opencode prices and Go limits, settings out of .env

- Fetch prices for opencode (Zen and Go) incl. limits, image input, reasoning,
  long-context tiers and peak-hour/date factors; costs apply them per request
- Record the cost opencode reports per response; track Go allowance in 5h/7d/month
  windows against a provider plan limit (budget table, status overlay)
- Settings → Config file: move values of ${NAME} references into the config
- Examples, presets and forms keep keys in the config instead of .env

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

server/src/budget.rs

@@ -129,6 +129,28 @@ fn entry(name: &str, budget: Option<f64>, spent: f64, warn: f64) -> Value {
 }
 
 /// Budget overview for the current month.
+/// Subscription windows of opencode Go, as share of the plan's monthly limit: rolling
+/// 5 hours (20 %) and 7 days (50 %), and the calendar month in UTC (100 %). Only usage
+/// through CodeCraft is counted.
+pub fn plan_usage(app: &App, provider: &str, limit: f64) -> Result<Value> {
+    let now = chrono::Utc::now();
+    let month = chrono::Utc.with_ymd_and_hms(now.year(), now.month(), 1, 0, 0, 0).single().map(|d| d.timestamp_millis()).unwrap_or(0);
+    let ms = now.timestamp_millis();
+    let window = |name: &str, from: i64, share: f64| -> Result<Value> {
+        let used = app.store.allowance_since(provider, from)?;
+        let cap = limit * share;
+        Ok(json!({"window": name, "used": used, "limit": cap, "ratio": if cap > 0.0 { used / cap } else { 0.0 }}))
+    };
+    Ok(json!({
+        "limit": limit,
+        "windows": [
+            window("5h", ms - 5 * 3_600_000, 0.2)?,
+            window("week", ms - 7 * 86_400_000, 0.5)?,
+            window("month", month, 1.0)?,
+        ],
+    }))
+}
+
 pub async fn overview(app: &App) -> Result<Value> {
     let cfg = app.config();
     let spent = app.store.cost_by_provider(month_start())?;
@@ -139,7 +161,11 @@ pub async fn overview(app: &App) -> Result<Value> {
         if !p.enabled {
             continue;
         }
-        rows.push(entry(name, p.monthly_budget, spent.get(name).copied().unwrap_or(0.0), warn));
+        let mut row = entry(name, p.monthly_budget, spent.get(name).copied().unwrap_or(0.0), warn);
+        if let Some(limit) = p.plan_limit.filter(|l| *l > 0.0) {
+            row["plan"] = plan_usage(app, name, limit)?;
+        }
+        rows.push(row);
         let p = p.clone();
         tasks.push(tokio::spawn(async move { remote_balance(&p).await }));
     }
@@ -174,13 +200,138 @@ pub async fn overview(app: &App) -> Result<Value> {
 }
 
