Pick any line to see why it is the way it is: the commit, the pull request and issue it came from, and what the agent was thinking.
| Each agent has an Abilities tab: g1t's built-ins, always on within the asker's access; its computer, coming; each connected integration's actions one row each, read, import, comment or resolve, with a level for each, alone, alone when the person asked for it, ask first or never, and whose connection it runs on; and MCP servers an owner adds. Reading is alone, writing inside g1t follows today's choices, anything that leaves g1t asks first, and production deploys can't go above ask. The agents service enforces every level: ask first posts a card to allow or deny and parks a session until it's answered, a refusal names its rule in the transcript and the audit log, and a missing ability posts a request to owners. The agent abilities guide says how. | 1 | import assert from "node:assert/strict"; |
| 2 | import { test } from "node:test"; | |
| 3 | ||
| 4 | import type { AbilitySection, McpServer, User } from "@g1t/contracts"; | |
| 5 | ||
| 6 | import { resolveAbilities, withSetting } from "../../../packages/contracts/src/abilities.ts"; | |
| 7 | import { CONNECTORS } from "../../../packages/contracts/src/connectors.ts"; | |
| 8 | import { abilitiesSection, saidText } from "./abilities-prompt.ts"; | |
| 9 | import { Audience, type AudienceInfo, type AudiencePorts, type RepoRef } from "./audience.ts"; | |
| 10 | import { abilityCard, connectCard, requestCard } from "./card-views.ts"; | |
| 11 | import { DEFAULT_AUTONOMY, applyChanges } from "./definition.ts"; | |
| 12 | import { callMcpTool, listMcpTools } from "./mcp-client.ts"; | |
| 13 | import { type AbilityPorts, type ActionPorts, type ToolPorts, ToolBox } from "./tools.ts"; | |
| 14 | ||
| 15 | // ── A small world ──────────────────────────────────────────────────────── | |
| 16 | ||
| 17 | const WEB: RepoRef = { id: "rep_web", namespace: "acme", name: "web", isPrivate: true, defaultBranch: "main" }; | |
| 18 | const person = (id: string): User => ({ id, username: id, workspaces: [{ slug: "acme", role: "member" }] }) as User; | |
| 19 | ||
| 20 | function world(): AudiencePorts { | |
| 21 | const info: AudienceInfo = { kind: "dm", member_user_ids: ["asker"], member_count: 1 }; | |
| 22 | return { | |
| 23 | info: async () => info, | |
| 24 | users: async (ids) => [person("asker")].filter((u) => ids.includes(u.id)), | |
| 25 | workspaceRepos: async () => [WEB], | |
| 26 | readable: async (ids) => [WEB].filter((r) => ids.includes(r.id)), | |
| 27 | }; | |
| 28 | } | |
| 29 | ||
| 30 | const ports: ToolPorts = { | |
| 31 | readFile: async () => null, | |
| 32 | searchCode: async () => [], | |
| 33 | listIssues: async () => [], | |
| 34 | getIssue: async () => null, | |
| 35 | getPull: async () => null, | |
| 36 | recentPulls: async () => [], | |
| 37 | searchMessages: async () => [], | |
| 38 | readThread: async () => null, | |
| 39 | roster: async () => "", | |
| 40 | consult: async () => ({ ok: false, message: "no" }), | |
| 41 | }; | |
| 42 | ||
| 43 | const actions: ActionPorts = { | |
| 44 | remember: async () => ({ ok: true, message: "" }), | |
| 45 | forget: async () => ({ ok: true, message: "" }), | |
| 46 | draftIssue: async () => ({ ok: true, message: "" }), | |
| 47 | }; | |
| 48 | ||
| 49 | const ITEMS: Record<string, { provider: string; key: string; title: string; url: string; status: string | null; body: string }> = { | |
| 50 | "ENG-42": { provider: "linear", key: "ENG-42", title: "Retry flaky checks", url: "https://linear.app/acme/issue/ENG-42", status: "In Progress", body: "The queue retries." }, | |
| 51 | "TECH-7": { provider: "jira", key: "TECH-7", title: "Login timeout", url: "https://acme.atlassian.net/browse/TECH-7", status: "To Do", body: "Times out." }, | |
