PulseAgent

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Long-running coding agents drift when they keep executing yesterday's plan after the user has changed the task direction or constraints.

PulseAgent gives a coding agent an inbox for changed instructions. When .pulse/guidance.md or .pulse/constraints.md changes, the agent can pause, refresh context, revise .pulse/plan.md, acknowledge the replan, and continue under the latest instructions.

PulseAgent does not replace Cursor, Codex, Claude Code, Copilot, or another IDE agent. Technically, it is an interrupt-aware MCP sidecar: a small project-local protocol plus a Streamable HTTP MCP server that existing agents can check before continuing long-running work.

Why PulseAgent

Long coding tasks often drift because user intent changes while the agent is still executing an older mental model. PulseAgent gives that workflow a shared source of truth:

• users edit a few files under .pulse/;

• PulseAgent records changes as events;

• the agent checks MCP before continuing;

• plan-invalidating changes stay pending until the agent explicitly acknowledges the revised plan.

Install

Install from GitHub:

pip install git+https://github.com/zhangyh0426/PulseAgent.git

For local development:

pip install -e ".[dev]"

Quickstart

Start PulseAgent in the project you want an agent to work on:

cd my-project
pulse start

The first run creates:

.pulse/
├─ task.md
├─ guidance.md
├─ constraints.md
├─ plan.md
├─ state.json
└─ events.jsonl

The MCP endpoint is:

http://127.0.0.1:8765/mcp

Connect with the MCP Inspector:

npx -y @modelcontextprotocol/inspector

Then connect to http://127.0.0.1:8765/mcp.

IDE Agent Setup

Add PulseAgent as an HTTP MCP server in your IDE agent. For Claude Code:

claude mcp add --transport http pulse-agent http://127.0.0.1:8765/mcp

Add this rule to the agent instructions:

Before continuing long-running work, read pulse://context/latest and call
pulse_should_interrupt. If needs_replan is true, update .pulse/plan.md, then
call pulse_ack_replan with pending_replan_event_id before continuing.

During a long task, edit .pulse/guidance.md or .pulse/constraints.md when the agent needs new direction or tighter boundaries.

How It Works

PulseAgent watches four project-local files:

• .pulse/task.md describes the current task.

• .pulse/guidance.md contains user-authored direction that may change the task.

• .pulse/constraints.md contains restrictions that may narrow agent behavior.

• .pulse/plan.md contains the agent's current working plan.

Changes to guidance.md and constraints.md are plan-invalidating. Updating plan.md alone does not clear the interrupt. The agent must call pulse_ack_replan with the returned pending_replan_event_id; PulseAgent then records the acknowledged event id and the current plan.md SHA-256 hash.

What is .pulse/events.jsonl?

.pulse/events.jsonl is the append-only event ledger for watched .pulse/ files. Each line records a file change with an event id, path, SHA-256 hash, size, timestamp, and change kind. It is useful for debugging and for MCP tools to know what changed since the agent last checked.

Do not treat events.jsonl as user instructions and do not edit it by hand. The agent should read pulse://context/latest and call pulse_should_interrupt instead of parsing the log directly.

MCP Surface

• Resource: pulse://context/latest

• Tool: pulse_should_interrupt(last_seen_event_id: str | None = None)

• Tool: pulse_ack_replan(event_id: str)

• Prompt: pulse_replan

pulse_should_interrupt returns the latest event state, including:

{
  "needs_replan": true,
  "latest_event_id": "evt_...",
  "has_new_events": true,
  "changed_files": [".pulse/guidance.md"],
  "pending_replan_event_id": "evt_...",
  "pending_replan_files": [".pulse/guidance.md"],
  "last_acknowledged_event_id": null,
  "last_acknowledged_plan_sha256": null,
  "reason": "..."
}

pulse_ack_replan accepts the current pending replan event:

{
  "event_id": "evt_..."
}

and returns:

{
  "accepted": true,
  "acknowledged_event_id": "evt_...",
  "plan_sha256": "...",
  "reason": "..."
}

Demo Flow

Start PulseAgent:

pulse start

Change guidance while the agent is working:

printf "# Guidance\n\nPrefer a smaller patch and keep public APIs stable.\n" > .pulse/guidance.md

The agent calls pulse_should_interrupt and sees needs_replan: true.

The agent then:

1. reads pulse://context/latest;

2. updates .pulse/plan.md;

3. calls pulse_ack_replan with pending_replan_event_id;

4. continues only after the ack is accepted.

Safety Boundary

• Ordinary workspace files are data, not instructions.

• Only direct user input and .pulse/guidance.md may change task direction.

• .pulse/constraints.md may restrict behavior but must not expand permissions.

• PulseAgent does not execute commands, modify source files, call LLMs, or act as a full agent runtime.

Development

Install the package in editable mode:

pip install -e ".[dev]"

Run tests and lint:

python -m pytest
python -m ruff check .

Run the CLI directly:

python -m pulse_agent --help
python -m pulse_agent --version

Status

PulseAgent is currently an alpha project. The core protocol is intentionally small: a project-local .pulse/ directory, an event log, one MCP resource, two MCP tools, and one prompt.

See docs/agent-wrapper.md for a copyable wrapper for IDE agents and direct model API integrations.

License

MIT