feat!: migrate to OpenCode V2

AGENTS.md

@@ -10,44 +10,61 @@ Always run after making changes:
 bun run typecheck
 ```
 
-There is no build step. TypeScript source files are published directly and loaded natively by Bun.
+There is no build step during local development. TypeScript source files are loaded natively by Bun; the published package is bundled by `prepack`.
 
 ## Testing
 
 ```bash
 bun test
 ```
 
+## Target runtime
+
+`main` targets **OpenCode V2** (`>=2`) and exports a `Plugin.define`-style default export
+(`id: "devtheops.otel"`, `setup`). The OpenCode V1 plugin lives on the `v1` branch and is
+released from the `1.x` line; do not add V1 compatibility shims to `main`.
+
 ## Project layout
 
 ```text
 src/
-├── index.ts              — Plugin entrypoint
-├── types.ts              — Shared types
-├── config.ts             — Env config and log level
+├── index.ts              — V2 plugin default export (id + setup)
+├── plugin.ts             — setup(): config, model.request hook, event subscription, dispatch
+├── state.ts              — per-process shared OTel SDK + tracing state (globalThis)
+├── types.ts              — Shared types (OpenCodeEvent, HandlerContext, TracingState, etc.)
+├── config.ts             — Env/option config loading and log level resolution
 ├── otel.ts               — OTel SDK setup and instruments
 ├── probe.ts              — OTLP endpoint TCP probe
-├── util.ts               — errorSummary, setBoundedMap
+├── headers.ts            — Dynamic OTLP headers / refreshing exporters
+├── trace-context.ts      — W3C trace-context inject/extract
+├── util.ts               — errorSummary, setBoundedMap, context resolution, attrs
 └── handlers/
-    ├── session.ts        — Session lifecycle events
-    ├── message.ts        — LLM message and tool part events
-    ├── permission.ts     — Tool permission events
-    └── activity.ts       — File diffs and git commits
+    ├── session.ts        — session.created, session.inbox.enqueued, session.execution.*, retry/idle/usage
+    ├── step.ts           — session.step.*, session.text.ended (LLM spans + token/cost/cache metrics)
+    ├── tool.ts           — session.tool.* (tool spans, subagent correlation, duration, commit detection)
+    ├── permission.ts     — permission.asked/replied
+    └── chat-headers.ts   — context preview and model.request / WebSocket trace propagation
 ```
 
 ## Key conventions
 
 - **Bun over Node** — use `bun`, `bun test`, `bun run`. Never use `node`, `npx`, `jest`, or `vitest`.
 - **No comments** unless explicitly requested.
 - **No `sdk-node`** — the OTel Node SDK meta-package is intentionally excluded; use individual packages.
-- **`HandlerContext`** — all event handlers receive a `HandlerContext` (defined in `src/types.ts`). Do not import `client` or OTel globals directly inside handlers; thread them through the context.
-- **`setBoundedMap`** — always use this instead of `Map.set` for `pendingToolSpans` and `pendingPermissions` to prevent unbounded growth.
-- **Single source of truth for tokens/cost** — token and cost counters are incremented only in `message.updated` (`src/handlers/message.ts`), never in `step-finish`.
-- **Shutdown** — OTel providers are flushed via `SIGTERM`/`SIGINT`/`beforeExit`. Do not use `process.on("exit")` for async flushing.
-- **All env vars are `OPENCODE_` prefixed** — `OPENCODE_ENABLE_TELEMETRY`, `OPENCODE_OTLP_ENDPOINT`, `OPENCODE_OTLP_METRICS_INTERVAL`, `OPENCODE_OTLP_LOGS_INTERVAL`, `OPENCODE_METRIC_PREFIX`, `OPENCODE_CAPTURE_PROMPT_IN_LOGS`, `OPENCODE_OTLP_HEADERS`, `OPENCODE_RESOURCE_ATTRIBUTES`, `OPENCODE_SPAN_ATTRIBUTES`. Never use bare `OTEL_*` names for plugin config. `loadConfig` copies `OPENCODE_OTLP_HEADERS` → `OTEL_EXPORTER_OTLP_HEADERS` and `OPENCODE_RESOURCE_ATTRIBUTES` → `OTEL_RESOURCE_ATTRIBUTES` before the SDK initializes.
-- **`OPENCODE_ENABLE_TELEMETRY`** — all OTel instrumentation is gated on this env var. The plugin always loads regardless; only telemetry is disabled when unset.
+- **`@opencode/plugin` is type-only** — import types from it (`import type { Plugin } from "@opencode/plugin"`); the plugin never imports it at runtime, so it stays a dev/optional peer dependency.
+- **`HandlerContext`** — all event handlers receive a `HandlerContext` (defined in `src/types.ts`). Do not import OTel globals directly inside handlers; thread them through the context.
+- **`setBoundedMap` / `markSeen`** — always use these for correlation maps (`toolMeta`, `stepMeta`, `pendingPrompts`, `pendingPermissions`, `seenEvents`) to prevent unbounded growth.
+- **Single source of truth for tokens/cost** — token and cost counters are incremented once per `session.step.ended`/`failed`; session totals come from `session.usage.updated` (cumulative) with a per-step fallback.
+- **Event de-duplication** — V2 may deliver the same event to multiple plugin instances; serialize shared dispatch before deduping by `event.id` via `markSeen` so later events cannot overtake an asynchronous session lookup.
+- **Session identity** — retain the agent, subagent parent, and creation time across executions, and hydrate missed `session.created` events with `ctx.session.get`.
+- **Subagent correlation** — only parent a child run under a dispatch tool span when a child session ID in tool progress/result metadata or one unambiguous live candidate identifies it; otherwise use the parent run.
+- **Model context capture** — opt-in only, text parts only, bounded; never serialize full media or structured tool payloads into span attributes.
+- **Multi-location configuration** — process-wide exporters require identical telemetry configuration; reject a conflicting setup and derive project attributes from the observed session, not the loading location.
+- **Shutdown** — providers are flushed (never shut down) on plugin cleanup and once per process on `beforeExit`. Shutting down the global OTel providers poisons them for the rest of the process.
+- **All env vars are `OPENCODE_` prefixed** — `OPENCODE_ENABLE_TELEMETRY`, `OPENCODE_OTLP_ENDPOINT`, `OPENCODE_OTLP_METRICS_INTERVAL`, `OPENCODE_OTLP_LOGS_INTERVAL`, `OPENCODE_METRIC_PREFIX`, `OPENCODE_CAPTURE_PROMPT_IN_LOGS`, `OPENCODE_OTLP_HEADERS`, `OPENCODE_RESOURCE_ATTRIBUTES`, `OPENCODE_SPAN_ATTRIBUTES`. Never use bare `OTEL_*` names for plugin config. Headers are passed directly to exporters; `loadConfig` copies `OPENCODE_RESOURCE_ATTRIBUTES` → `OTEL_RESOURCE_ATTRIBUTES` before the SDK initializes.
+- **`OPENCODE_ENABLE_TELEMETRY`** — all OTel instrumentation is gated on this env var (or the `enabled` plugin option). The plugin always loads regardless.
 - **`OPENCODE_METRIC_PREFIX`** — defaults to `opencode.`; set to `claude_code.` for Claude Code dashboard compatibility.
-- **Plugin options** — `loadConfig` also accepts an `OtelPluginOptions` object passed via opencode's plugin tuple form (`["opencode-plugin-otel", { ... }]`, threaded through `OtelPlugin`'s second argument). Precedence is option → `OPENCODE_*` env → default. Keep option keys 1:1 with `PluginConfig` field names.
+- **Plugin options** — read from `ctx.options` during `setup`. Precedence is option → `OPENCODE_*` env → default. Keep option keys 1:1 with `PluginConfig` field names.
 
 ## Commit message format
 
@@ -59,12 +76,5 @@ All commits must follow [Conventional Commits](https://www.conventionalcommits.o
 
 Common types: `feat`, `fix`, `perf`, `refactor`, `test`, `docs`, `ci`, `chore`, `build`.
 
-Use `!` or a `BREAKING CHANGE:` footer for breaking changes.
-
-Examples:
-
-```text
-feat(handlers): add support for file.edited event
-fix(probe): handle malformed endpoint URL without throwing
-chore(deps): bump @opentelemetry/api to 1.10.0
-```
+Use `!` or a `BREAKING CHANGE:` footer for breaking changes (this repo uses `release-please`, so a
+breaking commit bumps the major version automatically).

CONTRIBUTING.md

@@ -15,16 +15,19 @@ bun install
 
 ## Development workflow
 
-Point your local opencode config at the repo so changes are picked up immediately without a build step. In `~/.config/opencode/opencode.json`:
+Install dependencies in the checkout with `bun install`. In the project where you run
+OpenCode, create `.opencode/plugins/otel/index.ts`:
 
-```json
-{
-  "$schema": "https://opencode.ai/config.json",
-  "plugin": ["/path/to/opencode-plugin-otel/src/index.ts"]
-}
+```ts
+export { default } from "/path/to/opencode-plugin-otel/src/index.ts"
 ```
 