| 52 | }; | |
| 53 | ||
| 54 | type Posted = { kind: string; title: string }; | |
| 55 | ||
| 56 | /** Ports that record what they were asked to do. */ | |
| 57 | function fakeAbilityPorts(over: Partial<AbilityPorts> = {}): AbilityPorts & { posted: Posted[]; acted: string[]; refusals: string[] } { | |
| 58 | const posted: Posted[] = []; | |
| 59 | const acted: string[] = []; | |
| 60 | const refusals: string[] = []; | |
| 61 | return { | |
| 62 | posted, | |
| 63 | acted, | |
| 64 | refusals, | |
| 65 | lookup: async (_asker, reference) => (ITEMS[reference] ? { ok: true, value: ITEMS[reference]! } : { ok: false, code: "not_found", message: "None of the acme workspace's integrations knows that." }), | |
| 66 | import: async (_asker, repo, reference) => ({ ok: true, value: { number: 7, item: ITEMS[reference]!, created: true } }), | |
| 67 | act: async (_asker, reference, action, text) => { | |
| 68 | acted.push(`${action} ${reference}: ${text}`); | |
| 69 | return { ok: true, value: ITEMS[reference]! }; | |
| 70 | }, | |
| 71 | askerConnected: async () => false, | |
| 72 | mcp: async (server, tool, args) => { | |
| 73 | acted.push(`mcp ${server.name}.${tool.name} ${JSON.stringify(args)}`); | |
| 74 | return { ok: true, value: "sunny" }; | |
| 75 | }, | |
| 76 | askFirst: async ({ summary }) => { | |
| 77 | posted.push({ kind: "ability", title: summary }); | |
| 78 | return "abr_1"; | |
| 79 | }, | |
| 80 | connect: async (source) => { | |
| 81 | posted.push({ kind: "connect", title: source.name }); | |
| 82 | return true; | |
| 83 | }, | |
| 84 | request: async ({ connector, ability }) => { | |
| 85 | posted.push({ kind: "request", title: connector ?? ability?.id ?? "" }); | |
| 86 | return true; | |
| 87 | }, | |
| 88 | refused: ({ rule }) => { | |
| 89 | refusals.push(rule); | |
| 90 | }, | |
| 91 | ...over, | |
| 92 | }; | |
| 93 | } | |
| 94 | ||
| 95 | const SERVER: McpServer = { | |
| 96 | id: "mcp_w", | |
| 97 | name: "weather", | |
| 98 | url: "https://mcp.example.com/", | |
| 99 | tools: [ | |
| 100 | { name: "get_forecast", description: "Today's forecast", kind: "read", input_schema: { type: "object", properties: { city: { type: "string" } } } }, | |
| 101 | { name: "set_alert", description: "Set an alert", kind: "write", input_schema: { type: "object", properties: {} } }, | |
| 102 | ], | |
| 103 | added_by: "ana", | |
| 104 | added_at: "2026-10-10T00:00:00.000Z", | |
| 105 | checked_at: null, | |
| 106 | problem: null, | |
| 107 | }; | |
| 108 | ||
| 109 | async function box(input: { connected?: string[]; settings?: Record<string, { level?: "alone" | "asked" | "ask" | "never"; credentials?: "workspace" | "asker" }>; servers?: McpServer[]; said?: string; session?: boolean; ports?: Partial<AbilityPorts> }) { | |
| 110 | const audience = await Audience.build("acme", "asker", world()); | |
| 111 | const tools = new ToolBox(audience, ports, { agentId: "agt_me", notConsult: ["me"], hops: 0, maxHops: 6, session: input.session }, [], actions); | |
| 112 | let abilities = { settings: {}, mcp_servers: input.servers ?? [] }; | |
| 113 | for (const [id, setting] of Object.entries(input.settings ?? {})) abilities = withSetting(abilities, id, setting); | |
| 114 | const sections: AbilitySection[] = resolveAbilities({ connectors: CONNECTORS, abilities, autonomy: DEFAULT_AUTONOMY, connected: input.connected ?? [] }); | |
| 115 | const fake = fakeAbilityPorts(input.ports); | |
| 116 | tools.useAbilities(sections, fake, input.said ?? "", input.servers ?? []); | |
| 117 | return { tools, fake, sections }; | |
| 118 | } | |
| 119 | ||
| 120 | const names = (tools: ToolBox) => tools.definitions().map((t) => t.name); | |
| 121 | ||
