diff --git a/packages/core/src/filesystem.ts b/packages/core/src/filesystem.ts
index 8a1cc3a08fc3..9d68f3ff5b65 100644
--- a/packages/core/src/filesystem.ts
+++ b/packages/core/src/filesystem.ts
@@ -80,6 +80,7 @@ export namespace AppFileSystem {
       })
 
       const readJson = Effect.fn("FileSystem.readJson")(function* (path: string) {
+        yield* Effect.annotateCurrentSpan({ "file.path": path })
         const text = yield* fs.readFileString(path)
         return JSON.parse(text)
       })
@@ -99,6 +100,7 @@ export namespace AppFileSystem {
         content: string | Uint8Array,
         mode?: number,
       ) {
+        yield* Effect.annotateCurrentSpan({ "file.path": path })
         const write = typeof content === "string" ? fs.writeFileString(path, content) : fs.writeFile(path, content)
 
         yield* write.pipe(
@@ -122,6 +124,7 @@ export namespace AppFileSystem {
       })
 
       const findUp = Effect.fn("FileSystem.findUp")(function* (target: string, start: string, stop?: string) {
+        yield* Effect.annotateCurrentSpan({ "file.target": target, "file.start": start })
         const result: string[] = []
         let current = start
         while (true) {
diff --git a/packages/opencode/src/auth/index.ts b/packages/opencode/src/auth/index.ts
index f7c6319357a3..c5dee878f1c1 100644
--- a/packages/opencode/src/auth/index.ts
+++ b/packages/opencode/src/auth/index.ts
@@ -57,6 +57,7 @@ export const layer = Layer.effect(
     const decode = Schema.decodeUnknownOption(Info)
 
     const all = Effect.fn("Auth.all")(function* () {
+      yield* Effect.annotateCurrentSpan({ "auth.file": file })
       if (process.env.OPENCODE_AUTH_CONTENT) {
         try {
           return JSON.parse(process.env.OPENCODE_AUTH_CONTENT)
@@ -68,6 +69,7 @@ export const layer = Layer.effect(
     })
 
     const get = Effect.fn("Auth.get")(function* (providerID: string) {
+      yield* Effect.annotateCurrentSpan({ "provider.id": providerID })
       return (yield* all())[providerID]
     })
 
diff --git a/packages/opencode/src/plugin/index.ts b/packages/opencode/src/plugin/index.ts
index 7a7f260df897..127de3595f9b 100644
--- a/packages/opencode/src/plugin/index.ts
+++ b/packages/opencode/src/plugin/index.ts
@@ -260,6 +260,7 @@ export const layer = Layer.effect(
       Input = Parameters<Required<Hooks>[Name]>[0],
       Output = Parameters<Required<Hooks>[Name]>[1],
     >(name: Name, input: Input, output: Output) {
+      yield* Effect.annotateCurrentSpan({ "plugin.hook": name })
       if (!name) return output
       const s = yield* InstanceState.get(state)
       for (const hook of s.hooks) {
diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index c27b69b6a208..319eb6a58328 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -1564,9 +1564,10 @@ const layer: Layer.Layer<
       }
     }
 
-    const getProvider = Effect.fn("Provider.getProvider")((providerID: ProviderID) =>
-      InstanceState.use(state, (s) => s.providers[providerID]),
-    )
+    const getProvider = Effect.fn("Provider.getProvider")(function* (providerID: ProviderID) {
+      yield* Effect.annotateCurrentSpan({ "provider.id": providerID })
+      return yield* InstanceState.use(state, (s) => s.providers[providerID])
+    })
 
     const getModel = Effect.fn("Provider.getModel")(function* (providerID: ProviderID, modelID: ModelID) {
       const s = yield* InstanceState.get(state)
@@ -1587,6 +1588,7 @@ const layer: Layer.Layer<
     })
 
