# MCParser ```{raw} html
MCParser logo: a rotating cube MCParser, a CoNLL-U parser built on MCP MCParser, a CoNLL-U parser built on MCP
``` MCParser produces [Universal Dependencies](https://universaldependencies.org/) annotation (CoNLL-U) with a team of LLM agents. Trusted CoNLL-U files, such as a treebank's training data, provide the examples. The agents annotate a prediction file, score every cell, and refine the least certain cells over several rounds. ```text raw text ──init──▶ prediction.conllu ──run──▶ scored, refined prediction.conllu ──evaluate──▶ scores (tokenise + baseline) (scorer + one agent per column) ``` All access to the data goes through an [MCP](https://modelcontextprotocol.io) server over CoNLL-U files. The agents use it, and so can Claude Desktop or other projects (for example a parallel-corpus aligner). Main features: - **One agent per CoNLL-U element**: segmentation (FORM and multiword tokens), UPOS, XPOS, LEMMA, FEATS, syntax (HEAD and DEPREL decided together, or separately) and, optionally, DEPS, plus a **scorer** that judges every cell. - **A confidence for every cell**, stored in the MISC column (`Conf=upos:0.95,head:0.40,...`), which decides what gets refined next. - **Cross-agent review**: any agent can flag a probable mistake in a column it doesn't own, and the responsible agent picks the flag up. - **Read-only trusted sources and writable predictions**, enforced by the server, with a full edit history. - **A configurable model for each role** (default `anthropic:claude-opus-5-5`) via [pydantic-ai](https://ai.pydantic.dev). ```{toctree} :maxdepth: 2 :caption: Guide quickstart concepts pipeline agents providers mcp alignment evaluation results troubleshooting ``` ```{toctree} :maxdepth: 1 :caption: Reference _generated/cli api development changelog ```