Nix — 111 Operations for AI Agents
This page is the canonical reference an AI coding agent uses to refactor, query, and analyze Nix code through the act MCP server. 111 operations available: 37 refactor, 18 query, 42 analysis, 14 verification. Each operation is callable from Claude Code, Cursor, Codex, OpenCode, or any MCP-compatible agent host. Click any operation for a stable anchor link suitable for citation.
Query
18 query tools, the same on every supported language. Descriptions live in the shared reference: /docs/query-tools.
callers control_flow data_flow definition diagnostics effect_closure effect_summary fix_auto get_type graph import_organize interface mutations references repo_outline skeleton symbols symbols_batch
Refactor
| Operation | Description |
|---|---|
add-inherit-statement |
Add an `inherit` statement to an attribute set for given variables |
convert-boolean-to-if |
Convert a boolean expression into an if-then-else expression |
convert-if-to-boolean-expression |
Simplify `if x then true else false` to just `x` |
convert-import-to-let-binding |
Convert an inline `import ./file.nix` into a let binding |
convert-lambda-to-function |
Wrap an anonymous lambda in a named let-bound function |
convert-null-coalesce |
Convert `x // fallback` merge to an explicit conditional null check |
convert-rec-to-scope |
Convert `rec { ... }` to a `let...in` expression |
convert-string-concat-to-interpolation |
Transform string concatenation expressions to Nix string interpolation |
convert-to-attr-set-shorthand |
Convert attr = attr; bindings to inherit form |
convert-to-string-interpolation |
Convert string concatenation (+ operator) to Nix string interpolation |
extract-builtin-call |
Extract a repeated builtins function call into a named let binding |
extract-function |
Extract an expression into a new named function binding |
extract-function-from-lambda |
Convert an anonymous lambda into a named function binding |
extract-let-binding |
Extract an expression into a let-in binding |
extract_function |
Extract a code selection into a new function — automatically infers parameters, return types, and inserts the call site. Use instead of manually cutting/pasting code. Works without LSP; LSP improves type inference. Params: file (string), new_name (string), start_line (u32), start_column (u32), end_line (u32), end_column (u32) [, preview (bool), receipt (bool)] |
extract_variable |
Extract an expression into a named variable — inserts the declaration and replaces the expression with the variable name. Works without LSP. Params: file (string), new_name (string), start_line (u32), start_column (u32), end_line (u32), end_column (u32) [, preview (bool)] |
generate-attribute-set |
Generate an empty or structured attribute set |
generate-filter-function |
Generate a `filter` operation skeleton over a list |
generate-fold-operation |
Generate a `builtins.foldl'` operation skeleton |
generate-function |
Generate a new function binding skeleton in Nix |
generate-if-then-else |
Generate complete if-then-else structure |
generate-let-binding |
Generate a let-in expression with variable and body |
generate-map-function |
Generate a `map` operation skeleton over a list |
generate-mkderivation |
Generate mkDerivation skeleton with common attributes |
generate-test-scaffold |
Generate a test expression scaffold for Nix code |
inline |
Inline a variable, function, or method — replace every usage with its definition body, then remove the original. The inverse of extract. Works without LSP (single-file); LSP enables cross-file inlining. Params: file (string), symbol (string) [, line (u32), preview (bool), receipt (bool)] |
inline-function |
Inline a function binding by replacing calls with the body |
inline-variable |
Inline a let-bound variable by replacing uses with its definition |
insert_body |
Replace a function's implementation body with new code. AST-validated — rejects if the result has parse errors, so you can't accidentally break syntax. Use instead of manual text editing for function rewrites. Params: file (string), symbol (string), code (string) [, commit (bool)] |
move_symbol |
Move a function, class, or type to a different file and automatically update all imports across the codebase. Use instead of manually cut/paste + fixing imports. Works without LSP (single-file); LSP enables cross-file import updates. Params: file (string), symbol (string), destination (string) [, preview (bool), receipt (bool)] |
organize-imports |
Sort and organize import bindings at the top of a Nix file |
recipe_run |
Run a codemod recipe: declarative match → transform → optional verify across modeled grammars. Preview lists matches; apply writes with optional E7 receipts and all-or-nothing rollback. Returns a per-site report. |
remove-unused-parameter |
Remove a named parameter from a function's formal set |
remove-unused-variable |
Remove a let binding that is never used |
rename |
Rename a symbol and automatically update ALL references across the codebase. Safer and faster than find-and-replace — AST-aware, won't rename strings or comments. Works without LSP (single-file); LSP enables cross-file renames. Params: file (string), old_name (string), new_name (string) [, line (u32), column (u32), preview (bool), receipt (bool)] |
rename-identifier |
Rename a variable, function, or attribute across its scope |
reorder-function-arguments |
Reorder formal parameters in a function definition |
Analysis
42 analysis tools, the same on every supported language. Descriptions live in the shared reference: /docs/analysis-tools.
analyze_api_diff analyze_chokepoints analyze_clones analyze_clusters analyze_cohesion analyze_conformance analyze_coupling analyze_cycle_risk analyze_cycles analyze_dead_code analyze_depth analyze_entry_points analyze_export analyze_extraction analyze_fan_balance analyze_features analyze_hotspots analyze_impact analyze_inconsistencies analyze_inheritance analyze_interface_bloat analyze_interfaces analyze_layers analyze_orphan_types analyze_patterns analyze_platform_deps analyze_readiness analyze_roles analyze_seams analyze_stability analyze_surface analyze_test_gaps analyze_thickness analyze_type_completeness churn_hotspots co_change_clusters coverage_overlay ownership_map profile_overlay simulate split_module trace_overlay
Verify
14 verify tools, the same on every supported language. Descriptions live in the shared reference: /docs/verification.
bisect_regression gate generate_test_harness scan secret_surface summarize_pr taint_flow unsafe_surface verify_behavioral_equivalence verify_contract_preserved verify_diff_semantics verify_port_parity verify_side_effects verify_test_impact