 /// Per-token prices from the provider's model list, converted to per 1M tokens.
+fn is_opencode(p: &ProviderConfig) -> bool {
+    p.base_url.contains("opencode.ai")
+}
+
+async fn get_json(url: &str) -> Result<Value> {
+    Ok(crate::provider::http_client().get(url).timeout(Duration::from_secs(30)).send().await?.error_for_status()?.json().await?)
+}
+
+/// One opencode condition object → (days, hours, from, until); None if it uses
+/// something we do not understand.
+type When = (Vec<String>, Vec<(String, String)>, Option<String>, Option<String>);
+
+fn opencode_when(w: &Value) -> Option<When> {
+    let obj = w.as_object()?;
+    let (mut days, mut hours, mut from, mut until) = (Vec::new(), Vec::new(), None, None);
+    // A pair of utc_hours bounds, given as {"all": [{"utc_hours": {"gte"}}, {"utc_hours": {"lt"}}]}
+    // or directly as {"utc_hours": {"gte", "lt"}}.
+    let range = |v: &Value| -> Option<(String, String)> {
+        if let Some(h) = v.get("utc_hours") {
+            return Some((h["gte"].as_str()?.to_string(), h["lt"].as_str()?.to_string()));
+        }
+        let all = v.get("all")?.as_array()?;
+        let get = |k: &str| all.iter().find_map(|x| x["utc_hours"][k].as_str()).map(String::from);
+        Some((get("gte")?, get("lt")?))
+    };
+    for (k, v) in obj {
+        match k.as_str() {
+            "utc_days" => days = v["in"].as_array()?.iter().map(|d| d.as_str().map(String::from)).collect::<Option<_>>()?,
+            "any" => hours = v.as_array()?.iter().map(range).collect::<Option<_>>()?,
+            "all" | "utc_hours" => hours = vec![range(w)?],
+            "date" => {
+                from = v["gte"].as_str().map(String::from);
+                until = v["lt"].as_str().map(String::from);
+                if from.is_none() && until.is_none() {
+                    return None;
+                }
+            }
+            _ => return None,
+        }
+    }
+    Some((days, hours, from, until))
+}
+
+/// Model row from opencode's model list (prices per 1M tokens, tiers, time factors).
+fn opencode_model(m: &Value) -> Value {
+    let cost = &m["cost"]["text"];
+    let (input, output) = (&cost["input"], &cost["output"]);
+    // Context tiers: input and output overrides share their thresholds.
+    let mut tiers: std::collections::BTreeMap<u64, serde_json::Map<String, Value>> = Default::default();
+    for (side, field) in [(input, "input_price"), (output, "output_price")] {
+        for o in side["overrides"].as_array().into_iter().flatten() {
+            let Some(gt) = o["when"]["context"]["gt"].as_u64() else { continue };
+            let t = tiers.entry(gt).or_default();
+            t.insert(field.into(), o["price"].clone());
+            if field == "input_price" {
+                if o["cache"]["read"].is_number() {
+                    t.insert("cache_read_price".into(), o["cache"]["read"].clone());
+                }
+                if o["cache"]["write"].is_number() {
+                    t.insert("cache_write_price".into(), o["cache"]["write"].clone());
+                }
+            }
+        }
+    }
+    let price_tiers: Vec<Value> = tiers.into_iter().map(|(gt, mut t)| {
+        t.insert("above_context".into(), json!(gt));
+        Value::Object(t)
+    }).collect();
+    let mut notes = Vec::new();
+    let price_multipliers: Vec<Value> = m["cost"]["multipliers"]
+        .as_array()
+        .into_iter()
+        .flatten()
+        .filter_map(|x| match opencode_when(&x["when"]) {
+            Some((days, hours, from, until)) => Some(json!({"factor": x["factor"], "days": days, "hours_utc": hours, "from": from, "until": until})),
+            None => {
+                notes.push(format!("unsupported price condition: {}", x["when"]));
+                None
+            }
+        })
+        .map(|mut v| {
+            // Drop empty conditions so the config stays short.
+            v.as_object_mut().unwrap().retain(|_, x| !(x.is_null() || x.as_array().is_some_and(|a| a.is_empty())));
+            v
+        })
+        .collect();
+    let images = m["modalities"]["input"].as_array().is_some_and(|a| a.iter().any(|x| x.as_str().is_some_and(|s| s.starts_with("image"))));
+    json!({
+        "id": m["id"],
+        "context": m["limit"]["context"],
+        "max_output": m["limit"]["output"],
+        "vision": images,
+        "reasoning": m["capabilities"]["reasoning"]["supported"].as_bool().unwrap_or(false),
+        "input_price": input["price"],
+        "output_price": output["price"],
+        "cache_read_price": input["cache"]["read"],
+        "cache_write_price": input["cache"]["write"],
+        "price_tiers": price_tiers,
+        "price_multipliers": price_multipliers,
+        "notes": notes,
+    })
+}
+
+/// opencode (Zen and Go) publishes prices in its model list. The Anthropic-protocol
+/// endpoint lists models without them, so fall back to the gateway's own /v1/models.
+async fn opencode_prices(base: &str) -> Result<Value> {
+    let mut urls = vec![format!("{base}/models")];
+    for suffix in ["/openai/v1", "/anthropic/v1"] {
+        if let Some(root) = base.strip_suffix(suffix) {
+            urls.push(format!("{root}/v1/models"));
+        }
+    }
+    for url in &urls {
+        let Ok(v) = get_json(url).await else { continue };
+        let models: Vec<Value> = v["data"].as_array().into_iter().flatten().filter(|m| m.get("cost").is_some()).map(opencode_model).collect();
+        if !models.is_empty() {
+            return Ok(json!({"currency": "USD", "models": models}));
+        }
+    }
+    bail!("opencode did not return prices for this endpoint")
+}
+
 pub async fn discover_prices(app: &App, provider: &str) -> Result<Value> {
     let cfg = app.config();
     let p = cfg.providers.get(provider).context("unknown provider")?;
+    let base = expand_env(&p.base_url).trim_end_matches('/').to_string();
+    if is_opencode(p) {
+        return opencode_prices(&base).await;
+    }
     if !is_openrouter(p) {
         bail!("this provider does not publish prices via its API – enter them manually");
     }
-    let base = expand_env(&p.base_url).trim_end_matches('/').to_string();
     let v: Value = crate::provider::http_client()
         .get(format!("{base}/models"))
         .timeout(Duration::from_secs(30))
@@ -211,6 +362,28 @@ pub async fn discover_prices(app: &App, provider: &str) -> Result<Value> {
 
