diff --git a/changelog.md b/changelog.md
index 42d0d59c5..7bab579d6 100644
--- a/changelog.md
+++ b/changelog.md
@@ -2,6 +2,11 @@
 
 ## Unreleased
 <!-- Add all new changes here. They will be moved under a version at release -->
+* `NEW` Add devsper language support for `.devsper` workflow and tool files: type library (`meta/3rd/devsper/`) with full `---@class` annotations for the `devsper` global, `WorkflowBuilder`, and all spec types — enabling autocomplete and hover docs in any editor using this LSP
+* `NEW` Add `devsper-schema` diagnostic: warns on missing required fields (`prompt` in `wf.task`, `source` in `wf.plugin`, `description`/`run` in `devsper.tool`), unknown `builtin:` plugin names, and missing spec arguments
+* `NEW` Add `devsper-depends` diagnostic: cross-references `depends_on` task IDs against declared tasks in the same file; `"*"` wildcard always valid
+* `NEW` Add `devsper-model` diagnostic: hints on unrecognized literal model strings; skips variables and known provider prefixes (`claude-*`, `gpt-*`, `gemini-*`, `llama*`, etc.)
+* `NEW` Add VS Code extension scaffold (`tools/vscode/`) with `.devsper` file association, TextMate grammar inheriting Lua base, and five snippets (`workflow`, `task`, `plugin`, `input`, `tool`)
 
 ## 3.18.2
 * `CHG` `duplicate-set-field` diagnostic now supports linked suppression: when any occurrence of a duplicate field is suppressed with `---@diagnostic disable` or `---@diagnostic disable-next-line`, all warnings for that field name will be suppressed
diff --git a/meta/3rd/devsper/.luarc.json b/meta/3rd/devsper/.luarc.json
new file mode 100644
index 000000000..d35dcda47
--- /dev/null
+++ b/meta/3rd/devsper/.luarc.json
@@ -0,0 +1,14 @@
+{
+  "$schema": "https://raw.githubusercontent.com/sumneko/vscode-lua/master/setting/schema.json",
+  "runtime": {
+    "version": "Lua 5.4",
+    "extension": { ".devsper": "lua" }
+  },
+  "workspace": {
+    "library": ["${3rd}/devsper/library"],
+    "checkThirdParty": false
+  },
+  "diagnostics": {
+    "globals": ["devsper"]
+  }
+}
diff --git a/meta/3rd/devsper/library/devsper.lua b/meta/3rd/devsper/library/devsper.lua
new file mode 100644
index 000000000..f09fc2b10
--- /dev/null
+++ b/meta/3rd/devsper/library/devsper.lua
@@ -0,0 +1,122 @@
+---@meta devsper
+
+--- Result returned by devsper.exec().
+---@class devsper.ExecResult
+---@field code    integer  Exit code of the process.
+---@field stdout  string   Standard output captured from the process.
+---@field stderr  string   Standard error captured from the process.
+
+--- HTTP response returned by devsper.http methods.
+---@class devsper.HttpResponse
+---@field status  integer               HTTP status code (e.g. 200, 404).
+---@field body    string                Response body as a string.
+---@field headers table<string,string>  Response headers keyed by header name.
+
+---@class devsper.HttpLib
+---Fetch a URL and return the response.
+---@field get  fun(url: string, opts?: { headers?: table<string,string>, timeout?: integer }): devsper.HttpResponse
+---Perform an HTTP POST request.
+---@field post fun(url: string, body: string|table, opts?: { headers?: table<string,string>, timeout?: integer }): devsper.HttpResponse
+
+--- Context object passed to tool run functions.
+---@class devsper.ToolCtx
+---@field workflow_id string  ID of the parent workflow.
+---@field run_id      string  ID of the current run.
+local ToolCtx = {}
+
+--- Emit a structured log message from within a tool.
+---@param level "debug"|"info"|"warn"|"error"  Log level.
+---@param msg   string  Log message text.
