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valem
Valem - Deterministic reactive state models. Create your own calculators/forms with AI
Tools
27
GitHub stars
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Installs / wk
—
Licence
Apache-2.0
Transport
streamable-http
Last checked
26h ago
Tools & capabilities
27 toolsRead from the running server on 26h ago.
create_model
spec*
Create a new model from a declarative ModelSpec. The spec carries the JSON schema plus derivations (computed fields), constraints (invariants), and optional effects. Returns the cr… Create a new model from a declarative ModelSpec. The spec carries the JSON schema plus derivations (computed fields), constraints (invariants), and optional effects. Returns the created id. Fails (isError) on an invalid spec. If the requested id is already taken, a numeric postfix (-2, -3, …) is appended so the create still succeeds — always read the returned id, it may differ from the one you sent. When paired with a browser (remote_with_browser mode), ALWAYS include a viewDefinition in the spec so the model is immediately visible/usable in the sandbox — do not omit it and wait to be asked for one afterward. See the valem://guide/view-system resource for the component catalog.
delete_model
can modify data
id*
Remove a model from the registry. Fails (isError) if the model does not exist. Remove a model from the registry. Fails (isError) if the model does not exist.
download_blob
read-only
blobId*modelId
Fetch a blob's bytes by id, base64-encoded in the result. Pass 'modelId' to fetch a blob referenced by a specific model (access-scoped); omit it for a direct store fetch. Large blo… Fetch a blob's bytes by id, base64-encoded in the result. Pass 'modelId' to fetch a blob referenced by a specific model (access-scoped); omit it for a direct store fetch. Large blobs may exceed the result-size limit — this channel suits small binaries only.
dry_run
read-only
spec*mutations
Compile a candidate ModelSpec in an ISOLATED throwaway runtime, apply optional sample mutations, and return the resulting merged state (base + derived) — WITHOUT registering it in… Compile a candidate ModelSpec in an ISOLATED throwaway runtime, apply optional sample mutations, and return the resulting merged state (base + derived) — WITHOUT registering it in the live registry. Use this to preview the full reactive cascade of a draft spec.
eval_expression
read-only
expr*inputlibraryconstants
Evaluate a single JSONata expression against a sample input document and return the computed value, or the exact compile/eval error. Write the expr exactly as in a derivation/const… Evaluate a single JSONata expression against a sample input document and return the computed value, or the exact compile/eval error. Write the expr exactly as in a derivation/constraint 'expr': bare dot-paths, no leading $ (e.g. "loan.amount * loan.annualRate / 1200"). Use this to verify an expression before putting it in a spec — it uses the same compiler the runtime validates against. If the expression calls a library function, pass the model's library definition as 'library' — without it every $myFn(...) call fails as undefined.
evolve_spec
can modify data
id*evolution*
Apply an incremental SpecEvolution diff to a model, preserving live state. Returns the new version. Fails (isError) if the evolved spec is invalid, if expectedVersion no longer mat… Apply an incremental SpecEvolution diff to a model, preserving live state. Returns the new version. Fails (isError) if the evolved spec is invalid, if expectedVersion no longer matches, or if a schema change would strand existing state. Prefer targeted diffs (upsertSchemaNodes/upsertSchemaDefs, upsertComponents, upsertConstants) over resending a whole section (newSchema/newViewDefinition/newConstants).
explain
read-only
id*path*limit
Explain why a field is what it is: returns the recent derivation/constraint trace records for a path from the in-memory ring buffer (inputs, expression, result). For a constraint u… Explain why a field is what it is: returns the recent derivation/constraint trace records for a path from the in-memory ring buffer (inputs, expression, result). For a constraint use the synthetic path "$constraint:<id>". Trace records can be bulky — pass 'limit' to return only the most recent N.
get_audit
read-only
id*tofromlimitpathPrefix
Query a model's durable, append-only audit trail (newest-first): one record per committed reactive cycle (mutations, derivedUpdated, traces, flaggedConstraints, dispatchedEffects,… Query a model's durable, append-only audit trail (newest-first): one record per committed reactive cycle (mutations, derivedUpdated, traces, flaggedConstraints, dispatchedEffects, source, sequence). This is the queryable superset of get_history/explain — it survives the in-memory ring buffer rolling over. Filter with an optional 'pathPrefix' (canonical address), an ISO-8601 'from'/'to' window, and 'limit'. (Embedded mode keeps this in memory for the session; remote/paired mode reads the server's durable store.)
