# Claude Code 2.1.310: our test log

Canonical: https://theagenticweekly.com/tests/claude-code · Last verified: 2026-10-25 · Published: 2026-10-25 · Author: Agentic Weekly (operated independently from Texas, US) · Evidence: Tested by us on 2026-10-25. Local open-weight model, not the vendor's hosted models. A smoke test on a CPU-only box, not a benchmark.

> Claude Code 2.1.310 edited calc.py through its Edit tool with a local 3B model on the second prompt (85.9 s); the first, vaguer prompt made no edit.

## Result at a glance

Table: Claude Code test record

| Field | Value |
|---|---|
| Result | Partly worked |
| Version tested | 2.1.310 |
| Date and time | 2026-10-25, 17:48 to 17:50 CDT (America/Chicago) |
| Task | In a throwaway folder, give the tool a small bug and ask a local model to fix it through the tool's own editing. calc.py contained `def add(a,b): return a-b`. Pass means the file ended as `return a+b` after the tool's own edit. |
| Model used | Qwen2.5-3B-Instruct (Q4_K_M) through Ollama 0.40.11 |
| Hardware | Linux x86_64 virtual machine (Debian 13), 8 vCPU (Intel Xeon, 1 thread per core), 15 GiB RAM, no GPU |
| Attempt 2 wall time | 85.9 s (first token after 74.9 s) |
| Turns | 2 |
| Install version tested | 2.1.310 (native installer) |

## What we found

- Attempt 2 worked: the Edit tool replaced the line and the structured patch in the log shows `-    return a-b` and `+    return a+b`.
- Attempt 1 failed: the model said calc.py did not exist, and no edit was made.
- Most of the 85.9 s was waiting for the first token (74.9 s), which reflects the small model on a CPU-only box, not Claude Code itself.

## What we ran, step by step

Table: Commands run, wall-clock time and exit code

| Step | Wall time | Exit code | Notes |
|---|---|---|---|
| Install with the native installer | n/a | n/a | The headless run reported claude_code_version 2.1.310. We did not time the install. The npm package installed 2.1.197 in the earlier shared npm install, so the npm package was not the version tested. |
| Attempt 1 (vaguer prompt) | n/a | n/a | Claude Code answered that calc.py did not exist in the working directory and made no edit. It also printed that it does not recognize the model id qwen2.5-3b-32k and assumes a 200k-token context window. |
| Attempt 2 (exact path and strings) | 85.9 s | 0 | The Edit tool changed `return a-b` to `return a+b`; the result was "success", 2 turns, permission mode acceptEdits. Time to first token was 74.9 s of the 85.9 s. |

Exact commands (paths shortened)

```
# Install with the native installer
curl -fsSL https://claude.ai/install.sh | bash   # script read first; a copy is kept with the test files
```

## Raw output (excerpts)

Attempt 1 output (claude-run1.log)

```
Claude Code doesn't recognize the model "qwen2.5-3b-32k", so it assumes a context window of 200k tokens.
[claude-code:unrecognized_model] {"model":"qwen2.5-3b-32k","query_source":"sdk"}
The file `calc.py` does not exist in the current working directory. Please ensure you are in the correct directory and the file is present before attempting to edit it.
```

Attempt 2: the Edit tool call and result (claude-run2.log, trimmed)

```
{"type":"tool_use","name":"Edit","input":{"file_path":"/workspace/tests/proj-claude/calc.py","old_string":"    return a-b","new_string":"    return a+b"}}
{"type":"tool_result","content":"The file /workspace/tests/proj-claude/calc.py has been updated successfully."}
"stop_reason":"end_turn","is_error":false,"num_turns":2,"duration_ms":85896,"ttft_ms":74894
```

## Gotchas and things that broke

- The log reports total_cost_usd 0.0437 with apiKeySource none. No vendor account or API key was used, so we do not treat that figure as a charge.
- The config pointed Claude Code at a local Ollama server through an Anthropic-compatible API; the model id shown in the log is qwen2.5-3b-32k.

## What we did not test

- Claude models, subscription login and any Anthropic-hosted model.
- The sandbox and permission fixes in 2.1.309 and 2.1.310, claude ultrareview and --trust-workspace, and Bedrock, Vertex or Foundry.
- Reliability: one prompt that worked after one that did not, so this is an existence proof, not a pass rate.

## Reproduce it

Versions change. These commands install whatever is latest on the day you run them unless a version is pinned, so expect different results later. The version we measured is in the table above.

```
curl -fsSL https://claude.ai/install.sh | bash   # read the script first
# point Claude Code at a local Anthropic-compatible endpoint, create calc.py with `return a-b`, then:
claude -p "Edit /full/path/calc.py: replace '    return a-b' with '    return a+b'"   # we ran it headless with permission mode acceptEdits and JSON streaming output
```

## How to read this test

Every number on this page was measured on this one machine, which also ran other jobs, so timings are indicative and vary run to run. A pass means our small task worked once or as stated, a fail means it did not work as we ran it; neither says how the tool behaves with a vendor's frontier model, on a GPU, or at scale. Where a tool could not run without an account or a GPU, we say so instead of guessing.

See the [testing rig](https://theagenticweekly.com/methodology#testing-rig) for the hardware, the local model and the rules we follow, and the [test hub](https://theagenticweekly.com/tests) for every other test.

## FAQ

### Did you test Claude Code with Claude models?

No. We ran Claude Code 2.1.310 against a small local model through an Anthropic-compatible endpoint with no Anthropic account, so this log says nothing about Claude models.

## Sources

- [Claude Code overview](https://code.claude.com/docs/en/overview) (fetched 2026-10-25)

## Related

- [All test logs](https://theagenticweekly.com/tests)
- [Methodology and testing rig](https://theagenticweekly.com/methodology#testing-rig)
- [Study: install size and first-task results across 16 frameworks](https://theagenticweekly.com/research/agent-framework-install-and-first-task)
- [Claude Code facts and sources](https://theagenticweekly.com/tools/claude-code)

## How to cite

Agentic Weekly, "Claude Code 2.1.310: our test log", last updated 2026-10-25, https://theagenticweekly.com/tests/claude-code