions return `ExtensionResult` | Go **extension** APIs (`Releases().Start`, and so on) return `error`. Evaluation still does not throw through OpenFeature. ## Reasons that are not errors | `reason` | Meaning | | ----------------- | -------------------------------------------------------------------------------------------- | | `TARGETING_MATCH` | Conditions matched | | `SPLIT` | Backend reported percentage-rollout bucketing | | `DISABLED` | Control point exists and is off — you get the off/default value | | `STALE` | Last-good or timed-out prefetch (web boot ceiling). Check `fireweave.fromCache` when present | | `ERROR` | Inspect `errorCode` and `fireweave.errorKind` | | `DEFAULT` | Local/dev adapter: unknown key rewritten from `FLAG_NOT_FOUND` | ## `UnsupportedCapability` Expected in phase one for: 1. **Guardrails** in every language (`guardrails: false`). 2. **Java** `PostHogAdapter.create(config)` until a Java server SDK exists. Anywhere else, compare the name to `capabilities.get()`. ## Next Default values, auth, missing exposures How kinds appear on ResolutionDetails