Connect DeepSeek Harness to Coding Plan

DeepSeek Harness is a local coding agent that can inspect a workspace, invoke tools, and run commands while using an OpenAI-compatible Chat Completions endpoint for model requests.

This guide applies to deepseek-harness-sdk==0.1.0rc6 and deepseek-harness-runtime-bin==0.1.0rc6. Repeat the read-only fixture test below after upgrading the client.

Configuration

Item Value
API Base URL https://api.ace.324567.xyz/v1
Model deepseek-v4-pro
Protocol Streaming OpenAI-compatible Chat Completions
Capabilities Text, reasoning, function tools, local Bash tool loop, and usage reporting

The model catalog changes over time. Query it with your dedicated Coding Plan key before setup:

curl https://api.ace.324567.xyz/v1/models \
  -H "Authorization: Bearer $ACEDATACLOUD_API_KEY"

Confirm that deepseek-v4-pro is present. Do not substitute deepseek-v4-flash for the tool-mode example: its multi-turn reasoning history and tool replay did not pass this pinned-version verification.

1. Get a dedicated Coding key

Open your Coding Plan application, then create or copy the API key attached to that Coding Application. Coding Plan does not consume the general balance, so a key from another application does not prove plan access.

Export the key only in the current shell:

export ACEDATACLOUD_API_KEY="PASTE_YOUR_CODING_KEY_HERE"
export DEEPSEEK_BASE_URL="https://api.ace.324567.xyz/v1"
export DEEPSEEK_API_KEY="$ACEDATACLOUD_API_KEY"

Never commit the key or include it in scripts, screenshots, or session artifacts.

2. Create a disposable workspace

The bundled Harness runtime includes a local Bash tool. Do not point the first test at a real repository or your home directory. Create a disposable directory with no secrets:

mkdir -p /tmp/deepseek-harness-demo/workspace
mkdir -p /tmp/deepseek-harness-demo/sessions
printf 'compatibility fixture\n' > /tmp/deepseek-harness-demo/workspace/fixture.txt
python3 -m venv /tmp/deepseek-harness-demo/venv
/tmp/deepseek-harness-demo/venv/bin/pip install \
  "deepseek-harness-sdk==0.1.0rc6"

If your network uses a private PyPI mirror, make sure the same deepseek-harness-runtime-bin version is available. Do not broaden filesystem access with danger-full-access; this example passes only the disposable directory as cwd.

3. Run the official Python SDK

Save this as /tmp/deepseek-harness-demo/run.py:

import os

from deepseek_harness import DeepSeekHarness

with DeepSeekHarness(
    provider="deepseek-official",
    model="deepseek-v4-pro",
    max_tokens=160,
    cwd="/tmp/deepseek-harness-demo/workspace",
    session_root="/tmp/deepseek-harness-demo/sessions",
    base_url=os.environ["DEEPSEEK_BASE_URL"],
    api_key=os.environ["DEEPSEEK_API_KEY"],
    request_timeout_seconds=180,
) as harness:
    result = harness.run(
        "Read fixture.txt once, then reply with exactly: sdk-harness-ok",
        session_id="acedatacloud-compat",
    )

print(result.final_response)
print(result.finish_reason)

Run it:

/tmp/deepseek-harness-demo/venv/bin/python \
  /tmp/deepseek-harness-demo/run.py

Expected output:

sdk-harness-ok
completed

This verifies Bearer authentication, /v1/chat/completions, SSE, reasoning, tool calls, and tool-result replay. Delete /tmp/deepseek-harness-demo when finished. Treat retained session files as sensitively as source code because they may contain workspace context.

Troubleshooting

  • 401: export ACEDATACLOUD_API_KEY in the same shell that launches Python.
  • 403 or quota error: confirm that the key belongs to the active Coding Application and that Credits remain.
  • Model not listed: query /v1/models again instead of relying on an old screenshot.
  • reasoning_content or tool replay error: use the pinned SDK/runtime versions and deepseek-v4-pro.
  • Unexpected repeated tools: stop tasks with side effects and rerun this read-only fixture first.
  • Installation error: confirm Python 3.10+, supported OS/architecture, and matching SDK/runtime versions.

Scope

This guide verifies the local Python SDK with text and tool loops over Chat Completions. Images, Files API, /v1/responses, /v1/messages, remote workspaces, and a hosted sandbox are outside this guide. Workspace permissions and local command risks remain the responsibility of the machine running Harness.

Official references

Return to the Coding Plan Setup Center.