> ## 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.

# Compatibility

> Runtime floors, evaluation types, adapters, and conformance for the five FireWeave SDKs — from manifests and the SDK audit only.

Spec version **0.1.0**. OpenFeature specification floor **v0.8.0**. Source: SDK `master` `dfeb478` plus live registry checks on 2026-08-17.

<Note>
  Language surfaces are **not** identical. This page records the asymmetry. Do not assume a method exists in every SDK.
</Note>

## Packages and publish state

| Surface           | Package                                                            | Version in tree                            | Published? (verified 2026-08-17)                                                                                                               |
| ----------------- | ------------------------------------------------------------------ | ------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------- |
| Node / Bun / Deno | `@fireweaveai/sdk`                                                 | `2.1.0`                                    | **Yes.** npm `0.1.0`, `2.0.0`, `2.1.0`. Dist-tag `latest` = **2.1.0**. `2.0.0` is a different API (direct PostHog adapter). Pin `2.1.0`.       |
| Python            | `fireweave`                                                        | `0.1.0`                                    | **Yes on PyPI** (`fireweave==0.1.0`). `pip install 'fireweave[openfeature]'` is valid. Checkout remains an alternative for an unreleased tree. |
| Go                | `github.com/FireWeave-HQ/fireweave-sdk/sdks/go`                    | `0.1.0` (matrix); `go.mod` is `go 1.25.12` | **No.** Go proxy 404. Checkout + `replace` only.                                                                                               |
| Java              | `ai.fireweave:fireweave-{sdk,openfeature,adapter-posthog,testing}` | `0.1.0-SNAPSHOT`                           | **No.** POM: “DO NOT PUBLISH.” Maven Central has no `ai.fireweave` artifacts.                                                                  |
| Browser           | `@fireweaveai/web-sdk`                                             | `2.1.0`                                    | **Yes on npm** (`2.1.0`, `gitHead` = `dfeb478`). `npm install @fireweaveai/web-sdk@2.1.0` is valid.                                            |

<Note>
  Registry tags can move. Re-check npm/PyPI before you ship install copy. As of 2026-08-17: Node `latest` = 2.1.0, Web 2.1.0, Python 0.1.0; Go and Java stay unpublished.
</Note>

License MIT; “do not redistribute packages built from this repository until the license is ratified and publication is authorized.”

## Runtime floors (manifests)

CI also runs extra cells (`latest` / `stable` / `canary`). Those float. **Support floors are the manifest numbers**, not the floating cells.

| SDK                 | Manifest floor                          | Also exercised in CI (not a guarantee) |
| ------------------- | --------------------------------------- | -------------------------------------- |
| Node                | Node `>=20.20` (`engines`)              | Node 20 + 24                           |
| Bun (same package)  | Bun `1.2` (runtime docs)                | Bun 1.2.0 + latest                     |
| Deno (same package) | Deno `2.0` (runtime docs)               | `v2.x` + canary                        |
| Python              | Python `>=3.10` (`requires-python`)     | 3.10 + 3.14                            |
| Go                  | `go 1.25.12` (`go.mod`)                 | `1.25.x` + stable                      |
| Java                | Java **11+** (`maven.compiler.release`) | JDK 11 + 25                            |
| Web                 | Browser. No Node/Deno target.           | Bun + happy-dom only                   |

## Evaluation types

OpenFeature and the wire use `flagKey`. Native product noun is **control point** where that namespace exists.

|          | Native evaluate                                   | Boolean               | String               | Numeric                                      | Object               |
| -------- | ------------------------------------------------- | --------------------- | -------------------- | -------------------------------------------- | -------------------- |
| Node 2.1 | `client.controlPoints.*` (`flags` alias)          | `getBooleanValue`     | `getStringValue`     | **`number`** (IEEE-754 double)               | `getObjectValue`     |
| Python   | `client.control_points.*` (`flags` alias)         | `get_boolean_value`   | `get_string_value`   | **`integer` + `float`**                      | `get_object_value`   |
| Go       | `client.Flags().Evaluate` only                    | via `FlagTypeBoolean` | via `FlagTypeString` | **`integer` + `float`**                      | via `FlagTypeObject` |
| Java     | `evaluate` / `getBooleanValue` / `getStringValue` | helper                | helper               | **`INTEGER` / `FLOAT` via `evaluate` or OF** | via `evaluate` or OF |
| Web      | `client.controlPoints.*` (**sync**)               | `getBooleanValue`     | `getStringValue`     | **`number`**                                 | `getObjectValue`     |

### Numeric limitations (pre-declared)

| Language         | Limitation                                | Behavior                                                                     |
| ---------------- | ----------------------------------------- | ---------------------------------------------------------------------------- |
| Node / Web       | Single `number` resolver; IEEE-754 double | Integers beyond ±(2^53−1) are not lossless. Node: 2 conformance skips.       |
| Java OpenFeature | Integer resolver is 32-bit `Integer`      | Outside range → `TYPE_MISMATCH` + default (never silent truncation). 1 skip. |
| All              | Canonical JSON numbers                    | Cross-language integer reliability within ±(2^53−1).                         |

Go OpenFeature integers are `int64`.