+function ToolCtx:log(level, msg) end
+
+--- Parameter specification for a tool parameter.
+---@class devsper.ParamSpec
+---@field type     "string"|"number"|"boolean"|"object"  JSON-schema-style type.
+---@field required boolean?                              Whether the parameter is required. Defaults to false.
+---@field default  any?                                  Default value when the parameter is omitted.
+
+--- Configuration for the evolutionary/speculative execution engine.
+---@class devsper.EvolutionConfig
+---@field allow_mutations boolean?  Allow the swarm to mutate task prompts at runtime. Defaults to false.
+---@field max_depth       integer?  Maximum recursion/mutation depth. Defaults to 3.
+---@field speculative     boolean?  Enable speculative (parallel branch) execution. Defaults to false.
+
+--- Top-level configuration passed to devsper.workflow().
+---@class devsper.WorkflowConfig
+---@field name      string                                    Human-readable workflow name (required).
+---@field model     string?                                   Default LLM model ID for tasks in this workflow.
+---@field workers   integer?                                  Number of parallel worker goroutines/processes.
+---@field bus       "memory"|"redis"|"kafka"?                 Message bus backend. Defaults to "memory".
+---@field evolution devsper.EvolutionConfig?                  Optional evolutionary execution configuration.
+
+--- Specification for a single workflow task.
+---@class devsper.TaskSpec
+---@field prompt     string    Prompt sent to the LLM for this task (required).
+---@field model      string?   Override the workflow-level model for this task.
+---@field can_mutate boolean?  Allow this task's prompt to be mutated by the evolution engine.
+---@field depends_on? (string|"*")[]  Task IDs that must complete first. Use "*" to depend on all other tasks.
+
+--- Specification for a workflow plugin.
+---@class devsper.PluginSpec
+---@field source string  Path or import specifier for the plugin module (required).
+
+--- Specification for a workflow input parameter.
+---@class devsper.InputSpec
+---@field type     "string"|"number"|"boolean"|"object"?  Type of the input value.
+---@field required boolean?                               Whether this input must be supplied at run time.
+---@field default  any?                                   Default value used when the input is not supplied.
+
+--- Specification passed to devsper.tool().
+---@class devsper.ToolSpec
+---@field description string                                     Human-readable description of the tool (required).
+---@field params      table<string, devsper.ParamSpec>?          Map of parameter name to its spec.
+---@field run         fun(ctx: devsper.ToolCtx, args: table): any, string?  Tool implementation (required). Returns a result and an optional error string.
+
+--- Fluent builder returned by devsper.workflow().
+---@class devsper.WorkflowBuilder
+local WorkflowBuilder = {}
+
+--- Register a task in the workflow.
+---@param id   string            Unique task identifier within the workflow.
+---@param spec devsper.TaskSpec  Task configuration.
+---@return devsper.WorkflowBuilder  Returns the builder for chaining.
+function WorkflowBuilder:task(id, spec) end
+
+--- Register a plugin in the workflow.
+---@param name string              Plugin name used to reference it within tasks.
+---@param spec devsper.PluginSpec  Plugin configuration.
+---@return devsper.WorkflowBuilder  Returns the builder for chaining.
+function WorkflowBuilder:plugin(name, spec) end
+
+--- Declare an input parameter for the workflow.
+---@param name string             Input parameter name.
+---@param spec devsper.InputSpec  Input specification.
+---@return devsper.WorkflowBuilder  Returns the builder for chaining.
+function WorkflowBuilder:input(name, spec) end
+
+--- The devsper global injected into every .devsper file.
+---@class devsper
+---@field http devsper.HttpLib  HTTP client for use inside tools or workflows.
+devsper = {}
+
+--- Define and register a workflow. Returns a builder for adding tasks, plugins, and inputs.
+---@param config devsper.WorkflowConfig  Top-level workflow configuration.
+---@return devsper.WorkflowBuilder
+function devsper.workflow(config) end
+
+--- Define and register a tool that the swarm can invoke.
