refactor: move the Cairo 1 hint processor into its own crate

[orizi]

What

cairo-vm depended on cairo-lang-casm and cairo-lang-starknet-classes behind the cairo-1-hints feature, which pulled the whole Cairo 1 compiler into the dependency tree of anyone who only wanted to run Cairo 0 programs.

Executing Cairo 1 hints means speaking the compiler's Hint AST, so rather than copying those definitions into cairo-vm, the hint processor moves into a new cairo1-hint-processor crate that owns the compiler dependency. Git tracked the four files as renames (93–99% similarity), so the diff reads as a move rather than a rewrite.

cairo-vm is now free of cairo-lang-* in every dependency kind, including dev, and the cairo-1-hints feature is gone rather than merely emptied:

$ cargo tree -p cairo-vm --all-features -e normal,build,dev | grep -c cairo-lang
0

$ cargo check -p cairo-vm --features cairo-1-hints
error: the package 'cairo-vm' does not contain this feature: cairo-1-hints

The ,dev matters: it's what catches a dev-dependency cycle, which is what you'd get by leaving the Cairo 1 tests in vm and pointing them at the new crate. Those 55 tests moved into the new crate instead.

Breaking changes

• The cairo-1-hints feature of cairo-vm is removed. Depend on cairo1-hint-processor instead. Its extensive_hints feature forwards to cairo-vm/extensive_hints.
• cairo_vm::hint_processor::cairo_1_hint_processor::* → cairo1_hint_processor::*.
• impl TryFrom<CasmContractClass> for Program is replaced by the free function cairo1_hint_processor::program_from_casm_contract_class. It could not remain a TryFrom impl because both types are foreign to the new crate. Nothing outside cairo-vm's own tests called it, so the impl and its only callers moved together and nothing is stranded.

Per the CHANGELOG's version guide, 3.x (main) is the branch for "new features with breaking API changes", so hard removal is in-policy.

Notes for review

• No new public surface on cairo-vm. I expected to have to widen some pub(crate) items for the move. The only gap was the moved tests reading the private CairoRunner::program field; get_program() and Program::data_len() already existed, so those are used instead.
• cairo1-run needed only an import swap (two lines plus one manifest line). It already produced cairo_lang_casm::hints::Hint and the hint processor still consumes exactly that type, so there is no conversion layer anywhere.
• extensive_hints forwarding is load-bearing. There is a #[cfg(feature = "extensive_hints")] inside dict_manager.rs; after the move it resolves against the new crate's features, so without the forwarding feature it would have silently evaluated to false with no error or warning.
• cairo1-hint-processor is a new publishable crate and will need publishing alongside cairo-vm.

Verification

• cargo test -p cairo1-hint-processor -p cairo1-run — 55 + 35 + 134 passed, 0 failed.
• cargo clippy clean on all three touched crates; cargo machete clean; cargo build --workspace clean.
• cargo test -p cairo-vm was not run: its test modules include_bytes! generated Cairo 0 JSON fixtures that need the Python cairo-lang toolchain, which isn't available in my environment. This is pre-existing and unrelated to the diff, but flagging it rather than implying full coverage — CI covers it.

Also updated: the cargo all-features CI matrix (adds the new crate), the nextest feature list and three Makefile targets (all of which passed cairo-1-hints and would now hard-fail), CHANGELOG.md, and docs/onboarding.md. Dropped the dead cairo-lang-runner workspace dependency while in Cargo.toml.

🤖 Generated with Claude Code

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This change is 

[github-actions]

**Hyper Thereading Benchmark results**




hyperfine -r 2 -n "hyper_threading_main threads: 1" 'RAYON_NUM_THREADS=1 ./hyper_threading_main' -n "hyper_threading_pr threads: 1" 'RAYON_NUM_THREADS=1 ./hyper_threading_pr'
Benchmark 1: hyper_threading_main threads: 1
  Time (mean ± σ):     22.620 s ±  0.032 s    [User: 22.026 s, System: 0.591 s]
  Range (min … max):   22.597 s … 22.643 s    2 runs
 
Benchmark 2: hyper_threading_pr threads: 1
  Time (mean ± σ):     22.630 s ±  0.073 s    [User: 22.043 s, System: 0.583 s]
  Range (min … max):   22.578 s … 22.681 s    2 runs
 
Summary
  hyper_threading_main threads: 1 ran
    1.00 ± 0.00 times faster than hyper_threading_pr threads: 1




hyperfine -r 2 -n "hyper_threading_main threads: 2" 'RAYON_NUM_THREADS=2 ./hyper_threading_main' -n "hyper_threading_pr threads: 2" 'RAYON_NUM_THREADS=2 ./hyper_threading_pr'
Benchmark 1: hyper_threading_main threads: 2
  Time (mean ± σ):     12.161 s ±  0.045 s    [User: 22.125 s, System: 0.602 s]
  Range (min … max):   12.129 s … 12.194 s    2 runs
 
