CTCL · commoninstant.org
EveMissLab · Agent time infrastructure

One shared instant, every local time.

CTCL gives heterogeneous agents, simulators and persistent AI a verified common reference instant — without sharing a clock, calendar, or epoch. Same instant, different representations.

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unix_ns…
instant_id…
source · precisionedge clock · ms
aligning with your browser clock…
What it is

A common instant I*

A verified instant many parties can point at, with source and uncertainty — not a metaphysical absolute time, a protocol-level shared reference.

Explicit transforms

Precision-preserving conversion across Unix, UTC, timezones and custom world clocks. Different clocks, explicit transforms, no hidden semantics.

Honest precision

The edge clock is millisecond-grade, so we say so. The ns fields are format-padding; precision is not accuracy.

Endpoints
GET/v1/nowverified reference instant (source, uncertainty, instant_id)
POST/v1/convertconvert across encodings / timescales / timezones (precision-preserving)
POST/v1/transformmap into a custom linear-rate world clock
POST/v1/instantsregister I*, get a shareable id (multi-agent alignment)
GET/v1/instant/{id}retrieve the exact instant another agent registered
POST/v1/systemspersist a custom world clock
GET/v1/systems/{id}/nowcurrent time in that world + world calendar
POST/v1/temporal-groups/{id}/expandproject one instant across every system in a group (flagship Web feature)
POST/v1/boundaries/inspectproactive gap／fold／pause／rate-change check, never errors
GET/i/{id}human-readable share page — anyone can align on the same instant
POST/v1/resolveambiguous input → IANA candidates + confidence, never guesses
POST/v1/planner/shared-instantconstraint-solve for the best shared instant given weighted constraints
GET/ai/ctcl.jsonagent tool declaration — read this first
MCP/mcpRemote MCP Gateway — the 10 read/compute tools above, over stateless Streamable HTTP
Calling it

An agent reads /ai/ctcl.json to discover the API, then calls the endpoints. Get a verified instant:

curl -s https://commoninstant.org/v1/now

Register a shared instant so another agent (or your next session) can align on the exact same point:

curl -s https://commoninstant.org/v1/instants -H 'content-type: application/json' -d '{"label":"handoff"}'
# -> { "id": "ctcl:instant:…" }   then any agent:
curl -s https://commoninstant.org/v1/instant/ctcl:instant:…

Convert a Unix nanosecond value into Taipei time (precision preserved):

curl -s https://commoninstant.org/v1/convert -H 'content-type: application/json' -d '{
  "input":  {"value":"1783420000.123456789","encoding":"unix_s"},
  "output": {"encoding":"rfc3339","timezone":"Asia/Taipei"}
}'

Or skip REST entirely and connect an MCP client to https://commoninstant.org/mcp (stateless Streamable HTTP) — the same 10 tools, reachable directly.

Playground

Convert a Unix-seconds value into an RFC3339 timestamp for a timezone.

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One Instant, Many Systems

CTCL's core demonstration: the same common instant, projected into several temporal systems at once — timezones, timescales, and (soon) any custom world clock you register.

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Boundary Inspector

Proactively check whether a local time is safe — DST gap (nonexistent), fold (ambiguous), or normal. Unlike /v1/convert, this never errors — it always returns a status. The default below is 2026's US Eastern spring-forward gap (02:30 doesn't exist).

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Semantic Resolution

Does "CST" mean US Central Time or China Standard Time? CTCL never silently decides for you — it returns candidates with confidence, not a guess.

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Constraint Planner

Solve for the best shared instant in the next 7 days that satisfies "Taipei work hours, avoid a maintenance window, at least an hour of lead time" — not a full meeting-scheduler, a demonstration of CTCL-native constraint solving.

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