dsh-stream-rules

简体中文

Inject rules when needed, without wasting context.

You can write custom streaming rules for the agent.

These rules are injected only as a steering notice after a pattern match, then agent retry from the same point. This allows you to control the boundaries of agent behavior, without wasting context.

Port of my jiesou/opencode-stream-rules to DSH. Similar to oh-my-pi's "Time-traveling stream rules", but with a very simple and compact code implementation.

How it works

A rule fires on a tool call (tool name + serialized arguments) when its match returns true:

• default — injects a SYSTEM NOTICE steering message into the agent via agent.inject() (DSH's non-waking "queue model-facing context for the next pre-step"). The agent retries from the same point, now knowing the rule.
• reject: true — denies the FIRST tool call ({ kind: 'deny' }); later attempts are allowed. Steering without over-restricting, e.g. letting pip install through when it's already in a container.

Each rule fires at most once per session (per agent), mirroring the original's notified dedup.

Install

From npm (prebuilt, recommended):

dsh plugin --profile <name> add @jiesou/dsh-stream-rules

Or from GitHub (runs prepare to build on install):

dsh plugin --profile <name> add github:jiesou/dsh-stream-rules

Or add the row to your profile's cordis.patch.yml:

- id: stream-rules
  name: '@jiesou/dsh-stream-rules'

After installing

You need to write the rules in your own .js file. This plugin won't work by default until you edit the rules.

1. Locate the plugin's path:

$DSH_HOME/profiles/<name>/node_modules/@jiesou/dsh-stream-rules

where $DSH_HOME defaults to ~/.dsh.

2. Write rules:

mv rules/rules.js.example rules/rules.local.js

• Files starting with _ are skipped.
• To point at a different rules directory: config.rules:

- id: stream-rules
  name: '@jiesou/dsh-stream-rules'
  config:
    rules: /path/to/your/rules

• A rule with reject: true will only be rejected on the first toolcall; subsequent attempts by the agent will be allowed. This provides steering while avoiding overly restricting the model (e.g., allowing pip install if it's already in a container).

Writing rules

// rules/rules.local.js
export default [
  {
    match: (v) =>
      v.includes('pip') &&
      v.includes('install') &&
      !v.includes('uv pip') &&
      !v.includes('uvx'),
    reject: true,
    prompt: 'Use `uvx` or `uv venv` + `uv pip` instead of `pip install` directly',
  },
  {
    match: (v) => v.includes('curl') && v.includes('api.github.com'),
    prompt: 'Prefer using `gh` cli over `curl https://api.github.com/...`. gh offers more requests limits.',
  },
  {
    match: (v) => v.includes('pdf'),
    prompt: 'Use the `markitdown` skill to read PDF files.',
  },
  // add your rules here
]

field	required	description
match	✅	(v: string) => boolean; every tool call is flattened to a string and matched
prompt	✅	The prompt for steering
reject		If true, prevent the tool call first, instead of just steering

Compatibility

Declared in package.json under dsh.compatibility: DSH >=0.1.0-rc.6 <0.2.0, Node.js ^22.19.0 || >=24.0.0, profiles web / headless.

Per-release evidence (each release installed into a disposable profile with dsh plugin add <tarball>): the profile composes and cold-starts, the tool-call hook is exercised directly against that release's tools/pre-execute waterfall and agent.inject() (steering notice delivered, reject: true denies the first call and allows the retry), then the plugin is uninstalled and the profile boots again.

DSH version	install	start	hook	uninstall
0.1.5-alpha.1	passed	passed	passed	passed
0.1.5-alpha.2	passed	passed	passed	passed
0.1.5-rc.1	passed	passed	passed	passed

Implementation notes

• A single src/index.ts (~60 lines).
• Uses DSH's tools/pre-execute waterfall (deny) and agent.inject() (steering), the documented native extension points. No core changes, no monkey-patching.