Interactive browser for Filecoin Data Segment Index entries. Point it at a raw piece or sector file (or URL) and it parses the trailing index, then serves an HTML UI for browsing entries.
| Format | Entry Size | Description |
|---|---|---|
| v1 (FRC-0058) | 64 B (2 nodes) | Original data segment index. CommDs + padded offset/size. |
| v2-orig (Nov 2025 proposal) | 128 B (4 nodes) | Extended index with CommDS, pre-Fr32 offset/size/rawSize, multicodec, ACL. |
| v2 (revised, Mar 2026) | 128 B (4 nodes) | CID-based index with multihash, multicodec, flexible alignment. |
Format is auto-detected by examining the file tail for a valid sentinel entry and checksum validation.
go install github.com/magik6k/podsiv2-parser@latest
Or build from source:
git clone https://github.com/magik6k/podsiv2-parser
cd podsiv2-parser
go build -o piecebrowser .
piecebrowser <file | url>
Opens a local HTTP server and launches the browser. Examples:
# Local file
piecebrowser /path/to/piece.data
# HTTP URL (downloads to temp file first)
piecebrowser https://example.com/piece.dataThe UI provides:
- Summary bar with file size, detected format, and entry count
- Paginated table (handles millions of entries)
- Click any row to expand full details (all fields, hex dump, checksum status)
- Search / filter by CID, commitment hash, offset, codec name
- Sentinel entries highlighted
The server also exposes JSON endpoints:
GET /api/info-- file metadata, format, entry count, warningsGET /api/entries?offset=0&limit=100&search=...-- paginated entries
[0:32] CommDs (254 bits, piece commitment)
[32:40] Offset (uint64, padded bytes)
[40:48] Size (uint64, padded bytes)
[48:64] Checksum (126-bit SHA-256)
Node 1 [0:32]: CommDS (254 bits)
Node 2 [32:64]: Offset(8) | Size(8) | RawSize(8) | Multicodec(8)
Node 3 [64:96]: MulticodecDependent (254 bits)
Node 4 [96:128]: ACLType(1) | ACLData(8) | Reserved(7) | Checksum(16)
Node 1 [0:32]: CommData (254 bits of hash digest)
Node 2 [32:64]: Multicodec(8) | Multihash(8) | Reserved(15) | CommDataTail(2 bits)
Node 3 [64:96]: Reserved(8) | Offset(8) | Size(8) | RawSize(8)
Node 4 [96:128]: ACLType(1) | ACLData(8) | Reserved(7) | Checksum(16)
All sizes in v2 are pre-Fr32-padding bytes. Checksum is SHA-256 of the full entry with the checksum field zeroed, truncated to 126 bits.
- FIPs Discussion #1216 -- Self-Describing Data Aggregation proposal
- go-data-segment -- Go implementation of data segment index v2
- FRC-0058 -- Verifiable Data Aggregation (v1)
MIT