get_domain_guidance
read-only
topics*
Get vetted instructions for the hard modelling shapes this domain involves (progressive tax/fee charges, per-period schedules, classification, date math, group-by, …). Read the mod… Get vetted instructions for the hard modelling shapes this domain involves (progressive tax/fee charges, per-period schedules, classification, date math, group-by, …). Read the model description in ANY language, pick the matching topic ids, and call this BEFORE authoring the spec — then follow what it returns. Available topics: - amortization_schedule — A computed array / per-period schedule: an amortization table, time series, or per-period breakdown (one row per period). - group_by — Group-by / aggregation over an array: subtotals, counts, sums per category. - date_math — Date arithmetic: days/months/years between dates, elapsed duration, age from a birth date. - classification — Deriving a label / tier / band / risk level / status from data via thresholds. - currency_conversion — Currency / FX conversion of an amount by an exchange rate. - status_field — A status / state field with flags or labels derived from the current status. - rank_percentile — Rank / percentile / leaderboard / quartile over an array of values. - regulated_charge — An official published charge whose rates are set by an authority: a tax, duty, levy, tariff, fee, toll, excise, or customs charge. - percentage — Percentages / ratios: percent-of, markup, discount, tax-inclusive vs exclusive, share-as-percent. - unit_conversion — Unit conversion / dimensional consistency: cm-m, kg-lb, C-F, miles-km — one canonical unit per quantity. - compound_growth — Compound growth / interest: future value, compound interest, exponential growth (the ** operator). - weighted_average — Weighted sum / weighted average / score over an array of values and weights. - eligibility — A boolean eligibility / qualification verdict derived from several criteria (and/or of conditions). - proration — Prorating / allocating an amount across a count or period (per-unit share, partial-period). - editable_items — A user-edited list of items the user adds, edits and removes: line items, debts, expenses, passengers, participants — each with its own fields.
get_effective_schema
read-only
id*path*
Get the effective JSON Schema for a field: the static schema overlaid with LIVE meta-derived constraints (current min/max/required/…). Check this BEFORE writing a value to learn wh… Get the effective JSON Schema for a field: the static schema overlaid with LIVE meta-derived constraints (current min/max/required/…). Check this BEFORE writing a value to learn what the reactive pipeline will accept, instead of discovering an invalid mutation only by trying it and getting a schema-violation error.
get_field
read-only
id*path*
Get the value of a single field by its JSON Path address (e.g. "$.order.total"). Evaluates a LAZY derivation on demand. Get the value of a single field by its JSON Path address (e.g. "$.order.total"). Evaluates a LAZY derivation on demand.
get_history
read-only
id*
List the ISO-8601 timestamps of a model's committed mutations (most recent 100). List the ISO-8601 timestamps of a model's committed mutations (most recent 100).
get_library
read-only
id*
List the JSONata functions and values a model's library exports — what an expression in this model may call, with signature, arity and originating layer. Call it before writing an… List the JSONata functions and values a model's library exports — what an expression in this model may call, with signature, arity and originating layer. Call it before writing an expression so you reuse the model's existing vocabulary instead of re-deriving it. Returns null when the model declares no library.
get_model_info
read-only
id*
Get summary info for a model: id, version, and derivation/meta/constraint/effect counts. Get summary info for a model: id, version, and derivation/meta/constraint/effect counts.
get_spec
read-only
id*
Get the full stored ModelSpec JSON for a model. Get the full stored ModelSpec JSON for a model.
get_state
read-only
atid*depthpaths
Get a model's merged state (base fields plus all computed derived fields). On a large model this is the biggest context cost — narrow it: pass 'paths' to project only specific subt… Get a model's merged state (base fields plus all computed derived fields). On a large model this is the biggest context cost — narrow it: pass 'paths' to project only specific subtrees (canonical addresses, each spliced back into a pruned document at its address), and/or 'depth' to cap nesting (deeper containers collapse to a '<object: N fields>' / '<array: N items>' marker). Pass an optional ISO-8601 'at' timestamp for a point-in-time read from mutation history.
get_view
read-only
id*viewId
Evaluate a model's embedded view definition against current state and return the resolved component tree. Pass an optional 'viewId' for a named view; omit for the default view. Evaluate a model's embedded view definition against current state and return the resolved component tree. Pass an optional 'viewId' for a named view; omit for the default view.
list_models
read-only
List the ids of all currently registered Valem models (alphabetical). List the ids of all currently registered Valem models (alphabetical).