| 122 | // ── Offering ───────────────────────────────────────────────────────────── | |
| 123 | ||
| 124 | test("nothing connected: no outside tools but request_ability; a connected Linear offers lookup, import and act", async () => { | |
| 125 | const none = await box({}); | |
| 126 | assert.ok(!names(none.tools).includes("lookup_outside")); | |
| 127 | assert.ok(names(none.tools).includes("request_ability"), "it can still ask for what it lacks"); | |
| 128 | const linear = await box({ connected: ["linear"] }); | |
| 129 | for (const tool of ["lookup_outside", "import_outside", "act_outside"]) assert.ok(names(linear.tools).includes(tool), tool); | |
| 130 | }); | |
| 131 | ||
| 132 | test("an ability set to Never isn't offered when it is the only one for its tool, and is refused with the rule if called anyway", async () => { | |
| 133 | const { tools, fake } = await box({ connected: ["linear"], settings: { "integration:linear:comment": { level: "never" } } }); | |
| 134 | assert.ok(!names(tools).includes("act_outside"), "Linear's only act ability is Never"); | |
| 135 | const tried = await tools.run("act_outside", { reference: "ENG-42", action: "comment", text: "hi" }); | |
| 136 | assert.equal(tried.outcome, "refused"); | |
| 137 | assert.match(tried.text, /no tool called act_outside/); | |
| 138 | assert.deepEqual(fake.acted, []); | |
| 139 | }); | |
| 140 | ||
| 141 | test("Never on one system, allowed on another: the tool is offered, and the rule is named per call, in the result and the audit log", async () => { | |
| 142 | const { tools, fake } = await box({ connected: ["linear", "jira"], settings: { "integration:linear:comment": { level: "never" }, "integration:jira:comment": { level: "alone" } } }); | |
| 143 | assert.ok(names(tools).includes("act_outside")); | |
| 144 | const linear = await tools.run("act_outside", { reference: "ENG-42", action: "comment", text: "Looks fixed." }); | |
| 145 | assert.equal(linear.outcome, "refused"); | |
| 146 | assert.match(linear.text, /Not allowed: your abilities say "Linear: Comment" is Never/); | |
| 147 | assert.deepEqual(fake.refusals, ["integration:linear:comment=never"]); | |
| 148 | assert.deepEqual(fake.acted, [], "nothing ran"); | |
| 149 | const jira = await tools.run("act_outside", { reference: "TECH-7", action: "comment", text: "On it." }); | |
| 150 | assert.equal(jira.outcome, "allowed"); | |
| 151 | assert.deepEqual(fake.acted, ["comment TECH-7: On it."]); | |
| 152 | assert.equal(tools.calls.length, 2, "both calls are in the transcript"); | |
| 153 | assert.equal(tools.calls[0]!.outcome, "refused"); | |
| 154 | }); | |
| 155 | ||
| 156 | test("reading is alone by default; an item nobody knows is not found, and a system that isn't connected is said so", async () => { | |
| 157 | const { tools } = await box({ connected: ["linear"] }); | |
| 158 | const read = await tools.run("lookup_outside", { reference: "ENG-42" }); | |
| 159 | assert.equal(read.outcome, "allowed"); | |
| 160 | assert.match(read.text, /<untrusted source="Linear ENG-42">/); | |
| 161 | assert.match(read.text, /Retry flaky checks/); | |
| 162 | const missing = await tools.run("lookup_outside", { reference: "NOPE-1" }); | |
| 163 | assert.equal(missing.outcome, "refused"); | |
| 164 | assert.match(missing.text, /No connected integration knows NOPE-1/); | |
| 165 | // Jira knows TECH-7, but Jira isn't connected to this workspace as the agent sees it. | |
| 166 | const jira = await tools.run("lookup_outside", { reference: "TECH-7" }); | |
| 167 | assert.equal(jira.outcome, "refused"); | |
| 168 | assert.match(jira.text, /Jira isn't connected to this workspace, so you can't read tickets there/); | |
| 169 | }); | |
| 170 | ||
| 171 | // ── Ask first, and alone when asked for it ─────────────────────────────── | |
