View this page as Markdown

observation_fact

Declares a human-readable label for an address without scheduling a READ.

Example

Local

SELECT observation_fact(
  '0x2000000000000000000000000000000000000002'::ADDRESS,
  'writer'::VARCHAR
) IS NOT NULL AS declared;
-- => [{"declared":"true"}]

API reference

Exact signatures with descriptions, requirements, inputs, returns, and examples.

observation_fact(ADDRESS, VARCHAR) #

Declares a human-readable label for an address without scheduling a READ.

Inputs

Name Type Use
address ADDRESS

Address associated with the label in stored execution evidence.

 required positional
label VARCHAR

Text containing 1-256 valid UTF-8 bytes and no NUL byte; validated by this constructor.

 required positional

Returns

Name Type
observation OBSERVATION

Address-label OBSERVATION. Returns an address fact. If an observation list declares the same address repeatedly, the last declaration is effective and earlier declarations remain stored as ineffective.

Guidance

No state read

Address facts do not count as expanded observation points and do not execute EVM code.

Category and tags

Category
Simulation
Tag
Simulate