feat(main): opt-in prompt logging

Author: antoine-gauvain

README.md

@@ -56,7 +56,7 @@ An [opencode](https://opencode.ai) plugin that exports telemetry via OpenTelemet
 | `session.created` | Session started |
 | `session.idle` | Session went idle (includes total tokens, cost, messages) |
 | `session.error` | Session error |
-| `user_prompt` | User sent a message (includes `prompt_length`, `model`, `agent`) |
+| `user_prompt` | User sent a message (includes `prompt_length`, `model`, `agent`; also `prompt` when `OPENCODE_CAPTURE_PROMPT` is set) |
 | `api_request` | Completed assistant message (tokens, cost, duration) |
 | `api_error` | Failed assistant message (error summary, duration) |
 | `tool_result` | Tool completed or errored (duration, success, output size) |
@@ -99,6 +99,7 @@ The environment variables (set them in your shell profile — `~/.zshrc`, `~/.ba
 | `OPENCODE_METRIC_PREFIX` | `opencode.` | Prefix for all metric names (e.g. set to `claude_code.` for Claude Code dashboard compatibility) |
 | `OPENCODE_DISABLE_METRICS` | *(unset)* | Comma-separated list of metric name suffixes to disable (e.g. `cache.count,session.duration`) |
 | `OPENCODE_DISABLE_LOGS` | *(unset)* | Set to any non-empty value to suppress all OTLP log events while leaving metrics and traces unchanged |
+| `OPENCODE_CAPTURE_PROMPT` | *(unset)* | Set to any non-empty value to include the full prompt text in the `prompt` field of `user_prompt` log events. **Off by default — prompts may contain secrets or PII; enable only for trusted collectors.** |
 | `OPENCODE_DISABLE_TRACES` | *(unset)* | Comma-separated list of trace types to disable (`session`, `llm`, `tool`). Use `all`, `*`, `true`, or `1` to disable every trace type |
 | `OPENCODE_OTLP_HEADERS` | *(unset)* | Comma-separated `key=value` headers added to all OTLP exports. **Keep out of version control — may contain sensitive auth tokens.** |
 | `OPENCODE_OTLP_HEADERS_HELPER` | *(unset)* | Executable script/binary that returns dynamic OTLP headers as JSON after an auth failure. Helper headers override `OPENCODE_OTLP_HEADERS`. |

src/config.ts

@@ -13,6 +13,7 @@ const TRACE_DISABLE_ALL_VALUES = new Set(["all", "*", "true", "1"])
 export type PluginConfig = {
   enabled: boolean
   logsEnabled: boolean
+  capturePromptInLogs: boolean
   endpoint: string
   protocol: "grpc" | "http/protobuf" | "http/json"
   metricsInterval: number
@@ -55,6 +56,7 @@ export function parseAttributePairs(raw: string | undefined): Record<string, str
 export type OtelPluginOptions = {
   enabled?: boolean
   logsEnabled?: boolean
+  capturePromptInLogs?: boolean
   endpoint?: string
   protocol?: "grpc" | "http/protobuf" | "http/json"
   metricsInterval?: number
@@ -185,6 +187,7 @@ export function loadConfig(options: OtelPluginOptions = {}): PluginConfig {
   return {
     enabled: pickBoolean(resolvedOptions.enabled) ?? hasNonEmptyEnv("OPENCODE_ENABLE_TELEMETRY"),
     logsEnabled: pickBoolean(resolvedOptions.logsEnabled) ?? !hasNonEmptyEnv("OPENCODE_DISABLE_LOGS"),
+    capturePromptInLogs: pickBoolean(resolvedOptions.capturePromptInLogs) ?? hasNonEmptyEnv("OPENCODE_CAPTURE_PROMPT_IN_LOGS"),
     endpoint: pickString(resolvedOptions.endpoint) ?? process.env["OPENCODE_OTLP_ENDPOINT"] ?? "http://localhost:4317",
     protocol,
     metricsInterval: pickPositiveInt(resolvedOptions.metricsInterval) ?? parseEnvInt("OPENCODE_OTLP_METRICS_INTERVAL", 60000),

src/index.ts

@@ -133,6 +133,13 @@ export const OtelPlugin: Plugin = async ({ project, client, directory, worktree
     await log("info", "OTLP log events disabled")
   }
 
+  if (config.capturePromptInLogs) {
+    await log(
+      "info",
+      "prompt-in-logs capture enabled - full prompt text emitted in the `prompt` attribute of user_prompt log events (spans always carry the prompt regardless)",
+    )
+  }
+
   const ctx: HandlerContext = {
     log,
     emitLog,
@@ -269,6 +276,7 @@ export const OtelPlugin: Plugin = async ({ project, client, directory, worktree
           "session.id": input.sessionID,
           ...agentAttrs(agent, agentType),
           prompt_length: promptLength,
+          ...(config.capturePromptInLogs ? { prompt: promptText } : {}),
           model: input.model
             ? `${input.model.providerID}/${input.model.modelID}`
             : "unknown",

tests/config.test.ts

@@ -74,6 +74,7 @@ describe("loadConfig", () => {
     "OPENCODE_OTLP_METRICS_TEMPORALITY",
     "OPENCODE_DISABLE_METRICS",
     "OPENCODE_DISABLE_LOGS",
+    "OPENCODE_CAPTURE_PROMPT_IN_LOGS",
     "OPENCODE_DISABLE_TRACES",
     "OTEL_EXPORTER_OTLP_HEADERS",
     "OTEL_RESOURCE_ATTRIBUTES",
@@ -86,6 +87,7 @@ describe("loadConfig", () => {
     const cfg = loadConfig()
     expect(cfg.enabled).toBe(false)
     expect(cfg.logsEnabled).toBe(true)
+    expect(cfg.capturePromptInLogs).toBe(false)
     expect(cfg.endpoint).toBe("http://localhost:4317")
     expect(cfg.protocol).toBe("grpc")
     expect(cfg.metricsInterval).toBe(60000)
@@ -102,6 +104,11 @@ describe("loadConfig", () => {
     expect(loadConfig().logsEnabled).toBe(false)
   })
 
+  test("capturePromptInLogs is true when OPENCODE_CAPTURE_PROMPT_IN_LOGS is set", () => {
+    process.env["OPENCODE_CAPTURE_PROMPT_IN_LOGS"] = "1"
+    expect(loadConfig().capturePromptInLogs).toBe(true)
+  })
+
   test("reads custom endpoint", () => {
     process.env["OPENCODE_OTLP_ENDPOINT"] = "http://collector:4317"
     expect(loadConfig().endpoint).toBe("http://collector:4317")