global: fixes

crates/brk_bindgen/src/generators/javascript/api.rs

@@ -69,7 +69,7 @@ pub fn generate_api_methods(output: &mut String, endpoints: &[Endpoint]) {
 
         writeln!(
             output,
-            "   * @param {{{{ signal?: AbortSignal, onUpdate?: (value: {}) => void }}}} [options]",
+            "   * @param {{{{ signal?: AbortSignal, onValue?: (value: {}) => void }}}} [options]",
             return_type
         )
         .unwrap();
@@ -78,18 +78,18 @@ pub fn generate_api_methods(output: &mut String, endpoints: &[Endpoint]) {
 
         let params = build_method_params(endpoint);
         let params_with_opts = if params.is_empty() {
-            "{ signal, onUpdate } = {}".to_string()
+            "{ signal, onValue } = {}".to_string()
         } else {
-            format!("{}, {{ signal, onUpdate }} = {{}}", params)
+            format!("{}, {{ signal, onValue }} = {{}}", params)
         };
         writeln!(output, "  async {}({}) {{", method_name, params_with_opts).unwrap();
 
         let path = build_path_template(&endpoint.path, &endpoint.path_params);
 
         let fetch_call = if endpoint.returns_json() {
-            "this.getJson(path, { signal, onUpdate })"
+            "this.getJson(path, { signal, onValue })"
         } else {
-            "this.getText(path, { signal, onUpdate })"
+            "this.getText(path, { signal, onValue })"
         };
 
         if endpoint.query_params.is_empty() {
@@ -126,7 +126,7 @@ pub fn generate_api_methods(output: &mut String, endpoints: &[Endpoint]) {
         if endpoint.supports_csv {
             writeln!(
                 output,
-                "    if (format === 'csv') return this.getText(path, {{ signal, onUpdate }});"
+                "    if (format === 'csv') return this.getText(path, {{ signal, onValue }});"
             )
             .unwrap();
         }

crates/brk_bindgen/src/generators/javascript/client.rs

@@ -16,12 +16,16 @@ pub fn generate_base_client(output: &mut String) {
  * @typedef {{Object}} BrkClientOptions
  * @property {{string}} baseUrl - Base URL for the API
  * @property {{number}} [timeout] - Request timeout in milliseconds
- * @property {{string|boolean}} [cache] - Enable browser cache with default name (true), custom name (string), or disable (false). No effect in Node.js. Default: true
+ * @property {{string|boolean}} [browserCache] - Enable browser Cache API with default name (true), custom name (string), or disable (false). No effect in Node.js. Default: true
+ * @property {{number|boolean}} [memCache] - In-memory parsed-response cache size (LRU). true/undefined → 1000, false/0 → disabled. Lets 304 responses skip the JSON parse entirely. Default: 1000
  */
 
 const _isBrowser = typeof window !== 'undefined' && 'caches' in window;
 const _runIdle = (/** @type {{VoidFunction}} */ fn) => (globalThis.requestIdleCallback ?? setTimeout)(fn);
-const _defaultCacheName = '__BRK_CLIENT__';
+const _defaultBrowserCacheName = '__BRK_CLIENT__';
+const _DEFAULT_MEM_CACHE_SIZE = 1000;
+
+/** @template T @typedef {{{{ etag: string | null, value: T }}}} _MemEntry */
 /** @param {{*}} v */
 const _addCamelGetters = (v) => {{
   if (Array.isArray(v)) {{ v.forEach(_addCamelGetters); return v; }}
@@ -38,12 +42,12 @@ const _addCamelGetters = (v) => {{
 }};
 
 /**
- * @param {{string|boolean|undefined}} cache
+ * @param {{string|boolean|undefined}} option
  * @returns {{Promise<Cache | null>}}
  */
-const _openCache = (cache) => {{
-  if (!_isBrowser || cache === false) return Promise.resolve(null);
-  const name = typeof cache === 'string' ? cache : _defaultCacheName;
+const _openBrowserCache = (option) => {{
+  if (!_isBrowser || option === false) return Promise.resolve(null);
+  const name = typeof option === 'string' ? option : _defaultBrowserCacheName;
   return caches.open(name).catch(() => null);
 }};
 
