Tamperpilot

A GitHub Copilot modding tool for enhancing user's local experience by overriding app context with custom script.

Quick start

1. Clone this project

git clone https://github.com/knilink/tamperpilot.git

2. Clone the copilot script to be tamper with

git clone https://github.com/github/copilot.vim.git

3. Install dependencies

cd tamperpilot
npm install

4. Patch script

npm run patch openai ../copilot.vim/dist/language-server.js

where "openai" is the build entry of the script to be injected, which is src/openai.ts If this step succeed, there should be a ../copilot.vim/dist/language-server-tampered.js generated.

5. Test the script(optional). It should work with any openai compatible api, here use ollama at http://localhost:11434 as an example

npm run test-completion -- \
  ../copilot.vim/dist/language-server-tampered.js --stdio --debug \
  --baseUrl=http://localhost:11434/v1 \
  --model=qwen2.5-coder:7b-base-q4_K_M \
  --add-stop='<|file_sep|>'

Args explanation:

• --stdio: always required by language server.
• --debug (optional): language server built-in debug args to enable debug log level.
• --baseUrl: The base url of openai completions endpoint, e.g. http://localhost:11434/v1 for ollama
• --model: model parameter to be injected to completion request payload, or alternatively use language server's built-in env AGENT_DEBUG_OVERRIDE_ENGINE
• --stop (optional): overriding language server's built-in stop sequences
• --add-stop (optional): append stop sequences to language server's built-in stop sequences
• --unset-stop (optional): unset the built-in stop sequences

When testing with ollama, make sure the model support FIM and the model file is the latest, qwen2.5-coder is recommanded. If this step succeed, log message completion {"completions":[..., "text":" age = current_year - birth_year", ...}]} can be seen at the last line.

If the completion is empty, check the log for [fetchCompletions] request.response: [http://localhost:11434/v1/completions] to make sure the request is sending to the specified --baseUrl, as well as server's non 200 responses.

How build a custom script

Below is an example to show necessary to build a custom injection script. First, create a file in src folder, src/myScript.ts for example, with following content.

// file://.src/myScript.ts
// import TamperContext
import { TamperContext } from './utils/tamperContext';
// optionally import presets to be applied
import { dummyAuth } from './utils/presets';

// create a tamper context instance
const tctx = new TamperContext();

// optionally apply preset
dummyAuth(tctx);

// setup hook, here use 'BuildInfo' as an example
tctx.tamper(
  // name of the context, more can be found in src/utils/contextKeys.d.ts
  'BuildInfo',
  (
    // instance of the context
    instance,
    // class or abstract class of the context, could be optionally used for extending
    BuildInfo
  ) => {
    // overriding method function, monkey patching is recommanded to minimize the chance of breaking
    instance.getDisplayVersion = () => '3.14.159-tampered';

    // must return the instance of `BuildInfo` or classes extends `BuildInfo`
    return instance;
  }
);

// export context instance as default, this step is IMPORTANT.
export default tctx;

Then run the patch

npm run patch myScript ../copilot.vim/dist/language-server.js

Finally, test the patch

npm run test-completion -- ../copilot.vim/dist/language-server-tampered.js --stdio --debug

If succeed, version 3.14.159-tampered can be seen in the initial debug log message [lsp] GitHub Copilot Language Server 3.14.159-tampered initialized.

More context info can be found in src/utils/contextKeys.d.ts, typing was done based on copilot.vim#v1.38.0 so could be inconsistent with other versions, below are contexts that are considered useful:

• Fetcher: the context responsible sending all http requests.
• NetworkConfiguration: defines a bunch of URLs
• ConfigProvider: provides config
• AuthManager, CopilotTokenManager: handling auth