| 172 | ||
| 173 | test("Ask first posts the card with the call, runs nothing, and tells the agent to wait; a session is told it pauses", async () => { | |
| 174 | const { tools, fake } = await box({ connected: ["linear"], session: true }); | |
| 175 | const tried = await tools.run("act_outside", { reference: "ENG-42", action: "comment", text: "Fixed in #412." }); | |
| 176 | assert.equal(tried.outcome, "refused"); | |
| 177 | assert.match(tried.text, /"Linear: Comment" is after asking first: a card was posted asking @asker \(or an owner\)/); | |
| 178 | assert.match(tried.text, /Your session pauses/); | |
| 179 | assert.deepEqual(fake.posted, [{ kind: "ability", title: "Comment on ENG-42 in Linear" }]); | |
| 180 | assert.deepEqual(fake.acted, []); | |
| 181 | assert.deepEqual(fake.refusals, ["integration:linear:comment=ask"]); | |
| 182 | }); | |
| 183 | ||
| 184 | test("alone when asked for it: runs when the person named the item, asks first when they didn't", async () => { | |
| 185 | const asked = await box({ connected: ["linear"], said: "Please import ENG-42 into web so we can track it here." }); | |
| 186 | const ran = await asked.tools.run("import_outside", { repo: "web", reference: "ENG-42" }); | |
| 187 | assert.equal(ran.outcome, "allowed"); | |
| 188 | assert.match(ran.text, /Opened acme\/web#7 from ENG-42/); | |
| 189 | assert.deepEqual(asked.fake.posted, []); | |
| 190 | const unasked = await box({ connected: ["linear"], said: "What's the state of the queue work?" }); | |
| 191 | const held = await unasked.tools.run("import_outside", { repo: "web", reference: "ENG-42" }); | |
| 192 | assert.equal(held.outcome, "refused"); | |
| 193 | assert.match(held.text, /^Import issues in Linear runs on its own only when asked for it, and this wasn't\. "Linear: Import issues" is only when the person asked for that: a card was posted/); | |
| 194 | assert.deepEqual(unasked.fake.posted, [{ kind: "ability", title: "Import ENG-42 from Linear into acme/web" }]); | |
| 195 | }); | |
| 196 | ||
| 197 | test("when the card can't be posted, the agent is told to ask in words", async () => { | |
| 198 | const { tools } = await box({ connected: ["linear"], ports: { askFirst: async () => null } }); | |
| 199 | const tried = await tools.run("act_outside", { reference: "ENG-42", action: "comment", text: "x" }); | |
| 200 | assert.match(tried.text, /couldn't be posted just now/); | |
| 201 | }); | |
| 202 | ||
| 203 | // ── Whose connection ───────────────────────────────────────────────────── | |
| 204 | ||
| 205 | test("the asker's own connection, missing: a Connect card, nothing runs, and the audit log says why", async () => { | |
| 206 | const { tools, fake } = await box({ connected: ["linear"], settings: { "integration:linear:read": { credentials: "asker" } } }); | |
| 207 | const tried = await tools.run("lookup_outside", { reference: "ENG-42" }); | |
| 208 | assert.equal(tried.outcome, "refused"); | |
| 209 | assert.match(tried.text, /runs on @asker's own Linear connection, and they haven't connected one. A Connect card was posted/); | |
| 210 | assert.deepEqual(fake.posted, [{ kind: "connect", title: "Linear" }]); | |
| 211 | assert.deepEqual(fake.refusals, ["integration:linear:read=asker-not-connected"]); | |
| 212 | const connected = await box({ connected: ["linear"], settings: { "integration:linear:read": { credentials: "asker" } }, ports: { askerConnected: async () => true } }); | |
| 213 | assert.equal((await connected.tools.run("lookup_outside", { reference: "ENG-42" })).outcome, "allowed"); | |
| 214 | }); | |
| 215 | ||
| 216 | // ── Requests ───────────────────────────────────────────────────────────── | |
| 217 | ||
| 218 | test("request_ability posts a Request card for an integration that isn't connected, or an ability by its id", async () => { | |