@@ -233,7 +237,7 @@ function _wrapSeriesData(raw) {{
  * @property {{(n: number) => RangeBuilder<T>}} first - Get first n items
  * @property {{(n: number) => RangeBuilder<T>}} last - Get last n items
  * @property {{(n: number) => SkippedBuilder<T>}} skip - Skip first n items, chain with take()
- * @property {{(onUpdate?: (value: SeriesData<T>) => void) => Promise<SeriesData<T>>}} fetch - Fetch all data
+ * @property {{(onValue?: (value: SeriesData<T>) => void) => Promise<SeriesData<T>>}} fetch - Fetch all data
  * @property {{() => Promise<string>}} fetchCsv - Fetch all data as CSV
  * @property {{() => Promise<number>}} len - Get total number of data points
  * @property {{() => Promise<Version>}} version - Get the current version of the series
@@ -249,7 +253,7 @@ function _wrapSeriesData(raw) {{
  * @property {{(n: number) => DateRangeBuilder<T>}} first - Get first n items
  * @property {{(n: number) => DateRangeBuilder<T>}} last - Get last n items
  * @property {{(n: number) => DateSkippedBuilder<T>}} skip - Skip first n items, chain with take()
- * @property {{(onUpdate?: (value: DateSeriesData<T>) => void) => Promise<DateSeriesData<T>>}} fetch - Fetch all data
+ * @property {{(onValue?: (value: DateSeriesData<T>) => void) => Promise<DateSeriesData<T>>}} fetch - Fetch all data
  * @property {{() => Promise<string>}} fetchCsv - Fetch all data as CSV
  * @property {{() => Promise<number>}} len - Get total number of data points
  * @property {{() => Promise<Version>}} version - Get the current version of the series
@@ -260,39 +264,39 @@ function _wrapSeriesData(raw) {{
 /** @typedef {{SeriesEndpoint<any>}} AnySeriesEndpoint */
 
 /** @template T @typedef {{Object}} SingleItemBuilder
- * @property {{(onUpdate?: (value: SeriesData<T>) => void) => Promise<SeriesData<T>>}} fetch - Fetch the item
+ * @property {{(onValue?: (value: SeriesData<T>) => void) => Promise<SeriesData<T>>}} fetch - Fetch the item
  * @property {{() => Promise<string>}} fetchCsv - Fetch as CSV
  * @property {{Thenable<T>}} then - Thenable
  */
 
 /** @template T @typedef {{Object}} DateSingleItemBuilder
- * @property {{(onUpdate?: (value: DateSeriesData<T>) => void) => Promise<DateSeriesData<T>>}} fetch - Fetch the item
+ * @property {{(onValue?: (value: DateSeriesData<T>) => void) => Promise<DateSeriesData<T>>}} fetch - Fetch the item
  * @property {{() => Promise<string>}} fetchCsv - Fetch as CSV
  * @property {{DateThenable<T>}} then - Thenable
  */
 
 /** @template T @typedef {{Object}} SkippedBuilder
  * @property {{(n: number) => RangeBuilder<T>}} take - Take n items after skipped position
- * @property {{(onUpdate?: (value: SeriesData<T>) => void) => Promise<SeriesData<T>>}} fetch - Fetch from skipped position to end
+ * @property {{(onValue?: (value: SeriesData<T>) => void) => Promise<SeriesData<T>>}} fetch - Fetch from skipped position to end
  * @property {{() => Promise<string>}} fetchCsv - Fetch as CSV
  * @property {{Thenable<T>}} then - Thenable
  */
 
