MCP: the agent surface

Heinrich is, first, an instrument for a Claude instance to use. heinrich serve (or heinrich-mcp) runs JSON-RPC over stdio; the ToolServer wraps every pipeline stage as an MCP tool. Tools are subprocess-isolated: source changes propagate on every call, and a crash in one capture doesn't take down the server.

heinrich serve            # stdio MCP server

This is where the rigor lives. The front page is for humans; the spec is for the machine that drives the tool.

MRI tools: the working frontier

Tool	Does
heinrich_mri	complete model MRI capture (subprocess, 10h timeout, mode/backend flags)
heinrich_mri_backfill	fill missing weights / norms / embedding in an existing MRI
heinrich_mri_status	what's complete, incomplete, running
heinrich_mri_health	deep health check (shapes, NaN, gates, attention sums)

Profile tools

heinrich_frt_profile (tokenizer, in-process, fast) · heinrich_shrt_profile (residual, subprocess-isolated, accepts a layers param) · heinrich_sht_profile (output distribution).

Eval & DB tools

Tool	Does
heinrich_eval_run	full pipeline (discover + attack + eval + report)
heinrich_eval_report	report from the DB
heinrich_eval_disagreements	where the judge scorers disagree
heinrich_db_summary	database overview
heinrich_sql	read-only SQL (blocks DROP / ATTACH / PRAGMA)

Causal-bank & tokenizer tools (no model)

heinrich_cb_loss · heinrich_cb_routing · heinrich_cb_temporal · heinrich_cb_modes · heinrich_cb_decompose · heinrich_cb_gate_forensics · heinrich_cb_substrate_local · heinrich_tokenizer_difficulty · heinrich_tokenizer_compare.

Causal-bank diagnostics (need model)

heinrich_cb_causality (finite-difference causality verification) · heinrich_cb_reproduce (determinism check).

The complete, current tool list is maintained in CLAUDE.md.