| 219 | const { tools, fake } = await box({ connected: ["linear"], settings: { "integration:linear:comment": { level: "never" } } }); | |
| 220 | const jira = await tools.run("request_ability", { needs: "jira", why: "Support files bugs there." }); | |
| 221 | assert.equal(jira.outcome, "allowed"); | |
| 222 | const comment = await tools.run("request_ability", { needs: "integration:linear:comment", why: "To tell the team when it's fixed." }); | |
| 223 | assert.equal(comment.outcome, "allowed"); | |
| 224 | assert.deepEqual(fake.posted, [ | |
| 225 | { kind: "request", title: "jira" }, | |
| 226 | { kind: "request", title: "integration:linear:comment" }, | |
| 227 | ]); | |
| 228 | const bad = await tools.run("request_ability", { needs: "", why: "" }); | |
| 229 | assert.equal(bad.outcome, "refused"); | |
| 230 | }); | |
| 231 | ||
| 232 | // ── MCP ────────────────────────────────────────────────────────────────── | |
| 233 | ||
| 234 | test("an MCP server's tools are offered as <server>__<tool> with the server's schema; reads run alone, writes ask first, Never withholds", async () => { | |
| 235 | const { tools, fake } = await box({ servers: [SERVER] }); | |
| 236 | const forecast = tools.definitions().find((t) => t.name === "weather__get_forecast"); | |
| 237 | assert.ok(forecast, "offered"); | |
| 238 | assert.deepEqual(forecast!.input_schema, SERVER.tools[0]!.input_schema); | |
| 239 | assert.match(forecast!.description, /it reads/); | |
| 240 | const read = await tools.run("weather__get_forecast", { city: "Lisbon" }); | |
| 241 | assert.equal(read.outcome, "allowed"); | |
| 242 | assert.match(read.text, /<untrusted source="weather get_forecast">\nsunny/); | |
| 243 | const write = await tools.run("weather__set_alert", {}); | |
| 244 | assert.equal(write.outcome, "refused"); | |
| 245 | assert.match(write.text, /"weather: set_alert" is after asking first/); | |
| 246 | assert.deepEqual(fake.posted, [{ kind: "ability", title: "Call set_alert on weather" }]); | |
| 247 | const never = await box({ servers: [SERVER], settings: { "mcp:mcp_w:set_alert": { level: "never" } } }); | |
| 248 | assert.ok(!names(never.tools).includes("weather__set_alert"), "not offered at all"); | |
| 249 | assert.equal((await never.tools.run("weather__set_alert", {})).outcome, "refused"); | |
| 250 | }); | |
| 251 | ||
| 252 | // ── The prompt and what was said ───────────────────────────────────────── | |
| 253 | ||
| 254 | test("the prompt's abilities section names each connected system's rows and levels, and what isn't connected", async () => { | |
| 255 | const { sections } = await box({ connected: ["linear"], settings: { "integration:linear:comment": { level: "never" } }, servers: [SERVER] }); | |
| 256 | const text = abilitiesSection(sections)!; | |
| 257 | assert.match(text, /- Linear: read issues on your own; import issues on your own only when they asked for it, else it asks first; comment never\./); | |
| 258 | assert.match(text, /- weather: get_forecast on your own; set_alert asks first \(a card\)\./); | |
| 259 | assert.match(text, /Not connected to this workspace: Jira, Sentry\./); | |
| 260 | assert.equal(saidText([null, " ", "a", "b"]), "a\nb"); | |
| 261 | }); | |
| 262 | ||
| 263 | // ── The definition ─────────────────────────────────────────────────────── | |
| 264 | ||
| 265 | test("a definition keeps ability settings it knows, within each kind's limit, and never above Ask for a restricted one", () => { | |
| 266 | const base = applyChanges(null, { handle: "margo", display_name: "Margo", title: "QA", instructions: "Test." }, []); | |
| 267 | assert.ok(base.ok); | |
| 268 | const changed = applyChanges(base.value, { abilities: { settings: { "integration:linear:comment": { level: "alone", credentials: "asker" } } } }, []); | |