 /** @template T @typedef {{Object}} DateSkippedBuilder
  * @property {{(n: number) => DateRangeBuilder<T>}} take - Take n items after skipped position
- * @property {{(onUpdate?: (value: DateSeriesData<T>) => void) => Promise<DateSeriesData<T>>}} fetch - Fetch from skipped position to end
+ * @property {{(onValue?: (value: DateSeriesData<T>) => void) => Promise<DateSeriesData<T>>}} fetch - Fetch from skipped position to end
  * @property {{() => Promise<string>}} fetchCsv - Fetch as CSV
  * @property {{DateThenable<T>}} then - Thenable
  */
 
 /** @template T @typedef {{Object}} RangeBuilder
- * @property {{(onUpdate?: (value: SeriesData<T>) => void) => Promise<SeriesData<T>>}} fetch - Fetch the range
+ * @property {{(onValue?: (value: SeriesData<T>) => void) => Promise<SeriesData<T>>}} fetch - Fetch the range
  * @property {{() => Promise<string>}} fetchCsv - Fetch as CSV
  * @property {{Thenable<T>}} then - Thenable
  */
 
 /** @template T @typedef {{Object}} DateRangeBuilder
- * @property {{(onUpdate?: (value: DateSeriesData<T>) => void) => Promise<DateSeriesData<T>>}} fetch - Fetch the range
+ * @property {{(onValue?: (value: DateSeriesData<T>) => void) => Promise<DateSeriesData<T>>}} fetch - Fetch the range
  * @property {{() => Promise<string>}} fetchCsv - Fetch as CSV
  * @property {{DateThenable<T>}} then - Thenable
  */
@@ -340,7 +344,7 @@ function _endpoint(client, name, index) {{
    * @returns {{DateRangeBuilder<T>}}
    */
   const rangeBuilder = (start, end) => ({{
-    fetch(onUpdate) {{ return client._fetchSeriesData(buildPath(start, end), onUpdate); }},
+    fetch(onValue) {{ return client._fetchSeriesData(buildPath(start, end), onValue); }},
     fetchCsv() {{ return client.getText(buildPath(start, end, 'csv')); }},
     then(resolve, reject) {{ return this.fetch().then(resolve, reject); }},
   }});
@@ -350,7 +354,7 @@ function _endpoint(client, name, index) {{
    * @returns {{DateSingleItemBuilder<T>}}
    */
   const singleItemBuilder = (idx) => ({{
-    fetch(onUpdate) {{ return client._fetchSeriesData(buildPath(idx, idx + 1), onUpdate); }},
+    fetch(onValue) {{ return client._fetchSeriesData(buildPath(idx, idx + 1), onValue); }},
     fetchCsv() {{ return client.getText(buildPath(idx, idx + 1, 'csv')); }},
     then(resolve, reject) {{ return this.fetch().then(resolve, reject); }},
   }});
@@ -361,7 +365,7 @@ function _endpoint(client, name, index) {{
    */
   const skippedBuilder = (start) => ({{
     take(n) {{ return rangeBuilder(start, start + n); }},
-    fetch(onUpdate) {{ return client._fetchSeriesData(buildPath(start, undefined), onUpdate); }},
+    fetch(onValue) {{ return client._fetchSeriesData(buildPath(start, undefined), onValue); }},
     fetchCsv() {{ return client.getText(buildPath(start, undefined, 'csv')); }},
     then(resolve, reject) {{ return this.fetch().then(resolve, reject); }},
   }});
@@ -377,7 +381,7 @@ function _endpoint(client, name, index) {{
     first(n) {{ return rangeBuilder(undefined, n); }},
     last(n) {{ return n === 0 ? rangeBuilder(undefined, 0) : rangeBuilder(-n, undefined); }},
     skip(n) {{ return skippedBuilder(n); }},
-    fetch(onUpdate) {{ return client._fetchSeriesData(buildPath(), onUpdate); }},
+    fetch(onValue) {{ return client._fetchSeriesData(buildPath(), onValue); }},
     fetchCsv() {{ return client.getText(buildPath(undefined, undefined, 'csv')); }},
     len() {{ return client.getSeriesLen(name, index); }},
     version() {{ return client.getSeriesVersion(name, index); }},
@@ -401,10 +405,45 @@ class BrkClientBase {{
     this.baseUrl = rawUrl.endsWith('/') ? rawUrl.slice(0, -1) : rawUrl;
     this.timeout = isString ? 5000 : (options.timeout ?? 5000);
     /** @type {{Promise<Cache | null>}} */
-    this._cachePromise = _openCache(isString ? undefined : options.cache);
+    this._browserCachePromise = _openBrowserCache(isString ? undefined : options.browserCache);
     /** @type {{Cache | null}} */
-    this._cache = null;
-    this._cachePromise.then(c => this._cache = c);
+    this._browserCache = null;
+    this._browserCachePromise.then(c => this._browserCache = c);
+    const memOpt = isString ? undefined : options.memCache;
+    this._memCacheMax = memOpt === false || memOpt === 0
+      ? 0
+      : (typeof memOpt === 'number' ? memOpt : _DEFAULT_MEM_CACHE_SIZE);
+    /** @type {{Map<string, _MemEntry<unknown>>}} */
+    this._memCache = new Map();
+  }}
+
+  /**
+   * @template T
+   * @param {{string}} key
+   * @returns {{_MemEntry<T> | undefined}}
+   */
+  _memGet(key) {{
+    if (!this._memCacheMax) return undefined;
+    const hit = this._memCache.get(key);
+    if (!hit) return undefined;
+    this._memCache.delete(key);
+    this._memCache.set(key, hit);
+    return /** @type {{_MemEntry<T>}} */ (hit);
+  }}
+
+  /**
+   * @param {{string}} key
+   * @param {{string | null}} etag
+   * @param {{unknown}} value
+   */
+  _memSet(key, etag, value) {{
+    if (!this._memCacheMax) return;
+    if (this._memCache.has(key)) this._memCache.delete(key);
+    else if (this._memCache.size >= this._memCacheMax) {{
+      const oldest = this._memCache.keys().next().value;
+      if (oldest !== undefined) this._memCache.delete(oldest);
+    }}
+    this._memCache.set(key, {{ etag, value }});
   }}
 