 #[cfg(test)]
 mod tests {
+    #[test]
+    fn opencode_cost_conversion() {
+        let m: serde_json::Value = serde_json::from_str(r#"{"id":"grok","limit":{"context":500000,"output":8000},
+            "modalities":{"input":["text","image/png"]},"capabilities":{"reasoning":{"supported":true}},
+            "cost":{"text":{"input":{"price":2,"cache":{"read":0.5},"overrides":[{"when":{"context":{"gt":200000}},"price":4,"cache":{"read":1}}]},
+                            "output":{"price":6,"overrides":[{"when":{"context":{"gt":200000}},"price":12}]}},
+                    "multipliers":[{"when":{"utc_days":{"in":["mon","tue"]},"any":[{"all":[{"utc_hours":{"gte":"01:00"}},{"utc_hours":{"lt":"04:00"}}]}]},"factor":2},
+                                   {"when":{"date":{"gte":"2026-12-01"}},"factor":2},
+                                   {"when":{"region":"eu"},"factor":3}]}}"#).unwrap();
+        let r = super::opencode_model(&m);
+        assert_eq!(r["input_price"], 2);
+        assert_eq!(r["cache_read_price"], 0.5);
+        assert_eq!(r["vision"], true);
+        assert_eq!(r["price_tiers"][0], serde_json::json!({"above_context": 200000, "input_price": 4, "cache_read_price": 1, "output_price": 12}));
+        assert_eq!(r["price_multipliers"][0], serde_json::json!({"factor": 2, "days": ["mon", "tue"], "hours_utc": [["01:00", "04:00"]]}));
+        assert_eq!(r["price_multipliers"][1], serde_json::json!({"factor": 2, "from": "2026-12-01"}));
+        assert_eq!(r["notes"].as_array().unwrap().len(), 1, "unknown condition is reported, not guessed");
+        // The result must deserialize into the model config.
+        let mc: crate::config::ModelConfig = serde_json::from_value(serde_json::json!({"id": "grok", "price_tiers": r["price_tiers"], "price_multipliers": r["price_multipliers"]})).unwrap();
+        assert_eq!(mc.price_tiers[0].above_context, 200000);
+    }
+
     #[test]
     fn budget_entry_flags() {
         let e = super::entry("x", Some(10.0), 8.5, 0.8);