+---@param name string           Unique tool name.
+---@param spec devsper.ToolSpec Tool specification including description, params, and run function.
+---@return nil
+function devsper.tool(name, spec) end
+
+--- Execute a subprocess and return its result.
+---@param cmd  string    Executable to run.
+---@param args string[]? Arguments to pass to the executable.
+---@return devsper.ExecResult
+function devsper.exec(cmd, args) end
+
+--- Emit a structured log message at the workflow/global level.
+---@param level "debug"|"info"|"warn"|"error"  Log level.
+---@param msg   string  Log message text.
+function devsper.log(level, msg) end
diff --git a/script/core/diagnostics/devsper-depends.lua b/script/core/diagnostics/devsper-depends.lua
new file mode 100644
index 000000000..c603775a3
--- /dev/null
+++ b/script/core/diagnostics/devsper-depends.lua
@@ -0,0 +1,92 @@
+local files = require 'files'
+local guide = require 'parser.guide'
+local await = require 'await'
+
+-- Returns the value node of a named field in a table AST node, or nil.
+local function tableGet(tblNode, key)
+    if not tblNode or tblNode.type ~= 'table' then return nil end
+    for i = 1, #tblNode do
+        local child = tblNode[i]
+        if child and child.type == 'tablefield' and child.field and child.field[1] == key then
+            return child.value
+        end
+    end
+    return nil
+end
+
+-- Returns true if `node` is a getfield call like `<receiverName>.methodName(...)`
+local function isLocalMethod(source, receiverName, methodName)
+    if not source or source.type ~= 'call' then return false end
+    local callee = source.node
+    if not callee or callee.type ~= 'getfield' then return false end
+    if not callee.field or callee.field[1] ~= methodName then return false end
+    local receiver = callee.node
+    if not receiver or receiver.type ~= 'getlocal' then return false end
+    return receiver[1] == receiverName
+end
+
+return function (uri, callback)
+    -- Only run on .devsper files
+    if not uri:match('%.devsper$') then return end
+
+    local state = files.getState(uri)
+    if not state then return end
+
+    -- Pass 1: collect all declared task IDs from wf.task(id, spec) calls
+    local declaredIds = {}
+
+    guide.eachSourceType(state.ast, 'call', function (source)
+        await.delay()
+        if not isLocalMethod(source, 'wf', 'task') then return end
+        local args = source.args
+        if not args then return end
+        local idNode = args[1]
+        if not idNode or idNode.type ~= 'string' then return end
+        local id = idNode[1]
+        if id then
+            declaredIds[id] = { start = idNode.start, finish = idNode.finish }
+        end
+    end)
+
+    -- Build sorted ID list once for error messages
+    local sortedIds = {}
+    for k in pairs(declaredIds) do
+        sortedIds[#sortedIds + 1] = k
+    end
+    table.sort(sortedIds)
+    local declaredIdsStr = table.concat(sortedIds, ', ')
+
+    -- Pass 2: check depends_on entries in each wf.task spec
+    guide.eachSourceType(state.ast, 'call', function (source)
+        await.delay()
+        if not isLocalMethod(source, 'wf', 'task') then return end
+        local args = source.args
+        if not args then return end
+        local spec = args[2]
+        if not spec or spec.type ~= 'table' then return end
+
+        local dependsOn = tableGet(spec, 'depends_on')
+        if not dependsOn or dependsOn.type ~= 'table' then return end
+
+        -- Array table elements are wrapped in tableexp nodes in the luals AST
+        for i = 1, #dependsOn do
+            local exp = dependsOn[i]
+            if exp and exp.type == 'tableexp' then
+                local child = exp.value
+                if child and child.type == 'string' then
+                    local val = child[1]
+                    if val and val ~= '*' and not declaredIds[val] then
+                        callback {
+                            start   = child.start,
+                            finish  = child.finish,
+                            message = ("devsper: unknown task id '%s' in depends_on — declared ids: %s"):format(
+                                val, declaredIdsStr
+                            ),
+                        }
+                    end
+                end
+            end
+            -- Non-string/non-literal children silently skipped
+        end
+    end)
+end
diff --git a/script/core/diagnostics/devsper-model.lua b/script/core/diagnostics/devsper-model.lua
new file mode 100644
index 000000000..ef1b0c3bd
--- /dev/null
+++ b/script/core/diagnostics/devsper-model.lua
@@ -0,0 +1,104 @@
+local files = require 'files'
+local guide = require 'parser.guide'
+local await = require 'await'
+
+-- Returns the value node of a named field in a table AST node, or nil.