   /**
@@ -422,66 +461,86 @@ class BrkClientBase {{
   }}
 
   /**
-   * Make a GET request - races cache vs network, first to resolve calls onUpdate.
-   * Shared implementation backing `getJson` and `getText`.
+   * Make a GET request with layered caching.
+   *
+   * Contract:
+   * - The returned Promise resolves with the **freshest** value (post-revalidation).
+   * - `onValue` fires once with the freshest value, or twice if a stale snapshot
+   *   could be shown first (stale-while-revalidate). On a 304 there is no second fire.
+   *
+   * Layers:
+   * - L1 (memCache): in-memory parsed values keyed by URL+ETag. Lets 304s skip the parse entirely.
+   * - L2 (browserCache): Cache API, survives reload and feeds onValue fast on cold start.
+   *
    * @template T
    * @param {{string}} path
    * @param {{(res: Response) => Promise<T>}} parse - Response body reader
-   * @param {{{{ onUpdate?: (value: T) => void, signal?: AbortSignal }}}} [options]
+   * @param {{{{ onValue?: (value: T) => void, signal?: AbortSignal }}}} [options]
    * @returns {{Promise<T>}}
    */
-  async _getCached(path, parse, {{ onUpdate, signal }} = {{}}) {{
+  async _getCached(path, parse, {{ onValue, signal }} = {{}}) {{
     const url = `${{this.baseUrl}}${{path}}`;
-    const cache = this._cache ?? await this._cachePromise;
+    /** @type {{_MemEntry<T> | undefined}} */
+    const memHit = this._memGet(url);
+    const browserCache = this._browserCache ?? await this._browserCachePromise;
 