mutate
id*mutations*includeTraces
Apply field mutations to a model and run the reactive pipeline (derivations recompute, constraints enforce, effects dispatch). 'mutations' is a flat map keyed by canonical JSON Pat… Apply field mutations to a model and run the reactive pipeline (derivations recompute, constraints enforce, effects dispatch). 'mutations' is a flat map keyed by canonical JSON Path address, e.g. {"$.order.qty": 3}. A ROLLBACK constraint violation returns isError with the structured list of violated constraints. Returns the actionable summary (derivedUpdated / flaggedConstraints / dispatchedEffects); pass includeTraces:true for the full derivation/constraint trace (the same payload 'explain' serves — omit it and call explain only when a value looks wrong).
pair_browser
Pair this MCP session with a browser tab on the hosted Valem sandbox so both drive the same live model session. Mints a pairing on first call (or resumes an existing not-yet-approv… Pair this MCP session with a browser tab on the hosted Valem sandbox so both drive the same live model session. Mints a pairing on first call (or resumes an existing not-yet-approved one) and waits up to a minute for the developer to approve it. Returns {status:"paired"|"already_paired", namespaceId} once done, or {status:"pending", verificationUri, verificationUriComplete, userCode, expiresInSec} if the developer hasn't approved yet — show them verificationUriComplete when present (it already carries the confirmation code, so they only click Approve) and mention that the code on that screen should read userCode; fall back to verificationUri, which requires them to TYPE userCode. Then call this tool again (it resumes the SAME pairing, it does not mint a new one). Every other model tool (create_model, mutate, evolve_spec, get_state, explain, ...) fails with a clear error until pairing succeeds.
patch_model
id*patch*includeTraces
Apply an RFC 6902 JSON Patch document to a model and run the reactive pipeline. Unlike 'mutate' (a flat address→value map), a patch expresses array insert/remove/move and test/copy… Apply an RFC 6902 JSON Patch document to a model and run the reactive pipeline. Unlike 'mutate' (a flat address→value map), a patch expresses array insert/remove/move and test/copy ops, e.g. [{"op":"add","path":"/order/items/-","value":{...}}, {"op":"remove","path":"/order/items/0"}]. 'path' fields use RFC 6901 JSON Pointer (slash-separated, '-' for array append), NOT the $.-rooted address form. Same result shape and ROLLBACK/schema error handling as 'mutate'.
restore
can modify data
id*snapshot*
Restore a model's state from a snapshot previously returned by 'snapshot' (pass it back verbatim as 'snapshot'). Overwrites the model's current base state. The snapshot must be for… Restore a model's state from a snapshot previously returned by 'snapshot' (pass it back verbatim as 'snapshot'). Overwrites the model's current base state. The snapshot must be for the same model.
snapshot
read-only
id*
Capture an immutable point-in-time snapshot of a model's state (base document + derived/meta caches). A natural safety step before a risky evolve_spec: keep the returned snapshot a… Capture an immutable point-in-time snapshot of a model's state (base document + derived/meta caches). A natural safety step before a risky evolve_spec: keep the returned snapshot and, if the change goes wrong, hand it back to 'restore' to roll the state back.
test_spec
read-only
spec*tests
Run a spec's embedded test cases (or ad-hoc given->expect cases) through the real reactive pipeline in a throwaway runtime, returning pass/fail plus per-field failures (path, expec… Run a spec's embedded test cases (or ad-hoc given->expect cases) through the real reactive pipeline in a throwaway runtime, returning pass/fail plus per-field failures (path, expected, actual). Use this to certify domain behavior before create_model / promotion.
upload_blob
data*mediaType
Store binary content (base64-encoded in 'data') in the content-addressed blob store and get back a BlobRef {$blobId, $mediaType, $bytes} to embed in a model's binary field. Storage… Store binary content (base64-encoded in 'data') in the content-addressed blob store and get back a BlobRef {$blobId, $mediaType, $bytes} to embed in a model's binary field. Storage is content-addressed (SHA-256), so uploading identical bytes returns the same $blobId.
validate_spec
read-only
spec*
Validate a ModelSpec WITHOUT creating it: returns a 'valid' flag plus structured findings (errors + warnings, each with a location and message). Use this to iterate on a draft — fi… Validate a ModelSpec WITHOUT creating it: returns a 'valid' flag plus structured findings (errors + warnings, each with a location and message). Use this to iterate on a draft — fix the reported errors, re-validate — before committing with create_model.
verify_audit
read-only
id*