Error Confirmation
Error: JSON parsing failed. Unexpected token '<'
Expecting value: line 1 column 1 (char 0)
at JSON.parse (<anonymous>)
at ContinueExtension.handleResponse (/extensions/continue/core/handler.js:84)
What You See in JetBrains:
Continue plugin throws an error when DeepSeek R1 responds. The plugin expects clean JSON but receives thinking tags instead.
Full Response (The Problem):
DeepSeek R1 wraps its response in thinking tags before the actual JSON:
<!-- think -->
The user is asking for a JSON response. Let me format it properly...
<!-- /think -->
{"result": "actual data here"}
Scope: Continue's JSON parser fails because it receives <!-- think --> tags at position 0 instead of the expected {. The plugin doesn't strip DeepSeek's thinking tags before parsing JSON.
Error Code: Unexpected token '<' — JSON parser encountered thinking tag markup instead of opening brace.
Affected Environment
| Component | Version | Last Verified |
|---|---|---|
| JetBrains IDEs | IntelliJ IDEA, PyCharm, WebStorm, CLion | 2026-02-09 |
| Continue Plugin | Latest stable | 2026-02-09 |
| DeepSeek R1 | All variants (8b, 32b, 70b, distilled) | 2026-02-09 |
| Ollama | Latest | 2026-02-09 |
Note: This issue affects ALL JetBrains IDEs using Continue plugin with DeepSeek R1. The root cause is DeepSeek's thinking tags, not a bug in Continue or JetBrains.
3-Minute Sanity Check
Run these commands to confirm the issue:
# 1. Is DeepSeek R1 running?
ollama list | grep deepseek-r1
# Expected: deepseek-r1:latest (or variant)
# 2. Test raw JSON output (should show thinking tags)
ollama run deepseek-r1:latest 'Output JSON: {"status": "ok"}' | head -5
# Expected: You will see <!-- think --> tags before the JSON
# 3. Check Continue plugin is configured for JSON mode
# In JetBrains: File → Settings → Languages & Frameworks → AI → Continue
# Look for "Response format" or "JSON mode" setting
If step 2 shows NO thinking tags: Your issue may not be DeepSeek thinking tags. Check for other JSON formatting issues.
Decision Gate
:::decision-gate
Stop guessing. See the red lines.
Choose Manual Fix only if:
- You enjoy editing configuration files for each JetBrains IDE
- You have multiple development machines to maintain
- You're comfortable updating configs on each Continue plugin update
- You haven't spent more than 30 minutes on this
Choose Automated Fix if:
- You want to know whether continuing is worth it
- You value your time more than $9.90
- You want documented stop conditions before burning more time :::
Fork in the Road
Option A: Manual Fix (High Maintenance)
What you'll do:
- Edit Continue plugin's
ai.jsonconfiguration manually - Add system prompt override to disable DeepSeek thinking tags
- Repeat for each JetBrains IDE (IntelliJ, PyCharm, WebStorm, etc.)
- Re-apply fix every time Continue plugin updates
Time investment: 20-30 minutes initially, then 5-10 minutes per update
Risks:
- Config gets wiped on plugin update
- Different JetBrains IDEs store config in different locations
- Easy to forget which settings you changed
- No centralized management
Steps:
- Open JetBrains IDE
- Go to
File → Settings → Languages & Frameworks → AI → Continue - Find "System Prompt" or "Custom Instructions"
- Add:
"You are a JSON-only API. Output ONLY JSON. Do NOT use tags." - Restart IDE
- Test with a simple JSON request
Verdict: High maintenance. You will repeat this every time Continue updates.
Option B: Decision Pack (Stop Rules & Red Lines)
What you get:
- Verified red-line rules for JetBrains + DeepSeek R1 (because fixing JSON tags won't save you from a VRAM crash 5 minutes later)
- Known-safe configuration boundaries (what NOT to change)
- Clear stop conditions before you burn more time
- A documented exit path when local setup stops making sense
Time investment: 2 minutes to read
This does not patch your IDE. It does not automate fixes. It tells you when continuing is irrational.
Primary CTA
Manual Guide (SEO)
:::div{.border-l-4 border-blue-500 .glass-card .p-6 .mb-8}
The manual path is intentionally high-maintenance. Exact boundaries and known-safe rules are documented in the Survival Kit.
If you prefer manual editing:
- Locate Continue plugin config — Path varies by JetBrains IDE
- Override system prompt — Add instruction to suppress thinking tags
- Repeat after plugin updates — Config may be reset on update
:::
Why NOT Other Options
| Option | Rejection Reason |
|---|---|
| Switch to a different LLM | DeepSeek R1 is one of the best local models. Switching avoids the problem rather than fixing it. |
| Edit Continue plugin source code | Requires rebuilding the plugin from source. Breaks on every update. |
| Disable Continue plugin entirely | Loses the convenience of AI assistant in your IDE. Manual copy-pasting is slower. |
| Use web-based DeepSeek | No local context of your codebase. Privacy concerns. Requires internet connection. |
| Wait for Continue plugin update | Thinking tags are part of DeepSeek's architecture. No timeline for a fix. |
Summary
| Check | Command | Pass Criteria |
|---|---|---|
| DeepSeek R1 installed | ollama list | grep deepseek-r1 | Shows deepseek-r1:latest or variant |
| Thinking tags present | ollama run deepseek-r1:latest 'Output JSON' | head -5 | Shows <!-- think --> tags |
| Continue plugin configured | Check IDE settings for Continue config | Continue is enabled and configured |
Decision:
- Want decision clarity instead of config wrestling? Buy Clarity — $9.90
- Enjoy manual config editing? Follow the Manual Guide above
Related Guides
- How to Use DeepSeek R1 with OpenClaw - Complete DeepSeek R1 configuration guide
- Fix OpenClaw JSON Mode Errors - Same thinking tags issue, different tool
- Hardware Requirements Reality Check - Can your hardware run DeepSeek R1?
JetBrains / Cursor users: Local R1 failures usually happen before inference. The red lines are documented inside the Survival Kit.