## Feature matrix

| Capability                  | Node 2.1                                                      | Python                           | Go                                                              | Java                                                   | Web                                          |
| --------------------------- | ------------------------------------------------------------- | -------------------------------- | --------------------------------------------------------------- | ------------------------------------------------------ | -------------------------------------------- |
| Product namespace           | `controlPoints` (`flags` alias)                               | `control_points` (`flags` alias) | `Flags()` only                                                  | **none**                                               | `controlPoints` (sync)                       |
| `registerTarget` / identify | `runtime.registerTarget`                                      | `runtime.register_target`        | **absent**                                                      | **absent**                                             | `client.identify()` → `registerTarget`       |
| Remote adapter              | `FireweaveRemoteAdapter`                                      | `FireweaveRemoteAdapter`         | `adapters/remote`                                               | `FireweaveRemoteAdapter`                               | `FireweaveRemoteWebAdapter`                  |
| In-memory                   | `InMemoryAdapter`                                             | `InMemoryAdapter`                | `adapters/inmemory`                                             | `ai.fireweave.testing.InMemoryAdapter`                 | `InMemoryWebAdapter`                         |
| Local / dev adapter         | `FireweaveLocalAdapter`                                       | `FireweaveLocalAdapter`          | **absent**                                                      | **absent**                                             | `FireweaveLocalWebAdapter`                   |
| Direct PostHog adapter      | **removed**                                                   | `fireweave[posthog]`             | `adapters/posthog`                                              | seam only (`create(config)` → `UnsupportedCapability`) | **none**                                     |
| In-process local eval       | **none**                                                      | via PostHog extra                | via PostHog adapter                                             | blocked on unpublished `com.posthog:posthog-server`    | never (`localEvaluation` structurally false) |
| Env-var config              | `FW_API_URL`, `FW_PROJECT_API_KEY`, `FW_DEPRECATION_WARNINGS` | same on remote adapter           | `FW_API_URL`, `FW_PROJECT_API_KEY` on remote                    | **no `System.getenv`**                                 | **reads no environment**                     |
| Default host allowlist      | Fireweave hosts + loopback                                    | PostHog hosts + loopback         | PostHog (PostHog adapter) / configured host + loopback (remote) | PostHog hosts + loopback                               | Fireweave hosts + loopback                   |
| `sendExposure` default      | **false**                                                     | **false**                        | **false**                                                       | **false**                                              | **false**                                    |
| Shutdown flushes exposures  | yes                                                           | yes                              | via `Flush` / provider shutdown                                 | **`close()` does not**                                 | yes (+ unload flush)                         |
| Guardrails                  | stub                                                          | stub                             | stub                                                            | stub                                                   | stub                                         |
| OpenFeature Tracking (§6)   | **not implemented**                                           | **not implemented**              | **not implemented**                                             | **not implemented**                                    | **not implemented**                          |

## OpenFeature pins

| Binding | Provider                                     | OF SDK pin                               | Resolvers                                           |
| ------- | -------------------------------------------- | ---------------------------------------- | --------------------------------------------------- |
| Node    | `FireweaveProvider`                          | `@openfeature/server-sdk` ^1.22.0 (peer) | boolean, string, **number**, object                 |
| Python  | `fireweave.openfeature.FireweaveProvider`    | `openfeature-sdk` `>=0.10,<0.11` extra   | boolean, string, **integer**, **float**, object     |
| Go      | `openfeature.NewProvider`                    | `go-sdk` v1.17.2                         | boolean, string, float, **int64**, object           |
| Java    | `ai.fireweave.openfeature.FireweaveProvider` | `dev.openfeature:sdk` **1.15.1**         | boolean, string, **32-bit Integer**, double, object |
| Web     | `FireweaveWebProvider`                       | `@openfeature/web-sdk` ^1.9.0 (peer)     | boolean, string, **number**, object — **sync**      |

Verified: typed resolvers, detailed resolution, `flagMetadata`, provider initialize/shutdown, user-registered hooks. FireWeave ships **no** product hooks except Go’s reserved-key guard. Domains are domain-safe. Multi-provider: compatible where OpenFeature ships it (Node); **untested on Python**. Tracking: planned, not present.

See [OpenFeature](/openfeature).

## Conformance

From `docs/compatibility.md` + `contracts/README.md`:

|                        | Fixtures                                       |
| ---------------------- | ---------------------------------------------- |
| Server contracts (65)  | Python 65/65, Go 65/65, Java 64/65, Node 63/65 |
| Web (`contracts/web/`) | 10/10                                          |

All skips are pre-declared (`skipped-with-documented-limitation`). Node skips are the IEEE-754 integer fixtures. Java skip is the 32-bit integer range fixture.

## Server vs web

|                   | Server SDKs                         | Web                                                         |
| ----------------- | ----------------------------------- | ----------------------------------------------------------- |
| `controlPoints.*` | Promise / blocking                  | **synchronous**                                             |
| Evaluation source | per-call (Node remote has no cache) | prefetched cache                                            |
| Extra lifecycle   | —                                   | **STALE** (5s prefetch ceiling)                             |
| Telemetry flush   | shutdown hook (except Java `close`) | `visibilitychange` / `pagehide`, `keepalive` / `sendBeacon` |
| Config            | env where implemented               | constructor only                                            |

## Known gaps (do not paper over)

1. **Java PostHog** — `PostHogAdapter.create(config)` → `UnsupportedCapability` until upstream publishes a Java server SDK.
2. **Release/signal delivery skew** — Go (and Java via the adapter seam) deliver release transitions/signals to the backend telemetry sink; Node/Python may record some paths in-process only. **NEEDS VERIFICATION** per adapter before claiming “signals always reach fw-server.”
3. **OpenFeature Tracking (§6)** — not implemented. Default evaluate remains side-effect-free (`sendExposure` false).

## Language pages

<Card title="Node.js, Bun, Deno" href="/sdks/node">
  `@fireweaveai/sdk` 2.1.0 vs 2.0.0.
</Card>

<Card title="Python" href="/sdks/python">
  `fireweave` extras and snake\_case.
</Card>

<Card title="Go" href="/sdks/go">
  `Flags()` only; no registerTarget.
</Card>

<Card title="Java" href="/sdks/java">
  No env auto-read; close does not flush.
</Card>

<Card title="Browser" href="/sdks/web">
  Sync reads, identify, STALE.
</Card>