-    let resolved = false;
-    /** @type {{Response | null}} */
-    let cachedRes = null;
-
-    // Race cache vs network - first to resolve calls onUpdate
-    const cachePromise = cache?.match(url).then(async (res) => {{
-      cachedRes = res ?? null;
-      if (!res) return null;
-      const value = await parse(res);
-      if (!resolved && onUpdate) {{
-        resolved = true;
-        onUpdate(value);
-      }}
-      return value;
-    }});
-
-    const networkPromise = this.get(path, {{ signal }}).then(async (res) => {{
-      const cloned = res.clone();
-      const value = await parse(res);
-      // Skip update if ETag matches and cache already delivered
-      if (cachedRes?.headers.get('ETag') === res.headers.get('ETag')) {{
-        if (!resolved && onUpdate) {{
-          resolved = true;
-          onUpdate(value);
-        }}
+    // L1 fast path: deliver from memCache, revalidate via network.
+    // ETag match → zero parse, zero clone, zero cache write, no second onValue fire.
+    if (memHit) {{
+      if (onValue) onValue(memHit.value);
+      try {{
+        const res = await this.get(path, {{ signal }});
+        const netEtag = res.headers.get('ETag');
+        if (netEtag && netEtag === memHit.etag) return memHit.value;
+        const cloned = browserCache ? res.clone() : null;
+        const value = await parse(res);
+        this._memSet(url, netEtag, value);
+        if (onValue) onValue(value);
+        if (cloned) _runIdle(() => browserCache.put(url, cloned));
         return value;
+      }} catch {{
+        return memHit.value;
       }}
-      resolved = true;
-      if (onUpdate) onUpdate(value);
-      if (cache) _runIdle(() => cache.put(url, cloned));
-      return value;
-    }});
+    }}
+
+    // L1 miss: race browserCache (stale snapshot) vs network (fresh).
+    let networkSettled = false;
+    const stalePromise = onValue && browserCache
+      ? browserCache.match(url).then(async (res) => {{
+          if (!res || networkSettled) return null;
+          const value = await parse(res);
+          if (networkSettled) return value;
+          this._memSet(url, res.headers.get('ETag'), value);
+          onValue(value);
+          return value;
+        }}).catch(() => null)
+      : null;
 
     try {{
-      return await networkPromise;
+      const res = await this.get(path, {{ signal }});
+      networkSettled = true;
+      const netEtag = res.headers.get('ETag');
+      // Stale won and populated memCache with matching ETag → reuse, skip parse + second onValue.
+      const populated = /** @type {{_MemEntry<T> | undefined}} */ (this._memGet(url));
+      if (populated && netEtag && netEtag === populated.etag) return populated.value;
+      const cloned = browserCache ? res.clone() : null;
+      const value = await parse(res);
+      this._memSet(url, netEtag, value);
+      if (onValue) onValue(value);
+      if (cloned) _runIdle(() => browserCache.put(url, cloned));
+      return value;
     }} catch (e) {{
-      // Network failed - wait for cache
-      const cachedValue = await cachePromise?.catch(() => null);
-      if (cachedValue != null) return cachedValue;
+      const stale = await stalePromise;
+      if (stale != null) return stale;
       throw e;
     }}
   }}
 
   /**
-   * Make a GET request expecting a JSON response. Cached and supports `onUpdate`.
+   * Make a GET request expecting a JSON response. Cached and supports `onValue`.
    * @template T
    * @param {{string}} path
-   * @param {{{{ onUpdate?: (value: T) => void, signal?: AbortSignal }}}} [options]
+   * @param {{{{ onValue?: (value: T) => void, signal?: AbortSignal }}}} [options]
    * @returns {{Promise<T>}}
    */
   getJson(path, options) {{
@@ -490,9 +549,9 @@ class BrkClientBase {{
 