+local function tableGet(tblNode, key)
+    if not tblNode or tblNode.type ~= 'table' then return nil end
+    for i = 1, #tblNode do
+        local child = tblNode[i]
+        if child and child.type == 'tablefield' and child.field and child.field[1] == key then
+            return child.value
+        end
+    end
+    return nil
+end
+
+-- Returns true if `node` is a getfield call like `<receiverName>.methodName(...)`
+local function isLocalMethod(source, receiverName, methodName)
+    if not source or source.type ~= 'call' then return false end
+    local callee = source.node
+    if not callee or callee.type ~= 'getfield' then return false end
+    if not callee.field or callee.field[1] ~= methodName then return false end
+    local receiver = callee.node
+    if not receiver or receiver.type ~= 'getlocal' then return false end
+    return receiver[1] == receiverName
+end
+
+-- Returns true if `callNode` is `devsper.<methodName>(...)`
+local function isDevsperGlobalMethod(callNode, methodName)
+    local callee = callNode.node
+    if not callee then return false end
+    if callee.type ~= 'getfield' then return false end
+    if not callee.field then return false end
+    if callee.field[1] ~= methodName then return false end
+    local receiver = callee.node
+    if not receiver then return false end
+    if receiver.type ~= 'getglobal' then return false end
+    return receiver[1] == 'devsper'
+end
+
+local KNOWN_PREFIXES = {
+    '^claude%-',
+    '^gpt%-',
+    '^o%d',       -- o1, o3, etc.
+    '^gemini%-',
+    '^llama',
+    '^mistral',
+    '^phi',
+    '^qwen',
+    '^deepseek',
+    '^gemma',
+    '^falcon',
+}
+
+local KNOWN_EXACT = { auto = true }
+
+local function isKnownModel(modelStr)
+    if KNOWN_EXACT[modelStr] then return true end
+    for _, pattern in ipairs(KNOWN_PREFIXES) do
+        if modelStr:match(pattern) then return true end
+    end
+    return false
+end
+
+local function checkModelValue(modelNode, callback)
+    if not modelNode then return end
+    if modelNode.type ~= 'string' then return end  -- skip non-literal values
+    local modelStr = modelNode[1]
+    if not modelStr then return end
+    if not isKnownModel(modelStr) then
+        callback {
+            start   = modelNode.start,
+            finish  = modelNode.finish,
+            message = ("devsper: unrecognized model '%s' — verify this provider is configured"):format(modelStr),
+        }
+    end
+end
+
+return function (uri, callback)
+    -- Only run on .devsper files
+    if not uri:match('%.devsper$') then return end
+
+    local state = files.getState(uri)
+    if not state then return end
+
+    guide.eachSourceType(state.ast, 'call', function (source)
+        await.delay()
+
+        -- devsper.workflow(config) — check config.model
+        if isDevsperGlobalMethod(source, 'workflow') then
+            local config = source.args and source.args[1]
+            if config and config.type == 'table' then
+                checkModelValue(tableGet(config, 'model'), callback)
+            end
+
+        -- wf.task(id, spec) — check spec.model
+        elseif isLocalMethod(source, 'wf', 'task') then
+            local spec = source.args and source.args[2]
+            if spec and spec.type == 'table' then
+                checkModelValue(tableGet(spec, 'model'), callback)
+            end
+        end
+    end)
+end
diff --git a/script/core/diagnostics/devsper-schema.lua b/script/core/diagnostics/devsper-schema.lua
new file mode 100644
index 000000000..950feff5e
--- /dev/null
+++ b/script/core/diagnostics/devsper-schema.lua
@@ -0,0 +1,142 @@
+local files = require 'files'
+local guide = require 'parser.guide'
+local await = require 'await'
+
+-- Returns the value node of a named field in a table AST node, or nil.
