Pain in the Agent

Pain in the Agent MCP

Use the Pain in the Agent text tools from an AI client: remove text watermarks, humanize drafts, compare versions or check AI writing. Rewrites use the characters of your account's monthly plan: $5 a month for 100,000 characters, up to 10,000 per text, shared with the website and the remote MCP. Only a successful changed result is charged. Comparisons and AI checks are free and limited to 100 a day; without a plan they take texts of up to 1,000 characters, with it up to 10,000. The website's free tries (3 per browser) do not apply to the API or this client.

The research and examples describe tests of rewrite methods against reference SynthID Text watermarks. Those measurements are separate from the live tool workflow. This client cannot verify Claude or Gemini's private watermark keys. AI writing signals are experimental style observations, not proof of authorship.

Installation

First subscribe and create an API key while signed in; rewrites need the monthly plan on that account. Keep the key in your client's secret settings or environment, outside conversations and source control. You do not need an OpenRouter or OpenAI key.

Claude Desktop

Download the .mcpb file from the latest release, open it in Claude Desktop, and enter the service key in its API key setting. The MCPB bundle contains its Node dependencies. It uses Node.js 22 or later.

Codex

Clone this repository or extract a release. The committed dist/index.cjs is ready to run without npm install. Add this to your Codex MCP configuration, replacing the example absolute path with your checkout:

[mcp_servers.painintheagent]

command = "node" args = ["/absolute/path/painintheagent-mcp/dist/index.cjs"] env_vars = ["PAININTHEAGENT_API_KEY", "PAININTHEAGENT_BASE_URL"] startup_timeout_sec = 15 tool_timeout_sec = 40

Set PAININTHEAGENT_API_KEY in the environment that starts Codex. Omit PAININTHEAGENT_BASE_URL for the public service. Restart the client after changing its environment.

A Codex plugin is also included at plugins/painintheagent-mcp/, with a repository marketplace at .agents/plugins/marketplace.json. To add this source, run codex plugin marketplace add krllagent/painintheagent-mcp and select Pain in the Agent from that source in the app. The generated catalog is named personal; it is a repository source, separate from OpenAI's public plugin directory. The plugin forwards the same two environment variables.

Claude Code

Set PAININTHEAGENT_API_KEY in the environment that starts Claude Code. Then use:

/plugin marketplace add krllagent/painintheagent-mcp

/plugin install painintheagent-mcp@painintheagent

The plugin includes a rewrite skill and the MCP server. A local checkout can also be loaded with claude --plugin-dir /absolute/path/painintheagent-mcp/claude-plugins/painintheagent-mcp.

Cursor and other local MCP clients

Configure a stdio server with command node and one argument, the absolute path to dist/index.cjs. Supply PAININTHEAGENT_API_KEY through your client's environment or secret setting. Clients have different environment-variable substitution syntax, so use the format your client documents. The MCPB and source release contain the same server.

Tools

Ask your agent to use the tool you need and show its source notes or quoted style evidence. Keep the client open while it works; deep rewriting can take several minutes. The local MCP process holds the streaming connection. Closing it can interrupt the run. The separate remote MCP endpoint at https://painintheagent.com/mcp supports OAuth and continues queued jobs after disconnecting.

Save the request ID. If the stream fails, use get_result with that same ID. The earlier get_rewrite name still works. The client never automatically retries a POST. Reusing an ID with the same operation and input retrieves that run; a different operation, candidate or option is rejected. Failed runs use no characters. Pending requests reserve their characters until they finish or reach the server's deadline, and their IDs cannot start fresh work.

Privacy and gateways

Only supplied text is sent. This client does not read your files, save prose to disk, or emit telemetry. The hosted service sends prose to its model provider and stores source text and results as described in the privacy policy. Your MCP host may retain tool inputs and outputs under its own settings. Do not submit secrets or confidential personal data.

The client reads PAININTHEAGENT_API_KEY and optional PAININTHEAGENT_BASE_URL. The default base URL is https://painintheagent.com. A configured gateway receives every request; there is no credential or endpoint fallback. HTTP is accepted only for localhost gateways. Authentication uses a bearer header, and redirects are rejected.

Development

npm ci --ignore-scripts

npm run build npm test node scripts/package.mjs

The tests use fictional text and a local fake HTTP service. They cover endpoint selection, failed authentication, request reuse, dropped streams, and a fresh bundled installation speaking MCP over stdio. They do not call a paid model or claim to be live-provider validation.

See the API reference and distribution status. The client is MIT-licensed. The hosted service and research have their own terms and evidence.