chemistry

Compute a formula's exact (monoisotopic) mass and ion m/z

Computes the mass-spectrometry masses for a molecular formula, fully locally (no upstream call): average mass, neutral monoisotopic mass, nominal (integer) mass, and — for a charged species — the ion mass and m/z. Specify a named adduct ([M+H]+, [M+Na]+, [M-H]-, ...) or a bare charge (mutually exclusive — the adduct defines the charge; passing both returns an invalid-input result); both apply the electron-mass correction. Unlike /chemistry/formula/weight (average molar mass), this is the exact mass for MS work. Unparseable formula, unknown element, or unknown adduct -> confidence 0.0. Charges 1 cost_unit.

post/v1/chemistry/exact-mass

Request

  • Base URL: https://api.snipget.ai (the document declares no server; this is the origin it was published from)
  • URL: https://api.snipget.ai/v1/chemistry/exact-mass
  • Auth: none declared

Query parameters

include_receiptboolean

Set true to attach an execution receipt at meta.receipt — caller-verifiable sha256 hashes over the RFC 8785 (JCS) canonicalization of this call's as-received JSON body and its result (free, like include_trace). Reproduce with any JCS library: input_hash = sha256(jcs({"tool": <request path>, "args": <your body minus include_trace/include_receipt>})); result_hash = sha256(jcs(result)). For deterministic tools, same input on the same build reproduces result_hash.

Headers

authorizationstring nullable
X-API-Keystring nullable

Request body

formulastring required

The molecular formula (e.g. 'C6H12O6', 'Ca(OH)2').

chargeinteger

Bare ionic charge (e.g. 1 for the EI molecular ion [M]+). Mutually exclusive with adduct — a nonzero charge alongside an adduct is rejected as ambiguous. Default 0 (neutral).

adductstring nullable

Named LC-MS adduct: [M+H]+, [M+Na]+, [M+K]+, [M+NH4]+, [M-H]-, [M+Cl]-, [M+2H]2+, [M-2H]2-. Determines charge + mass shift; m/z is reported. Default null (neutral).

precisioninteger

Decimal places for the reported masses. Default 6 (clamped 0-10).

include_traceboolean

Response

Successful Response

statusstring
confidencenumber required

Changes

No recorded changes to this operation across all 1 revision of this API.