+local function tableGet(tblNode, key)
+    if not tblNode or tblNode.type ~= 'table' then return nil end
+    for i = 1, #tblNode do
+        local child = tblNode[i]
+        if child and child.type == 'tablefield' and child.field and child.field[1] == key then
+            return child.value
+        end
+    end
+    return nil
+end
+
+-- Returns true if `node` is a getfield call like `<receiverName>.methodName(...)`
+local function isLocalMethod(source, receiverName, methodName)
+    if not source or source.type ~= 'call' then return false end
+    local callee = source.node
+    if not callee or callee.type ~= 'getfield' then return false end
+    if not callee.field or callee.field[1] ~= methodName then return false end
+    local receiver = callee.node
+    if not receiver or receiver.type ~= 'getlocal' then return false end
+    return receiver[1] == receiverName
+end
+
+-- Returns true if `callNode` is `devsper.<methodName>(...)`
+local function isDevsperGlobalMethod(callNode, methodName)
+    local callee = callNode.node
+    if not callee then return false end
+    if callee.type ~= 'getfield' then return false end
+    if not callee.field then return false end
+    if callee.field[1] ~= methodName then return false end
+    local receiver = callee.node
+    if not receiver then return false end
+    if receiver.type ~= 'getglobal' then return false end
+    return receiver[1] == 'devsper'
+end
+
+local validBuiltins = {
+    git        = true,
+    search     = true,
+    http       = true,
+    code       = true,
+    filesystem = true,
+}
+
+return function (uri, callback)
+    -- Only run on .devsper files
+    if not uri:match('%.devsper$') then return end
+
+    local state = files.getState(uri)
+    if not state then return end
+
+    guide.eachSourceType(state.ast, 'call', function (source)
+        await.delay()
+        local args = source.args
+        if not args then return end
+
+        -- wf.task(id, spec) — spec must have a `prompt` key
+        if isLocalMethod(source, 'wf', 'task') then
+            local spec = source.args and source.args[2]
+            if not spec or spec.type == 'nil' then
+                callback {
+                    start   = source.start,
+                    finish  = source.finish,
+                    message = "devsper: wf.task() requires a spec table as second argument",
+                }
+                return  -- no further checks possible
+            end
+            if spec.type ~= 'table' then return end  -- non-literal, skip
+            if not tableGet(spec, 'prompt') then
+                callback {
+                    start   = spec.start,
+                    finish  = spec.finish,
+                    message = 'devsper: wf.task() spec is missing required field "prompt"',
+                }
+            end
+
+        -- wf.plugin(name, spec) — spec must have a `source` key; builtin: prefix validated
+        elseif isLocalMethod(source, 'wf', 'plugin') then
+            local spec = source.args and source.args[2]
+            if not spec or spec.type == 'nil' then
+                callback {
+                    start   = source.start,
+                    finish  = source.finish,
+                    message = "devsper: wf.plugin() requires a spec table as second argument",
+                }
+                return  -- no further checks possible
+            end
+            if spec.type ~= 'table' then return end  -- non-literal, skip
+            local sourceVal = tableGet(spec, 'source')
+            if not sourceVal then
+                callback {
+                    start   = spec.start,
+                    finish  = spec.finish,
+                    message = 'devsper: wf.plugin() spec is missing required field "source"',
