add experimental.open_telemetry config option to enable OTEL spans (#4978)

Co-authored-by: noamzbr <noamzbr@users.noreply.github.com>
Co-authored-by: opencode-agent[bot] <opencode-agent[bot]@users.noreply.github.com>
Co-authored-by: rekram1-node <rekram1-node@users.noreply.github.com>

packages/opencode/src/agent/agent.ts

@@ -222,6 +222,7 @@ export namespace Agent {
   }
 
   export async function generate(input: { description: string }) {
+    const cfg = await Config.get()
     const defaultModel = await Provider.defaultModel()
     const model = await Provider.getModel(defaultModel.providerID, defaultModel.modelID)
     const language = await Provider.getLanguage(model)
@@ -229,6 +230,7 @@ export namespace Agent {
     system.push(PROMPT_GENERATE)
     const existing = await list()
     const result = await generateObject({
+      experimental_telemetry: { isEnabled: cfg.experimental?.openTelemetry },
       temperature: 0.3,
       prompt: [
         ...system.map(

packages/opencode/src/config/config.ts

@@ -670,6 +670,10 @@ export namespace Config {
           chatMaxRetries: z.number().optional().describe("Number of retries for chat completions on failure"),
           disable_paste_summary: z.boolean().optional(),
           batch_tool: z.boolean().optional().describe("Enable the batch tool"),
+          openTelemetry: z
+            .boolean()
+            .optional()
+            .describe("Enable OpenTelemetry spans for AI SDK calls (using the 'experimental_telemetry' flag)"),
           primary_tools: z
             .array(z.string())
             .optional()

packages/opencode/src/session/compaction.ts

@@ -10,6 +10,7 @@ import z from "zod"
 import { SessionPrompt } from "./prompt"
 import { Flag } from "../flag/flag"
 import { Token } from "../util/token"
+import { Config } from "../config/config"
 import { Log } from "../util/log"
 import { ProviderTransform } from "@/provider/transform"
 import { SessionProcessor } from "./processor"
@@ -96,6 +97,7 @@ export namespace SessionCompaction {
     abort: AbortSignal
     auto: boolean
   }) {
+    const cfg = await Config.get()
     const model = await Provider.getModel(input.model.providerID, input.model.modelID)
     const language = await Provider.getLanguage(model)
     const system = [...SystemPrompt.compaction(model.providerID)]
@@ -191,6 +193,7 @@ export namespace SessionCompaction {
           },
         ],
       }),
+      experimental_telemetry: { isEnabled: cfg.experimental?.openTelemetry },
     })
     if (result === "continue" && input.auto) {
       const continueMsg = await Session.updateMessage({

packages/opencode/src/session/prompt.ts

@@ -42,6 +42,7 @@ import { Command } from "../command"
 import { $, fileURLToPath } from "bun"
 import { ConfigMarkdown } from "../config/markdown"
 import { SessionSummary } from "./summary"
+import { Config } from "../config/config"
 import { NamedError } from "@opencode-ai/util/error"
 import { fn } from "@/util/fn"
 import { SessionProcessor } from "./processor"
@@ -433,6 +434,7 @@ export namespace SessionPrompt {
       }
 
       // normal processing
+      const cfg = await Config.get()
       const agent = await Agent.get(lastUser.agent)
       msgs = insertReminders({
         messages: msgs,
@@ -613,6 +615,7 @@ export namespace SessionPrompt {
             },
           ],
         }),
+        experimental_telemetry: { isEnabled: cfg.experimental?.openTelemetry },
       })
       if (result === "stop") break
       continue
@@ -1418,6 +1421,7 @@ export namespace SessionPrompt {
       input.history.filter((m) => m.info.role === "user" && !m.parts.every((p) => "synthetic" in p && p.synthetic))
         .length === 1
     if (!isFirst) return
+    const cfg = await Config.get()
     const small =
       (await Provider.getSmallModel(input.providerID)) ?? (await Provider.getModel(input.providerID, input.modelID))
     const language = await Provider.getLanguage(small)
@@ -1464,6 +1468,7 @@ export namespace SessionPrompt {
       ],
       headers: small.headers,
       model: language,
+      experimental_telemetry: { isEnabled: cfg.experimental?.openTelemetry },
     })
       .then((result) => {
         if (result.text)

packages/opencode/src/session/summary.ts

@@ -1,4 +1,5 @@
 import { Provider } from "@/provider/provider"
+import { Config } from "@/config/config"
 import { fn } from "@/util/fn"
 import z from "zod"
 import { Session } from "."
@@ -60,6 +61,7 @@ export namespace SessionSummary {
   }
 
   async function summarizeMessage(input: { messageID: string; messages: MessageV2.WithParts[] }) {
+    const cfg = await Config.get()
     const messages = input.messages.filter(
       (m) => m.info.id === input.messageID || (m.info.role === "assistant" && m.info.parentID === input.messageID),
     )
@@ -109,6 +111,7 @@ export namespace SessionSummary {
         ],
         headers: small.headers,
         model: language,
+        experimental_telemetry: { isEnabled: cfg.experimental?.openTelemetry },
       })
       log.info("title", { title: result.text })
       userMsg.summary.title = result.text
@@ -150,6 +153,7 @@ export namespace SessionSummary {
             },
           ],
           headers: small.headers,
+          experimental_telemetry: { isEnabled: cfg.experimental?.openTelemetry },
         }).catch(() => {})
         if (result) summary = result.text
       }