Control fonts and text styling over NextPDF Connect

At a glance

Build a document with multiple text styles by switching fonts between text blocks. set_font sets the active typeface, style, and size. That state applies to each following add_text call until you change it. You need create_pdf, set_font, add_text, and output_pdf — all Core tools. Text state parameters control glyph rendering (ISO 32000-2 §9).

Install

composer require nextpdf/server

Bind a transport. You can use three built-in font families without adding font files: helvetica, times, and courier.

Conceptual overview

set_font takes family, style ("", "B", "I", "BI", "U"), and size. The font you set applies to every later add_text call until you call set_font again. There is no automatic reset. When add_text includes font_size, that value overrides the active size for that single call only. The set_font size returns for the next call. Text is emitted by text-showing operators in content-stream order (ISO 32000-2 §9.4). add_text has no colour parameter. Text colour comes from the document’s graphics-state ink colour.

API surface

Tool	Role	Risk tier
`create_pdf`	Open the session	Safe
`set_font`	Set the active typeface/style/size	Caution
`add_text`	Write text in the active font	Caution
`output_pdf`	Render and return the PDF	Approval Required / Review (base64)

The tool catalog is the catalog of record. The tools you can use depend on the installed tier.

Code sample — Quick start

create_pdf (A4 portrait) → document_id.
set_font (helvetica, B, 24) then add_text (title, centered).
set_font (helvetica, "", 12) then add_text (justified body).
set_font (courier, I, 10) then add_text (a code snippet).
output_pdf.

Code sample — Production

Set the font explicitly before each block where typography matters. Never rely on inherited state across logical sections. Use the per-call font_size override only for one-off emphasis, because it does not persist. Build the document section by section, and verify that each add_text returns a position.

Edge cases & gotchas

Unknown family. Anything outside helvetica/times/courier (for example arial) is rejected.
Empty family. family must be a non-empty string.
Invalid style. Use the uppercase codes. "bold" is rejected.
Non-positive size. size must be a positive number.
Per-call size is temporary. It does not change the set_font state.

Performance

Built-in fonts add negligible weight, and output is a few KB. The profile is structural.

Security notes

Base64 mode has no filesystem side effect. Built-in fonts do not ingest external font files, so this recipe has no font-parsing attack surface.

Conformance

Statement	Spec	Clause	reference_id
Text is shown by text operators in stream order.	ISO 32000-2	§9.4
Text-state parameters govern glyph rendering.	ISO 32000-2	§9

Commercial context

Not applicable — all tools are Core.

Transport availability

Transport	Available	Notes
MCP (stdio)	Yes	`tools/call` per tool.
REST	Yes	One operation per tool.
gRPC	Yes	Unary per tool.

HITL risk tier

create_pdf Safe; set_font/add_text Caution; output_pdf Approval Required, downgraded to Review in base64 mode (HITL risk tiers).

Confirmation gate JSON envelope

Base64 output:

{ "allowed": true }