+                }
+            elseif sourceVal.type == 'string' then
+                local strVal = sourceVal[1]
+                if strVal then
+                    local builtinName = strVal:match('^builtin:(.+)$')
+                    if builtinName and not validBuiltins[builtinName] then
+                        callback {
+                            start   = sourceVal.start,
+                            finish  = sourceVal.finish,
+                            message = ('devsper: unknown builtin plugin %q (valid: git, search, http, code, filesystem)'):format(builtinName),
+                        }
+                    end
+                end
+            end
+
+        -- devsper.tool(name, spec) — spec must have `description` and `run` keys
+        elseif isDevsperGlobalMethod(source, 'tool') then
+            local spec = source.args and source.args[2]
+            if not spec or spec.type == 'nil' then
+                callback {
+                    start   = source.start,
+                    finish  = source.finish,
+                    message = "devsper: devsper.tool() requires a spec table as second argument",
+                }
+                return  -- no further checks possible
+            end
+            if spec.type ~= 'table' then return end  -- non-literal, skip
+            if not tableGet(spec, 'description') then
+                callback {
+                    start   = spec.start,
+                    finish  = spec.finish,
+                    message = 'devsper: devsper.tool() spec is missing required field "description"',
+                }
+            end
+            if not tableGet(spec, 'run') then
+                callback {
+                    start   = spec.start,
+                    finish  = spec.finish,
+                    message = 'devsper: devsper.tool() spec is missing required field "run"',
+                }
+            end
+        end
+    end)
+end
diff --git a/script/proto/diagnostic.lua b/script/proto/diagnostic.lua
index 72761493e..b743992bb 100644
--- a/script/proto/diagnostic.lua
+++ b/script/proto/diagnostic.lua
@@ -227,6 +227,30 @@ m.register {
     status   = 'Any',
 }
 
+m.register {
+    'devsper-schema',
+} {
+    group    = 'devsper',
+    severity = 'Warning',
+    status   = 'Any',
+}
+
+m.register {
+    'devsper-depends',
+} {
+    group    = 'devsper',
+    severity = 'Warning',
+    status   = 'Any',
+}
+
+m.register {
+    'devsper-model',
+} {
+    group    = 'devsper',
+    severity = 'Hint',
+    status   = 'Any',
+}
+
 ---@return table<string, DiagnosticSeverity>
 function m.getDefaultSeverity()
     local severity = {}
diff --git a/tools/vscode/language-configuration.json b/tools/vscode/language-configuration.json
new file mode 100644
index 000000000..d720f1655
--- /dev/null
+++ b/tools/vscode/language-configuration.json
@@ -0,0 +1,26 @@
+{
+  "comments": {
+    "lineComment": "--",
+    "blockComment": ["--[[", "]]"]
+  },
+  "brackets": [
+    ["{", "}"],
+    ["[", "]"],
+    ["(", ")"]
+  ],
+  "autoClosingPairs": [
+    { "open": "{", "close": "}" },
+    { "open": "[", "close": "]" },
+    { "open": "(", "close": ")" },
+    { "open": "\"", "close": "\"" },
+    { "open": "'", "close": "'" },
+    { "open": "--[[", "close": "]]" }
+  ],
+  "surroundingPairs": [
+    ["{", "}"],
+    ["[", "]"],
+    ["(", ")"],
+    ["\"", "\""],
+    ["'", "'"]
+  ]
+}
diff --git a/tools/vscode/package.json b/tools/vscode/package.json
new file mode 100644
index 000000000..05fa77c8f
--- /dev/null
+++ b/tools/vscode/package.json
@@ -0,0 +1,32 @@
+{
+  "name": "devsper-lsp",
+  "displayName": "Devsper Language Support",
