--- name: upgrade-claude-adapter description: >- Sync this fork of @anthropic-ai/claude-agent-acp (packages/agent/src/adapters/claude) with a newer upstream release: bump the claude-agent-sdk / @agentclientprotocol/sdk, port upstream bug fixes and new SDK message handling, preserve the fork's divergences, verify, and update UPSTREAM.md. Use when asked to "upgrade/sync the claude adapter", "bump the agent SDK", or "port upstream claude-agent-acp changes". --- # Upgrade the Claude ACP adapter (upstream sync) This is a runbook for syncing our **fork** of `@anthropic-ai/claude-agent-acp` (the upstream Zed/agentclientprotocol ACP agent) that lives in `packages/agent/src/adapters/claude/` with a newer upstream release. The fork is heavily diverged. The job is to port the *valuable* upstream changes (SDK bumps, bug fixes, new SDK-message handling) while preserving every intentional divergence — not to make the fork identical to upstream. `UPSTREAM.md` (this directory) is the source of truth for the **fork point**, **last-synced version/commit**, the **file mapping**, the **PostHog-only code**, and the **intentional divergences**. Read it first, update it last. > This file is a runbook, not an auto-registered slash command. Invoke it by telling Claude to > "follow the upgrade skill in the claude adapter dir." Move it to `.claude/skills//SKILL.md` > if you ever want it runnable as `/`. ## Inputs you need before starting 1. **Upstream source checkout** — a local git clone of `github.com/agentclientprotocol/claude-agent-acp`. You need its history to diff. If the user hasn't given the path, **ask for it** (it's usually somewhere like `~/Cloud/claude-agent-acp`). Do not guess. 2. **This repo** — the fork under `packages/agent/`. ## Process ### 0. Orient (read, don't write) - Read `UPSTREAM.md`. Note **Last sync** (commit + version), the pinned **SDK** versions, the **File Mapping**, **PostHog-Only Code (Do Not Sync)**, and **Intentional Divergences**. - In the upstream checkout, list the change set since the last sync and skim the changelog: - `git -C log --oneline ..HEAD` - `git -C show /CHANGELOG.md:CHANGELOG.md` (or just read `CHANGELOG.md`) - Confirm the new target version + HEAD sha and the target SDK versions from the upstream `package.json`. ### 1. Triage every commit Bucket each commit since the last sync: - **Port** — bug fixes and new feature / SDK-message handling that are *not* in the PostHog-only list and don't fight a divergence. - **Dep bump** — record the target SDK versions; the diff tells you if code changes ride along. - **Skip** — `chore(main): release …`, `actions/* ` CI bumps, pure dependabot **dev**-dep bumps, and anything matching the PostHog-only / divergence lists. Read intent from source diffs (exclude tests + JSON first): ``` git -C show -- src/ ':(exclude)src/tests/*' ':(exclude)*.json' ``` A dependabot SDK-bump commit often *also* carries real code (new message handling). Don't assume "deps" == "no code". ### 2. Map upstream → fork Upstream is one large `src/acp-agent.ts`; our fork is split. Use the File Mapping in `UPSTREAM.md`. Rough guide: | Upstream | Fork | | --- | --- | | `acp-agent.ts` prompt loop, lifecycle, cancel | `claude-agent.ts` | | inline message/stream/result/system conversion | `conversion/sdk-to-acp.ts` | | inline prompt→SDK conversion | `conversion/acp-to-sdk.ts` | | `tools.ts` (tool_use→ACP, PostToolUse hook) | `conversion/tool-use-to-acp.ts`, `hooks.ts` | | model alias resolution | `session/models.ts`, `session/model-config.ts` | | options / system prompt | `session/options.ts` | | permissions | `permissions/*` | For each upstream change, `rg` the fork for the touched symbol first — the fork usually already has a diverged version of it, so you're editing, not adding. ### 3. Bump dependencies In `packages/agent/package.json`, set `@anthropic-ai/claude-agent-sdk`, `@agentclientprotocol/sdk`, and `@anthropic-ai/sdk` to the upstream `package.json` versions, then `pnpm install` from the repo root. (`packages/shared` pins its own older `@agentclientprotocol/sdk`; leave it unless a cross-package type error forces a bump.) ### 4. Find the breaking-change surface Run `pnpm --filter agent typecheck`. The errors are your ACP/SDK breaking-change list. Gotchas seen in past syncs: - **The ACP SDK ships name-mangled generated types.** `dist/schema/*.gen.d.ts` shows enum literals as `n` (e.g. `StopReason = "…" | "n" | "cancelled"`). Don't trust grep there. Read the hand-written `dist/acp.d.ts`, or download the exact target to inspect cleanly: ``` cd /tmp && npm pack @agentclientprotocol/sdk@ && tar xzf *.tgz rg -n "type StopReason|deleteSession|SessionModelState" package/dist/schema/types.gen.d.ts package/dist/acp.d.ts ``` - **`node -e "require('/package.json')"` may fail** on the SDKs (exports map blocks the subpath). Read `node_modules//package.json` directly for the installed version. - **An ACP SDK bump can break code outside the claude adapter.