Font converter: TTF/OTF, WOFF and WOFF2 containers, with the font's own embedding permission checked

$0.01 USDC per call · Business, finance and compliance · POST /api/v1/font-convert · Id font-convert

Repackages a font you supply as base64 (up to 2 MB) between the sfnt (.ttf/.otf), WOFF and WOFF2 containers, for an agent or build step that needs a web font in a particular format: every table is carried over unchanged, the result is read back and its table digest compared with the source, and the font's own OS/2 embedding bits are checked first (a restricted font fails and nothing is returned). It does not convert outlines (TrueType to CFF or back), subset, hint, optimise or rename a font, does not read font collections (.ttc), and a declared embedding permission is not legal advice. WOFF2 output is not size-optimal: glyf, loca and hmtx are stored untransformed.

What you get

Gets a font into WOFF2 or back to TTF without installing fontTools or brotli, and refuses a font whose vendor forbids embedding before it ships on a site.

Call it

Send the JSON body below to https://agents.writerslogic.com/api/v1/font-convert. An unpaid request answers 402 with the price and how to pay; a request that fails with a 5xx status is not charged.

curl -i -X POST https://agents.writerslogic.com/api/v1/font-convert \
  -H 'content-type: application/json' \
  -d '{"fontBase64":"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","to":"woff2"}'

Input

Field	Type	Required	Description
`fontBase64`	string; length 8..2796204	yes	Base64 of a .ttf, .otf, .woff or .woff2 file (not a .ttc collection), up to 2 MB.
`to`	string; one of "sfnt", "woff", "woff2"	yes	Target container. sfnt is the plain .ttf/.otf file.

Example request body

{
  "fontBase64": "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",
  "to": "woff2"
}

Result

The response is { "data": ..., "_provenance": ... }. data carries these fields; _provenance is a signed W3C Verifiable Credential with a C2PA-style manifest, checked free at POST /api/v1/verify-provenance.

Field	Type	Required	Description
`status`	string; one of "pass", "fail", "unknown", "unsupported"	no	pass: every rule held. fail: a rule was violated (see witnesses). unknown: the input lacks the evidence to decide. unsupported: outside what this engine covers. Missing evidence is never a pass.
`sourceFormat`	one of	no
`outline`	one of	no
`targetFormat`	string; one of "ttf/otf", "woff", "woff2"	no
`fontBase64`	one of	no
`bytes`	one of	no
`sha256`	one of	no
`fontDigest`	one of	no
`tables`	array<string>	no
`family`	one of	no
`licence`	one of	no
`witnesses`	array<object>	no
`versions`	object	no	Every semantic dependency of this answer (engine, tables and their as-of dates, tokenizer, calendar, rounding profile).
`limits`	array<string>	no
`deterministic`	boolean	no	Always true: pure code, no model.

Pay and connect

Available through: x402 (USDC on Base), MCP. MCP clients reach it through the identifier-text-kit package.

Machine-readable

This agent as JSON (schemas, example, OpenAPI operation)
Free signed sample response
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