     const getLanguage = Effect.fn("Provider.getLanguage")(function* (model: Model) {
+      yield* Effect.annotateCurrentSpan({ "provider.id": model.providerID, "model.id": model.id })
       const s = yield* InstanceState.get(state)
       const envs = yield* env.all()
       const key = `${model.providerID}/${model.id}`
diff --git a/packages/opencode/src/session/compaction.ts b/packages/opencode/src/session/compaction.ts
index 3ca4f074f9e4..7c6ae50c8feb 100644
--- a/packages/opencode/src/session/compaction.ts
+++ b/packages/opencode/src/session/compaction.ts
@@ -319,6 +319,7 @@ export const layer: Layer.Layer<
     // goes backwards through parts until there are PRUNE_PROTECT tokens worth of tool
     // calls, then erases output of older tool calls to free context space
     const prune = Effect.fn("SessionCompaction.prune")(function* (input: { sessionID: SessionID }) {
+      yield* Effect.annotateCurrentSpan({ "session.id": input.sessionID })
       const cfg = yield* config.get()
       if (!cfg.compaction?.prune) return
       log.info("pruning")
diff --git a/packages/opencode/src/session/instruction.ts b/packages/opencode/src/session/instruction.ts
index 6629ce67bc9f..dd706ba9eac0 100644
--- a/packages/opencode/src/session/instruction.ts
+++ b/packages/opencode/src/session/instruction.ts
@@ -99,6 +99,7 @@ export const layer: Layer.Layer<
     })
 
     const clear = Effect.fn("Instruction.clear")(function* (messageID: MessageID) {
+      yield* Effect.annotateCurrentSpan({ "message.id": messageID })
       const s = yield* InstanceState.get(state)
       s.claims.delete(messageID)
     })
diff --git a/packages/opencode/src/session/processor.ts b/packages/opencode/src/session/processor.ts
index 579c4cc42c54..7d2f1593846d 100644
--- a/packages/opencode/src/session/processor.ts
+++ b/packages/opencode/src/session/processor.ts
@@ -636,6 +636,10 @@ export const layer: Layer.Layer<
       })
 
       const cleanup = Effect.fn("SessionProcessor.cleanup")(function* () {
+        yield* Effect.annotateCurrentSpan({
+          "session.id": ctx.sessionID,
+          "message.id": ctx.assistantMessage.id,
+        })
         if (ctx.snapshot) {
           const patch = yield* snapshot.patch(ctx.snapshot)
           if (patch.files.length) {
@@ -725,6 +729,10 @@ export const layer: Layer.Layer<
       })
 
       const process = Effect.fn("SessionProcessor.process")(function* (streamInput: LLM.StreamInput) {
+        yield* Effect.annotateCurrentSpan({
+          "session.id": ctx.sessionID,
+          "message.id": ctx.assistantMessage.id,
+        })
         slog.info("process")
         ctx.needsCompaction = false
         ctx.shouldBreak = (yield* config.get()).experimental?.continue_loop_on_deny !== true
diff --git a/packages/opencode/src/session/session.ts b/packages/opencode/src/session/session.ts
index f50f8750b32b..62c072fefc07 100644
--- a/packages/opencode/src/session/session.ts
+++ b/packages/opencode/src/session/session.ts
@@ -583,7 +583,11 @@ export const layer: Layer.Layer<Service, never, Bus.Service | Storage.Service |
       Effect.gen(function* () {
         yield* sync.run(MessageV2.Event.Updated, { sessionID: msg.sessionID, info: msg })
         return msg
-      }).pipe(Effect.withSpan("Session.updateMessage"))
+      }).pipe(
+        Effect.withSpan("Session.updateMessage", {
+          attributes: { "session.id": msg.sessionID, "message.id": msg.id },
+        }),
+      )
 
     const updatePart = <T extends MessageV2.Part>(part: T): Effect.Effect<T> =>
       Effect.gen(function* () {
@@ -593,7 +597,15 @@ export const layer: Layer.Layer<Service, never, Bus.Service | Storage.Service |
           time: Date.now(),
         })
         return part
-      }).pipe(Effect.withSpan("Session.updatePart"))
+      }).pipe(
+        Effect.withSpan("Session.updatePart", {
+          attributes: {
+            "session.id": part.sessionID,
+            "message.id": part.messageID,
+            "part.id": part.id,
+          },
+        }),
+      )
 
     const getPart: Interface["getPart"] = Effect.fn("Session.getPart")(function* (input) {
       const row = Database.use((db) =>
@@ -719,6 +731,7 @@ export const layer: Layer.Layer<Service, never, Bus.Service | Storage.Service |
       sessionID: SessionID
       summary: Info["summary"]
     }) {
+      yield* Effect.annotateCurrentSpan({ "session.id": input.sessionID })
       yield* patch(input.sessionID, { time: { updated: Date.now() }, summary: input.summary })
     })
 
