Kirkus Reviews:
A sharply observed, slender novel set in familiar Shepard (The One Inside, 2017, etc.) territory: a dusty, windblown West of limitless horizons and limited means of escape... It’s exactly of a piece with "True West" and other early Shepard standards, and one can imagine Shepard himself playing the part of that old man in an understated, stoical film. In between, it’s all impression, small snapshots of odd people and odd moments.

It’s easy to lose track of where one voice ends and another begins, where the young man leaves off and the old man picks up the story: explaining the title, the young narrator likens himself to an employee of a "cryptic detective agency," even as the old man, taking up the narration in turn, wonders why he’s being so closely watched when he can barely move. In the end, this is a story less of action than of mood, and that mood is overwhelmingly, achingly melancholic.

The story is modest, the poetry superb. A most worthy valediction.

Donna Seaman, Booklist:
A gorgeously courageous and sagacious coda to Shepard’s innovative and soulful body of work... A meshing of memoir and invention, it snares with virtuoso precision both nature’s constant vibrancy and the stop-action of illness. Told in short takes pulsing with life and rueful wit, it portrays one man spying on another from across the street, raising binoculars to better watch his subject struggling to make the simplest motions and family members appearing from within the house to offer help and company.

Colette Bancroft, Tampa Bay Times:
Few deaths are kind, I think, but Sam Shepard’s seemed almost theatrically cruel... For a man whose life was an embodiment of the power of words, dying of a disease that steals its victims’ ability to speak and write sounds like tragedy.

Shepard, however, gets the last word in Spy of the First Person, a brief and impressionistic novella he wrote in his last days... The result is spare but not slight, surreal yet stoic, an intriguing and moving glimpse into what falls away and what still matters at the end.

Alasdair Lees, Independent.co.uk:
Clocking in just over 80 pages, Spy of the First Person is clearly partly autobiographical, narrated by a man in his later years being treated for a crippling illness. Sitting in a rocking chair on the porch of his house in New Mexico and being cared for by his family, he looks back over his life and reflects on a changing America. All the while a younger man in a property opposite watches him, fascinated by his enigmatic neighbour.

"Spy of the First Person" captivates in its distillation of many of Shepard’s enduring themes - the death of America’s frontier, identity and loneliness... There’s foreboding amid the wistfulness, but it’s tempting to read this novella as Shepard looking at America in a more elegiac light.

Elisabeth Vincentelli, Newsday:
It is impossible to dissociate Sam Shepard’s latest and last book, "Spy of the First Person," from how and when it was written... That dogged determination to put a final word out into the world recalls musicians recently inspired to create records imbued with a melancholy awareness of their impending mortality... Loosely structured, to say the least, it is not the easiest thing to label, and not the easiest thing to read, either. Those new to Shepard’s world may not want to start here, but his fans may find the elegiac tone haunting.

"Spy of the First Person" is a short book, with short chapters — some of them just a few lines long, most less than two pages. The point of view continually switches, and so does the chronology: You are never quite sure what is now, what is past, who is speaking...

Death is filigreed throughout the book, but Shepard does not force his hand and avoids anything that could look like a definitive last statement, or a philosophy of life or art.

Molly Boyle, Santa Fe New Mexican:
In Sam Shepard’s final work, the author rakes up the leaves of his life, turning them over and over again for inspection, knowing the end result is not quite a neat and tidy collection... The feverishness of this writing process makes every word count in this slim volume, as the reader who picks up Spy is aware that this is Shepard’s attempt at his own elegy. If his first hybrid work of memoir and fiction, The One Inside, charts a slower process of aging and self-reflection, Spy tackles what has already been lost, and now floats in the ether — the image fragments, emotional memories, and physical remnants of a life spent rambling and making art from those rambles.

Heller McAlpin, Barnes & Noble:
Shifting between first- and third-person perspectives, the book’s focus is an old man rocking on a screened porch or parked under a tree in a wheelchair. A sort of doppelgänger spies on him, peering through binoculars from across the street, trying to figure out what’s going on... The increasingly incapacitated man is trying to figure out what’s going on, too. ALS is never mentioned by name, but he paints a clear enough picture of the disease’s ravages...

His previous book, "The One Inside", which was published earlier this year, was a muddled, intensely interior mix of dreamscape and memory... This slim posthumous volume is a more coherent, urgent, and moving work of autobiographical fiction. It packs a punch, and not just because we know the circumstances under which it was written, or that it’s his last. There are things Shepard wants to say, and he knows it’s now or never.

Dwight Garner, The New York Times:
Moving... Sly and revealing... This novel’s themes are echt Shepard: fathers and sons; shifting identities and competing versions of reality; a sense that there are watchers and there are watchees in this world of dusty gravitas. . . . You can tell you are moving into the realm of myth when you are holding a slender novel like this one that has large type and ample margins, to give the words room to reverberate... There are echoes of Beckett in this novel’s abstemious style and existential echoes.

Poet M. Sarki:
The death of Sam Shepard creates a sudden void in the landscape of contemporary literature. This talented writer, dramatist, horseman, actor, and musician leaves as his final gift to those of us fortunate to have known his body of work a thinly veiled memoir of the first rank. In prose reminiscent at times of his good friend Patti Smith, Shepard eventually recounts the last of his precious days on earth surrounded by his loving family and friends. In one poignant sentence Shepard affirms that in a span of one year he went from being a fiercely independent and private wanderer traveling in his pickup truck to a man in a wheelchair who can barely raise his head and cannot possibly wipe his own ass. There is nothing sentimental or self-serving in this book. Shepard’s honesty on the page remains as seething as his life. A testament to one great artist, and for some, a very good friend.

Sam Sacks, The Wall Street Journal:
"Spy of the First Person" returns to the uncanny experience evoked in all of Shepard’s fiction of being both the observer and the observed... Shepard has always been a spare and oblique writer, creating a sense of dreamy discomfort... The sketches jump to northern California, the Alcatraz prison, a doctor’s office in Arizona and even the squats of the Lower East Side in the 1970s. But as always, the itinerancy masks a profound feeling of imprisonment, as the scenes inevitably circle back to the old man on the porch, who has been rendered so immobile that he has to ask for help to scratch an itch on his face. Yet that appeal for help marks a small but significant change. Shepard’s wanderers have usually been on unaccompanied journeys with no departure or destination, only an ever-repeating present instant.