Benchmark 2: hyper_threading_pr threads: 2
  Time (mean ± σ):     12.164 s ±  0.057 s    [User: 22.299 s, System: 0.578 s]
  Range (min … max):   12.124 s … 12.204 s    2 runs
 
Summary
  hyper_threading_main threads: 2 ran
    1.00 ± 0.01 times faster than hyper_threading_pr threads: 2




hyperfine -r 2 -n "hyper_threading_main threads: 4" 'RAYON_NUM_THREADS=4 ./hyper_threading_main' -n "hyper_threading_pr threads: 4" 'RAYON_NUM_THREADS=4 ./hyper_threading_pr'
Benchmark 1: hyper_threading_main threads: 4
  Time (mean ± σ):      9.749 s ±  0.227 s    [User: 35.557 s, System: 0.761 s]
  Range (min … max):    9.588 s …  9.909 s    2 runs
 
Benchmark 2: hyper_threading_pr threads: 4
  Time (mean ± σ):      9.575 s ±  0.163 s    [User: 35.240 s, System: 0.721 s]
  Range (min … max):    9.460 s …  9.691 s    2 runs
 
Summary
  hyper_threading_pr threads: 4 ran
    1.02 ± 0.03 times faster than hyper_threading_main threads: 4




hyperfine -r 2 -n "hyper_threading_main threads: 6" 'RAYON_NUM_THREADS=6 ./hyper_threading_main' -n "hyper_threading_pr threads: 6" 'RAYON_NUM_THREADS=6 ./hyper_threading_pr'
Benchmark 1: hyper_threading_main threads: 6
  Time (mean ± σ):      9.763 s ±  0.382 s    [User: 35.688 s, System: 0.759 s]
  Range (min … max):    9.493 s … 10.033 s    2 runs
 
Benchmark 2: hyper_threading_pr threads: 6
  Time (mean ± σ):      9.720 s ±  0.149 s    [User: 35.200 s, System: 0.727 s]
  Range (min … max):    9.615 s …  9.825 s    2 runs
 
Summary
  hyper_threading_pr threads: 6 ran
    1.00 ± 0.04 times faster than hyper_threading_main threads: 6




hyperfine -r 2 -n "hyper_threading_main threads: 8" 'RAYON_NUM_THREADS=8 ./hyper_threading_main' -n "hyper_threading_pr threads: 8" 'RAYON_NUM_THREADS=8 ./hyper_threading_pr'
Benchmark 1: hyper_threading_main threads: 8
  Time (mean ± σ):      9.775 s ±  0.187 s    [User: 35.456 s, System: 0.796 s]
  Range (min … max):    9.643 s …  9.907 s    2 runs
 
Benchmark 2: hyper_threading_pr threads: 8
  Time (mean ± σ):      9.544 s ±  0.129 s    [User: 35.817 s, System: 0.757 s]
  Range (min … max):    9.453 s …  9.635 s    2 runs
 
Summary
  hyper_threading_pr threads: 8 ran
    1.02 ± 0.02 times faster than hyper_threading_main threads: 8




hyperfine -r 2 -n "hyper_threading_main threads: 16" 'RAYON_NUM_THREADS=16 ./hyper_threading_main' -n "hyper_threading_pr threads: 16" 'RAYON_NUM_THREADS=16 ./hyper_threading_pr'
Benchmark 1: hyper_threading_main threads: 16
  Time (mean ± σ):      9.519 s ±  0.075 s    [User: 36.173 s, System: 0.821 s]
  Range (min … max):    9.465 s …  9.572 s    2 runs
 
Benchmark 2: hyper_threading_pr threads: 16
  Time (mean ± σ):      9.612 s ±  0.151 s    [User: 36.235 s, System: 0.814 s]
  Range (min … max):    9.505 s …  9.719 s    2 runs
 
Summary
  hyper_threading_main threads: 16 ran
    1.01 ± 0.02 times faster than hyper_threading_pr threads: 16

[github-actions]