** The whole `packages/agent` package must typecheck — expect to also fix `adapters/codex/*` and `server/agent-server.ts`. Keep those fixes minimal and behavior-preserving (e.g. when ACP removed the `models` response field, the codex adapter derived the model id from `configOptions` instead). ### 5. Port in phases — bug fixes first, then features For each ported change: - **Preserve divergences** (see `UPSTREAM.md` → Intentional Divergences + PostHog-only). The big ones: single-session `this.session` (not `this.sessions[id]`); `interruptReason` on cancel; gateway models via `fetchGatewayModels` (not `initializationResult.models`); `_posthog/*` ext notifications; the "Unsupported slash command" gate on `knownSlashCommands`; `SYSTEM_REMINDER` stripping; plan / questions / MCP-metadata machinery. - **New SDK `system` subtypes are safe by default.** `handleSystemMessage` ends in `default: break`, and the prompt-loop top-level `switch (message.type)` only `unreachable()`s unknown top-level *types*. So a new subtype won't crash the loop — port real handling only where there's user value (e.g. `permission_denied` → failed tool_call, `tool_progress` → in_progress, `commands_changed` → available_commands_update, `mirror_error` → log). - When upstream reads new fields (`stop_details`, `getContextUsage`, `thinking`), confirm the installed SDK `.d.ts` actually has them before porting. Skip ports the fork can't use (e.g. the fork doesn't read `MAX_THINKING_TOKENS`, so upstream's `resolveThinkingConfig` was N/A). - Typecheck after each logical group, not just at the end. ### 6. Verify (all of it) ``` pnpm --filter agent typecheck pnpm --filter agent build npx biome check --write # biome is the formatter/linter, not prettier/eslint pnpm typecheck # whole repo: confirms apps/code compiles vs the new ACP SDK pnpm --filter agent test pnpm --filter code test ``` - The `apps/code` renderer unit tests `analytics.test.ts` and `panelLayoutStore.test.ts` are **flaky** — they sometimes throw in `getElectronTRPC` / electron-trpc `ipcLink` depending on test ordering. If they fail, re-run; a clean rerun (or `git stash` + run on the clean tree) passing confirms it's the known flake, not your change. ### 7. Update `UPSTREAM.md` (do this last) - Bump **Last sync** (version + HEAD sha + date) and the pinned **SDK** versions. - Add `## Changes Ported in v Sync` (one bullet per change, with PR # and short sha) and `## Skipped in v Sync` (with the reason for each skip). - If a port made a former divergence match upstream, move it out of the Intentional Divergences table. ## Fork facts worth remembering - **Single session.** The agent owns one `this.session` (from `BaseAcpAgent`), not a `sessions` map. Upstream's per-session refactors usually collapse to "just use `this.session`". - **Prompt loop is a persistent consumer** (since the v0.54.1 sync, upstream #780): `prompt()` enqueues a `Turn` deferred; `runConsumer` drains the query stream for the session's life, settles turns at their terminal `result`, and captures `query` + `session.queryGeneration` so the fork-only `refreshSession()` can retire it (bump generation → abort wake-up → end input). Steer mode, `interruptReason`, per-turn broadcast-at-activation and the unsupported-slash-command gate all live inside it — port upstream prompt-loop changes into the consumer, not a per-prompt loop. - **ACP connection classes are the deprecated ones on purpose.** The fork stays on `AgentSideConnection`/`ClientSideConnection` (still shipped in ACP 1.x) because they carry the `extMethod`/`extNotification` surface `_posthog/*` uses; permission requests reach the client via the class's generic `request(..., { cancellationSignal })`. Don't port the `agent()` builder without a plan for the extension surface. - **Renderer uses config options only.** Model/mode/effort selection is `SessionConfigOption` end to end; the renderer never reads the legacy `models` response field or calls `unstable_setSessionModel`. That's why upstream's ACP-0.24/0.25 model-state removals are safe to follow. - **`toolUseCache` is never cleared** in the fork (created once in the constructor), so long sessions accumulate — keep the prune-at-tool_result behavior, and make any PostToolUse hook close over the data it needs rather than re-reading the cache. - **Conversion is split out.** `claude-agent.ts` calls `handleSystemMessage` / `handleStreamEvent` / `handleResultMessage` / `handleUserAssistantMessage` from `conversion/sdk-to-acp.ts`. Upstream inlines all of this in `acp-agent.ts`. - **Don't commit or push** unless the user explicitly asks. Leave the work on the current branch.