> ## Documentation Index > Fetch the complete documentation index at: https://arizeai-433a7140.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # OpenCode > Trace OpenCode terminal coding sessions, model calls, and tool usage in Phoenix. > Trace OpenCode terminal coding sessions, model calls, and tool usage with Phoenix for full observability. Trace your [OpenCode](https://opencode.ai/) sessions in Phoenix with the [coding-harness-tracing](https://github.com/Arize-ai/coding-harness-tracing) toolkit — every turn shows up as a trace, with the model call and every tool invocation captured as nested spans and grouped into its session. No application code changes required: the toolkit loads an in-process plugin and streams [OpenInference](https://github.com/Arize-ai/openinference) spans to Phoenix. ## Launch Phoenix The fastest way to get started with Phoenix is by signing up for a [free Phoenix Cloud account](https://app.arize.com/auth/phoenix/signup). If you prefer, you can also run Phoenix in a [notebook](/docs/phoenix/environments#notebooks), [self-host it](/docs/phoenix/environments#container), or use it directly from your [terminal](/docs/phoenix/environments#terminal). Go to the settings page in your Phoenix instance to find your **endpoint** and **API key**. A self-hosted Phoenix defaults to `http://localhost:6006`; the API key is only required when auth is enabled. ## Install The **curl installer** is the simplest — it runs a short wizard that saves your Phoenix credentials for you. Use a **local clone** if you'd rather run the installer from a checkout of the source. ### Curl installer (recommended) **macOS / Linux:** ```bash theme={null} curl -sSL https://raw.githubusercontent.com/Arize-ai/coding-harness-tracing/main/install.sh | bash -s -- opencode ``` **Windows (PowerShell):** ```powershell theme={null} iwr -useb https://raw.githubusercontent.com/Arize-ai/coding-harness-tracing/main/install.bat -OutFile $env:TEMP\install.bat & $env:TEMP\install.bat opencode ``` ### Local clone ```bash theme={null} git clone https://github.com/Arize-ai/coding-harness-tracing.git cd coding-harness-tracing ./install.sh opencode # macOS / Linux install.bat opencode # Windows ``` The installer prompts for your backend — select **Phoenix**, then enter your endpoint and optional API key — and your project name, writes them to `~/.arize/harness/config.json`, and copies the tracing plugin to `~/.config/opencode/plugin/arize-tracing.ts`. OpenCode auto-discovers plugins from both the `plugin/` and `plugins/` directories under `~/.config/opencode/`, so no `opencode.json` edit is required. ## Configuration Credentials live in `~/.arize/harness/config.json`. Environment variables override values in `config.json` and can be set in your shell profile so they apply to every OpenCode session. ```bash theme={null} export PHOENIX_ENDPOINT="http://localhost:6006" export PHOENIX_API_KEY="" # optional, only if auth is enabled export PHOENIX_PROJECT="opencode" export ARIZE_TRACE_ENABLED="true" ``` On the Phoenix backend, set the project name with `PHOENIX_PROJECT` (or `PHOENIX_PROJECT_NAME`); `ARIZE_PROJECT_NAME` is Arize-only and ignored here. `ARIZE_TRACE_ENABLED` is a backend-agnostic harness setting and keeps the `ARIZE_` prefix regardless of destination. If `ARIZE_TRACE_ENABLED=false` is set in your shell environment — for example, inherited from another harness's configuration — tracing is silently disabled. Set `ARIZE_TRACE_ENABLED=true` before launching OpenCode, or unset the variable to fall back to the default of `true`. ### Redaction controls Each `ARIZE_LOG_*` flag accepts `"true"` or `"false"` and defaults to `"true"`. Set to `"false"` to opt out per category: ```bash theme={null} export ARIZE_LOG_PROMPTS="false" export ARIZE_LOG_TOOL_DETAILS="false" export ARIZE_LOG_TOOL_CONTENT="false" ``` | Flag | Redacts | | :----------------------- | :-------------------------------------- | | `ARIZE_LOG_PROMPTS` | User prompt and assistant response text | | `ARIZE_LOG_TOOL_DETAILS` | Tool names and arguments | | `ARIZE_LOG_TOOL_CONTENT` | Tool call output content | ## Observe Once tracing is enabled, OpenCode activity is streamed to Phoenix. Each turn (one user prompt to the assistant's response) is captured as a trace. ## How Tracing Works OpenCode is architecturally different from the other coding agents in this repo. Extensions load as [plugins](https://opencode.ai/docs/plugins/) inside OpenCode's Bun runtime — there is no per-event subprocess. The integration has two pieces: 1. A **TypeScript plugin shim** at `~/.config/opencode/plugin/arize-tracing.ts` that listens for `message.updated` and `session.idle` events, pulls the authoritative session snapshot via the OpenCode SDK, and pipes it to the reconciler. 2. A **Python reconciler** (`arize-hook-opencode`) that walks the snapshot and emits any new `Turn`, `LLM`, and `TOOL` spans, deduplicated by message ID and tool call ID. Spans are sent directly to Phoenix — no separate buffer or collector service is required. ## Limitations Sub-agent and `task` sessions trace independently. OpenCode's built-in `task` tool spawns sub-agents that each get their own `sessionID`. In v1, each sub-agent session produces its own independent trace; they are not linked back to the parent session's trace. ## Reference For the full list of environment variables, default file paths, and troubleshooting steps, see the [OpenCode tracing README](https://github.com/Arize-ai/coding-harness-tracing/blob/main/tracing/opencode/README.md). ## Uninstall ```bash theme={null} curl -sSL https://raw.githubusercontent.com/Arize-ai/coding-harness-tracing/main/install.sh | bash -s -- uninstall opencode ``` ## Resources