[Bug] LSP freezes and diagnostics timeout too short (3s) for heavy language servers

[ojh102]

Description

Multiple users are experiencing LSP-related freezes and timeouts across different scenarios:

• Kotlin LSP exceeding 45s timeout ([FEATURE]: Allow configurable timeouts to be set on LSPs #7477)
• ESLint diagnostics timing out at 3s, returning empty results (ESLint LSP server initializes but diagnostics timeout with empty result #13272)
• Windows app freezes related to blocking LSP operations (1.1.57.0 OpenCode Desktop bug after update: Freezes, terminal loop - No longer usable #13154)

Root Cause Analysis:

1. Blocking initialization: getClients() blocks the UI thread when LSP servers are slow to start
2. Insufficient timeout defaults: Diagnostics timeout was hardcoded at 3s — too short for heavy linters like ESLint and Kotlin LSP
3. No user escape hatch: No way for users to configure timeouts for their specific environment

Related PRs:

PR	Approach	Status
#13332	Non-blocking init + configurable diagnostics timeout	Open
#13281	Diagnostics timeout 3s→10s	Open
#6997	Configurable per-server timeout via config	Open
#13287	Startup package-manager timeout guard	Open (independent)
#13299	UI freeze on large diffs	Open (independent)

Resolution Path:

Addressed by PR #13332:

• ✅ Non-blocking LSP initialization (getClients returns immediately)
• ✅ Configurable diagnostics timeout (10s default, override via OPENCODE_EXPERIMENTAL_LSP_DIAGNOSTICS_TIMEOUT_MS)

Remaining work (separate concerns):

• Per-server timeout config (feat: Add configurable lsp timeout #6997) — more granular control
• Startup timeout (fix(installation): guard startup package-manager probes with timeout #13287) — different timeout location
• UI rendering performance (perf(app): collapse large diffs in review panel to prevent UI freeze #13299) — not LSP-related

Plugins

No response

OpenCode version

dev (latest)

Steps to reproduce

1. Open a project with a heavy LSP (e.g., Kotlin, ESLint with many plugins)
2. Start OpenCode
3. Observe: UI blocks during LSP initialization, and diagnostics timeout at 3s returning empty results for slow language servers

Screenshot and/or share link

No response

Operating System

Cross-platform (reported on macOS, Windows, Linux)

Terminal

Multiple terminals affected (not terminal-specific)