   /**
    * Make a GET request expecting a text response (text/plain, text/csv, ...).
-   * Cached and supports `onUpdate`, same as `getJson`.
+   * Cached and supports `onValue`, same as `getJson`.
    * @param {{string}} path
-   * @param {{{{ onUpdate?: (value: string) => void, signal?: AbortSignal }}}} [options]
+   * @param {{{{ onValue?: (value: string) => void, signal?: AbortSignal }}}} [options]
    * @returns {{Promise<string>}}
    */
   getText(path, options) {{
@@ -503,12 +562,12 @@ class BrkClientBase {{
    * Fetch series data and wrap with helper methods (internal)
    * @template T
    * @param {{string}} path
-   * @param {{(value: DateSeriesData<T>) => void}} [onUpdate]
+   * @param {{(value: DateSeriesData<T>) => void}} [onValue]
    * @returns {{Promise<DateSeriesData<T>>}}
    */
-  async _fetchSeriesData(path, onUpdate) {{
-    const wrappedOnUpdate = onUpdate ? (/** @type {{SeriesData<T>}} */ raw) => onUpdate(_wrapSeriesData(raw)) : undefined;
-    const raw = await this.getJson(path, {{ onUpdate: wrappedOnUpdate }});
+  async _fetchSeriesData(path, onValue) {{
+    const wrappedOnValue = onValue ? (/** @type {{SeriesData<T>}} */ raw) => onValue(_wrapSeriesData(raw)) : undefined;
+    const raw = await this.getJson(path, {{ onValue: wrappedOnValue }});
     return _wrapSeriesData(raw);
   }}
 }}

crates/brk_bindgen/src/generators/python/client.rs

@@ -325,13 +325,13 @@ AnyDateSeriesData = DateSeriesData[Any]
 
 class _EndpointConfig:
     """Shared endpoint configuration."""
-    client: BrkClientBase
+    client: BrkClient
     name: str
     index: Index
     start: Optional[int]
     end: Optional[int]
 
-    def __init__(self, client: BrkClientBase, name: str, index: Index,
+    def __init__(self, client: BrkClient, name: str, index: Index,
                  start: Optional[int] = None, end: Optional[int] = None):
         self.client = client
         self.name = name
@@ -366,6 +366,12 @@ class _EndpointConfig:
     def get_csv(self) -> str:
         return self.client.get_text(self._build_path(format='csv'))
 
+    def get_len(self) -> int:
+        return self.client.get_series_len(self.name, self.index)
+
+    def get_version(self) -> Version:
+        return self.client.get_series_version(self.name, self.index)
+
 
 class RangeBuilder(Generic[T]):
     """Builder with range specified."""
@@ -449,7 +455,7 @@ class SeriesEndpoint(Generic[T]):
         data = endpoint.skip(100).take(10).fetch()
     """
 
-    def __init__(self, client: BrkClientBase, name: str, index: Index):
+    def __init__(self, client: BrkClient, name: str, index: Index):
         self._config = _EndpointConfig(client, name, index)
 
     @overload
@@ -483,6 +489,14 @@ class SeriesEndpoint(Generic[T]):
         """Fetch all data as CSV."""
         return self._config.get_csv()
 
+    def len(self) -> int:
+        """Total number of data points for this series."""
+        return self._config.get_len()
+
+    def version(self) -> Version:
+        """Current version of the series."""
+        return self._config.get_version()
+
     def path(self) -> str:
         """Get the base endpoint path."""
         return self._config.path()
@@ -500,7 +514,7 @@ class DateSeriesEndpoint(Generic[T]):
         data = endpoint[:10].fetch()
     """
 
-    def __init__(self, client: BrkClientBase, name: str, index: Index):
+    def __init__(self, client: BrkClient, name: str, index: Index):
         self._config = _EndpointConfig(client, name, index)
 
     @overload
@@ -546,6 +560,14 @@ class DateSeriesEndpoint(Generic[T]):
         """Fetch all data as CSV."""
         return self._config.get_csv()
 