+  "description": "Autocomplete, hover docs, and diagnostics for .devsper workflow and tool files",
+  "version": "0.1.0",
+  "publisher": "devsper",
+  "engines": { "vscode": "^1.85.0" },
+  "categories": ["Programming Languages", "Snippets"],
+  "contributes": {
+    "languages": [
+      {
+        "id": "devsper",
+        "aliases": ["Devsper", "devsper"],
+        "extensions": [".devsper"],
+        "configuration": "./language-configuration.json"
+      }
+    ],
+    "grammars": [
+      {
+        "language": "devsper",
+        "scopeName": "source.devsper",
+        "path": "./syntaxes/devsper.tmLanguage.json"
+      }
+    ],
+    "snippets": [
+      {
+        "language": "devsper",
+        "path": "./snippets/devsper.json"
+      }
+    ]
+  }
+}
diff --git a/tools/vscode/snippets/devsper.json b/tools/vscode/snippets/devsper.json
new file mode 100644
index 000000000..2fbc6eb25
--- /dev/null
+++ b/tools/vscode/snippets/devsper.json
@@ -0,0 +1,61 @@
+{
+  "Workflow": {
+    "prefix": "workflow",
+    "body": [
+      "local wf = devsper.workflow({",
+      "\tname    = \"${1:my-workflow}\",",
+      "\tmodel   = \"${2:auto}\",",
+      "\tworkers = ${3:4},",
+      "})",
+      "",
+      "wf.task(\"${4:task-1}\", {",
+      "\tprompt = \"${5:Describe what this task should do.}\",",
+      "})",
+      "",
+      "return wf"
+    ],
+    "description": "New devsper workflow"
+  },
+  "Task": {
+    "prefix": "task",
+    "body": [
+      "wf.task(\"${1:task-name}\", {",
+      "\tprompt     = \"${2:Describe what this task should do.}\",",
+      "\tdepends_on = { ${3} },",
+      "})"
+    ],
+    "description": "Add a task to the workflow DAG"
+  },
+  "Plugin": {
+    "prefix": "plugin",
+    "body": [
+      "wf.plugin(\"${1:git}\", { source = \"builtin:${1:git}\" })"
+    ],
+    "description": "Load a builtin plugin (git, search, http, code, filesystem)"
+  },
+  "Input": {
+    "prefix": "input",
+    "body": [
+      "wf.input(\"${1:param_name}\", {",
+      "\ttype     = \"${2|string,number,boolean,object|}\",",
+      "\trequired = ${3|true,false|},",
+      "})"
+    ],
+    "description": "Declare a typed workflow input"
+  },
+  "Tool": {
+    "prefix": "tool",
+    "body": [
+      "devsper.tool(\"${1:tool.name}\", {",
+      "\tdescription = \"${2:What this tool does.}\",",
+      "\tparams = {",
+      "\t\t${3:param} = { type = \"${4|string,number,boolean,object|}\", required = ${5|true,false|} },",
+      "\t},",
+      "\trun = function(ctx, args)",
+      "\t\t${6:-- implementation}",
+      "\tend,",
+      "})"
+    ],
+    "description": "Register a new devsper tool"
+  }
+}
diff --git a/tools/vscode/syntaxes/devsper.tmLanguage.json b/tools/vscode/syntaxes/devsper.tmLanguage.json
new file mode 100644
index 000000000..ea95b1c1d
--- /dev/null
+++ b/tools/vscode/syntaxes/devsper.tmLanguage.json
@@ -0,0 +1,30 @@
+{
+  "$schema": "https://raw.githubusercontent.com/martinring/tmlanguage/master/tmlanguage.json",
+  "name": "Devsper",
+  "scopeName": "source.devsper",
+  "patterns": [
+    { "include": "#devsper-keywords" },
+    { "include": "source.lua" }
+  ],
+  "repository": {
+    "devsper-keywords": {
+      "patterns": [
+        {
+          "comment": "devsper global and wf builder",
+          "match": "\\b(devsper|wf)\\b(?=\\.)",
+          "name": "support.class.devsper"
+        },
+        {
+          "comment": "builtin: plugin name prefix",
+          "match": "\"builtin:[a-zA-Z0-9_-]+\"",
+          "name": "support.constant.devsper"
+        },
+        {
+          "comment": "devsper method names",
+          "match": "\\.(workflow|tool|exec|log|http|get|post|task|plugin|input)\\b",
+          "name": "support.function.devsper"
+        }
+      ]
+    }
+  }
+}