-opencode loads TypeScript natively via Bun, so there is no build step required during development.
+OpenCode V2 discovers the directory automatically and loads TypeScript via Bun, so
+there is no build step during development. A `plugins` entry pointing directly to
+an absolute `.ts` file is rejected by OpenCode `2.0.1`.
+
+> **Branching:** `main` targets OpenCode V2. The OpenCode V1 plugin is maintained on the `v1` branch
+> (branched from the last `1.x` tag) — open V1 bug/security fixes against `v1`, not `main`.
 
 ## Commands
 
@@ -39,17 +42,20 @@ opencode loads TypeScript natively via Bun, so there is no build step required d
 
 ```text
 src/
-├── index.ts              — Plugin entrypoint, wires everything together
+├── index.ts              — Plugin entrypoint (V2 default export)
+├── plugin.ts             — setup(): config, hooks, event subscription
+├── state.ts              — shared OTel SDK + tracing state
 ├── types.ts              — Shared types (Level, HandlerContext, Instruments, etc.)
 ├── config.ts             — Environment config loading and log level resolution
 ├── otel.ts               — OTel SDK setup, resource construction, instrument creation
 ├── probe.ts              — TCP connectivity probe for the OTLP endpoint
 ├── util.ts               — Utility functions (errorSummary, setBoundedMap)
 └── handlers/
-    ├── session.ts        — session.created / session.idle / session.error
-    ├── message.ts        — message.updated / message.part.updated
-    ├── permission.ts     — permission.updated / permission.replied
-    └── activity.ts       — session.diff / command.executed
+    ├── session.ts        — session.created / session.execution.* / session.status
+    ├── step.ts           — session.step.* (LLM spans + token/cost metrics)
+    ├── tool.ts           — session.tool.* (tool spans, subagents, duration, commits)
+    ├── permission.ts     — permission.asked / permission.replied
+    └── chat-headers.ts   — context preview and model.request / WebSocket propagation
 ```
 
 ## Testing locally with a collector