Tidigar share link specification

See sharing a roadmap as a link, with the Share link dialog and the steps to copy a link.

Status: public pre-release specification, version 1. It defines how any tool, script or AI agent writes a link that opens a complete, editable Tidigar roadmap. The link carries the whole roadmap itself, so nothing is uploaded, nothing is stored on a server and no account is needed. A link is plain text, written one record at a time; it needs no code, compression or encoding.

License: published by Hamacher Software AB under CC BY 4.0. Anyone may implement the format it describes, in any software, without asking.

The keywords MUST, MUST NOT, SHOULD and MAY are normative. The roadmap model, its field rules and limits are defined in the Tidigar Roadmap Interoperability Specification.

Link format

https://open.tidigar.com/s#t=1~<record>~<record>~…~!

It opens the Tidigar web app with the roadmap, or the Tidigar app when it is installed and claims the link. The opener is not deployed yet; until it is, https://app.tidigar.com/#t=1~… opens the same roadmap in the web app.

• The fragment starts with t=1. Records follow, each after a ~, as key=value or a one-letter flag, in any order. ! ends the link.
• The whole link SHOULD stay within 2,000 characters: the fragment within 1,900. A larger roadmap is shared as a project file. Links are meant to be small, useful starting plans that fit in a chat message, an email or a QR code.
• The fragment is never sent to a server by browsers, so the roadmap stays between the sender and the recipient.

Records

Numbered records count from 1: a1, a2, … A link MUST NOT skip a number, and c= MUST give the counts, so a missing record or a cut link is noticed.

Activities

a3=Install_new_unit/11-02/5/Installer,Install/@a2,s2/50p/d=Ask_for_permits

• Title, then start: MM-DD in year y, or YYYY-MM-DD for another year. Then days: how many days it lasts, 1 for a single day. In a roadmap planned in work days these are work days, skipping weekends and vacation periods.
• Then, in any order: - Options by name, comma-separated, one per dimension. Where two dimensions have an option of the same name, write Team:Design. - Dependencies after @, comma-separated: activities and fixed milestones by key, such as @a1,s2. The activity starts after each of them ends; @a1:50 lets it start once 50% of a1's planned days have passed (0, 25, 50 or 75). An activity MUST NOT start before what it depends on allows, and dependencies MUST NOT form a cycle. - Progress as 0p, 25p, 50p, 75p or 100p. An option whose name looks like this is written with its dimension, such as Size:50p. - d= a description.

Milestones and periods

s1=Heat_pump_in_operation/11-09/@a3
s2=Contract_signed/10-30/fixed
p1=Autumn_break/10-26/5

• A milestone has a title and a date, then @ and the activities it waits for, at least one day after each ends; or fixed for an event on a set date, such as a decision, that activities wait for.
• A period is a titled band across the timeline, such as a holiday: title, start and days. It is a vacation, without work days, unless work follows.

Dimensions and the view

• m1=Team:Household,Installer names a dimension and its options in order. A link has no colors: options take Tidigar's standard colors in order.
• v= opens the roadmap in timeline, board, list or flow, followed by rows:, columns:, color: or group: and a dimension's name, and by start: and end: and a date for the timeline's span: v=timeline/color:Team/group:Phase/start:10-01/end:12-31.
• Words set how a timeline looks: classic shows one activity per row under a fixed label column with reference keys, as in MS Project, and opens the roadmap in its Classic view; compact lets activities share rows; minimal, airy, contrast and terminal choose a style. A word alone means a timeline: v=classic.

Text

• _ is a space.
• In a title, a note or a name, write these characters escaped: ~ %7E, / %2F, _ %5F, % %25, & %26, # %23, ( %28, ) %29, " %22, < %3C and > %3E. In a dimension or option name also , %2C, : %3A, @ %40 and = %3D.
• Other characters, such as å, ä, ö or –, are written as they are.
• Titles are up to 180 characters, names up to 100, the roadmap's description up to 500.

Example

https://open.tidigar.com/s#t=1~n=Heat_pump_replacement~y=2026~w~m1=Team:Household,Installer~m2=Phase:Plan,Install~a1=Review_current_system/10-12/3/Household,Plan~a2=Request_quotes/10-15/6/Household,Plan/@a1~a3=Install_new_unit/11-02/5/Installer,Install/@a2,s2~s1=Heat_pump_in_operation/11-09/@a3~s2=Contract_signed/10-30/fixed~p1=Autumn_break/10-26/5~v=timeline/color:Team/group:Phase~c=3.2.1~!

A heat pump replacement planned in work days: three activities by Team and Phase, the installation waiting both for the quotes and for the signed contract, a completion milestone, and the autumn break as a vacation week. It opens as a timeline grouped by Phase and colored by Team.

Opening a link

Tidigar adds the opened roadmap to the recipient's own library and shows it in the link's view. Every record gets a new identity, so each opening is an independent copy: editing it never changes the link or anyone else's copy. Opening the same link again on a device selects the copy it made.

The copy is made as a new roadmap is: its activities and milestones get reference keys in the link's order, such as WL-1, WL-2, under the prefix r= gives or one made from the roadmap's name, and it gets the Classic view beside the view it opens in.

Tidigar reads a link leniently and says what it did. What has an obvious fix is fixed and reported by record, for example a3: no dimension has the option "Done"; it was left empty, or an activity that starts before what it depends on is moved later. A link with a problem that has no fix, such as a1: start "02-30" is not a date, is refused with every problem listed. Tidigar shows the report so it can be passed back to whoever wrote the link. Tidigar never drops an activity, a milestone or a period.

Tidigar shares links of its own in a compressed form, #s=1.…. They are not meant to be read or written by hand; open them in Tidigar.

Optional validation

Agents can write links directly using llms.txt, without tools or code. To check a finished link locally, optionally run:

node tidigar-link.mjs --validate "<finished URL>"

The module below reports the plan's dates and dependencies, record counts, fragment length and any corrections Tidigar would make. It exits 0 only when the link opens without corrections. Invalid input, a fragment over 1,900 characters or corrections to review produce exit 1. It does not rewrite the link or save anything; fix the original records and validate again if desired.

Building a link from JSON

https://tidigar.com/agents/v1/tidigar-link.mjs (Node.js 20 or later, Deno or Bun) and https://tidigar.com/agents/v1/tidigar_link.py (Python 3.8 or later) build a link from a plan: the roadmap as JSON with real dates and names, described by https://tidigar.com/agents/schema/plan-v1.json. They validate it with Tidigar's own rules, print the link, a summary with real dates and the fragment length, or an error that names the broken rule and the record, such as activities[2] "Build". --read <link> prints a link's roadmap as a plan to change and build again. They run locally and send nothing anywhere. As a module, tidigar-link.mjs exports createLink(plan), readLink(link) and embedCode(link, title).

Instructions for AI agents, with these builders and a worked example, are at tidigar.com/llms.txt.