+    def len(self) -> int:
+        """Total number of data points for this series."""
+        return self._config.get_len()
+
+    def version(self) -> Version:
+        """Current version of the series."""
+        return self._config.get_version()
+
     def path(self) -> str:
         """Get the base endpoint path."""
         return self._config.path()
@@ -604,10 +626,10 @@ pub fn generate_index_accessors(output: &mut String, patterns: &[IndexSetPattern
     // Generate helper functions
     writeln!(
         output,
-        r#"def _ep(c: BrkClientBase, n: str, i: Index) -> SeriesEndpoint[Any]:
+        r#"def _ep(c: BrkClient, n: str, i: Index) -> SeriesEndpoint[Any]:
     return SeriesEndpoint(c, n, i)
 
-def _dep(c: BrkClientBase, n: str, i: Index) -> DateSeriesEndpoint[Any]:
+def _dep(c: BrkClient, n: str, i: Index) -> DateSeriesEndpoint[Any]:
     return DateSeriesEndpoint(c, n, i)
 "#
     )
@@ -623,7 +645,7 @@ def _dep(c: BrkClientBase, n: str, i: Index) -> DateSeriesEndpoint[Any]:
         writeln!(output, "class {}(Generic[T]):", by_class_name).unwrap();
         writeln!(
             output,
-            "    def __init__(self, c: BrkClientBase, n: str): self._c, self._n = c, n"
+            "    def __init__(self, c: BrkClient, n: str): self._c, self._n = c, n"
         )
         .unwrap();
         for index in &pattern.indexes {
@@ -648,7 +670,7 @@ def _dep(c: BrkClientBase, n: str, i: Index) -> DateSeriesEndpoint[Any]:
         writeln!(output, "    by: {}[T]", by_class_name).unwrap();
         writeln!(
             output,
-            "    def __init__(self, c: BrkClientBase, n: str): self._n, self.by = n, {}(c, n)",
+            "    def __init__(self, c: BrkClient, n: str): self._n, self.by = n, {}(c, n)",
             by_class_name
         )
         .unwrap();
@@ -705,13 +727,13 @@ pub fn generate_structural_patterns(
         if pattern.is_templated() {
             writeln!(
                 output,
-                "    def __init__(self, client: BrkClientBase, acc: str, disc: str):"
+                "    def __init__(self, client: BrkClient, acc: str, disc: str):"
             )
             .unwrap();
         } else {
             writeln!(
                 output,
-                "    def __init__(self, client: BrkClientBase, acc: str):"
+                "    def __init__(self, client: BrkClient, acc: str):"
             )
             .unwrap();
         }

crates/brk_bindgen/src/generators/python/tree.rs

@@ -64,7 +64,7 @@ fn generate_tree_class(
     writeln!(output, "    ").unwrap();
     writeln!(
         output,
-        "    def __init__(self, client: BrkClientBase, base_path: str = ''):"
+        "    def __init__(self, client: BrkClient, base_path: str = ''):"
     )
     .unwrap();
 

crates/brk_bindgen/src/generators/rust/client.rs

@@ -187,6 +187,14 @@ impl EndpointConfig {{
     fn get_text(&self, format: Option<&str>) -> Result<String> {{
         self.client.get_text(&self.build_path(format))
     }}
+
+    fn get_len(&self) -> Result<i64> {{
+        self.client.get_json(&format!("/api/series/{{}}/{{}}/len", self.name, self.index.name()))
+    }}
+
+    fn get_version(&self) -> Result<Version> {{
+        self.client.get_json(&format!("/api/series/{{}}/{{}}/version", self.name, self.index.name()))
+    }}
 }}
 
 /// Builder for series endpoint queries.
@@ -280,6 +288,17 @@ impl<T: DeserializeOwned, D: DeserializeOwned> SeriesEndpoint<T, D> {{
         self.config.get_text(Some("csv"))
     }}
 
+    /// Total number of data points for this series.
+    #[allow(clippy::len_without_is_empty)]
+    pub fn len(&self) -> Result<i64> {{
+        self.config.get_len()
+    }}
+
+    /// Current version of the series.
+    pub fn version(&self) -> Result<Version> {{
+        self.config.get_version()
+    }}
+
     /// Get the base endpoint path.
     pub fn path(&self) -> String {{
         self.config.path()