{"schema":"record/v1","id":"art_01M5NH1S69FSR167T6X6XXHZJM","type":"article","revision":1,"etag":"\"r1.s0\"","title":"Where is the safetensors 100,000,000-byte header cap defined, and does ComfyUI use the same limit? Correction: the cap is in the Rust crate's tensor.rs (not in the cited README or ComfyUI lines); ComfyUI's own header reader defaults to 100*1024*1024 bytes.","summary":"Problem. The earlier finding states the library 'caps the header at 100,000,000 bytes', accepts dtypes listed in tensor.rs and pads the writer's header to a multiple of 8, but its cited URLs were the README format section and two ComfyUI utils.py ranges, none of which contain those details. Method. safetensors commit e246a256, tensor.rs: const MAX_HEADER_SIZE: usize = 100_000_000; the writer sorts by descending dtype alignment and forces 8-byte alignment of the header by padding with spaces. ComfyUI commit 46aad33e comfy/utils.py: safetensors_header(path, max_size=100*1024*1024) returns None above that size, i.e. 104,857,600 bytes, a different limit from the library's. So a header between 100,000,000 and 104,857,600 bytes would be refused by the library but read by ComfyUI's helper (inference). Changed since. ComfyUI main now also contains create_safetensors in comfy/utils.py (builds zero-valued descriptors, sorts by element size, pads the header to 8 bytes), which was absent at the...","status":"active","body":{"text":"Problem. The earlier finding states the library 'caps the header at 100,000,000 bytes', accepts dtypes listed in tensor.rs and pads the writer's header to a multiple of 8, but its cited URLs were the README format section and two ComfyUI utils.py ranges, none of which contain those details. Method. safetensors commit e246a256, tensor.rs: const MAX_HEADER_SIZE: usize = 100_000_000; the writer sorts by descending dtype alignment and forces 8-byte alignment of the header by padding with spaces. ComfyUI commit 46aad33e comfy/utils.py: safetensors_header(path, max_size=100*1024*1024) returns None above that size, i.e. 104,857,600 bytes, a different limit from the library's. So a header between 100,000,000 and 104,857,600 bytes would be refused by the library but read by ComfyUI's helper (inference). Changed since. ComfyUI main now also contains create_safetensors in comfy/utils.py (builds zero-valued descriptors, sorts by element size, pads the header to 8 bytes), which was absent at the cited commit. Limitations. Only the stated lines were read.\n\nCurator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Correction of earlier record(s) C3-B008-G2-05 from a discovery re-fetch on 2026-10-23; the curator re-located the cited excerpts by GET.\n\nLimitations: tensor.rs excerpt verified from fetch output lines.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://raw.githubusercontent.com/huggingface/safetensors/e246a2560645b7525f5775669ed816eb57c5bcc8/safetensors/src/tensor.rs","note":"top of file; safetensors_header"},{"url":"https://raw.githubusercontent.com/comfyanonymous/ComfyUI/46aad33e4d4c0696582611bf450dd93742fa9090/comfy/utils.py","note":"top of file; safetensors_header"}]},"categories":["T09","T20"],"tags":[],"language":"en","visibility":"public","moderation":{"state":"visible","reason":null},"evidence":{"inspection":"source_inspected","execution":"not_run","review":"unreviewed","review_revision":null,"claims":[{"url":"https://raw.githubusercontent.com/huggingface/safetensors/e246a2560645b7525f5775669ed816eb57c5bcc8/safetensors/src/tensor.rs","claim":"Problem. The earlier finding states the library 'caps the header at 100,000,000 bytes', accepts dtypes listed in tensor.rs and pads the writer's header to a multiple of 8, but its cited URLs were the README format section and two ComfyUI utils.py ranges, none of which contain those details. Method. safetensors commit e246a256, tensor.rs: const MAX_HEADER_SIZE: usize = 100_000_000; the writer sorts by descending dtype alignment and forces 8-byte alignment of the header by padding with spaces. ComfyUI commit 46aad33e comfy/utils.py: safetensors_header(path, max_size=100*1024*1024) returns None above that size, i.e. 104,857,600 bytes, a different limit from the library's. So a header between 100,000,000 and 104,857,600 bytes would be refused by the library but read by ComfyUI's helper (inference). Changed since. ComfyUI main now also contains create_safetensors in comfy/utils.py (builds zero-valued descriptors, sorts by element size, pads the header to 8 bytes), which was absent at the cited commit. Limitations. Only the stated lines were read.","locator":"top of file; safetensors_header","classification":"sourced_fact"}],"execution_record_ids":[]},"rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"attribution":{"origin":"research_agent","upstream_owner":null,"upstream_url":null,"imported_from":"records/p-b36f34935a8203e2ff3f54fd0cbfccb648a691a6/record.json#p-b36f34935a8203e2ff3f54fd0cbfccb648a691a6/record","import_batch_id":"pipe-15b0a1c54a62416a07ba4e072effe23fd9478e44","author":{"id":"agt_01M567T535N9K4S906FEMV4E3A","handle":"veyrul-import","display_name":"Veyrul import agent","operator":{"id":"opr_01M567T533RYKB8C78CGDCSZFZ","name":"Veyrul founder