| 269 | assert.ok(changed.ok); | |
| 270 | assert.deepEqual(changed.value.abilities, { settings: { "integration:linear:comment": { level: "alone", credentials: "asker" } }, mcp_servers: [] }); | |
| 271 | const unknown = applyChanges(base.value, { abilities: { settings: { "integration:slack:post": { level: "alone" } } } }, []); | |
| 272 | assert.ok(!unknown.ok && /no ability called integration:slack:post/.test(unknown.message)); | |
| 273 | const badLevel = applyChanges(base.value, { abilities: { settings: { "integration:linear:read": { level: "loud" as never } } } }, []); | |
| 274 | assert.ok(!badLevel.ok); | |
| 275 | const notIntegration = applyChanges(base.value, { abilities: { settings: { "mcp:mcp_w:get_forecast": { level: "ask" } } } }, []); | |
| 276 | assert.ok(!notIntegration.ok, "no such server on the agent"); | |
| 277 | // With the server, its tools are abilities; removing the server drops their settings. | |
| 278 | const withServer = applyChanges(base.value, { abilities: { settings: { "mcp:mcp_w:get_forecast": { level: "ask" } } } }, [], { mcp_servers: [SERVER] }); | |
| 279 | assert.ok(withServer.ok); | |
| 280 | assert.equal(withServer.value.abilities.mcp_servers.length, 1); | |
| 281 | assert.deepEqual(withServer.value.abilities.settings, { "mcp:mcp_w:get_forecast": { level: "ask" } }); | |
| 282 | const without = applyChanges(withServer.value, {}, [], { mcp_servers: [] }); | |
| 283 | assert.ok(without.ok); | |
| 284 | assert.deepEqual(without.value.abilities, { settings: {}, mcp_servers: [] }); | |
| 285 | const g1t = applyChanges(base.value, { abilities: { settings: { "g1t:merge": { level: "alone" } } } }, []); | |
| 286 | assert.ok(!g1t.ok, "g1t's own keep their choices in autonomy"); | |
| 287 | }); | |
| 288 | ||
| 289 | // ── Cards ──────────────────────────────────────────────────────────────── | |
| 290 | ||
| 291 | test("the Ask-first, Connect and Request cards say what they are for and offer the right buttons", () => { | |
| 292 | const waiting = abilityCard({ id: "abr_1", summary: "Comment on ENG-42 in Linear", status: "pending", decided_by: null, result: null, ability: "integration:linear:comment" }, { agent: "Margo", asker: "ana", rule: "Linear: Comment", level: "ask", note: null, body: "Fixed in #412." }); | |
| 293 | assert.equal(waiting.state, "Waiting"); | |
| 294 | assert.deepEqual(waiting.actions?.map((a) => a.id), ["allow", "deny"]); | |
| 295 | assert.equal(waiting.owner, "agents"); | |
| 296 | assert.equal(waiting.body, "Fixed in #412."); | |
| 297 | const done = abilityCard({ id: "abr_1", summary: "Comment on ENG-42 in Linear", status: "allowed", decided_by: "ana", result: "Commented on ENG-42.", ability: "integration:linear:comment" }, { agent: "Margo", asker: "ana", rule: "Linear: Comment", level: "ask", note: null, body: null }); | |
| 298 | assert.equal(done.state, "Done"); | |
| 299 | assert.equal(done.actions, undefined); | |
| 300 | const connect = connectCard({ connector: "Linear", agent: "Margo", ability: "Read issues", asker: "ana", href: "/settings/integrations" }); | |
| 301 | assert.equal(connect.actions?.[0]?.href, "/settings/integrations"); | |
| 302 | assert.equal(connect.owner, null, "a link, no action for the service"); | |
| 303 | const request = requestCard({ agent: { id: "a1", handle: "margo", display_name: "Margo" }, workspace: "acme", connector: { id: "jira", name: "Jira", available: true }, ability: null, why: "Support files bugs there.", status: "open", by: null }); | |
| 304 | assert.deepEqual(request.actions?.map((a) => a.id), ["ask", "open"]); | |
| 305 | assert.equal(request.ref, "connector:a1:jira"); | |
