# Exact multipart form body encoder

Build-time release reference. Runtime readiness, deployment, payment settlement and external indexing are not evaluated here. Prices are proposed; this file cannot authorize execution or payment.

WHEN TO USE: Construct exact inert multipart/form-data bytes from ordered supplied text or binary file parts, preserving repeated field names. Caller supplies a collision-checked boundary; explicit utf8 or canonical padded Base64 output and decoded wire byte count. Strict ASCII names prevent header injection; no upload, custom headers, nested multipart, automatic field flattening or API acceptance claim.

Release: 0.29.0. Built: 2026-10-06T15:38:00Z.

## Choose for
- Encode ordered multipart form-data upload bodies with binary files and repeated field names
- Measure exact multipart request bytes with deterministic collision-checked boundaries

## Outside this profile
- Performing HTTP requests or uploads, headers beyond Content-Disposition and Content-Type, nested multipart or endpoint compatibility
- Non-ASCII field names or filenames, path filenames, filename*, or implicit charset guessing
- Uploading, executing artifacts, contacting agents or registries, publishing, or changing remote state
- Verifying semantic truth, source authenticity, permissions, target API acceptance or signatures

Proposed nominal USD 0.005 per successful call; payer fees excluded. No verified runtime availability.

- [Exact release contract](/reference/services/multipart-form-encode.json)
- [Input schema](/reference/schemas/multipart-form-encode.input.json)
- [Output schema](/reference/schemas/multipart-form-encode.output.json)
- [Fixed example](/reference/examples/multipart-form-encode.json)
- [Complete HTML reference](/discover/tools/multipart-form-encode)