@@ -729,6 +742,7 @@ export const layer: Layer.Layer<Service, never, Bus.Service | Storage.Service |
     })
 
     const messages = Effect.fn("Session.messages")(function* (input: { sessionID: SessionID; limit?: number }) {
+      yield* Effect.annotateCurrentSpan({ "session.id": input.sessionID })
       if (input.limit) {
         return MessageV2.page({ sessionID: input.sessionID, limit: input.limit }).items
       }
@@ -774,6 +788,7 @@ export const layer: Layer.Layer<Service, never, Bus.Service | Storage.Service |
       sessionID: SessionID,
       predicate: (msg: MessageV2.WithParts) => boolean,
     ) {
+      yield* Effect.annotateCurrentSpan({ "session.id": sessionID })
       for (const item of MessageV2.stream(sessionID)) {
         if (predicate(item)) return Option.some(item)
       }
diff --git a/packages/opencode/src/session/summary.ts b/packages/opencode/src/session/summary.ts
index e39bd85e9ac9..09308b386bf2 100644
--- a/packages/opencode/src/session/summary.ts
+++ b/packages/opencode/src/session/summary.ts
@@ -81,6 +81,7 @@ export const layer = Layer.effect(
     const bus = yield* Bus.Service
 
     const computeDiff = Effect.fn("SessionSummary.computeDiff")(function* (input: { messages: MessageV2.WithParts[] }) {
+      yield* Effect.annotateCurrentSpan({ "messages.count": input.messages.length })
       let from: string | undefined
       let to: string | undefined
       for (const item of input.messages) {
@@ -104,6 +105,7 @@ export const layer = Layer.effect(
       sessionID: SessionID
       messageID: MessageID
     }) {
+      yield* Effect.annotateCurrentSpan({ "session.id": input.sessionID, "message.id": input.messageID })
       const all = yield* sessions.messages({ sessionID: input.sessionID })
       if (!all.length) return
 
diff --git a/packages/opencode/src/snapshot/index.ts b/packages/opencode/src/snapshot/index.ts
index 848a067c3d11..4e01c051695b 100644
--- a/packages/opencode/src/snapshot/index.ts
+++ b/packages/opencode/src/snapshot/index.ts
@@ -750,7 +750,9 @@ export const layer: Layer.Layer<
         return yield* InstanceState.useEffect(state, (s) => s.cleanup())
       }),
       track: Effect.fn("Snapshot.track")(function* () {
-        return yield* InstanceState.useEffect(state, (s) => s.track())
+        const hash = yield* InstanceState.useEffect(state, (s) => s.track())
+        if (hash) yield* Effect.annotateCurrentSpan({ "snapshot.hash": hash })
+        return hash
       }),
       patch: Effect.fn("Snapshot.patch")(function* (hash: string) {
         return yield* InstanceState.useEffect(state, (s) => s.patch(hash))
diff --git a/packages/opencode/src/tool/truncate.ts b/packages/opencode/src/tool/truncate.ts
index ffc16c0b9f99..2b1d5a207cd7 100644
--- a/packages/opencode/src/tool/truncate.ts
+++ b/packages/opencode/src/tool/truncate.ts
@@ -53,6 +53,7 @@ export const layer = Layer.effect(
     const fs = yield* AppFileSystem.Service
 
     const cleanup = Effect.fn("Truncate.cleanup")(function* () {
+      yield* Effect.annotateCurrentSpan({ "truncate.dir": TRUNCATION_DIR })
       const cutoff = Identifier.timestamp(
         Identifier.create("tool", "ascending", Date.now() - Duration.toMillis(RETENTION)),
       )
@@ -60,10 +61,13 @@ export const layer = Layer.effect(
         Effect.map((all) => all.filter((name) => name.startsWith("tool_"))),
         Effect.catch(() => Effect.succeed([])),
       )
+      let removed = 0
       for (const entry of entries) {
         if (Identifier.timestamp(entry) >= cutoff) continue
         yield* fs.remove(path.join(TRUNCATION_DIR, entry)).pipe(Effect.catch(() => Effect.void))
+        removed++
       }
+      yield* Effect.annotateCurrentSpan({ "truncate.scanned": entries.length, "truncate.removed": removed })
     })
 
     const write = Effect.fn("Truncate.write")(function* (text: string) {