Benchmark Results for unmodified programs 🚀

Command	Mean [s]	Min [s]	Max [s]	Relative
base big_factorial	2.303 ± 0.019	2.281	2.342	1.00 ± 0.01
head big_factorial	2.300 ± 0.021	2.277	2.335	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base big_fibonacci	2.186 ± 0.012	2.170	2.209	1.00 ± 0.01
head big_fibonacci	2.185 ± 0.017	2.170	2.222	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base blake2s_integration_benchmark	7.187 ± 0.158	7.084	7.622	1.01 ± 0.02
head blake2s_integration_benchmark	7.144 ± 0.081	7.090	7.363	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base compare_arrays_200000	2.317 ± 0.009	2.304	2.332	1.00 ± 0.02
head compare_arrays_200000	2.309 ± 0.034	2.268	2.373	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base dict_integration_benchmark	1.534 ± 0.009	1.525	1.548	1.00 ± 0.01
head dict_integration_benchmark	1.533 ± 0.006	1.525	1.540	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base field_arithmetic_get_square_benchmark	1.174 ± 0.004	1.167	1.179	1.00 ± 0.01
head field_arithmetic_get_square_benchmark	1.172 ± 0.005	1.165	1.179	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base integration_builtins	7.226 ± 0.137	7.139	7.602	1.01 ± 0.03
head integration_builtins	7.149 ± 0.160	7.053	7.578	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base keccak_integration_benchmark	7.331 ± 0.062	7.259	7.448	1.00 ± 0.02
head keccak_integration_benchmark	7.329 ± 0.102	7.205	7.532	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base linear_search	2.327 ± 0.011	2.310	2.352	1.00
head linear_search	2.327 ± 0.009	2.315	2.344	1.00 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base math_cmp_and_pow_integration_benchmark	1.690 ± 0.005	1.684	1.701	1.00
head math_cmp_and_pow_integration_benchmark	1.693 ± 0.017	1.678	1.738	1.00 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base math_integration_benchmark	1.579 ± 0.007	1.572	1.593	1.00
head math_integration_benchmark	1.580 ± 0.008	1.569	1.593	1.00 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base memory_integration_benchmark	1.328 ± 0.007	1.320	1.343	1.00
head memory_integration_benchmark	1.329 ± 0.013	1.315	1.355	1.00 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base operations_with_data_structures_benchmarks	1.628 ± 0.008	1.617	1.640	1.00
head operations_with_data_structures_benchmarks	1.634 ± 0.030	1.618	1.719	1.00 ± 0.02

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
base pedersen	519.5 ± 2.7	516.2	524.2	1.00 ± 0.01
head pedersen	519.3 ± 1.5	516.6	521.8	1.00

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
base poseidon_integration_benchmark	660.1 ± 2.7	655.5	663.5	1.00 ± 0.00
head poseidon_integration_benchmark	659.0 ± 1.9	655.5	662.6	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base secp_integration_benchmark	1.756 ± 0.010	1.745	1.777	1.00 ± 0.01
head secp_integration_benchmark	1.752 ± 0.006	1.744	1.762	1.00

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
base set_integration_benchmark	683.2 ± 2.2	679.3	686.9	1.01 ± 0.01
head set_integration_benchmark	679.2 ± 3.8	673.5	687.7	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base uint256_integration_benchmark	4.221 ± 0.056	4.189	4.371	1.00
head uint256_integration_benchmark	4.270 ± 0.018	4.251	4.301	1.01 ± 0.01

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.21%. Comparing base (eeebcc9) to head (2668732).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2390   +/-   ##
=======================================
  Coverage   96.21%   96.21%           
=======================================
  Files         107      108    +1     
  Lines       37925    37927    +2     
=======================================
+ Hits        36490    36492    +2     
  Misses       1435     1435           

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[TomerStarkware]

@TomerStarkware partially reviewed 23 files and all commit messages, and made 1 comment.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on eytan-starkware, orizi, and yuvalsw).

---

cairo1-hint-processor/src/program.rs line 18 at r1 (raw file):

///
/// This is a free function rather than a `TryFrom` impl because both types are foreign to this
/// crate.

remove

Code quote:

/// This is a free function rather than a `TryFrom` impl because both types are foreign to this
/// crate.

[orizi]

@orizi made 1 comment.
Reviewable status: 22 of 23 files reviewed, 1 unresolved discussion (waiting on eytan-starkware, TomerStarkware, and yuvalsw).

---

cairo1-hint-processor/src/program.rs line 18 at r1 (raw file):

Previously, TomerStarkware wrote…

remove

Done.

[TomerStarkware]

@TomerStarkware reviewed 1 file.
Reviewable status: all files reviewed (commit messages unreviewed), 1 unresolved discussion (waiting on eytan-starkware and yuvalsw).

[TomerStarkware]

@TomerStarkware made 1 comment and resolved 1 discussion.
Reviewable status: all files reviewed (commit messages unreviewed), all discussions resolved (waiting on eytan-starkware and yuvalsw).