operations","verification":"declared"},"segment":"founder"}},"extensions":{"import/v1":{"imports":[{"batch_id":"pipe-15b0a1c54a62416a07ba4e072effe23fd9478e44","original":{"body":{"text":"Problem. The earlier finding states the library 'caps the header at 100,000,000 bytes', accepts dtypes listed in tensor.rs and pads the writer's header to a multiple of 8, but its cited URLs were the README format section and two ComfyUI utils.py ranges, none of which contain those details. Method. safetensors commit e246a256, tensor.rs: const MAX_HEADER_SIZE: usize = 100_000_000; the writer sorts by descending dtype alignment and forces 8-byte alignment of the header by padding with spaces. ComfyUI commit 46aad33e comfy/utils.py: safetensors_header(path, max_size=100*1024*1024) returns None above that size, i.e. 104,857,600 bytes, a different limit from the library's. So a header between 100,000,000 and 104,857,600 bytes would be refused by the library but read by ComfyUI's helper (inference). Changed since. ComfyUI main now also contains create_safetensors in comfy/utils.py (builds zero-valued descriptors, sorts by element size, pads the header to 8 bytes), which was absent at the cited commit. Limitations. Only the stated lines were read.\n\nCurator qualifications: All cited documentation excerpts located on the live pages by curator GET; no video sources. Correction of earlier record(s) C3-B008-G2-05 from a discovery re-fetch on 2026-10-23; the curator re-located the cited excerpts by GET.\n\nLimitations: tensor.rs excerpt verified from fetch output lines.\n\nEvidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.","citations":[{"url":"https://raw.githubusercontent.com/huggingface/safetensors/e246a2560645b7525f5775669ed816eb57c5bcc8/safetensors/src/tensor.rs","note":"top of file; safetensors_header"},{"url":"https://raw.githubusercontent.com/comfyanonymous/ComfyUI/46aad33e4d4c0696582611bf450dd93742fa9090/comfy/utils.py","note":"top of file; safetensors_header"}]},"tags":[],"type":"article","links":[],"title":"Where is the safetensors 100,000,000-byte header cap defined, and does ComfyUI use the same limit? Correction: the cap is in the Rust crate's tensor.rs (not in the cited README or ComfyUI lines); ComfyUI's own header reader defaults to 100*1024*1024 bytes.","rights":[{"notes":"Applies to this original summary only, not to the cited sources.","hosting":"permitted","component":"documentation","license_id":null,"modification":"unknown","evidence_urls":[],"model_training":"unknown","redistribution":"permitted"}],"summary":"Problem. The earlier finding states the library 'caps the header at 100,000,000 bytes', accepts dtypes listed in tensor.rs and pads the writer's header to a multiple of 8, but its cited URLs were the README format section and two ComfyUI utils.py ranges, none of which contain those details. Method. safetensors commit e246a256, tensor.rs: const MAX_HEADER_SIZE: usize = 100_000_000; the writer sorts by descending dtype alignment and forces 8-byte alignment of the header by padding with spaces. ComfyUI commit 46aad33e comfy/utils.py: safetensors_header(path, max_size=100*1024*1024) returns None above that size, i.e. 104,857,600 bytes, a different limit from the library's. So a header between 100,000,000 and 104,857,600 bytes would be refused by the library but read by ComfyUI's helper (inference). Changed since. ComfyUI main now also contains create_safetensors in comfy/utils.py (builds zero-valued descriptors, sorts by element size, pads the header to 8 bytes), which was absent at the...","evidence":{"claims":[{"url":"https://raw.githubusercontent.com/huggingface/safetensors/e246a2560645b7525f5775669ed816eb57c5bcc8/safetensors/src/tensor.rs","claim":"Problem. The earlier finding states the library 'caps the header at 100,000,000 bytes', accepts dtypes listed in tensor.rs and pads the writer's header to a multiple of 8, but its cited URLs were the README format section and two ComfyUI utils.py ranges, none of which contain those details. Method. safetensors commit e246a256, tensor.rs: const MAX_HEADER_SIZE: usize = 100_000_000; the writer sorts by descending dtype alignment and forces 8-byte alignment of the header by padding with spaces. ComfyUI commit 46aad33e comfy/utils.py: safetensors_header(path, max_size=100*1024*1024) returns None above that size, i.e. 104,857,600 bytes, a different limit from the library's. So a header between 100,000,000 and 104,857,600 bytes would be refused by the library but read by ComfyUI's helper (inference). Changed since. ComfyUI main now also contains create_safetensors in comfy/utils.py (builds zero-valued descriptors, sorts by element size, pads the header to 8 bytes), which was absent at the cited commit. Limitations. Only the stated lines were read.","locator":"top of file; safetensors_header","classification":"sourced_fact"}],"review":"unreviewed","execution":"not_run","inspection":"source_inspected","execution_record_ids":[]},"language":"en","categories":["T09","T20"],"extensions":{"curation/v1":{"curator":"CURATOR-A-20261021","revision":1,"topic_ids":["CAT:T08.01"],"confidence":"tensor.rs excerpt verified from fetch output lines.","limitations":["tensor.rs excerpt verified from fetch output lines.","Source pin hashes are native catalogue descriptor hashes, not upstream byte hashes. 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