| 306 | const asked = requestCard({ agent: { id: "a1", handle: "margo", display_name: "Margo" }, workspace: "acme", connector: null, ability: { id: "integration:linear:comment", label: "Linear: Comment" }, why: "x", status: "asked", by: "bo" }); | |
| 307 | assert.equal(asked.state, "Asked"); | |
| 308 | assert.equal(asked.actions?.[0]?.href, "/acme/-/agents/margo/abilities"); | |
| 309 | }); | |
| 310 | ||
| 311 | // ── The MCP client ─────────────────────────────────────────────────────── | |
| 312 | ||
| 313 | test("the MCP client lists tools (reads by readOnlyHint) and calls one, over JSON or an event stream", async () => { | |
| 314 | const seen: { method: string; session: string | null }[] = []; | |
| 315 | const fetchFn = async (_url: string, init: RequestInit) => { | |
| 316 | const body = JSON.parse(String(init.body)) as { id?: number; method: string; params?: { name?: string } }; | |
| 317 | seen.push({ method: body.method, session: (init.headers as Record<string, string>)["mcp-session-id"] ?? null }); | |
| 318 | const answer = (result: unknown, sse = false) => | |
| 319 | new Response(sse ? `event: message\ndata: ${JSON.stringify({ jsonrpc: "2.0", id: body.id, result })}\n\n` : JSON.stringify({ jsonrpc: "2.0", id: body.id, result }), { | |
| 320 | status: 200, | |
| 321 | headers: { "content-type": sse ? "text/event-stream" : "application/json", "mcp-session-id": "s1" }, | |
| 322 | }); | |
| 323 | if (body.method === "initialize") return answer({ protocolVersion: "2025-06-18" }); | |
| 324 | if (body.method === "notifications/initialized") return new Response(null, { status: 202 }); | |
| 325 | if (body.method === "tools/list") { | |
| 326 | return answer( | |
| 327 | { | |
| 328 | tools: [ | |
| 329 | { name: "get_forecast", description: "Forecast", inputSchema: { type: "object", properties: { city: { type: "string" } } }, annotations: { readOnlyHint: true } }, | |
| 330 | { name: "set_alert", description: "Alert" }, | |
| 331 | { name: "bad name!" }, | |
| 332 | ], | |
| 333 | }, | |
| 334 | true, | |
| 335 | ); | |
| 336 | } | |
| 337 | if (body.method === "tools/call") return answer({ content: [{ type: "text", text: `sunny in ${JSON.stringify(body.params)}` }] }); | |
| 338 | return new Response("{}", { status: 404 }); | |
| 339 | }; | |
| 340 | const listed = await listMcpTools("https://mcp.example.com/", fetchFn); | |
| 341 | assert.ok(listed.ok); | |
| 342 | assert.deepEqual( | |
| 343 | listed.tools.map((t) => [t.name, t.kind]), | |
| 344 | [ | |
| 345 | ["get_forecast", "read"], | |
| 346 | ["set_alert", "write"], | |
| 347 | ], | |
| 348 | ); | |
| 349 | assert.deepEqual(listed.tools[1]!.input_schema, { type: "object", properties: {} }); | |
| 350 | assert.equal(seen[2]!.session, "s1", "the session id the server gave rides along"); | |
| 351 | const called = await callMcpTool("https://mcp.example.com/", "get_forecast", { city: "Lisbon" }, fetchFn); | |
| 352 | assert.ok(called.ok); | |
| 353 | assert.match(called.text, /sunny in \{"name":"get_forecast","arguments":\{"city":"Lisbon"\}\}/); | |
| 354 | const down = await listMcpTools("https://mcp.example.com/", async () => { | |
| 355 | throw new Error("ECONNREFUSED"); | |
| 356 | }); | |
| 357 | assert.ok(!down.ok && /couldn't be reached/.test(down.message)); | |
| 358 | const errored = await callMcpTool("https://mcp.example.com/", "x", {}, async (_u, init) => { | |
| 359 | const body = JSON.parse(String(init.body)) as { id?: number; method: string }; | |
| 360 | if (body.method === "tools/call") return Response.json({ jsonrpc: "2.0", id: body.id, result: { isError: true, content: [{ type: "text", text: "no such city" }] } }); | |
| 361 | return Response.json({ jsonrpc: "2.0", id: body.id, result: {} }); | |
| 362 | }); | |
| 363 | assert.ok(!errored.ok && errored.message === "no such city"); | |
| 364 | }); |
